open-nomad/client/driver/docker.go

2143 lines
72 KiB
Go
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

package driver
import (
"context"
"encoding/json"
"fmt"
"log"
"net"
"os"
"os/exec"
"path/filepath"
"runtime"
"strconv"
"strings"
"sync"
"syscall"
"time"
"github.com/armon/circbuf"
docker "github.com/fsouza/go-dockerclient"
"github.com/docker/docker/cli/config/configfile"
"github.com/docker/docker/reference"
"github.com/docker/docker/registry"
"github.com/hashicorp/go-multierror"
"github.com/hashicorp/go-plugin"
"github.com/hashicorp/nomad/client/allocdir"
"github.com/hashicorp/nomad/client/driver/env"
"github.com/hashicorp/nomad/client/driver/executor"
dstructs "github.com/hashicorp/nomad/client/driver/structs"
cstructs "github.com/hashicorp/nomad/client/structs"
"github.com/hashicorp/nomad/helper"
"github.com/hashicorp/nomad/helper/fields"
shelpers "github.com/hashicorp/nomad/helper/stats"
"github.com/hashicorp/nomad/nomad/structs"
"github.com/mitchellh/mapstructure"
)
var (
// We store the clients globally to cache the connection to the docker daemon.
createClients sync.Once
// client is a docker client with a timeout of 1 minute. This is for doing
// all operations with the docker daemon besides which are not long running
// such as creating, killing containers, etc.
client *docker.Client
// waitClient is a docker client with no timeouts. This is used for long
// running operations such as waiting on containers and collect stats
waitClient *docker.Client
// The statistics the Docker driver exposes
DockerMeasuredMemStats = []string{"RSS", "Cache", "Swap", "Max Usage"}
DockerMeasuredCpuStats = []string{"Throttled Periods", "Throttled Time", "Percent"}
// recoverableErrTimeouts returns a recoverable error if the error was due
// to timeouts
recoverableErrTimeouts = func(err error) error {
r := false
if strings.Contains(err.Error(), "Client.Timeout exceeded while awaiting headers") ||
strings.Contains(err.Error(), "EOF") {
r = true
}
return structs.NewRecoverableError(err, r)
}
)
const (
// NoSuchContainerError is returned by the docker daemon if the container
// does not exist.
NoSuchContainerError = "No such container"
// The key populated in Node Attributes to indicate presence of the Docker
// driver
dockerDriverAttr = "driver.docker"
// dockerSELinuxLabelConfigOption is the key for configuring the
// SELinux label for binds.
dockerSELinuxLabelConfigOption = "docker.volumes.selinuxlabel"
// dockerVolumesConfigOption is the key for enabling the use of custom
// bind volumes to arbitrary host paths.
dockerVolumesConfigOption = "docker.volumes.enabled"
dockerVolumesConfigDefault = true
// dockerPrivilegedConfigOption is the key for running containers in
// Docker's privileged mode.
dockerPrivilegedConfigOption = "docker.privileged.enabled"
// dockerCleanupImageConfigOption is the key for whether or not to
// cleanup images after the task exits.
dockerCleanupImageConfigOption = "docker.cleanup.image"
dockerCleanupImageConfigDefault = true
// dockerPullTimeoutConfigOption is the key for setting an images pull
// timeout
dockerImageRemoveDelayConfigOption = "docker.cleanup.image.delay"
dockerImageRemoveDelayConfigDefault = 3 * time.Minute
// dockerCapsWhitelistConfigOption is the key for setting the list of
// allowed Linux capabilities
dockerCapsWhitelistConfigOption = "docker.caps.whitelist"
dockerCapsWhitelistConfigDefault = dockerBasicCaps
// dockerTimeout is the length of time a request can be outstanding before
// it is timed out.
dockerTimeout = 5 * time.Minute
// dockerImageResKey is the CreatedResources key for docker images
dockerImageResKey = "image"
// dockerAuthHelperPrefix is the prefix to attach to the credential helper
// and should be found in the $PATH. Example: ${prefix-}${helper-name}
dockerAuthHelperPrefix = "docker-credential-"
// dockerBasicCaps is comma-separated list of Linux capabilities that are
// allowed by docker by default, as documented in
// https://docs.docker.com/engine/reference/run/#block-io-bandwidth-blkio-constraint
dockerBasicCaps = "CHOWN,DAC_OVERRIDE,FSETID,FOWNER,MKNOD,NET_RAW,SETGID," +
"SETUID,SETFCAP,SETPCAP,NET_BIND_SERVICE,SYS_CHROOT,KILL,AUDIT_WRITE"
// This is cpu.cfs_period_us: the length of a period.
// The default values is 100 milliseconds (ms) represented in microseconds (us).
// Below is the documentation:
// https://www.kernel.org/doc/Documentation/scheduler/sched-bwc.txt
// https://docs.docker.com/engine/api/v1.35/#
defaultCFSPeriodUS = 100000
)
type DockerDriver struct {
DriverContext
driverConfig *DockerDriverConfig
imageID string
// A tri-state boolean to know if the fingerprinting has happened and
// whether it has been successful
fingerprintSuccess *bool
}
type DockerDriverAuth struct {
Username string `mapstructure:"username"` // username for the registry
Password string `mapstructure:"password"` // password to access the registry
Email string `mapstructure:"email"` // email address of the user who is allowed to access the registry
ServerAddress string `mapstructure:"server_address"` // server address of the registry
}
type DockerLoggingOpts struct {
Type string `mapstructure:"type"`
ConfigRaw []map[string]string `mapstructure:"config"`
Config map[string]string `mapstructure:"-"`
}
type DockerMount struct {
Target string `mapstructure:"target"`
Source string `mapstructure:"source"`
ReadOnly bool `mapstructure:"readonly"`
VolumeOptions []*DockerVolumeOptions `mapstructure:"volume_options"`
}
type DockerDevice struct {
HostPath string `mapstructure:"host_path"`
ContainerPath string `mapstructure:"container_path"`
CgroupPermissions string `mapstructure:"cgroup_permissions"`
}
type DockerVolumeOptions struct {
NoCopy bool `mapstructure:"no_copy"`
Labels []map[string]string `mapstructure:"labels"`
DriverConfig []DockerVolumeDriverConfig `mapstructure:"driver_config"`
}
// VolumeDriverConfig holds a map of volume driver specific options
type DockerVolumeDriverConfig struct {
Name string `mapstructure:"name"`
Options []map[string]string `mapstructure:"options"`
}
// DockerDriverConfig defines the user specified config block in a jobspec
type DockerDriverConfig struct {
ImageName string `mapstructure:"image"` // Container's Image Name
LoadImage string `mapstructure:"load"` // LoadImage is a path to an image archive file
Command string `mapstructure:"command"` // The Command to run when the container starts up
Args []string `mapstructure:"args"` // The arguments to the Command
Entrypoint []string `mapstructure:"entrypoint"` // Override the containers entrypoint
IpcMode string `mapstructure:"ipc_mode"` // The IPC mode of the container - host and none
NetworkMode string `mapstructure:"network_mode"` // The network mode of the container - host, nat and none
NetworkAliases []string `mapstructure:"network_aliases"` // The network-scoped alias for the container
IPv4Address string `mapstructure:"ipv4_address"` // The container ipv4 address
IPv6Address string `mapstructure:"ipv6_address"` // the container ipv6 address
PidMode string `mapstructure:"pid_mode"` // The PID mode of the container - host and none
UTSMode string `mapstructure:"uts_mode"` // The UTS mode of the container - host and none
UsernsMode string `mapstructure:"userns_mode"` // The User namespace mode of the container - host and none
PortMapRaw []map[string]string `mapstructure:"port_map"` //
PortMap map[string]int `mapstructure:"-"` // A map of host port labels and the ports exposed on the container
Privileged bool `mapstructure:"privileged"` // Flag to run the container in privileged mode
SysctlRaw []map[string]string `mapstructure:"sysctl"` //
Sysctl map[string]string `mapstructure:"-"` // The sysctl custom configurations
UlimitRaw []map[string]string `mapstructure:"ulimit"` //
Ulimit []docker.ULimit `mapstructure:"-"` // The ulimit custom configurations
DNSServers []string `mapstructure:"dns_servers"` // DNS Server for containers
DNSSearchDomains []string `mapstructure:"dns_search_domains"` // DNS Search domains for containers
DNSOptions []string `mapstructure:"dns_options"` // DNS Options
ExtraHosts []string `mapstructure:"extra_hosts"` // Add host to /etc/hosts (host:IP)
Hostname string `mapstructure:"hostname"` // Hostname for containers
LabelsRaw []map[string]string `mapstructure:"labels"` //
Labels map[string]string `mapstructure:"-"` // Labels to set when the container starts up
Auth []DockerDriverAuth `mapstructure:"auth"` // Authentication credentials for a private Docker registry
AuthSoftFail bool `mapstructure:"auth_soft_fail"` // Soft-fail if auth creds are provided but fail
TTY bool `mapstructure:"tty"` // Allocate a Pseudo-TTY
Interactive bool `mapstructure:"interactive"` // Keep STDIN open even if not attached
ShmSize int64 `mapstructure:"shm_size"` // Size of /dev/shm of the container in bytes
WorkDir string `mapstructure:"work_dir"` // Working directory inside the container
Logging []DockerLoggingOpts `mapstructure:"logging"` // Logging options for syslog server
Volumes []string `mapstructure:"volumes"` // Host-Volumes to mount in, syntax: /path/to/host/directory:/destination/path/in/container
Mounts []DockerMount `mapstructure:"mounts"` // Docker volumes to mount
VolumeDriver string `mapstructure:"volume_driver"` // Docker volume driver used for the container's volumes
ForcePull bool `mapstructure:"force_pull"` // Always force pull before running image, useful if your tags are mutable
MacAddress string `mapstructure:"mac_address"` // Pin mac address to container
SecurityOpt []string `mapstructure:"security_opt"` // Flags to pass directly to security-opt
Devices []DockerDevice `mapstructure:"devices"` // To allow mounting USB or other serial control devices
CapAdd []string `mapstructure:"cap_add"` // Flags to pass directly to cap-add
CapDrop []string `mapstructure:"cap_drop"` // Flags to pass directly to cap-drop
ReadonlyRootfs bool `mapstructure:"readonly_rootfs"` // Mount the containers root filesystem as read only
AdvertiseIPv6Address bool `mapstructure:"advertise_ipv6_address"` // Flag to use the GlobalIPv6Address from the container as the detected IP
CPUHardLimit bool `mapstructure:"cpu_hard_limit"` // Enforce CPU hard limit.
