Add the Stats api to driverhandle

client/driver/docker.go

@@ -908,6 +908,19 @@ func (h *DockerHandle) Kill() error {
 	return nil
 }
 
+func (h *DockerHandle) Stats() (*cstructs.TaskResourceUsage, error) {
+	stats := make(chan *docker.Stats)
+	done := make(chan bool)
+	statsOpts := docker.StatsOptions{ID: h.containerID, Done: done, Stats: stats, Stream: false, Timeout: 2 * time.Second}
+	if err := h.client.Stats(statsOpts); err != nil {
+		return nil, err
+	}
+	containerStats := <-stats
+	close(done)
+	resourceUsage := cstructs.TaskResourceUsage{MemoryStats: &cstructs.MemoryStats{RSS: containerStats.MemoryStats.Stats.Rss}}
+	return &resourceUsage, nil
+}
+
 func (h *DockerHandle) run() {
 	// Wait for it...
 	exitCode, err := h.client.WaitContainer(h.containerID)

client/driver/driver.go

@@ -113,6 +113,8 @@ type DriverHandle interface {
 
 	// Kill is used to stop the task
 	Kill() error
+
+	Stats() (*cstructs.TaskResourceUsage, error)
 }
 
 // ExecContext is shared between drivers within an allocation

client/driver/exec.go

@@ -280,6 +280,10 @@ func (h *execHandle) Kill() error {
 	}
 }
 
+func (h *execHandle) Stats() (*cstructs.TaskResourceUsage, error) {
+	return h.executor.Stats()
+}
+
 func (h *execHandle) run() {
 	ps, err := h.executor.Wait()
 	close(h.doneCh)

client/driver/executor/executor.go

@@ -38,6 +38,7 @@ type Executor interface {
 	SyncServices(ctx *ConsulContext) error
 	DeregisterServices() error
 	Version() (*ExecutorVersion, error)
+	Stats() (*cstructs.TaskResourceUsage, error)
 }
 
 // ConsulContext holds context to configure the consul client and run checks

client/driver/executor/executor_basic.go

@@ -2,7 +2,10 @@
 
 package executor
 
-import cgroupConfig "github.com/opencontainers/runc/libcontainer/configs"
+import (
+	cstructs "github.com/hashicorp/nomad/client/driver/structs"
+	cgroupConfig "github.com/opencontainers/runc/libcontainer/configs"
+)
 
 func (e *UniversalExecutor) configureChroot() error {
 	return nil
@@ -27,3 +30,7 @@ func (e *UniversalExecutor) applyLimits(pid int) error {
 func (e *UniversalExecutor) configureIsolation() error {
 	return nil
 }
+
+func (e *UniversalExecutor) Stats() (*cstructs.TaskResourceUsage, error) {
+	return nil, nil
+}

client/driver/executor/executor_linux.go

@@ -15,6 +15,7 @@ import (
 	cgroupConfig "github.com/opencontainers/runc/libcontainer/configs"
 
 	"github.com/hashicorp/nomad/client/allocdir"
+	cstructs "github.com/hashicorp/nomad/client/driver/structs"
 	"github.com/hashicorp/nomad/nomad/structs"
 )
 
@@ -116,6 +117,16 @@ func (e *UniversalExecutor) configureCgroups(resources *structs.Resources) error
 	return nil
 }
 
+func (e *UniversalExecutor) Stats() (*cstructs.TaskResourceUsage, error) {
+	manager := getCgroupManager(e.groups, e.cgPaths)
+	stats, err := manager.GetStats()
+	if err != nil {
+		return nil, err
+	}
+	e.logger.Printf("DIPTANU stats %#v", stats.MemoryStats.Stats)
+	return &cstructs.TaskResourceUsage{}, nil
+}
+
 // runAs takes a user id as a string and looks up the user, and sets the command
 // to execute as that user.
 func (e *UniversalExecutor) runAs(userid string) error {

client/driver/executor_plugin.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/hashicorp/go-plugin"
 	"github.com/hashicorp/nomad/client/driver/executor"
+	cstructs "github.com/hashicorp/nomad/client/driver/structs"
 	"github.com/hashicorp/nomad/nomad/structs"
 )
 
@@ -88,6 +89,12 @@ func (e *ExecutorRPC) Version() (*executor.ExecutorVersion, error) {
 	return &version, err
 }
 
+func (e *ExecutorRPC) Stats() (*cstructs.TaskResourceUsage, error) {
+	var resourceUsage cstructs.TaskResourceUsage
+	err := e.client.Call("Plugin.Stats", new(interface{}), &resourceUsage)
+	return &resourceUsage, err
+}
+
 type ExecutorRPCServer struct {
 	Impl   executor.Executor
 	logger *log.Logger
@@ -149,6 +156,14 @@ func (e *ExecutorRPCServer) Version(args interface{}, version *executor.Executor
 	return err
 }
 
+func (e *ExecutorRPCServer) Stats(args interface{}, resourceUsage *cstructs.TaskResourceUsage) error {
+	ru, err := e.Impl.Stats()
+	if ru != nil {
+		*resourceUsage = *ru
+	}
+	return err
+}
+
 type ExecutorPlugin struct {
 	logger *log.Logger
 	Impl   *ExecutorRPCServer

client/driver/java.go

@@ -380,6 +380,10 @@ func (h *javaHandle) Kill() error {
 	}
 }
 
+func (h *javaHandle) Stats() (*cstructs.TaskResourceUsage, error) {
+	return h.executor.Stats()
+}
+
 func (h *javaHandle) run() {
 	ps, err := h.executor.Wait()
 	close(h.doneCh)

client/driver/qemu.go

@@ -375,6 +375,10 @@ func (h *qemuHandle) Kill() error {
 	}
 }
 
+func (h *qemuHandle) Stats() (*cstructs.TaskResourceUsage, error) {
+	return h.executor.Stats()
+}
+
 func (h *qemuHandle) run() {
 	ps, err := h.executor.Wait()
 	if ps.ExitCode == 0 && err != nil {

client/driver/raw_exec.go

@@ -277,6 +277,10 @@ func (h *rawExecHandle) Kill() error {
 	}
 }
 
+func (h *rawExecHandle) Stats() (*cstructs.TaskResourceUsage, error) {
+	return h.executor.Stats()
+}
+
 func (h *rawExecHandle) run() {
 	ps, err := h.executor.Wait()
 	close(h.doneCh)

client/driver/rkt.go

@@ -399,6 +399,10 @@ func (h *rktHandle) Kill() error {
 	}
 }
 
+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)

client/driver/structs/structs.go

@@ -84,3 +84,11 @@ type CheckResult struct {
 	// Err is the error that a check returned
 	Err error
 }
+
+type MemoryStats struct {
+	RSS uint64
+}
+
+type TaskResourceUsage struct {
+	MemoryStats *MemoryStats
+}