open-nomad/drivers/rawexec/driver.go
Alex Dadgar 204ca8230c Device manager
Introduce a device manager that manages the lifecycle of device plugins
on the client. It fingerprints, collects stats, and forwards Reserve
requests to the correct plugin. The manager, also handles device plugins
failing and validates their output.
2018-11-07 10:43:15 -08:00

502 lines
13 KiB
Go

package rawexec
import (
"fmt"
"os"
"path/filepath"
"strconv"
"time"
"github.com/hashicorp/consul-template/signals"
hclog "github.com/hashicorp/go-hclog"
plugin "github.com/hashicorp/go-plugin"
"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/drivers/shared/eventer"
"github.com/hashicorp/nomad/plugins/base"
"github.com/hashicorp/nomad/plugins/drivers"
"github.com/hashicorp/nomad/plugins/drivers/utils"
"github.com/hashicorp/nomad/plugins/shared"
"github.com/hashicorp/nomad/plugins/shared/hclspec"
"github.com/hashicorp/nomad/plugins/shared/loader"
"golang.org/x/net/context"
)
const (
// pluginName is the name of the plugin
pluginName = "raw_exec"
// fingerprintPeriod is the interval at which the driver will send fingerprint responses
fingerprintPeriod = 30 * time.Second
)
var (
// PluginID is the rawexec plugin metadata registered in the plugin
// catalog.
PluginID = loader.PluginID{
Name: pluginName,
PluginType: base.PluginTypeDriver,
}
// PluginConfig is the rawexec factory function registered in the
// plugin catalog.
PluginConfig = &loader.InternalPluginConfig{
Config: map[string]interface{}{},
Factory: func(l hclog.Logger) interface{} { return NewRawExecDriver(l) },
}
)
// PluginLoader maps pre-0.9 client driver options to post-0.9 plugin options.
func PluginLoader(opts map[string]string) (map[string]interface{}, error) {
conf := map[string]interface{}{}
if v, err := strconv.ParseBool(opts["driver.raw_exec.enable"]); err == nil {
conf["enabled"] = v
}
if v, err := strconv.ParseBool(opts["driver.raw_exec.no_cgroups"]); err == nil {
conf["no_cgroups"] = v
}
return conf, nil
}
var (
// pluginInfo is the response returned for the PluginInfo RPC
pluginInfo = &base.PluginInfoResponse{
Type: base.PluginTypeDriver,
PluginApiVersion: "0.0.1",
PluginVersion: "0.1.0",
Name: pluginName,
}
// configSpec is the hcl specification returned by the ConfigSchema RPC
configSpec = hclspec.NewObject(map[string]*hclspec.Spec{
"enabled": hclspec.NewDefault(
hclspec.NewAttr("enabled", "bool", false),
hclspec.NewLiteral("false"),
),
"no_cgroups": hclspec.NewDefault(
hclspec.NewAttr("no_cgroups", "bool", false),
hclspec.NewLiteral("false"),
),
})
// taskConfigSpec is the hcl specification for the driver config section of
// a task within a job. It is returned in the TaskConfigSchema RPC
taskConfigSpec = hclspec.NewObject(map[string]*hclspec.Spec{
"command": hclspec.NewAttr("command", "string", true),
"args": hclspec.NewAttr("args", "list(string)", false),
})
// capabilities is returned by the Capabilities RPC and indicates what
// optional features this driver supports
capabilities = &drivers.Capabilities{
SendSignals: true,
Exec: true,
FSIsolation: cstructs.FSIsolationNone,
}
)
// Driver is a privileged version of the exec driver. It provides no
// resource isolation and just fork/execs. The Exec driver should be preferred
// and this should only be used when explicitly needed.