}
func sliceMergeUlimit(ulimitsRaw map[string]string) ([]docker.ULimit, error) {
var ulimits []docker.ULimit
for name, ulimitRaw := range ulimitsRaw {
if len(ulimitRaw) == 0 {
return []docker.ULimit{}, fmt.Errorf("Malformed ulimit specification %v: %q, cannot be empty", name, ulimitRaw)
}
// hard limit is optional
if strings.Contains(ulimitRaw, ":") == false {
ulimitRaw = ulimitRaw + ":" + ulimitRaw
}
splitted := strings.SplitN(ulimitRaw, ":", 2)
if len(splitted) < 2 {
return []docker.ULimit{}, fmt.Errorf("Malformed ulimit specification %v: %v", name, ulimitRaw)
}
soft, err := strconv.Atoi(splitted[0])
if err != nil {
return []docker.ULimit{}, fmt.Errorf("Malformed soft ulimit %v: %v", name, ulimitRaw)
}
hard, err := strconv.Atoi(splitted[1])
if err != nil {
return []docker.ULimit{}, fmt.Errorf("Malformed hard ulimit %v: %v", name, ulimitRaw)
}
ulimit := docker.ULimit{
Name: name,
Soft: int64(soft),
Hard: int64(hard),
}
ulimits = append(ulimits, ulimit)
}
return ulimits, nil
}
// Validate validates a docker driver config
func (c *DockerDriverConfig) Validate() error {
if c.ImageName == "" {
return fmt.Errorf("Docker Driver needs an image name")
}
if len(c.Devices) > 0 {
for _, dev := range c.Devices {
if dev.HostPath == "" {
return fmt.Errorf("host path must be set in configuration for devices")
}
if dev.CgroupPermissions != "" {
for _, c := range dev.CgroupPermissions {
ch := string(c)
if ch != "r" && ch != "w" && ch != "m" {
return fmt.Errorf("invalid cgroup permission string: %q", dev.CgroupPermissions)
}
}
}
}
}
c.Sysctl = mapMergeStrStr(c.SysctlRaw...)
c.Labels = mapMergeStrStr(c.LabelsRaw...)
if len(c.Logging) > 0 {
c.Logging[0].Config = mapMergeStrStr(c.Logging[0].ConfigRaw...)
}
mergedUlimitsRaw := mapMergeStrStr(c.UlimitRaw...)
ulimit, err := sliceMergeUlimit(mergedUlimitsRaw)
if err != nil {
return err
}
c.Ulimit = ulimit
return nil
}
// NewDockerDriverConfig returns a docker driver config by parsing the HCL
// config
func NewDockerDriverConfig(task *structs.Task, env *env.TaskEnv) (*DockerDriverConfig, error) {
var dconf DockerDriverConfig
if err := mapstructure.WeakDecode(task.Config, &dconf); err != nil {
return nil, err
}
// Interpolate everything that is a string
dconf.ImageName = env.ReplaceEnv(dconf.ImageName)
dconf.Command = env.ReplaceEnv(dconf.Command)
dconf.Entrypoint = env.ParseAndReplace(dconf.Entrypoint)
dconf.IpcMode = env.ReplaceEnv(dconf.IpcMode)
dconf.NetworkMode = env.ReplaceEnv(dconf.NetworkMode)
dconf.NetworkAliases = env.ParseAndReplace(dconf.NetworkAliases)
dconf.IPv4Address = env.ReplaceEnv(dconf.IPv4Address)
dconf.IPv6Address = env.ReplaceEnv(dconf.IPv6Address)
dconf.PidMode = env.ReplaceEnv(dconf.PidMode)
dconf.UTSMode = env.ReplaceEnv(dconf.UTSMode)
dconf.Hostname = env.ReplaceEnv(dconf.Hostname)
dconf.WorkDir = env.ReplaceEnv(dconf.WorkDir)
dconf.LoadImage = env.ReplaceEnv(dconf.LoadImage)
dconf.Volumes = env.ParseAndReplace(dconf.Volumes)
dconf.VolumeDriver = env.ReplaceEnv(dconf.VolumeDriver)
dconf.DNSServers = env.ParseAndReplace(dconf.DNSServers)
dconf.DNSSearchDomains = env.ParseAndReplace(dconf.DNSSearchDomains)
dconf.DNSOptions = env.ParseAndReplace(dconf.DNSOptions)
dconf.ExtraHosts = env.ParseAndReplace(dconf.ExtraHosts)
dconf.MacAddress = env.ReplaceEnv(dconf.MacAddress)
dconf.SecurityOpt = env.ParseAndReplace(dconf.SecurityOpt)
dconf.CapAdd = env.ParseAndReplace(dconf.CapAdd)
dconf.CapDrop = env.ParseAndReplace(dconf.CapDrop)
for _, m := range dconf.SysctlRaw {
for k, v := range m {
delete(m, k)
m[env.ReplaceEnv(k)] = env.ReplaceEnv(v)
}
}
for _, m := range dconf.UlimitRaw {
for k, v := range m {
delete(m, k)
m[env.ReplaceEnv(k)] = env.ReplaceEnv(v)
}
}
for _, m := range dconf.LabelsRaw {
for k, v := range m {
delete(m, k)
m[env.ReplaceEnv(k)] = env.ReplaceEnv(v)
}
}
dconf.Labels = mapMergeStrStr(dconf.LabelsRaw...)
for i, a := range dconf.Auth {
dconf.Auth[i].Username = env.ReplaceEnv(a.Username)
dconf.Auth[i].Password = env.ReplaceEnv(a.Password)
dconf.Auth[i].Email = env.ReplaceEnv(a.Email)
dconf.Auth[i].ServerAddress = env.ReplaceEnv(a.ServerAddress)
}
for i, l := range dconf.Logging {
dconf.Logging[i].Type = env.ReplaceEnv(l.Type)
for _, c := range l.ConfigRaw {
for k, v := range c {
delete(c, k)
c[env.ReplaceEnv(k)] = env.ReplaceEnv(v)
}
}
}
for i, m := range dconf.Mounts {
dconf.Mounts[i].Target = env.ReplaceEnv(m.Target)
dconf.Mounts[i].Source = env.ReplaceEnv(m.Source)
if len(m.VolumeOptions) > 1 {
return nil, fmt.Errorf("Only one volume_options stanza allowed")
}
if len(m.VolumeOptions) == 1 {
vo := m.VolumeOptions[0]
if len(vo.Labels) > 1 {
return nil, fmt.Errorf("labels may only be specified once in volume_options stanza")
}
if len(vo.Labels) == 1 {
for k, v := range vo.Labels[0] {
if k != env.ReplaceEnv(k) {
delete(vo.Labels[0], k)
}
vo.Labels[0][env.ReplaceEnv(k)] = env.ReplaceEnv(v)
}
}
if len(vo.DriverConfig) > 1 {
return nil, fmt.Errorf("volume driver config may only be specified once")
}
if len(vo.DriverConfig) == 1 {
vo.DriverConfig[0].Name = env.ReplaceEnv(vo.DriverConfig[0].Name)
if len(vo.DriverConfig[0].Options) > 1 {
return nil, fmt.Errorf("volume driver options may only be specified once")
}
if len(vo.DriverConfig[0].Options) == 1 {
options := vo.DriverConfig[0].Options[0]
for k, v := range options {
if k != env.ReplaceEnv(k) {
delete(options, k)
}
options[env.ReplaceEnv(k)] = env.ReplaceEnv(v)
}
}
}
}
}
if len(dconf.Logging) > 0 {
dconf.Logging[0].Config = mapMergeStrStr(dconf.Logging[0].ConfigRaw...)
