Make a basic executor that can be shared and fix some fingerprinting/tests

client/executor/exec_basic.go

@@ -0,0 +1,107 @@
+package executor
+
+import (
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+
+	"github.com/hashicorp/nomad/client/allocdir"
+	"github.com/hashicorp/nomad/client/driver/args"
+	"github.com/hashicorp/nomad/client/driver/environment"
+	"github.com/hashicorp/nomad/nomad/structs"
+)
+
+// BasicExecutor should work everywhere, and as a result does not include
+// any resource restrictions or runas capabilities.
+type BasicExecutor struct {
+	cmd
+}
+
+// TODO: Update to use the Spawner.
+// TODO: Have raw_exec use this as well.
+func NewBasicExecutor() Executor {
+	return &BasicExecutor{}
+}
+
+func (e *BasicExecutor) Limit(resources *structs.Resources) error {
+	if resources == nil {
+		return errNoResources
+	}
+	return nil
+}
+
+func (e *BasicExecutor) ConfigureTaskDir(taskName string, alloc *allocdir.AllocDir) error {
+	taskDir, ok := alloc.TaskDirs[taskName]
+	if !ok {
+		return fmt.Errorf("Error finding task dir for (%s)", taskName)
+	}
+	e.Dir = taskDir
+	return nil
+}
+
+func (e *BasicExecutor) Start() error {
+	// Parse the commands arguments and replace instances of Nomad environment
+	// variables.
+	envVars, err := environment.ParseFromList(e.cmd.Env)
+	if err != nil {
+		return err
+	}
+
+	parsedPath, err := args.ParseAndReplace(e.cmd.Path, envVars.Map())
+	if err != nil {
+		return err
+	} else if len(parsedPath) != 1 {
+		return fmt.Errorf("couldn't properly parse command path: %v", e.cmd.Path)
+	}
+
+	e.cmd.Path = parsedPath[0]
+	combined := strings.Join(e.cmd.Args, " ")
+	parsed, err := args.ParseAndReplace(combined, envVars.Map())
+	if err != nil {
+		return err
+	}
+	e.Cmd.Args = parsed
+
+	// We don't want to call ourself. We want to call Start on our embedded Cmd
+	return e.cmd.Start()
+}
+
+func (e *BasicExecutor) Open(pid string) error {
+	pidNum, err := strconv.Atoi(pid)
+	if err != nil {
+		return fmt.Errorf("Failed to parse pid %v: %v", pid, err)
+	}
+
+	process, err := os.FindProcess(pidNum)
+	if err != nil {
+		return fmt.Errorf("Failed to reopen pid %d: %v", pidNum, err)
+	}
+	e.Process = process
+	return nil
+}
+
+func (e *BasicExecutor) Wait() error {
+	// We don't want to call ourself. We want to call Start on our embedded Cmd
+	return e.cmd.Wait()
+}
+
+func (e *BasicExecutor) ID() (string, error) {
+	if e.cmd.Process != nil {
+		return strconv.Itoa(e.cmd.Process.Pid), nil
+	} else {
+		return "", fmt.Errorf("Process has finished or was never started")
+	}
+}
+
+func (e *BasicExecutor) Shutdown() error {
+	return e.ForceStop()
+}
+
+func (e *BasicExecutor) ForceStop() error {
+	return e.Process.Kill()
+}
+
+func (e *BasicExecutor) Command() *cmd {
+	return &e.cmd
+}