type Driver struct {
// eventer is used to handle multiplexing of TaskEvents calls such that an
// event can be broadcast to all callers
eventer *eventer.Eventer
// config is the driver configuration set by the SetConfig RPC
config *Config
// nomadConfig is the client config from nomad
nomadConfig *base.ClientDriverConfig
// tasks is the in memory datastore mapping taskIDs to rawExecDriverHandles
tasks *taskStore
// ctx is the context for the driver. It is passed to other subsystems to
// coordinate shutdown
ctx context.Context
// signalShutdown is called when the driver is shutting down and cancels the
// ctx passed to any subsystems
signalShutdown context.CancelFunc
// logger will log to the Nomad agent
logger hclog.Logger
}
// Config is the driver configuration set by the SetConfig RPC call
type Config struct {
// NoCgroups tracks whether we should use a cgroup to manage the process
// tree
NoCgroups bool `codec:"no_cgroups"`
// Enabled is set to true to enable the raw_exec driver
Enabled bool `codec:"enabled"`
}
// TaskConfig is the driver configuration of a task within a job
type TaskConfig struct {
Command string `codec:"command"`
Args []string `codec:"args"`
}
// TaskState is the state which is encoded in the handle returned in
// StartTask. This information is needed to rebuild the task state and handler
// during recovery.
type TaskState struct {
ReattachConfig *shared.ReattachConfig
TaskConfig *drivers.TaskConfig
Pid int
StartedAt time.Time
}
// NewRawExecDriver returns a new DriverPlugin implementation
func NewRawExecDriver(logger hclog.Logger) drivers.DriverPlugin {
ctx, cancel := context.WithCancel(context.Background())
logger = logger.Named(pluginName)
return &Driver{
eventer: eventer.NewEventer(ctx, logger),
config: &Config{},
tasks: newTaskStore(),
ctx: ctx,
signalShutdown: cancel,
logger: logger,
}
}
func (d *Driver) PluginInfo() (*base.PluginInfoResponse, error) {
return pluginInfo, nil
}
func (d *Driver) ConfigSchema() (*hclspec.Spec, error) {
return configSpec, nil
}
func (d *Driver) SetConfig(data []byte, cfg *base.ClientAgentConfig) error {
var config Config
if err := base.MsgPackDecode(data, &config); err != nil {
return err
}
d.config = &config
if cfg != nil {
d.nomadConfig = cfg.Driver
}
return nil
}
func (d *Driver) Shutdown(ctx context.Context) error {
d.signalShutdown()
return nil
}
func (d *Driver) TaskConfigSchema() (*hclspec.Spec, error) {
return taskConfigSpec, nil
}
func (d *Driver) Capabilities() (*drivers.Capabilities, error) {
return capabilities, nil
}
func (d *Driver) Fingerprint(ctx context.Context) (<-chan *drivers.Fingerprint, error) {
ch := make(chan *drivers.Fingerprint)
go d.handleFingerprint(ctx, ch)
return ch, nil
}
func (d *Driver) handleFingerprint(ctx context.Context, ch chan<- *drivers.Fingerprint) {
defer close(ch)
ticker := time.NewTimer(0)
for {
select {
case <-ctx.Done():
return
case <-d.ctx.Done():
return
case <-ticker.C:
ticker.Reset(fingerprintPeriod)
ch <- d.buildFingerprint()
}
}
}
func (d *Driver) buildFingerprint() *drivers.Fingerprint {
var health drivers.HealthState
var desc string
attrs := map[string]string{}
if d.config.Enabled {
health = drivers.HealthStateHealthy
desc = "ready"
attrs["driver.raw_exec"] = "1"
} else {
health = drivers.HealthStateUndetected
desc = "disabled"
}
return &drivers.Fingerprint{
Attributes: attrs,
Health: health,
HealthDescription: desc,
}
}
func (d *Driver) RecoverTask(handle *drivers.TaskHandle) error {
if handle == nil {
return fmt.Errorf("handle cannot be nil")
}
// If already attached to handle there's nothing to recover.