}
portMap := make(map[string]int)
for _, m := range dconf.PortMapRaw {
for k, v := range m {
ki, vi := env.ReplaceEnv(k), env.ReplaceEnv(v)
p, err := strconv.Atoi(vi)
if err != nil {
return nil, fmt.Errorf("failed to parse port map value %v to %v: %v", ki, vi, err)
}
portMap[ki] = p
}
}
dconf.PortMap = portMap
// Remove any http
if strings.Contains(dconf.ImageName, "https://") {
dconf.ImageName = strings.Replace(dconf.ImageName, "https://", "", 1)
}
// If devices are configured set default cgroup permissions
if len(dconf.Devices) > 0 {
for i, dev := range dconf.Devices {
if dev.CgroupPermissions == "" {
dev.CgroupPermissions = "rwm"
}
dconf.Devices[i] = dev
}
}
if err := dconf.Validate(); err != nil {
return nil, err
}
return &dconf, nil
}
type dockerPID struct {
Version string
Image string
ImageID string
ContainerID string
KillTimeout time.Duration
MaxKillTimeout time.Duration
PluginConfig *PluginReattachConfig
}
type DockerHandle struct {
pluginClient *plugin.Client
executor executor.Executor
client *docker.Client
waitClient *docker.Client
logger *log.Logger
Image string
ImageID string
containerID string
version string
killTimeout time.Duration
maxKillTimeout time.Duration
resourceUsageLock sync.RWMutex
resourceUsage *cstructs.TaskResourceUsage
waitCh chan *dstructs.WaitResult
doneCh chan bool
}
func NewDockerDriver(ctx *DriverContext) Driver {
return &DockerDriver{DriverContext: *ctx}
}
func (d *DockerDriver) Fingerprint(req *cstructs.FingerprintRequest, resp *cstructs.FingerprintResponse) error {
client, _, err := d.dockerClients()
if err != nil {
if d.fingerprintSuccess == nil || *d.fingerprintSuccess {
d.logger.Printf("[INFO] driver.docker: failed to initialize client: %s", err)
}
d.fingerprintSuccess = helper.BoolToPtr(false)
return nil
}
// This is the first operation taken on the client so we'll try to
// establish a connection to the Docker daemon. If this fails it means
// Docker isn't available so we'll simply disable the docker driver.
env, err := client.Version()
if err != nil {
if d.fingerprintSuccess == nil || *d.fingerprintSuccess {
d.logger.Printf("[DEBUG] driver.docker: could not connect to docker daemon at %s: %s", client.Endpoint(), err)
}
d.fingerprintSuccess = helper.BoolToPtr(false)
resp.RemoveAttribute(dockerDriverAttr)
return nil
}
resp.AddAttribute(dockerDriverAttr, "1")
resp.AddAttribute("driver.docker.version", env.Get("Version"))
resp.Detected = true
privileged := d.config.ReadBoolDefault(dockerPrivilegedConfigOption, false)
if privileged {
resp.AddAttribute(dockerPrivilegedConfigOption, "1")
}
// Advertise if this node supports Docker volumes
if d.config.ReadBoolDefault(dockerVolumesConfigOption, dockerVolumesConfigDefault) {
resp.AddAttribute("driver."+dockerVolumesConfigOption, "1")
}
// Detect bridge IP address - #2785
if nets, err := client.ListNetworks(); err != nil {
d.logger.Printf("[WARN] driver.docker: error discovering bridge IP: %v", err)
} else {
for _, n := range nets {
if n.Name != "bridge" {
continue
}
if len(n.IPAM.Config) == 0 {
d.logger.Printf("[WARN] driver.docker: no IPAM config for bridge network")
break
}
if n.IPAM.Config[0].Gateway != "" {
resp.AddAttribute("driver.docker.bridge_ip", n.IPAM.Config[0].Gateway)
} else if d.fingerprintSuccess == nil {
// Docker 17.09.0-ce dropped the Gateway IP from the bridge network
// See https://github.com/moby/moby/issues/32648
d.logger.Printf("[DEBUG] driver.docker: bridge_ip could not be discovered")
}
break
}
}
d.fingerprintSuccess = helper.BoolToPtr(true)
return nil
}
// HealthCheck implements the interface for the HealthCheck interface. This
// performs a health check on the docker driver, asserting whether the docker
// driver is responsive to a `docker ps` command.
func (d *DockerDriver) HealthCheck(req *cstructs.HealthCheckRequest, resp *cstructs.HealthCheckResponse) error {
dinfo := &structs.DriverInfo{
UpdateTime: time.Now(),
}
client, _, err := d.dockerClients()
if err != nil {
d.logger.Printf("[WARN] driver.docker: failed to retrieve Docker client in the process of a docker health check: %v", err)
dinfo.HealthDescription = fmt.Sprintf("Failed retrieving Docker client: %v", err)
resp.AddDriverInfo("docker", dinfo)
return nil
}
_, err = client.ListContainers(docker.ListContainersOptions{All: false})
if err != nil {
d.logger.Printf("[WARN] driver.docker: failed to list Docker containers in the process of a Docker health check: %v", err)
dinfo.HealthDescription = fmt.Sprintf("Failed to list Docker containers: %v", err)
resp.AddDriverInfo("docker", dinfo)
return nil
}
d.logger.Printf("[TRACE] driver.docker: docker driver is available and is responsive to `docker ps`")
dinfo.Healthy = true
dinfo.HealthDescription = "Driver is available and responsive"
resp.AddDriverInfo("docker", dinfo)
return nil
}
// GetHealthChecks implements the interface for the HealthCheck interface. This
// sets whether the driver is eligible for periodic health checks and the
// interval at which to do them.
func (d *DockerDriver) GetHealthCheckInterval(req *cstructs.HealthCheckIntervalRequest, resp *cstructs.HealthCheckIntervalResponse) error {
resp.Eligible = true
resp.Period = 1 * time.Minute
return nil
}
// Validate is used to validate the driver configuration
func (d *DockerDriver) Validate(config map[string]interface{}) error {
fd := &fields.FieldData{
Raw: config,
Schema: map[string]*fields.FieldSchema{
"image": {
Type: fields.TypeString,
Required: true,
},
"load": {
Type: fields.TypeString,
},
"command": {
Type: fields.TypeString,
},
"args": {
Type: fields.TypeArray,
},
"entrypoint": {
Type: fields.TypeArray,
},
"ipc_mode": {
Type: fields.TypeString,
},
"network_mode": {
Type: fields.TypeString,
},
"network_aliases": {
Type: fields.TypeArray,
},
"ipv4_address": {
Type: fields.TypeString,
},
"ipv6_address": {
Type: fields.TypeString,
},
"mac_address": {
Type: fields.TypeString,
},
"pid_mode": {
Type: fields.TypeString,
},
"uts_mode": {
Type: fields.TypeString,
},
"userns_mode": {
Type: fields.TypeString,
},
"sysctl": {
Type: fields.TypeArray,
},
"ulimit": {
Type: fields.TypeArray,
},
"port_map": {
Type: fields.TypeArray,
},
"privileged": {
Type: fields.TypeBool,
},
"dns_servers": {
Type: fields.TypeArray,
},
"dns_options": {
Type: fields.TypeArray,
},
"dns_search_domains": {
Type: fields.TypeArray,
},
"extra_hosts": {
Type: fields.TypeArray,
},
"hostname": {
Type: fields.TypeString,
},
"labels": {
Type: fields.TypeArray,
},
"auth": {
Type: fields.TypeArray,
},
"auth_soft_fail": {
Type: fields.TypeBool,
},
// COMPAT: Remove in 0.6.0. SSL is no longer needed
"ssl": {
Type: fields.TypeBool,
},
"tty": {
Type: fields.TypeBool,
},
"interactive": {
Type: fields.TypeBool,
},
"shm_size": {
Type: fields.TypeInt,
},
"work_dir": {
Type: fields.TypeString,
},
"logging": {
Type: fields.TypeArray,
},
"volumes": {
Type: fields.TypeArray,
},
"volume_driver": {
Type: fields.TypeString,
},
"mounts": {
Type: fields.TypeArray,
},
"force_pull": {
Type: fields.TypeBool,
},
"security_opt": {
Type: fields.TypeArray,
},
"devices": {
Type: fields.TypeArray,
},
"cap_add": {
Type: fields.TypeArray,
},
"cap_drop": {
Type: fields.TypeArray,
},
"readonly_rootfs": {
Type: fields.TypeBool,
},
"advertise_ipv6_address": {
Type: fields.TypeBool,
},
"cpu_hard_limit": {
Type: fields.TypeBool,
},
},
}
if err := fd.Validate(); err != nil {
return err
}
return nil
}
func (d *DockerDriver) Abilities() DriverAbilities {
return DriverAbilities{
SendSignals: true,
Exec: true,
}
}
func (d *DockerDriver) FSIsolation() cstructs.FSIsolation {
return cstructs.FSIsolationImage
}
// getDockerCoordinator returns the docker coordinator and the caller ID to use when
// interacting with the coordinator
func (d *DockerDriver) getDockerCoordinator(client *docker.Client) (*dockerCoordinator, string) {
config := &dockerCoordinatorConfig{
client: client,
cleanup: d.config.ReadBoolDefault(dockerCleanupImageConfigOption, dockerCleanupImageConfigDefault),
logger: d.logger,
removeDelay: d.config.ReadDurationDefault(dockerImageRemoveDelayConfigOption, dockerImageRemoveDelayConfigDefault),
}
return GetDockerCoordinator(config), fmt.Sprintf("%s-%s", d.DriverContext.allocID, d.DriverContext.taskName)
}
func (d *DockerDriver) Prestart(ctx *ExecContext, task *structs.Task) (*PrestartResponse, error) {
driverConfig, err := NewDockerDriverConfig(task, ctx.TaskEnv)
if err != nil {
return nil, err
}
// Set state needed by Start
d.driverConfig = driverConfig
// Initialize docker API clients
client, _, err := d.dockerClients()
if err != nil {
return nil, fmt.Errorf("Failed to connect to docker daemon: %s", err)
}
// Ensure the image is available
id, err := d.createImage(driverConfig, client, ctx.TaskDir)
if err != nil {
return nil, err
}
d.imageID = id
resp := NewPrestartResponse()
resp.CreatedResources.Add(dockerImageResKey, id)
// Return the PortMap if it's set
if len(driverConfig.PortMap) > 0 {
resp.Network = &cstructs.DriverNetwork{
PortMap: driverConfig.PortMap,
}
}
return resp, nil
}
func (d *DockerDriver) Start(ctx *ExecContext, task *structs.Task) (*StartResponse, error) {
pluginLogFile := filepath.Join(ctx.TaskDir.Dir, "executor.out")
executorConfig := &dstructs.ExecutorConfig{
LogFile: pluginLogFile,
LogLevel: d.config.LogLevel,
}
exec, pluginClient, err := createExecutor(d.config.LogOutput, d.config, executorConfig)
if err != nil {
return nil, err
}
executorCtx := &executor.ExecutorContext{
TaskEnv: ctx.TaskEnv,
Task: task,
Driver: "docker",
LogDir: ctx.TaskDir.LogDir,
TaskDir: ctx.TaskDir.Dir,
PortLowerBound: d.config.ClientMinPort,
PortUpperBound: d.config.ClientMaxPort,
}
if err := exec.SetContext(executorCtx); err != nil {
pluginClient.Kill()
return nil, fmt.Errorf("failed to set executor context: %v", err)
}
// The user hasn't specified any logging options so launch our own syslog
// server if possible.
