14807: Add comments to "error indicates success" code.

[arvados.git] / services / crunch-run / crunchrun.go

diff --git a/services/crunch-run/crunchrun.go b/services/crunch-run/crunchrun.go
index 1c6c58009fac71bd5fa5015a4922821937e61d5a..0576337aa13c280841187db3a7aea2dcf4af65c0 100644 (file)
--- a/services/crunch-run/crunchrun.go
+++ b/services/crunch-run/crunchrun.go
@@ -1518,6 +1518,14 @@ func (runner *ContainerRunner) Run() (err error) {
                runner.CrunchLog.Close()
        }()
 
+       err = runner.fetchContainerRecord()
+       if err != nil {
+               return
+       }
+       if runner.Container.State != "Locked" {
+               return fmt.Errorf("dispatch error detected: container %q has state %q", runner.Container.UUID, runner.Container.State)
+       }
+
        defer func() {
                // checkErr prints e (unless it's nil) and sets err to
                // e (unless err is already non-nil). Thus, if err
@@ -1558,10 +1566,6 @@ func (runner *ContainerRunner) Run() (err error) {
                checkErr("UpdateContainerFinal", runner.UpdateContainerFinal())
        }()
 
-       err = runner.fetchContainerRecord()
-       if err != nil {
-               return
-       }
        runner.setupSignals()
        err = runner.startHoststat()
        if err != nil {
@@ -1733,6 +1737,7 @@ func main() {
        cgroupParentSubsystem := flag.String("cgroup-parent-subsystem", "", "use current cgroup for given subsystem as parent cgroup for container")
        caCertsPath := flag.String("ca-certs", "", "Path to TLS root certificates")
        detach := flag.Bool("detach", false, "Detach from parent process and run in the background")
+       stdinEnv := flag.Bool("stdin-env", false, "Load environment variables from JSON message on stdin")
        sleep := flag.Duration("sleep", 0, "Delay before starting (testing use only)")
        kill := flag.Int("kill", -1, "Send signal to an existing crunch-run process for given UUID")
        list := flag.Bool("list", false, "List UUIDs of existing crunch-run processes")
@@ -1748,22 +1753,29 @@ func main() {
        getVersion := flag.Bool("version", false, "Print version information and exit.")
        flag.Duration("check-containerd", 0, "Ignored. Exists for compatibility with older versions.")
 
-       detached := false
-       if len(os.Args) > 1 && os.Args[1] == "-detached" {
+       ignoreDetachFlag := false
+       if len(os.Args) > 1 && os.Args[1] == "-no-detach" {
                // This process was invoked by a parent process, which
                // has passed along its own arguments, including
-               // -detach, after the leading -detached flag.  Strip
-               // the leading -detached flag (it's not recognized by
-               // flag.Parse()) ... and remember not to detach all
-               // over again in this process.
+               // -detach, after the leading -no-detach flag.  Strip
+               // the leading -no-detach flag (it's not recognized by
+               // flag.Parse()) and ignore the -detach flag that
+               // comes later.
                os.Args = append([]string{os.Args[0]}, os.Args[2:]...)
-               detached = true
+               ignoreDetachFlag = true
        }
 
        flag.Parse()
 
+       if *stdinEnv && !ignoreDetachFlag {
+               // Load env vars on stdin if asked (but not in a
+               // detached child process, in which case stdin is
+               // /dev/null).
+               loadEnv(os.Stdin)
+       }
+
        switch {
-       case *detach && !detached:
+       case *detach && !ignoreDetachFlag:
                os.Exit(Detach(flag.Arg(0), os.Args, os.Stdout, os.Stderr))
        case *kill >= 0:
                os.Exit(KillProcess(flag.Arg(0), syscall.Signal(*kill), os.Stdout, os.Stderr))
@@ -1852,3 +1864,21 @@ func main() {
                log.Fatalf("%s: %v", containerId, runerr)
        }
 }
+
+func loadEnv(rdr io.Reader) {
+       buf, err := ioutil.ReadAll(rdr)
+       if err != nil {
+               log.Fatalf("read stdin: %s", err)
+       }
+       var env map[string]string
+       err = json.Unmarshal(buf, &env)
+       if err != nil {
+               log.Fatalf("decode stdin: %s", err)
+       }
+       for k, v := range env {
+               err = os.Setenv(k, v)
+               if err != nil {
+                       log.Fatalf("setenv(%q): %s", k, err)
+               }
+       }
+}