open-nomad/client/driver/rkt.go

491 lines
15 KiB
Go

package driver
import (
"bytes"
"encoding/json"
"fmt"
"log"
"net"
"os"
"os/exec"
"path/filepath"
"regexp"
"runtime"
"strings"
"syscall"
"time"
"github.com/hashicorp/go-plugin"
"github.com/hashicorp/go-version"
"github.com/hashicorp/nomad/client/allocdir"
"github.com/hashicorp/nomad/client/config"
"github.com/hashicorp/nomad/client/driver/executor"
dstructs "github.com/hashicorp/nomad/client/driver/structs"
"github.com/hashicorp/nomad/client/fingerprint"
cstructs "github.com/hashicorp/nomad/client/structs"
"github.com/hashicorp/nomad/helper/discover"
"github.com/hashicorp/nomad/helper/fields"
"github.com/hashicorp/nomad/nomad/structs"
"github.com/mitchellh/mapstructure"
)
var (
reRktVersion = regexp.MustCompile(`rkt [vV]ersion[:]? (\d[.\d]+)`)
reAppcVersion = regexp.MustCompile(`appc [vV]ersion[:]? (\d[.\d]+)`)
)
const (
// minRktVersion is the earliest supported version of rkt. rkt added support
// for CPU and memory isolators in 0.14.0. We cannot support an earlier
// version to maintain an uniform interface across all drivers
minRktVersion = "1.0.0"
// The key populated in the Node Attributes to indicate the presence of the
// Rkt driver
rktDriverAttr = "driver.rkt"
// rktVolumesConfigOption is the key for enabling the use of custom
// bind volumes.
rktVolumesConfigOption = "rkt.volumes.enabled"
rktVolumesConfigDefault = true
// rktCmd is the command rkt is installed as.
rktCmd = "rkt"
)
// RktDriver is a driver for running images via Rkt
// We attempt to chose sane defaults for now, with more configuration available
// planned in the future
type RktDriver struct {
DriverContext
fingerprint.StaticFingerprinter
}
type RktDriverConfig struct {
ImageName string `mapstructure:"image"`
Command string `mapstructure:"command"`
Args []string `mapstructure:"args"`
TrustPrefix string `mapstructure:"trust_prefix"`
DNSServers []string `mapstructure:"dns_servers"` // DNS Server for containers
DNSSearchDomains []string `mapstructure:"dns_search_domains"` // DNS Search domains for containers
Debug bool `mapstructure:"debug"` // Enable debug option for rkt command
Volumes []string `mapstructure:"volumes"` // Host-Volumes to mount in, syntax: /path/to/host/directory:/destination/path/in/container
}
// rktHandle is returned from Start/Open as a handle to the PID
type rktHandle struct {
pluginClient *plugin.Client
executorPid int
executor executor.Executor
allocDir *allocdir.AllocDir
logger *log.Logger
killTimeout time.Duration
maxKillTimeout time.Duration
waitCh chan *dstructs.WaitResult
doneCh chan struct{}
}
// rktPID is a struct to map the pid running the process to the vm image on
// disk
type rktPID struct {
PluginConfig *PluginReattachConfig
AllocDir *allocdir.AllocDir
ExecutorPid int
KillTimeout time.Duration
MaxKillTimeout time.Duration
}
// NewRktDriver is used to create a new exec driver
func NewRktDriver(ctx *DriverContext) Driver {
return &RktDriver{DriverContext: *ctx}
}
// Validate is used to validate the driver configuration
func (d *RktDriver) Validate(config map[string]interface{}) error {
fd := &fields.FieldData{
Raw: config,
Schema: map[string]*fields.FieldSchema{
"image": &fields.FieldSchema{
Type: fields.TypeString,
Required: true,
},
"command": &fields.FieldSchema{
Type: fields.TypeString,
},
"args": &fields.FieldSchema{
Type: fields.TypeArray,
},
"trust_prefix": &fields.FieldSchema{
Type: fields.TypeString,
},
"dns_servers": &fields.FieldSchema{
Type: fields.TypeArray,
},
"dns_search_domains": &fields.FieldSchema{
Type: fields.TypeArray,
},
"debug": &fields.FieldSchema{
Type: fields.TypeBool,
},
},
}
if err := fd.Validate(); err != nil {
return err
}
return nil
}
func (d *RktDriver) Fingerprint(cfg *config.Config, node *structs.Node) (bool, error) {
// Get the current status so that we can log any debug messages only if the
// state changes
_, currentlyEnabled := node.Attributes[rktDriverAttr]
// Only enable if we are root when running on non-windows systems.