syslogAddr := ""
if len(d.driverConfig.Logging) == 0 {
if runtime.GOOS == "darwin" {
d.logger.Printf("[DEBUG] driver.docker: disabling syslog driver as Docker for Mac workaround")
} else {
ss, err := exec.LaunchSyslogServer()
if err != nil {
pluginClient.Kill()
return nil, fmt.Errorf("failed to start syslog collector: %v", err)
}
syslogAddr = ss.Addr
}
}
config, err := d.createContainerConfig(ctx, task, d.driverConfig, syslogAddr)
if err != nil {
d.logger.Printf("[ERR] driver.docker: failed to create container configuration for image %q (%q): %v", d.driverConfig.ImageName, d.imageID, err)
pluginClient.Kill()
return nil, fmt.Errorf("Failed to create container configuration for image %q (%q): %v", d.driverConfig.ImageName, d.imageID, err)
}
container, err := d.createContainer(client, config)
if err != nil {
wrapped := fmt.Sprintf("Failed to create container: %v", err)
d.logger.Printf("[ERR] driver.docker: %s", wrapped)
pluginClient.Kill()
return nil, structs.WrapRecoverable(wrapped, err)
}
d.logger.Printf("[INFO] driver.docker: created container %s", container.ID)
// We don't need to start the container if the container is already running
// since we don't create containers which are already present on the host
// and are running
if !container.State.Running {
// Start the container
if err := d.startContainer(container); err != nil {
d.logger.Printf("[ERR] driver.docker: failed to start container %s: %s", container.ID, err)
pluginClient.Kill()
return nil, structs.NewRecoverableError(fmt.Errorf("Failed to start container %s: %s", container.ID, err), structs.IsRecoverable(err))
}
// InspectContainer to get all of the container metadata as
// much of the metadata (eg networking) isn't populated until
// the container is started
runningContainer, err := client.InspectContainer(container.ID)
if err != nil {
err = fmt.Errorf("failed to inspect started container %s: %s", container.ID, err)
d.logger.Printf("[ERR] driver.docker: %v", err)
pluginClient.Kill()
return nil, structs.NewRecoverableError(err, true)
}
container = runningContainer
d.logger.Printf("[INFO] driver.docker: started container %s", container.ID)
} else {
d.logger.Printf("[DEBUG] driver.docker: re-attaching to container %s with status %q",
container.ID, container.State.String())
}
// Return a driver handle
maxKill := d.DriverContext.config.MaxKillTimeout
h := &DockerHandle{
client: client,
waitClient: waitClient,
executor: exec,
pluginClient: pluginClient,
logger: d.logger,
Image: d.driverConfig.ImageName,
ImageID: d.imageID,
containerID: container.ID,
version: d.config.Version.VersionNumber(),
killTimeout: GetKillTimeout(task.KillTimeout, maxKill),
maxKillTimeout: maxKill,
doneCh: make(chan bool),
waitCh: make(chan *dstructs.WaitResult, 1),
}
go h.collectStats()
go h.run()
// Detect container address
ip, autoUse := d.detectIP(container)
// Create a response with the driver handle and container network metadata
resp := &StartResponse{
Handle: h,
Network: &cstructs.DriverNetwork{
PortMap: d.driverConfig.PortMap,
IP: ip,
AutoAdvertise: autoUse,
},
}
return resp, nil
}
// detectIP of Docker container. Returns the first IP found as well as true if
// the IP should be advertised (bridge network IPs return false). Returns an
// empty string and false if no IP could be found.
func (d *DockerDriver) detectIP(c *docker.Container) (string, bool) {
if c.NetworkSettings == nil {
// This should only happen if there's been a coding error (such
// as not calling InspectContainer after CreateContainer). Code
// defensively in case the Docker API changes subtly.
d.logger.Printf("[ERROR] driver.docker: no network settings for container %s", c.ID)
return "", false
}
ip, ipName := "", ""
auto := false
for name, net := range c.NetworkSettings.Networks {
if net.IPAddress == "" {
// Ignore networks without an IP address
continue
}
ip = net.IPAddress
if d.driverConfig.AdvertiseIPv6Address {
ip = net.GlobalIPv6Address
auto = true
}
ipName = name
// Don't auto-advertise IPs for default networks (bridge on
// Linux, nat on Windows)
if name != "bridge" && name != "nat" {
auto = true
}
break
}
if n := len(c.NetworkSettings.Networks); n > 1 {
d.logger.Printf("[WARN] driver.docker: task %s multiple (%d) Docker networks for container %q but Nomad only supports 1: choosing %q", d.taskName, n, c.ID, ipName)
}
return ip, auto
}
func (d *DockerDriver) Cleanup(_ *ExecContext, res *CreatedResources) error {
retry := false
var merr multierror.Error
for key, resources := range res.Resources {
switch key {
case dockerImageResKey:
for _, value := range resources {
err := d.cleanupImage(value)
if err != nil {
if structs.IsRecoverable(err) {
retry = true
}
merr.Errors = append(merr.Errors, err)
continue
}
// Remove cleaned image from resources
res.Remove(dockerImageResKey, value)
}
default:
d.logger.Printf("[ERR] driver.docker: unknown resource to cleanup: %q", key)
}
}
return structs.NewRecoverableError(merr.ErrorOrNil(), retry)
}
// cleanupImage removes a Docker image. No error is returned if the image
// doesn't exist or is still in use. Requires the global client to already be
// initialized.
func (d *DockerDriver) cleanupImage(imageID string) error {
if !d.config.ReadBoolDefault(dockerCleanupImageConfigOption, dockerCleanupImageConfigDefault) {
// Config says not to cleanup
return nil
}
coordinator, callerID := d.getDockerCoordinator(client)
coordinator.RemoveImage(imageID, callerID)
return nil
}
// dockerClients creates two *docker.Client, one for long running operations and
// the other for shorter operations. In test / dev mode we can use ENV vars to
// connect to the docker daemon. In production mode we will read docker.endpoint
// from the config file.
func (d *DockerDriver) dockerClients() (*docker.Client, *docker.Client, error) {
if client != nil && waitClient != nil {
return client, waitClient, nil
}
var err error
var merr multierror.Error
createClients.Do(func() {
// Default to using whatever is configured in docker.endpoint. If this is
// not specified we'll fall back on NewClientFromEnv which reads config from
// the DOCKER_* environment variables DOCKER_HOST, DOCKER_TLS_VERIFY, and
// DOCKER_CERT_PATH. This allows us to lock down the config in production
// but also accept the standard ENV configs for dev and test.
dockerEndpoint := d.config.Read("docker.endpoint")
if dockerEndpoint != "" {
cert := d.config.Read("docker.tls.cert")
key := d.config.Read("docker.tls.key")
ca := d.config.Read("docker.tls.ca")
if cert+key+ca != "" {
d.logger.Printf("[DEBUG] driver.docker: using TLS client connection to %s", dockerEndpoint)
client, err = docker.NewTLSClient(dockerEndpoint, cert, key, ca)
if err != nil {
merr.Errors = append(merr.Errors, err)
}
waitClient, err = docker.NewTLSClient(dockerEndpoint, cert, key, ca)
if err != nil {
merr.Errors = append(merr.Errors, err)
}
} else {
d.logger.Printf("[DEBUG] driver.docker: using standard client connection to %s", dockerEndpoint)
client, err = docker.NewClient(dockerEndpoint)
if err != nil {
merr.Errors = append(merr.Errors, err)
}
waitClient, err = docker.NewClient(dockerEndpoint)
if err != nil {
merr.Errors = append(merr.Errors, err)
}
}
client.SetTimeout(dockerTimeout)
return
}
d.logger.Println("[DEBUG] driver.docker: using client connection initialized from environment")
client, err = docker.NewClientFromEnv()
if err != nil {
merr.Errors = append(merr.Errors, err)
}
client.SetTimeout(dockerTimeout)
waitClient, err = docker.NewClientFromEnv()
if err != nil {
merr.Errors = append(merr.Errors, err)
}
})
return client, waitClient, merr.ErrorOrNil()
}
func (d *DockerDriver) containerBinds(driverConfig *DockerDriverConfig, ctx *ExecContext,
task *structs.Task) ([]string, error) {
allocDirBind := fmt.Sprintf("%s:%s", ctx.TaskDir.SharedAllocDir, ctx.TaskEnv.EnvMap[env.AllocDir])
taskLocalBind := fmt.Sprintf("%s:%s", ctx.TaskDir.LocalDir, ctx.TaskEnv.EnvMap[env.TaskLocalDir])
secretDirBind := fmt.Sprintf("%s:%s", ctx.TaskDir.SecretsDir, ctx.TaskEnv.EnvMap[env.SecretsDir])
binds := []string{allocDirBind, taskLocalBind, secretDirBind}
volumesEnabled := d.config.ReadBoolDefault(dockerVolumesConfigOption, dockerVolumesConfigDefault)
if !volumesEnabled && driverConfig.VolumeDriver != "" {
return nil, fmt.Errorf("%s is false; cannot use volume driver %q", dockerVolumesConfigOption, driverConfig.VolumeDriver)
}
for _, userbind := range driverConfig.Volumes {
parts := strings.Split(userbind, ":")
if len(parts) < 2 {
return nil, fmt.Errorf("invalid docker volume: %q", userbind)
}
// Resolve dotted path segments
parts[0] = filepath.Clean(parts[0])
// Absolute paths aren't always supported
if filepath.IsAbs(parts[0]) {
if !volumesEnabled {
// Disallow mounting arbitrary absolute paths
return nil, fmt.Errorf("%s is false; cannot mount host paths: %+q", dockerVolumesConfigOption, userbind)
}
binds = append(binds, userbind)
continue
}
// Relative paths are always allowed as they mount within a container
// When a VolumeDriver is set, we assume we receive a binding in the format volume-name:container-dest
// Otherwise, we assume we receive a relative path binding in the format relative/to/task:/also/in/container
if driverConfig.VolumeDriver == "" {
// Expand path relative to alloc dir
parts[0] = filepath.Join(ctx.TaskDir.Dir, parts[0])
}
binds = append(binds, strings.Join(parts, ":"))
}
if selinuxLabel := d.config.Read(dockerSELinuxLabelConfigOption); selinuxLabel != "" {
// Apply SELinux Label to each volume
for i := range binds {
binds[i] = fmt.Sprintf("%s:%s", binds[i], selinuxLabel)
}
}
return binds, nil
}
// createContainerConfig initializes a struct needed to call docker.client.CreateContainer()
func (d *DockerDriver) createContainerConfig(ctx *ExecContext, task *structs.Task,
driverConfig *DockerDriverConfig, syslogAddr string) (docker.CreateContainerOptions, error) {
var c docker.CreateContainerOptions
if task.Resources == nil {
// Guard against missing resources. We should never have been able to
// schedule a job without specifying this.
