Switch java/exec to use Exec in Executor

client/alloc_runner.go

@@ -195,7 +195,6 @@ func (r *AllocRunner) RestoreState() error {
 
 			// Restart task runner if RestoreState gave a reason
 			if restartReason != "" {
-				r.logger.Printf("[INFO] client: restarting alloc %s task %q due to upgrade: %s", r.alloc.ID, name, restartReason)
 				tr.Restart("upgrade", restartReason)
 			}
 		}

client/driver/exec.go

@@ -259,7 +259,12 @@ func (h *execHandle) Update(task *structs.Task) error {
 }
 
 func (h *execHandle) Exec(ctx context.Context, cmd string, args []string) ([]byte, int, error) {
-	return execChroot(ctx, h.taskDir.Dir, cmd, args)
+	deadline, ok := ctx.Deadline()
+	if !ok {
+		// No deadline set on context; default to 1 minute
+		deadline = time.Now().Add(time.Minute)
+	}
+	return h.executor.Exec(deadline, cmd, args)
 }
 
 func (h *execHandle) Signal(s os.Signal) error {

client/driver/executor/executor.go

@@ -1,6 +1,7 @@
 package executor
 
 import (
+	"context"
 	"fmt"
 	"io/ioutil"
 	"log"
@@ -15,6 +16,7 @@ import (
 	"syscall"
 	"time"
 
+	"github.com/armon/circbuf"
 	"github.com/hashicorp/go-multierror"
 	"github.com/mitchellh/go-ps"
 	"github.com/shirou/gopsutil/process"
@@ -57,6 +59,7 @@ type Executor interface {
 	Version() (*ExecutorVersion, error)
 	Stats() (*cstructs.TaskResourceUsage, error)
 	Signal(s os.Signal) error
+	Exec(deadline time.Time, cmd string, args []string) ([]byte, int, error)
 }
 
 // ExecutorContext holds context to configure the command user
@@ -203,8 +206,8 @@ func (e *UniversalExecutor) SetContext(ctx *ExecutorContext) error {
 	return nil
 }
 
-// LaunchCmd launches a process and returns it's state. It also configures an
-// applies isolation on certain platforms.
+// LaunchCmd launches the main process and returns its state. It also
+// configures an applies isolation on certain platforms.
 func (e *UniversalExecutor) LaunchCmd(command *ExecCommand) (*ProcessState, error) {
 	e.logger.Printf("[DEBUG] executor: launching command %v %v", command.Cmd, strings.Join(command.Args, " "))
 
@@ -283,6 +286,45 @@ func (e *UniversalExecutor) LaunchCmd(command *ExecCommand) (*ProcessState, erro
 	return &ProcessState{Pid: e.cmd.Process.Pid, ExitCode: -1, IsolationConfig: ic, Time: time.Now()}, nil
 }
 
+// Exec a command inside a container for exec and java drivers.
+func (e *UniversalExecutor) Exec(deadline time.Time, name string, args []string) ([]byte, int, error) {
+	ctx, cancel := context.WithDeadline(context.Background(), deadline)
+	defer cancel()
+
+	name = e.ctx.TaskEnv.ReplaceEnv(name)
+	cmd := exec.CommandContext(ctx, name, e.ctx.TaskEnv.ParseAndReplace(args)...)
+
+	// Copy runtime environment from the main command
+	cmd.SysProcAttr = e.cmd.SysProcAttr
+	cmd.Dir = e.cmd.Dir
+	cmd.Env = e.ctx.TaskEnv.EnvList()
+
+	// Capture output
+	buf, _ := circbuf.NewBuffer(int64(dstructs.CheckBufSize))
+	cmd.Stdout = buf
+	cmd.Stderr = buf
+
+	if err := cmd.Run(); err != nil {
+		exitErr, ok := err.(*exec.ExitError)
+		if !ok {
+			// Non-exit error, return it and let the caller treat
+			// it as a critical failure
+			return nil, 0, err
+		}
+
+		// Some kind of error happened; default to critical
+		exitCode := 2
+		if status, ok := exitErr.Sys().(syscall.WaitStatus); ok {
+			exitCode = status.ExitStatus()
+		}
+
+		// Don't return the exitError as the caller only needs the
+		// output and code.
+		return buf.Bytes(), exitCode, nil
+	}
+	return buf.Bytes(), 0, nil
+}
+
 // configureLoggers sets up the standard out/error file rotators
 func (e *UniversalExecutor) configureLoggers() error {
 	e.rotatorLock.Lock()

client/driver/executor_plugin.go

@@ -6,6 +6,7 @@ import (
 	"net/rpc"
 	"os"
 	"syscall"
+	"time"
 