if runtime.GOOS != "windows" && syscall.Geteuid() != 0 {
if currentlyEnabled {
d.logger.Printf("[DEBUG] driver.rkt: must run as root user, disabling")
}
delete(node.Attributes, rktDriverAttr)
return false, nil
}
outBytes, err := exec.Command(rktCmd, "version").Output()
if err != nil {
delete(node.Attributes, rktDriverAttr)
return false, nil
}
out := strings.TrimSpace(string(outBytes))
rktMatches := reRktVersion.FindStringSubmatch(out)
appcMatches := reAppcVersion.FindStringSubmatch(out)
if len(rktMatches) != 2 || len(appcMatches) != 2 {
delete(node.Attributes, rktDriverAttr)
return false, fmt.Errorf("Unable to parse Rkt version string: %#v", rktMatches)
}
node.Attributes[rktDriverAttr] = "1"
node.Attributes["driver.rkt.version"] = rktMatches[1]
node.Attributes["driver.rkt.appc.version"] = appcMatches[1]
minVersion, _ := version.NewVersion(minRktVersion)
currentVersion, _ := version.NewVersion(node.Attributes["driver.rkt.version"])
if currentVersion.LessThan(minVersion) {
// Do not allow ancient rkt versions
d.logger.Printf("[WARN] driver.rkt: please upgrade rkt to a version >= %s", minVersion)
node.Attributes[rktDriverAttr] = "0"
}
return true, nil
}
// Run an existing Rkt image.
func (d *RktDriver) Start(ctx *ExecContext, task *structs.Task) (DriverHandle, error) {
var driverConfig RktDriverConfig
if err := mapstructure.WeakDecode(task.Config, &driverConfig); err != nil {
return nil, err
}
// ACI image
img := driverConfig.ImageName
// Get the tasks local directory.
taskName := d.DriverContext.taskName
taskDir, ok := ctx.AllocDir.TaskDirs[taskName]
if !ok {
return nil, fmt.Errorf("Could not find task directory for task: %v", d.DriverContext.taskName)
}
// Build the command.
var cmdArgs []string
// Add debug option to rkt command.
debug := driverConfig.Debug
// Add the given trust prefix
trustPrefix := driverConfig.TrustPrefix
insecure := false
if trustPrefix != "" {
var outBuf, errBuf bytes.Buffer
cmd := exec.Command(rktCmd, "trust", "--skip-fingerprint-review=true", fmt.Sprintf("--prefix=%s", trustPrefix), fmt.Sprintf("--debug=%t", debug))
cmd.Stdout = &outBuf
cmd.Stderr = &errBuf
if err := cmd.Run(); err != nil {
return nil, fmt.Errorf("Error running rkt trust: %s\n\nOutput: %s\n\nError: %s",
err, outBuf.String(), errBuf.String())
}
d.logger.Printf("[DEBUG] driver.rkt: added trust prefix: %q", trustPrefix)
} else {
// Disble signature verification if the trust command was not run.
insecure = true
}
cmdArgs = append(cmdArgs, "run")
// Mount /alloc
allocVolName := fmt.Sprintf("%s-%s-alloc", ctx.AllocID, task.Name)
cmdArgs = append(cmdArgs, fmt.Sprintf("--volume=%s,kind=host,source=%s", allocVolName, ctx.AllocDir.SharedDir))
cmdArgs = append(cmdArgs, fmt.Sprintf("--mount=volume=%s,target=%s", allocVolName, allocdir.SharedAllocContainerPath))
// Mount /local
localVolName := fmt.Sprintf("%s-%s-local", ctx.AllocID, task.Name)
cmdArgs = append(cmdArgs, fmt.Sprintf("--volume=%s,kind=host,source=%s", localVolName, filepath.Join(taskDir, allocdir.TaskLocal)))
cmdArgs = append(cmdArgs, fmt.Sprintf("--mount=volume=%s,target=%s", localVolName, allocdir.TaskLocalContainerPath))
// Mount /secrets
secretsVolName := fmt.Sprintf("%s-%s-secrets", ctx.AllocID, task.Name)
cmdArgs = append(cmdArgs, fmt.Sprintf("--volume=%s,kind=host,source=%s", secretsVolName, filepath.Join(taskDir, allocdir.TaskSecrets)))
cmdArgs = append(cmdArgs, fmt.Sprintf("--mount=volume=%s,target=%s", secretsVolName, allocdir.TaskSecretsContainerPath))
// Mount arbitrary volumes if enabled
if len(driverConfig.Volumes) > 0 {
if enabled := d.config.ReadBoolDefault(rktVolumesConfigOption, rktVolumesConfigDefault); !enabled {