d.logger.Println("[ERR] driver.docker: task.Resources is empty")
return c, fmt.Errorf("task.Resources is empty")
}
binds, err := d.containerBinds(driverConfig, ctx, task)
if err != nil {
return c, err
}
// create the config block that will later be consumed by go-dockerclient
config := &docker.Config{
Image: d.imageID,
Entrypoint: driverConfig.Entrypoint,
Hostname: driverConfig.Hostname,
User: task.User,
Tty: driverConfig.TTY,
OpenStdin: driverConfig.Interactive,
StopTimeout: int(task.KillTimeout.Seconds()),
StopSignal: task.KillSignal,
}
if driverConfig.WorkDir != "" {
config.WorkingDir = driverConfig.WorkDir
}
memLimit := int64(task.Resources.MemoryMB) * 1024 * 1024
if len(driverConfig.Logging) == 0 {
if runtime.GOOS == "darwin" {
d.logger.Printf("[DEBUG] driver.docker: deferring logging to docker on Docker for Mac")
} else {
d.logger.Printf("[DEBUG] driver.docker: Setting default logging options to syslog and %s", syslogAddr)
driverConfig.Logging = []DockerLoggingOpts{
{Type: "syslog", Config: map[string]string{"syslog-address": syslogAddr}},
}
}
}
hostConfig := &docker.HostConfig{
// Convert MB to bytes. This is an absolute value.
Memory: memLimit,
// Convert Mhz to shares. This is a relative value.
CPUShares: int64(task.Resources.CPU),
// Binds are used to mount a host volume into the container. We mount a
// local directory for storage and a shared alloc directory that can be
// used to share data between different tasks in the same task group.
Binds: binds,
VolumeDriver: driverConfig.VolumeDriver,
}
// Calculate CPU Quota
// cfs_quota_us is the time per core, so we must
// multiply the time by the number of cores available
// See https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/6/html/resource_management_guide/sec-cpu
if driverConfig.CPUHardLimit {
numCores := runtime.NumCPU()
percentTicks := float64(task.Resources.CPU) / float64(d.node.Resources.CPU)
hostConfig.CPUQuota = int64(percentTicks*defaultCFSPeriodUS) * int64(numCores)
}
// Windows does not support MemorySwap/MemorySwappiness #2193
if runtime.GOOS == "windows" {
hostConfig.MemorySwap = 0
hostConfig.MemorySwappiness = -1
} else {
hostConfig.MemorySwap = memLimit // MemorySwap is memory + swap.
}
if len(driverConfig.Logging) != 0 {
d.logger.Printf("[DEBUG] driver.docker: Using config for logging: %+v", driverConfig.Logging[0])
hostConfig.LogConfig = docker.LogConfig{
Type: driverConfig.Logging[0].Type,
Config: driverConfig.Logging[0].Config,
}
}
d.logger.Printf("[DEBUG] driver.docker: using %d bytes memory for %s", hostConfig.Memory, task.Name)
d.logger.Printf("[DEBUG] driver.docker: using %d cpu shares for %s", hostConfig.CPUShares, task.Name)
if driverConfig.CPUHardLimit {
d.logger.Printf("[DEBUG] driver.docker: using %dms cpu quota and %dms cpu period for %s", hostConfig.CPUQuota, defaultCFSPeriodUS, task.Name)
}
d.logger.Printf("[DEBUG] driver.docker: binding directories %#v for %s", hostConfig.Binds, task.Name)
// set privileged mode
hostPrivileged := d.config.ReadBoolDefault(dockerPrivilegedConfigOption, false)
if driverConfig.Privileged && !hostPrivileged {
return c, fmt.Errorf(`Docker privileged mode is disabled on this Nomad agent`)
}
hostConfig.Privileged = driverConfig.Privileged
// set capabilities
hostCapsWhitelistConfig := d.config.ReadDefault(
dockerCapsWhitelistConfigOption, dockerCapsWhitelistConfigDefault)
hostCapsWhitelist := make(map[string]struct{})
for _, cap := range strings.Split(hostCapsWhitelistConfig, ",") {
cap = strings.ToLower(strings.TrimSpace(cap))
hostCapsWhitelist[cap] = struct{}{}
}
if _, ok := hostCapsWhitelist["all"]; !ok {
effectiveCaps, err := tweakCapabilities(
strings.Split(dockerBasicCaps, ","),
driverConfig.CapAdd,
driverConfig.CapDrop,
)
if err != nil {
return c, err
}
var missingCaps []string
for _, cap := range effectiveCaps {
cap = strings.ToLower(cap)
if _, ok := hostCapsWhitelist[cap]; !ok {
missingCaps = append(missingCaps, cap)
}
}
if len(missingCaps) > 0 {
return c, fmt.Errorf("Docker driver doesn't have the following caps whitelisted on this Nomad agent: %s", missingCaps)
}
}
hostConfig.CapAdd = driverConfig.CapAdd
hostConfig.CapDrop = driverConfig.CapDrop
// set SHM size
if driverConfig.ShmSize != 0 {
hostConfig.ShmSize = driverConfig.ShmSize
}
// set DNS servers
for _, ip := range driverConfig.DNSServers {
if net.ParseIP(ip) != nil {
hostConfig.DNS = append(hostConfig.DNS, ip)
} else {
d.logger.Printf("[ERR] driver.docker: invalid ip address for container dns server: %s", ip)
}
}
if len(driverConfig.Devices) > 0 {
var devices []docker.Device
for _, device := range driverConfig.Devices {
dev := docker.Device{
PathOnHost: device.HostPath,
PathInContainer: device.ContainerPath,
CgroupPermissions: device.CgroupPermissions}
devices = append(devices, dev)
}
hostConfig.Devices = devices
}
// Setup mounts
for _, m := range driverConfig.Mounts {
hm := docker.HostMount{
Target: m.Target,
Source: m.Source,
Type: "volume", // Only type supported
ReadOnly: m.ReadOnly,
}
if len(m.VolumeOptions) == 1 {
vo := m.VolumeOptions[0]
hm.VolumeOptions = &docker.VolumeOptions{
NoCopy: vo.NoCopy,
}
if len(vo.DriverConfig) == 1 {
dc := vo.DriverConfig[0]
hm.VolumeOptions.DriverConfig = docker.VolumeDriverConfig{
Name: dc.Name,
}
if len(dc.Options) == 1 {
hm.VolumeOptions.DriverConfig.Options = dc.Options[0]
}
}
if len(vo.Labels) == 1 {
hm.VolumeOptions.Labels = vo.Labels[0]
}
}
hostConfig.Mounts = append(hostConfig.Mounts, hm)
}
// set DNS search domains and extra hosts
hostConfig.DNSSearch = driverConfig.DNSSearchDomains
hostConfig.DNSOptions = driverConfig.DNSOptions
hostConfig.ExtraHosts = driverConfig.ExtraHosts
hostConfig.IpcMode = driverConfig.IpcMode
hostConfig.PidMode = driverConfig.PidMode
hostConfig.UTSMode = driverConfig.UTSMode
hostConfig.UsernsMode = driverConfig.UsernsMode
hostConfig.SecurityOpt = driverConfig.SecurityOpt
hostConfig.Sysctls = driverConfig.Sysctl
hostConfig.Ulimits = driverConfig.Ulimit
hostConfig.ReadonlyRootfs = driverConfig.ReadonlyRootfs
hostConfig.NetworkMode = driverConfig.NetworkMode
if hostConfig.NetworkMode == "" {
// docker default
d.logger.Printf("[DEBUG] driver.docker: networking mode not specified; defaulting to %s", defaultNetworkMode)
hostConfig.NetworkMode = defaultNetworkMode
}
// Setup port mapping and exposed ports
if len(task.Resources.Networks) == 0 {
d.logger.Println("[DEBUG] driver.docker: No network interfaces are available")
if len(driverConfig.PortMap) > 0 {
return c, fmt.Errorf("Trying to map ports but no network interface is available")
}
} else {
// TODO add support for more than one network
network := task.Resources.Networks[0]
publishedPorts := map[docker.Port][]docker.PortBinding{}
exposedPorts := map[docker.Port]struct{}{}
for _, port := range network.ReservedPorts {
// By default we will map the allocated port 1:1 to the container
containerPortInt := port.Value
// If the user has mapped a port using port_map we'll change it here
if mapped, ok := driverConfig.PortMap[port.Label]; ok {
containerPortInt = mapped
}
hostPortStr := strconv.Itoa(port.Value)
containerPort := docker.Port(strconv.Itoa(containerPortInt))
publishedPorts[containerPort+"/tcp"] = getPortBinding(network.IP, hostPortStr)
publishedPorts[containerPort+"/udp"] = getPortBinding(network.IP, hostPortStr)
d.logger.Printf("[DEBUG] driver.docker: allocated port %s:%d -> %d (static)", network.IP, port.Value, port.Value)
exposedPorts[containerPort+"/tcp"] = struct{}{}
exposedPorts[containerPort+"/udp"] = struct{}{}
d.logger.Printf("[DEBUG] driver.docker: exposed port %d", port.Value)
}
for _, port := range network.DynamicPorts {
// By default we will map the allocated port 1:1 to the container
containerPortInt := port.Value
// If the user has mapped a port using port_map we'll change it here
if mapped, ok := driverConfig.PortMap[port.Label]; ok {
containerPortInt = mapped
}
hostPortStr := strconv.Itoa(port.Value)
containerPort := docker.Port(strconv.Itoa(containerPortInt))
publishedPorts[containerPort+"/tcp"] = getPortBinding(network.IP, hostPortStr)
publishedPorts[containerPort+"/udp"] = getPortBinding(network.IP, hostPortStr)
d.logger.Printf("[DEBUG] driver.docker: allocated port %s:%d -> %d (mapped)", network.IP, port.Value, containerPortInt)
exposedPorts[containerPort+"/tcp"] = struct{}{}
exposedPorts[containerPort+"/udp"] = struct{}{}
d.logger.Printf("[DEBUG] driver.docker: exposed port %s", containerPort)
}
hostConfig.PortBindings = publishedPorts
config.ExposedPorts = exposedPorts
}
parsedArgs := ctx.TaskEnv.ParseAndReplace(driverConfig.Args)
// If the user specified a custom command to run, we'll inject it here.