 	"github.com/hashicorp/go-plugin"
 	"github.com/hashicorp/nomad/client/driver/executor"
@@ -33,6 +34,17 @@ type LaunchCmdArgs struct {
 	Cmd *executor.ExecCommand
 }
 
+type ExecCmdArgs struct {
+	Deadline time.Time
+	Name     string
+	Args     []string
+}
+
+type ExecCmdReturn struct {
+	Output []byte
+	Code   int
+}
+
 func (e *ExecutorRPC) LaunchCmd(cmd *executor.ExecCommand) (*executor.ProcessState, error) {
 	var ps *executor.ProcessState
 	err := e.client.Call("Plugin.LaunchCmd", LaunchCmdArgs{Cmd: cmd}, &ps)
@@ -91,6 +103,20 @@ func (e *ExecutorRPC) Signal(s os.Signal) error {
 	return e.client.Call("Plugin.Signal", &s, new(interface{}))
 }
 
+func (e *ExecutorRPC) Exec(deadline time.Time, name string, args []string) ([]byte, int, error) {
+	req := ExecCmdArgs{
+		Deadline: deadline,
+		Name:     name,
+		Args:     args,
+	}
+	var resp *ExecCmdReturn
+	err := e.client.Call("Plugin.Exec", req, &resp)
+	if resp == nil {
+		return nil, 0, err
+	}
+	return resp.Output, resp.Code, err
+}
+
 type ExecutorRPCServer struct {
 	Impl   executor.Executor
 	logger *log.Logger
@@ -165,6 +191,16 @@ func (e *ExecutorRPCServer) Signal(args os.Signal, resp *interface{}) error {
 	return e.Impl.Signal(args)
 }
 
+func (e *ExecutorRPCServer) Exec(args ExecCmdArgs, result *ExecCmdReturn) error {
+	out, code, err := e.Impl.Exec(args.Deadline, args.Name, args.Args)
+	ret := &ExecCmdReturn{
+		Output: out,
+		Code:   code,
+	}
+	*result = *ret
+	return err
+}
+
 type ExecutorPlugin struct {
 	logger *log.Logger
 	Impl   *ExecutorRPCServer

client/driver/java.go

@@ -390,7 +390,12 @@ func (h *javaHandle) Update(task *structs.Task) error {
 }
 
 func (h *javaHandle) Exec(ctx context.Context, cmd string, args []string) ([]byte, int, error) {
-	return execChroot(ctx, h.taskDir, cmd, args)
+	deadline, ok := ctx.Deadline()
+	if !ok {
+		// No deadline set on context; default to 1 minute
+		deadline = time.Now().Add(time.Minute)
+	}
+	return h.executor.Exec(deadline, cmd, args)
 }
 
 func (h *javaHandle) Signal(s os.Signal) error {

client/task_runner.go

@@ -297,7 +297,7 @@ func (r *TaskRunner) RestoreState() (string, error) {
 			return "", nil
 		}
 
-		if pre06ScriptCheck(snap.Version, r.task.Services) {
+		if pre06ScriptCheck(snap.Version, r.task.Driver, r.task.Services) {
 			restartReason = "upgrading pre-0.6 script checks"
 		}
 
@@ -323,7 +323,11 @@ func (r *TaskRunner) RestoreState() (string, error) {
 var ver06 = version.Must(version.NewVersion("0.6.0dev"))
 
 // pre06ScriptCheck returns true if version is prior to 0.6.0dev.
-func pre06ScriptCheck(ver string, services []*structs.Service) bool {
+func pre06ScriptCheck(ver, driver string, services []*structs.Service) bool {
+	if driver != "exec" && driver != "java" {
+		// Only exec and java are affected
+		return false
+	}
 	v, err := version.NewVersion(ver)
 	if err != nil {
 		// Treat it as old