if _, ok := d.tasks.Get(handle.Config.ID); ok {
d.logger.Trace("nothing to recover; task already exists",
"task_id", handle.Config.ID,
"task_name", handle.Config.Name,
)
return nil
}
// Handle doesn't already exist, try to reattach
var taskState TaskState
if err := handle.GetDriverState(&taskState); err != nil {
d.logger.Error("failed to decode task state from handle", "error", err, "task_id", handle.Config.ID)
return fmt.Errorf("failed to decode task state from handle: %v", err)
}
plugRC, err := shared.ReattachConfigToGoPlugin(taskState.ReattachConfig)
if err != nil {
d.logger.Error("failed to build ReattachConfig from task state", "error", err, "task_id", handle.Config.ID)
return fmt.Errorf("failed to build ReattachConfig from task state: %v", err)
}
pluginConfig := &plugin.ClientConfig{
Reattach: plugRC,
}
// Create client for reattached executor
exec, pluginClient, err := utils.CreateExecutorWithConfig(pluginConfig, os.Stderr)
if err != nil {
d.logger.Error("failed to reattach to executor", "error", err, "task_id", handle.Config.ID)
return fmt.Errorf("failed to reattach to executor: %v", err)
}
h := &taskHandle{
exec: exec,
pid: taskState.Pid,
pluginClient: pluginClient,
taskConfig: taskState.TaskConfig,
procState: drivers.TaskStateRunning,
startedAt: taskState.StartedAt,
exitResult: &drivers.ExitResult{},
}
d.tasks.Set(taskState.TaskConfig.ID, h)
go h.run()
return nil
}
func (d *Driver) StartTask(cfg *drivers.TaskConfig) (*drivers.TaskHandle, *cstructs.DriverNetwork, error) {
if _, ok := d.tasks.Get(cfg.ID); ok {
return nil, nil, fmt.Errorf("task with ID %q already started", cfg.ID)
}
var driverConfig TaskConfig
if err := cfg.DecodeDriverConfig(&driverConfig); err != nil {
return nil, nil, fmt.Errorf("failed to decode driver config: %v", err)
}
d.logger.Info("starting task", "driver_cfg", hclog.Fmt("%+v", driverConfig))
handle := drivers.NewTaskHandle(pluginName)
handle.Config = cfg
pluginLogFile := filepath.Join(cfg.TaskDir().Dir, "executor.out")
executorConfig := &dstructs.ExecutorConfig{
LogFile: pluginLogFile,
LogLevel: "debug",
}
exec, pluginClient, err := utils.CreateExecutor(os.Stderr, hclog.Debug, d.nomadConfig, executorConfig)
if err != nil {
return nil, nil, fmt.Errorf("failed to create executor: %v", err)
}
execCmd := &executor.ExecCommand{
Cmd: driverConfig.Command,
Args: driverConfig.Args,
Env: cfg.EnvList(),
User: cfg.User,
BasicProcessCgroup: !d.config.NoCgroups,
TaskDir: cfg.TaskDir().Dir,
StdoutPath: cfg.StdoutPath,
StderrPath: cfg.StderrPath,
}
ps, err := exec.Launch(execCmd)
if err != nil {
pluginClient.Kill()
return nil, nil, fmt.Errorf("failed to launch command with executor: %v", err)
}
h := &taskHandle{
exec: exec,
pid: ps.Pid,
pluginClient: pluginClient,
taskConfig: cfg,
procState: drivers.TaskStateRunning,
startedAt: time.Now().Round(time.Millisecond),
logger: d.logger,
}
driverState := TaskState{
ReattachConfig: shared.ReattachConfigFromGoPlugin(pluginClient.ReattachConfig()),
Pid: ps.Pid,
TaskConfig: cfg,
StartedAt: h.startedAt,
}
if err := handle.SetDriverState(&driverState); err != nil {
d.logger.Error("failed to start task, error setting driver state", "error", err)