if driverConfig.Command != "" {
// Validate command
if err := validateCommand(driverConfig.Command, "args"); err != nil {
return c, err
}
cmd := []string{driverConfig.Command}
if len(driverConfig.Args) != 0 {
cmd = append(cmd, parsedArgs...)
}
d.logger.Printf("[DEBUG] driver.docker: setting container startup command to: %s", strings.Join(cmd, " "))
config.Cmd = cmd
} else if len(driverConfig.Args) != 0 {
config.Cmd = parsedArgs
}
if len(driverConfig.Labels) > 0 {
config.Labels = driverConfig.Labels
d.logger.Printf("[DEBUG] driver.docker: applied labels on the container: %+v", config.Labels)
}
config.Env = ctx.TaskEnv.List()
containerName := fmt.Sprintf("%s-%s", task.Name, d.DriverContext.allocID)
d.logger.Printf("[DEBUG] driver.docker: setting container name to: %s", containerName)
var networkingConfig *docker.NetworkingConfig
if len(driverConfig.NetworkAliases) > 0 || driverConfig.IPv4Address != "" || driverConfig.IPv6Address != "" {
networkingConfig = &docker.NetworkingConfig{
EndpointsConfig: map[string]*docker.EndpointConfig{
hostConfig.NetworkMode: {},
},
}
}
if len(driverConfig.NetworkAliases) > 0 {
networkingConfig.EndpointsConfig[hostConfig.NetworkMode].Aliases = driverConfig.NetworkAliases
d.logger.Printf("[DEBUG] driver.docker: using network_mode %q with network aliases: %v",
hostConfig.NetworkMode, strings.Join(driverConfig.NetworkAliases, ", "))
}
if driverConfig.IPv4Address != "" || driverConfig.IPv6Address != "" {
networkingConfig.EndpointsConfig[hostConfig.NetworkMode].IPAMConfig = &docker.EndpointIPAMConfig{
IPv4Address: driverConfig.IPv4Address,
IPv6Address: driverConfig.IPv6Address,
}
d.logger.Printf("[DEBUG] driver.docker: using network_mode %q with ipv4: %q and ipv6: %q",
hostConfig.NetworkMode, driverConfig.IPv4Address, driverConfig.IPv6Address)
}
if driverConfig.MacAddress != "" {
config.MacAddress = driverConfig.MacAddress
d.logger.Printf("[DEBUG] driver.docker: using pinned mac address: %q", config.MacAddress)
}
return docker.CreateContainerOptions{
Name: containerName,
Config: config,
HostConfig: hostConfig,
NetworkingConfig: networkingConfig,
}, nil
}
func (d *DockerDriver) Periodic() (bool, time.Duration) {
return true, 15 * time.Second
}
// createImage creates a docker image either by pulling it from a registry or by
// loading it from the file system
func (d *DockerDriver) createImage(driverConfig *DockerDriverConfig, client *docker.Client, taskDir *allocdir.TaskDir) (string, error) {
image := driverConfig.ImageName
repo, tag := docker.ParseRepositoryTag(image)
if tag == "" {
tag = "latest"
}
coordinator, callerID := d.getDockerCoordinator(client)
// We're going to check whether the image is already downloaded. If the tag
// is "latest", or ForcePull is set, we have to check for a new version every time so we don't
// bother to check and cache the id here. We'll download first, then cache.
if driverConfig.ForcePull {
d.logger.Printf("[DEBUG] driver.docker: force pull image '%s:%s' instead of inspecting local", repo, tag)
} else if tag != "latest" {
if dockerImage, _ := client.InspectImage(image); dockerImage != nil {
// Image exists so just increment its reference count
coordinator.IncrementImageReference(dockerImage.ID, image, callerID)
return dockerImage.ID, nil
}
}
// Load the image if specified
if driverConfig.LoadImage != "" {
return d.loadImage(driverConfig, client, taskDir)
}
// Download the image
return d.pullImage(driverConfig, client, repo, tag)
}
// pullImage creates an image by pulling it from a docker registry
func (d *DockerDriver) pullImage(driverConfig *DockerDriverConfig, client *docker.Client, repo, tag string) (id string, err error) {
authOptions, err := d.resolveRegistryAuthentication(driverConfig, repo)
if err != nil {
if d.driverConfig.AuthSoftFail {
d.logger.Printf("[WARN] Failed to find docker auth for repo %q: %v", repo, err)
} else {
return "", fmt.Errorf("Failed to find docker auth for repo %q: %v", repo, err)
}
}
if authIsEmpty(authOptions) {
d.logger.Printf("[DEBUG] driver.docker: did not find docker auth for repo %q", repo)
}
d.emitEvent("Downloading image %s:%s", repo, tag)
coordinator, callerID := d.getDockerCoordinator(client)
return coordinator.PullImage(driverConfig.ImageName, authOptions, callerID)
}
// authBackend encapsulates a function that resolves registry credentials.
type authBackend func(string) (*docker.AuthConfiguration, error)
// resolveRegistryAuthentication attempts to retrieve auth credentials for the
// repo, trying all authentication-backends possible.
func (d *DockerDriver) resolveRegistryAuthentication(driverConfig *DockerDriverConfig, repo string) (*docker.AuthConfiguration, error) {
return firstValidAuth(repo, []authBackend{
authFromTaskConfig(driverConfig),
authFromDockerConfig(d.config.Read("docker.auth.config")),
authFromHelper(d.config.Read("docker.auth.helper")),
})
}
// loadImage creates an image by loading it from the file system
func (d *DockerDriver) loadImage(driverConfig *DockerDriverConfig, client *docker.Client,
taskDir *allocdir.TaskDir) (id string, err error) {
archive := filepath.Join(taskDir.LocalDir, driverConfig.LoadImage)
d.logger.Printf("[DEBUG] driver.docker: loading image from: %v", archive)
f, err := os.Open(archive)
if err != nil {
return "", fmt.Errorf("unable to open image archive: %v", err)
}
if err := client.LoadImage(docker.LoadImageOptions{InputStream: f}); err != nil {
return "", err
}
f.Close()
dockerImage, err := client.InspectImage(driverConfig.ImageName)
if err != nil {
return "", recoverableErrTimeouts(err)
}
coordinator, callerID := d.getDockerCoordinator(client)
coordinator.IncrementImageReference(dockerImage.ID, driverConfig.ImageName, callerID)
return dockerImage.ID, nil
}
// createContainer creates the container given the passed configuration. It
// attempts to handle any transient Docker errors.
func (d *DockerDriver) createContainer(client createContainerClient, config docker.CreateContainerOptions) (*docker.Container, error) {
// Create a container
attempted := 0
CREATE:
container, createErr := client.CreateContainer(config)
if createErr == nil {
return container, nil
}
d.logger.Printf("[DEBUG] driver.docker: failed to create container %q from image %q (ID: %q) (attempt %d): %v",
config.Name, d.driverConfig.ImageName, d.imageID, attempted+1, createErr)
// Volume management tools like Portworx may not have detached a volume
// from a previous node before Nomad started a task replacement task.