return nil, fmt.Errorf("%s is false; cannot use rkt volumes: %+q", rktVolumesConfigOption, driverConfig.Volumes)
}
for i, rawvol := range driverConfig.Volumes {
parts := strings.Split(rawvol, ":")
if len(parts) != 2 {
return nil, fmt.Errorf("invalid rkt volume: %q", rawvol)
}
volName := fmt.Sprintf("%s-%s-%d", ctx.AllocID, task.Name, i)
cmdArgs = append(cmdArgs, fmt.Sprintf("--volume=%s,kind=host,source=%s", volName, i, parts[0]))
cmdArgs = append(cmdArgs, fmt.Sprintf("--mount=volume=%s,target=%s", volName, i, parts[1]))
}
}
cmdArgs = append(cmdArgs, img)
if insecure {
cmdArgs = append(cmdArgs, "--insecure-options=all")
}
cmdArgs = append(cmdArgs, fmt.Sprintf("--debug=%t", debug))
// Inject environment variables
d.taskEnv.SetAllocDir(allocdir.SharedAllocContainerPath)
d.taskEnv.SetTaskLocalDir(allocdir.TaskLocalContainerPath)
d.taskEnv.SetTaskLocalDir(allocdir.TaskSecretsContainerPath)
d.taskEnv.Build()
for k, v := range d.taskEnv.EnvMap() {
cmdArgs = append(cmdArgs, fmt.Sprintf("--set-env=%v=%v", k, v))
}
// Check if the user has overridden the exec command.
if driverConfig.Command != "" {
cmdArgs = append(cmdArgs, fmt.Sprintf("--exec=%v", driverConfig.Command))
}
// Add memory isolator
cmdArgs = append(cmdArgs, fmt.Sprintf("--memory=%vM", int64(task.Resources.MemoryMB)))
// Add CPU isolator
cmdArgs = append(cmdArgs, fmt.Sprintf("--cpu=%vm", int64(task.Resources.CPU)))
// Add DNS servers
for _, ip := range driverConfig.DNSServers {
if err := net.ParseIP(ip); err == nil {
msg := fmt.Errorf("invalid ip address for container dns server %q", ip)
d.logger.Printf("[DEBUG] driver.rkt: %v", msg)
return nil, msg
} else {
cmdArgs = append(cmdArgs, fmt.Sprintf("--dns=%s", ip))
}
}
// set DNS search domains
for _, domain := range driverConfig.DNSSearchDomains {
cmdArgs = append(cmdArgs, fmt.Sprintf("--dns-search=%s", domain))
}
// Add user passed arguments.
if len(driverConfig.Args) != 0 {
parsed := d.taskEnv.ParseAndReplace(driverConfig.Args)
// Need to start arguments with "--"
if len(parsed) > 0 {
cmdArgs = append(cmdArgs, "--")
}
for _, arg := range parsed {
cmdArgs = append(cmdArgs, fmt.Sprintf("%v", arg))
}
}
// Set the host environment variables.
filter := strings.Split(d.config.ReadDefault("env.blacklist", config.DefaultEnvBlacklist), ",")
d.taskEnv.AppendHostEnvvars(filter)
bin, err := discover.NomadExecutable()
if err != nil {
return nil, fmt.Errorf("unable to find the nomad binary: %v", err)
}
pluginLogFile := filepath.Join(taskDir, fmt.Sprintf("%s-executor.out", task.Name))
pluginConfig := &plugin.ClientConfig{
Cmd: exec.Command(bin, "executor", pluginLogFile),
}
execIntf, pluginClient, err := createExecutor(pluginConfig, d.config.LogOutput, d.config)
if err != nil {
return nil, err
}
executorCtx := &executor.ExecutorContext{
TaskEnv: d.taskEnv,
Driver: "rkt",
AllocDir: ctx.AllocDir,
AllocID: ctx.AllocID,
Task: task,
}
if err := execIntf.SetContext(executorCtx); err != nil {
pluginClient.Kill()
return nil, fmt.Errorf("failed to set executor context: %v", err)
}
absPath, err := GetAbsolutePath(rktCmd)
if err != nil {
return nil, err
}
execCmd := &executor.ExecCommand{
Cmd: absPath,
Args: cmdArgs,
User: task.User,
}
ps, err := execIntf.LaunchCmd(execCmd)
if err != nil {
pluginClient.Kill()
return nil, err
}
d.logger.Printf("[DEBUG] driver.rkt: started ACI %q with: %v", img, cmdArgs)
maxKill := d.DriverContext.config.MaxKillTimeout
h := &rktHandle{
pluginClient: pluginClient,
executor: execIntf,
executorPid: ps.Pid,
allocDir: ctx.AllocDir,
logger: d.logger,
killTimeout: GetKillTimeout(task.KillTimeout, maxKill),
maxKillTimeout: maxKill,
doneCh: make(chan struct{}),
