Merge pull request #160 from mrunalp/feature/hooks

Add prestart/poststop hooks to runc

Author: LK4D4

libcontainer/configs/config.go

@@ -173,6 +173,9 @@ type Config struct {
 	// Hooks are a collection of actions to perform at various container lifecycle events.
 	// Hooks are not able to be marshaled to json but they are also not needed to.
 	Hooks *Hooks `json:"-"`
+
+	// Version is the version of opencontainer specification that is supported.
+	Version string `json:"version"`
 }
 
 type Hooks struct {
@@ -186,9 +189,10 @@ type Hooks struct {
 
 // HookState is the payload provided to a hook on execution.
 type HookState struct {
-	ID   string `json:"id"`
-	Pid  int    `json:"pid"`
-	Root string `json:"root"`
+	Version string `json:"version"`
+	ID      string `json:"id"`
+	Pid     int    `json:"pid"`
+	Root    string `json:"root"`
 }
 
 type Hook interface {

libcontainer/container_linux.go

@@ -250,8 +250,9 @@ func (c *linuxContainer) Destroy() error {
 	c.initProcess = nil
 	if c.config.Hooks != nil {
 		s := configs.HookState{
-			ID:   c.id,
-			Root: c.config.Rootfs,
+			Version: c.config.Version,
+			ID:      c.id,
+			Root:    c.config.Rootfs,
 		}
 		for _, hook := range c.config.Hooks.Poststop {
 			if err := hook.Run(s); err != nil {

libcontainer/process_linux.go

@@ -203,9 +203,10 @@ func (p *initProcess) start() (err error) {
 	}()
 	if p.config.Config.Hooks != nil {
 		s := configs.HookState{
-			ID:   p.container.id,
-			Pid:  p.pid(),
-			Root: p.config.Config.Rootfs,
+			Version: p.container.config.Version,
+			ID:      p.container.id,
+			Pid:     p.pid(),
+			Root:    p.config.Config.Rootfs,
 		}
 		for _, hook := range p.config.Config.Hooks.Prestart {
 			if err := hook.Run(s); err != nil {

spec.go

@@ -391,6 +391,8 @@ func createLibcontainerConfig(cgroupName string, spec *specs.LinuxSpec, rspec *s
 	config.Sysctl = rspec.Linux.Sysctl
 	config.ProcessLabel = rspec.Linux.SelinuxProcessLabel
 	config.AppArmorProfile = rspec.Linux.ApparmorProfile
+	createHooks(rspec, config)
+	config.Version = specs.Version
 	return config, nil
 }
 
@@ -653,3 +655,23 @@ func setupSeccomp(config *specs.Seccomp) (*configs.Seccomp, error) {
 
 	return newConfig, nil
 }
+
+func createHooks(rspec *specs.LinuxRuntimeSpec, config *configs.Config) {
+	config.Hooks = &configs.Hooks{}
+	for _, h := range rspec.Hooks.Prestart {
+		cmd := configs.Command{
+			Path: h.Path,
+			Args: h.Args,
+			Env:  h.Env,
+		}
+		config.Hooks.Prestart = append(config.Hooks.Prestart, configs.NewCommandHook(cmd))
+	}
+	for _, h := range rspec.Hooks.Poststop {
+		cmd := configs.Command{
+			Path: h.Path,
+			Args: h.Args,
+			Env:  h.Env,
+		}
+		config.Hooks.Poststop = append(config.Hooks.Poststop, configs.NewCommandHook(cmd))
+	}
+}