// Treat these errors as recoverable so we retry.
if strings.Contains(strings.ToLower(createErr.Error()), "volume is attached on another node") {
return nil, structs.NewRecoverableError(createErr, true)
}
// If the container already exists determine whether it's already
// running or if it's dead and needs to be recreated.
if strings.Contains(strings.ToLower(createErr.Error()), "container already exists") {
containers, err := client.ListContainers(docker.ListContainersOptions{
All: true,
})
if err != nil {
d.logger.Printf("[ERR] driver.docker: failed to query list of containers matching name:%s", config.Name)
return nil, recoverableErrTimeouts(fmt.Errorf("Failed to query list of containers: %s", err))
}
// Delete matching containers
// Adding a / infront of the container name since Docker returns the
// container names with a / pre-pended to the Nomad generated container names
containerName := "/" + config.Name
d.logger.Printf("[DEBUG] driver.docker: searching for container name %q to purge", containerName)
for _, shimContainer := range containers {
d.logger.Printf("[DEBUG] driver.docker: listed container %+v", shimContainer.Names)
found := false
for _, name := range shimContainer.Names {
if name == containerName {
d.logger.Printf("[DEBUG] driver.docker: Found container %v: %v", containerName, shimContainer.ID)
found = true
break
}
}
if !found {
continue
}
// Inspect the container and if the container isn't dead then return
// the container
container, err := client.InspectContainer(shimContainer.ID)
if err != nil {
err = fmt.Errorf("Failed to inspect container %s: %s", shimContainer.ID, err)
// This error is always recoverable as it could
// be caused by races between listing
// containers and this container being removed.
// See #2802
return nil, structs.NewRecoverableError(err, true)
}
if container != nil && container.State.Running {
return container, nil
}
err = client.RemoveContainer(docker.RemoveContainerOptions{
ID: container.ID,
Force: true,
})
if err != nil {
d.logger.Printf("[ERR] driver.docker: failed to purge container %s", container.ID)
return nil, recoverableErrTimeouts(fmt.Errorf("Failed to purge container %s: %s", container.ID, err))
} else if err == nil {
d.logger.Printf("[INFO] driver.docker: purged container %s", container.ID)
}
}
if attempted < 5 {
attempted++
time.Sleep(1 * time.Second)
goto CREATE
}
} else if strings.Contains(strings.ToLower(createErr.Error()), "no such image") {
// There is still a very small chance this is possible even with the
// coordinator so retry.
return nil, structs.NewRecoverableError(createErr, true)
}
return nil, recoverableErrTimeouts(createErr)
}
// startContainer starts the passed container. It attempts to handle any
// transient Docker errors.
func (d *DockerDriver) startContainer(c *docker.Container) error {
// Start a container
attempted := 0
START:
startErr := client.StartContainer(c.ID, c.HostConfig)
if startErr == nil {
return nil
}
d.logger.Printf("[DEBUG] driver.docker: failed to start container %q (attempt %d): %v", c.ID, attempted+1, startErr)
// If it is a 500 error it is likely we can retry and be successful
if strings.Contains(startErr.Error(), "API error (500)") {
if attempted < 5 {
attempted++
time.Sleep(1 * time.Second)
goto START
}
return structs.NewRecoverableError(startErr, true)
}
return recoverableErrTimeouts(startErr)
}
func (d *DockerDriver) Open(ctx *ExecContext, handleID string) (DriverHandle, error) {
// Split the handle
pidBytes := []byte(strings.TrimPrefix(handleID, "DOCKER:"))
pid := &dockerPID{}
if err := json.Unmarshal(pidBytes, pid); err != nil {
return nil, fmt.Errorf("Failed to parse handle '%s': %v", handleID, err)
}
d.logger.Printf("[INFO] driver.docker: re-attaching to docker process: %s", pid.ContainerID)
d.logger.Printf("[DEBUG] driver.docker: re-attached to handle: %s", handleID)
pluginConfig := &plugin.ClientConfig{
Reattach: pid.PluginConfig.PluginConfig(),
}
client, waitClient, err := d.dockerClients()
if err != nil {
return nil, fmt.Errorf("Failed to connect to docker daemon: %s", err)
}
// Look for a running container with this ID
containers, err := client.ListContainers(docker.ListContainersOptions{
Filters: map[string][]string{
"id": {pid.ContainerID},
},
})
if err != nil {
return nil, fmt.Errorf("Failed to query for container %s: %v", pid.ContainerID, err)
}
found := false
for _, container := range containers {
if container.ID == pid.ContainerID {
found = true
}
}
if !found {
return nil, fmt.Errorf("Failed to find container %s", pid.ContainerID)
}
exec, pluginClient, err := createExecutorWithConfig(pluginConfig, d.config.LogOutput)
if err != nil {
d.logger.Printf("[INFO] driver.docker: couldn't re-attach to the plugin process: %v", err)
d.logger.Printf("[DEBUG] driver.docker: stopping container %q", pid.ContainerID)
if e := client.StopContainer(pid.ContainerID, uint(pid.KillTimeout.Seconds())); e != nil {
d.logger.Printf("[DEBUG] driver.docker: couldn't stop container: %v", e)
}
return nil, err
}
ver, _ := exec.Version()
d.logger.Printf("[DEBUG] driver.docker: version of executor: %v", ver.Version)
// Increment the reference count since we successfully attached to this
// container
coordinator, callerID := d.getDockerCoordinator(client)
coordinator.IncrementImageReference(pid.ImageID, pid.Image, callerID)
// Return a driver handle
h := &DockerHandle{
client: client,
waitClient: waitClient,
executor: exec,
pluginClient: pluginClient,
logger: d.logger,
Image: pid.Image,
ImageID: pid.ImageID,
containerID: pid.ContainerID,
version: pid.Version,
killTimeout: pid.KillTimeout,
maxKillTimeout: pid.MaxKillTimeout,
doneCh: make(chan bool),
waitCh: make(chan *dstructs.WaitResult, 1),
}
go h.collectStats()
go h.run()
return h, nil
}
func (h *DockerHandle) ID() string {
// Return a handle to the PID
pid := dockerPID{
Version: h.version,
ContainerID: h.containerID,
Image: h.Image,
ImageID: h.ImageID,
KillTimeout: h.killTimeout,
MaxKillTimeout: h.maxKillTimeout,
PluginConfig: NewPluginReattachConfig(h.pluginClient.ReattachConfig()),
}
data, err := json.Marshal(pid)
if err != nil {
h.logger.Printf("[ERR] driver.docker: failed to marshal docker PID to JSON: %s", err)
}
return fmt.Sprintf("DOCKER:%s", string(data))
}
func (h *DockerHandle) ContainerID() string {
return h.containerID
}
func (h *DockerHandle) WaitCh() chan *dstructs.WaitResult {
return h.waitCh
}
func (h *DockerHandle) Update(task *structs.Task) error {
// Store the updated kill timeout.
h.killTimeout = GetKillTimeout(task.KillTimeout, h.maxKillTimeout)
if err := h.executor.UpdateTask(task); err != nil {
h.logger.Printf("[DEBUG] driver.docker: failed to update log config: %v", err)
}
// Update is not possible
return nil
}
func (h *DockerHandle) Exec(ctx context.Context, cmd string, args []string) ([]byte, int, error) {
fullCmd := make([]string, len(args)+1)
fullCmd[0] = cmd
copy(fullCmd[1:], args)
createExecOpts := docker.CreateExecOptions{
AttachStdin: false,
AttachStdout: true,
AttachStderr: true,
Tty: false,
Cmd: fullCmd,
Container: h.containerID,
Context: ctx,
}
exec, err := h.client.CreateExec(createExecOpts)
if err != nil {
return nil, 0, err
}
output, _ := circbuf.NewBuffer(int64(dstructs.CheckBufSize))
startOpts := docker.StartExecOptions{
Detach: false,
Tty: false,
OutputStream: output,
ErrorStream: output,
Context: ctx,
}
if err := client.StartExec(exec.ID, startOpts); err != nil {
return nil, 0, err
}
res, err := client.InspectExec(exec.ID)
if err != nil {
return output.Bytes(), 0, err
}
return output.Bytes(), res.ExitCode, nil
}
func (h *DockerHandle) Signal(s os.Signal) error {
// Convert types
sysSig, ok := s.(syscall.Signal)
if !ok {
return fmt.Errorf("Failed to determine signal number")
}
// TODO When we expose signals we will need a mapping layer that converts
// MacOS signals to the correct signal number for docker. Or we change the
// interface to take a signal string and leave it up to driver to map?
dockerSignal := docker.Signal(sysSig)
opts := docker.KillContainerOptions{
ID: h.containerID,
Signal: dockerSignal,
}
return h.client.KillContainer(opts)
}
// Kill is used to terminate the task. This uses `docker stop -t killTimeout`
func (h *DockerHandle) Kill() error {
// Stop the container
err := h.client.StopContainer(h.containerID, uint(h.killTimeout.Seconds()))
if err != nil {
h.executor.Exit()
h.pluginClient.Kill()
// Container has already been removed.
if strings.Contains(err.Error(), NoSuchContainerError) {
h.logger.Printf("[DEBUG] driver.docker: attempted to stop nonexistent container %s", h.containerID)
return nil
}
h.logger.Printf("[ERR] driver.docker: failed to stop container %s: %v", h.containerID, err)
return fmt.Errorf("Failed to stop container %s: %s", h.containerID, err)
}
h.logger.Printf("[INFO] driver.docker: stopped container %s", h.containerID)
return nil
}
func (h *DockerHandle) Stats() (*cstructs.TaskResourceUsage, error) {
h.resourceUsageLock.RLock()
defer h.resourceUsageLock.RUnlock()
var err error
if h.resourceUsage == nil {
err = fmt.Errorf("stats collection hasn't started yet")
}
return h.resourceUsage, err
}
func (h *DockerHandle) run() {
// Wait for it...