waitCh: make(chan *dstructs.WaitResult, 1),
}
if err := h.executor.SyncServices(consulContext(d.config, "")); err != nil {
h.logger.Printf("[ERR] driver.rkt: error registering services for task: %q: %v", task.Name, err)
}
go h.run()
return h, nil
}
func (d *RktDriver) Open(ctx *ExecContext, handleID string) (DriverHandle, error) {
// Parse the handle
pidBytes := []byte(strings.TrimPrefix(handleID, "Rkt:"))
id := &rktPID{}
if err := json.Unmarshal(pidBytes, id); err != nil {
return nil, fmt.Errorf("failed to parse Rkt handle '%s': %v", handleID, err)
}
pluginConfig := &plugin.ClientConfig{
Reattach: id.PluginConfig.PluginConfig(),
}
exec, pluginClient, err := createExecutor(pluginConfig, d.config.LogOutput, d.config)
if err != nil {
d.logger.Println("[ERROR] driver.rkt: error connecting to plugin so destroying plugin pid and user pid")
if e := destroyPlugin(id.PluginConfig.Pid, id.ExecutorPid); e != nil {
d.logger.Printf("[ERROR] driver.rkt: error destroying plugin and executor pid: %v", e)
}
return nil, fmt.Errorf("error connecting to plugin: %v", err)
}
ver, _ := exec.Version()
d.logger.Printf("[DEBUG] driver.rkt: version of executor: %v", ver.Version)
// Return a driver handle
h := &rktHandle{
pluginClient: pluginClient,
executorPid: id.ExecutorPid,
allocDir: id.AllocDir,
executor: exec,
logger: d.logger,
killTimeout: id.KillTimeout,
maxKillTimeout: id.MaxKillTimeout,
doneCh: make(chan struct{}),
waitCh: make(chan *dstructs.WaitResult, 1),
}
if err := h.executor.SyncServices(consulContext(d.config, "")); err != nil {
h.logger.Printf("[ERR] driver.rkt: error registering services: %v", err)
}
go h.run()
return h, nil
}
func (h *rktHandle) ID() string {
// Return a handle to the PID
pid := &rktPID{
PluginConfig: NewPluginReattachConfig(h.pluginClient.ReattachConfig()),
KillTimeout: h.killTimeout,
MaxKillTimeout: h.maxKillTimeout,
ExecutorPid: h.executorPid,
AllocDir: h.allocDir,
}
data, err := json.Marshal(pid)
if err != nil {
h.logger.Printf("[ERR] driver.rkt: failed to marshal rkt PID to JSON: %s", err)
}
return fmt.Sprintf("Rkt:%s", string(data))
}
func (h *rktHandle) WaitCh() chan *dstructs.WaitResult {
return h.waitCh
}
func (h *rktHandle) Update(task *structs.Task) error {
// Store the updated kill timeout.
h.killTimeout = GetKillTimeout(task.KillTimeout, h.maxKillTimeout)
h.executor.UpdateTask(task)
// Update is not possible
return nil
}
func (h *rktHandle) Signal(s os.Signal) error {
return fmt.Errorf("Rkt does not support signals")
}
// Kill is used to terminate the task. We send an Interrupt
// and then provide a 5 second grace period before doing a Kill.
func (h *rktHandle) Kill() error {
h.executor.ShutDown()
select {
case <-h.doneCh:
return nil
case <-time.After(h.killTimeout):
return h.executor.Exit()
}
}
func (h *rktHandle) Stats() (*cstructs.TaskResourceUsage, error) {
return nil, fmt.Errorf("stats not implemented for rkt")
}
func (h *rktHandle) run() {
ps, err := h.executor.Wait()
close(h.doneCh)
if ps.ExitCode == 0 && err != nil {
if e := killProcess(h.executorPid); e != nil {
h.logger.Printf("[ERROR] driver.rkt: error killing user process: %v", e)
}
if e := h.allocDir.UnmountAll(); e != nil {
h.logger.Printf("[ERROR] driver.rkt: unmounting dev,proc and alloc dirs failed: %v", e)
}
}
h.waitCh <- dstructs.NewWaitResult(ps.ExitCode, 0, err)
close(h.waitCh)
// Remove services
if err := h.executor.DeregisterServices(); err != nil {
h.logger.Printf("[ERR] driver.rkt: failed to deregister services: %v", err)
}
if err := h.executor.Exit(); err != nil {
h.logger.Printf("[ERR] driver.rkt: error killing executor: %v", err)
}
h.pluginClient.Kill()
}