exec.Shutdown("", 0)
pluginClient.Kill()
return nil, nil, fmt.Errorf("failed to set driver state: %v", err)
}
d.tasks.Set(cfg.ID, h)
go h.run()
return handle, nil, nil
}
func (d *Driver) WaitTask(ctx context.Context, taskID string) (<-chan *drivers.ExitResult, error) {
handle, ok := d.tasks.Get(taskID)
if !ok {
return nil, drivers.ErrTaskNotFound
}
ch := make(chan *drivers.ExitResult)
go d.handleWait(ctx, handle, ch)
return ch, nil
}
func (d *Driver) handleWait(ctx context.Context, handle *taskHandle, ch chan *drivers.ExitResult) {
defer close(ch)
var result *drivers.ExitResult
ps, err := handle.exec.Wait()
if err != nil {
result = &drivers.ExitResult{
Err: fmt.Errorf("executor: error waiting on process: %v", err),
}
} else {
result = &drivers.ExitResult{
ExitCode: ps.ExitCode,
Signal: ps.Signal,
}
}
select {
case <-ctx.Done():
return
case <-d.ctx.Done():
return
case ch <- result:
}
}
func (d *Driver) StopTask(taskID string, timeout time.Duration, signal string) error {
handle, ok := d.tasks.Get(taskID)
if !ok {
return drivers.ErrTaskNotFound
}
if err := handle.exec.Shutdown(signal, timeout); err != nil {
if handle.pluginClient.Exited() {
return nil
}
return fmt.Errorf("executor Shutdown failed: %v", err)
}
return nil
}
func (d *Driver) DestroyTask(taskID string, force bool) error {
handle, ok := d.tasks.Get(taskID)
if !ok {
return drivers.ErrTaskNotFound
}
if handle.IsRunning() && !force {
return fmt.Errorf("cannot destroy running task")
}
if !handle.pluginClient.Exited() {
if handle.IsRunning() {
if err := handle.exec.Shutdown("", 0); err != nil {
handle.logger.Error("destroying executor failed", "err", err)
}
}
handle.pluginClient.Kill()
}
d.tasks.Delete(taskID)
return nil
}
func (d *Driver) InspectTask(taskID string) (*drivers.TaskStatus, error) {
handle, ok := d.tasks.Get(taskID)
if !ok {
return nil, drivers.ErrTaskNotFound
}
return handle.TaskStatus(), nil
}
func (d *Driver) TaskStats(taskID string) (*cstructs.TaskResourceUsage, error) {
handle, ok := d.tasks.Get(taskID)
if !ok {
return nil, drivers.ErrTaskNotFound
}
return handle.exec.Stats()
}
func (d *Driver) TaskEvents(ctx context.Context) (<-chan *drivers.TaskEvent, error) {
return d.eventer.TaskEvents(ctx)
}
func (d *Driver) SignalTask(taskID string, signal string) error {
handle, ok := d.tasks.Get(taskID)
if !ok {
return drivers.ErrTaskNotFound
}
sig := os.Interrupt
if s, ok := signals.SignalLookup[signal]; ok {
d.logger.Warn("signal to send to task unknown, using SIGINT", "signal", signal, "task_id", handle.taskConfig.ID)
sig = s
}
return handle.exec.Signal(sig)
}
func (d *Driver) ExecTask(taskID string, cmd []string, timeout time.Duration) (*drivers.ExecTaskResult, error) {
if len(cmd) == 0 {
return nil, fmt.Errorf("error cmd must have at least one value")
}
handle, ok := d.tasks.Get(taskID)
if !ok {
return nil, drivers.ErrTaskNotFound
}
out, exitCode, err := handle.exec.Exec(time.Now().Add(timeout), cmd[0], cmd[1:])
if err != nil {
return nil, err
}
return &drivers.ExecTaskResult{
Stdout: out,
ExitResult: &drivers.ExitResult{
ExitCode: exitCode,
},
}, nil
}