exitCode, werr := h.waitClient.WaitContainer(h.containerID)
if werr != nil {
h.logger.Printf("[ERR] driver.docker: failed to wait for %s; container already terminated", h.containerID)
}
if exitCode != 0 {
werr = fmt.Errorf("Docker container exited with non-zero exit code: %d", exitCode)
}
container, ierr := h.waitClient.InspectContainer(h.containerID)
if ierr != nil {
h.logger.Printf("[ERR] driver.docker: failed to inspect container %s: %v", h.containerID, ierr)
} else if container.State.OOMKilled {
werr = fmt.Errorf("OOM Killed")
}
close(h.doneCh)
// Shutdown the syslog collector
if err := h.executor.Exit(); err != nil {
h.logger.Printf("[ERR] driver.docker: failed to kill the syslog collector: %v", err)
}
h.pluginClient.Kill()
// Stop the container just incase the docker daemon's wait returned
// incorrectly
if err := h.client.StopContainer(h.containerID, 0); err != nil {
_, noSuchContainer := err.(*docker.NoSuchContainer)
_, containerNotRunning := err.(*docker.ContainerNotRunning)
if !containerNotRunning && !noSuchContainer {
h.logger.Printf("[ERR] driver.docker: error stopping container: %v", err)
}
}
// Remove the container
if err := h.client.RemoveContainer(docker.RemoveContainerOptions{ID: h.containerID, RemoveVolumes: true, Force: true}); err != nil {
h.logger.Printf("[ERR] driver.docker: error removing container: %v", err)
}
// Send the results
h.waitCh <- dstructs.NewWaitResult(exitCode, 0, werr)
close(h.waitCh)
}
// collectStats starts collecting resource usage stats of a docker container
func (h *DockerHandle) collectStats() {
statsCh := make(chan *docker.Stats)
statsOpts := docker.StatsOptions{ID: h.containerID, Done: h.doneCh, Stats: statsCh, Stream: true}
go func() {
//TODO handle Stats error
if err := h.waitClient.Stats(statsOpts); err != nil {
h.logger.Printf("[DEBUG] driver.docker: error collecting stats from container %s: %v", h.containerID, err)
}
}()
numCores := runtime.NumCPU()
for {
select {
case s := <-statsCh:
if s != nil {
ms := &cstructs.MemoryStats{
RSS: s.MemoryStats.Stats.Rss,
Cache: s.MemoryStats.Stats.Cache,
Swap: s.MemoryStats.Stats.Swap,
MaxUsage: s.MemoryStats.MaxUsage,
Measured: DockerMeasuredMemStats,
}
cs := &cstructs.CpuStats{
ThrottledPeriods: s.CPUStats.ThrottlingData.ThrottledPeriods,
ThrottledTime: s.CPUStats.ThrottlingData.ThrottledTime,
Measured: DockerMeasuredCpuStats,
}
// Calculate percentage
cs.Percent = calculatePercent(
s.CPUStats.CPUUsage.TotalUsage, s.PreCPUStats.CPUUsage.TotalUsage,
s.CPUStats.SystemCPUUsage, s.PreCPUStats.SystemCPUUsage, numCores)
cs.SystemMode = calculatePercent(
s.CPUStats.CPUUsage.UsageInKernelmode, s.PreCPUStats.CPUUsage.UsageInKernelmode,
s.CPUStats.CPUUsage.TotalUsage, s.PreCPUStats.CPUUsage.TotalUsage, numCores)
cs.UserMode = calculatePercent(
s.CPUStats.CPUUsage.UsageInUsermode, s.PreCPUStats.CPUUsage.UsageInUsermode,
s.CPUStats.CPUUsage.TotalUsage, s.PreCPUStats.CPUUsage.TotalUsage, numCores)
cs.TotalTicks = (cs.Percent / 100) * shelpers.TotalTicksAvailable() / float64(numCores)
h.resourceUsageLock.Lock()
h.resourceUsage = &cstructs.TaskResourceUsage{
ResourceUsage: &cstructs.ResourceUsage{
MemoryStats: ms,
CpuStats: cs,
},
Timestamp: s.Read.UTC().UnixNano(),
}
h.resourceUsageLock.Unlock()
}
case <-h.doneCh:
return
}
}
}
func calculatePercent(newSample, oldSample, newTotal, oldTotal uint64, cores int) float64 {
numerator := newSample - oldSample
denom := newTotal - oldTotal
if numerator <= 0 || denom <= 0 {
return 0.0
}
return (float64(numerator) / float64(denom)) * float64(cores) * 100.0
}
// loadDockerConfig loads the docker config at the specified path, returning an
// error if it couldn't be read.
func loadDockerConfig(file string) (*configfile.ConfigFile, error) {
f, err := os.Open(file)
if err != nil {
return nil, fmt.Errorf("Failed to open auth config file: %v, error: %v", file, err)
}
defer f.Close()
cfile := new(configfile.ConfigFile)
if err = cfile.LoadFromReader(f); err != nil {
return nil, fmt.Errorf("Failed to parse auth config file: %v", err)
}
return cfile, nil
}
// parseRepositoryInfo takes a repo and returns the Docker RepositoryInfo. This
// is useful for interacting with a Docker config object.
func parseRepositoryInfo(repo string) (*registry.RepositoryInfo, error) {
name, err := reference.ParseNamed(repo)
if err != nil {
return nil, fmt.Errorf("Failed to parse named repo %q: %v", repo, err)
}
repoInfo, err := registry.ParseRepositoryInfo(name)
if err != nil {
return nil, fmt.Errorf("Failed to parse repository: %v", err)
}
return repoInfo, nil
}
// firstValidAuth tries a list of auth backends, returning first error or AuthConfiguration
func firstValidAuth(repo string, backends []authBackend) (*docker.AuthConfiguration, error) {
for _, backend := range backends {
auth, err := backend(repo)
if auth != nil || err != nil {
return auth, err
}
}
return nil, nil
}
// authFromTaskConfig generates an authBackend for any auth given in the task-configuration
func authFromTaskConfig(driverConfig *DockerDriverConfig) authBackend {
return func(string) (*docker.AuthConfiguration, error) {
if len(driverConfig.Auth) == 0 {
return nil, nil
}
auth := driverConfig.Auth[0]
return &docker.AuthConfiguration{
Username: auth.Username,
Password: auth.Password,
Email: auth.Email,
ServerAddress: auth.ServerAddress,
}, nil
}
}
// authFromDockerConfig generate an authBackend for a dockercfg-compatible file.
// The authBacken can either be from explicit auth definitions or via credential
// helpers
func authFromDockerConfig(file string) authBackend {
return func(repo string) (*docker.AuthConfiguration, error) {
if file == "" {
return nil, nil
}
repoInfo, err := parseRepositoryInfo(repo)
if err != nil {
return nil, err
}
cfile, err := loadDockerConfig(file)
if err != nil {
return nil, err
}
return firstValidAuth(repo, []authBackend{
func(string) (*docker.AuthConfiguration, error) {
dockerAuthConfig := registry.ResolveAuthConfig(cfile.AuthConfigs, repoInfo.Index)
auth := &docker.AuthConfiguration{
Username: dockerAuthConfig.Username,
Password: dockerAuthConfig.Password,
Email: dockerAuthConfig.Email,
ServerAddress: dockerAuthConfig.ServerAddress,
}
if authIsEmpty(auth) {
return nil, nil
}
return auth, nil
},
authFromHelper(cfile.CredentialHelpers[registry.GetAuthConfigKey(repoInfo.Index)]),
authFromHelper(cfile.CredentialsStore),
})
}
}
// authFromHelper generates an authBackend for a docker-credentials-helper;
// A script taking the requested domain on input, outputting JSON with
// "Username" and "Secret"
func authFromHelper(helperName string) authBackend {
return func(repo string) (*docker.AuthConfiguration, error) {
if helperName == "" {
return nil, nil
}
helper := dockerAuthHelperPrefix + helperName
cmd := exec.Command(helper, "get")
// Ensure that the HTTPs prefix exists
if !strings.HasPrefix(repo, "https://") {
repo = fmt.Sprintf("https://%s", repo)
}
cmd.Stdin = strings.NewReader(repo)
output, err := cmd.Output()
if err != nil {
switch err.(type) {
default:
return nil, err
case *exec.ExitError:
return nil, fmt.Errorf("%s with input %q failed with stderr: %s", helper, repo, output)
}
}
var response map[string]string
if err := json.Unmarshal(output, &response); err != nil {
return nil, err
}
auth := &docker.AuthConfiguration{
Username: response["Username"],
Password: response["Secret"],
}
if authIsEmpty(auth) {
return nil, nil
}
return auth, nil
}
}
// authIsEmpty returns if auth is nil or an empty structure
func authIsEmpty(auth *docker.AuthConfiguration) bool {
if auth == nil {
return false
}
return auth.Username == "" &&
auth.Password == "" &&
auth.Email == "" &&
auth.ServerAddress == ""
}
// createContainerClient is the subset of Docker Client methods used by the
// createContainer method to ease testing subtle error conditions.
type createContainerClient interface {
CreateContainer(docker.CreateContainerOptions) (*docker.Container, error)
InspectContainer(id string) (*docker.Container, error)
ListContainers(docker.ListContainersOptions) ([]docker.APIContainers, error)
RemoveContainer(opts docker.RemoveContainerOptions) error
}