Merge pull request containerd#68 from coryb/wrap-errors

preserve exit status with wrapped errors

Author: AkihiroSuda

.travis.yml

@@ -1,7 +1,8 @@
 language: go
 go:
-    - 1.12.x
     - 1.13.x
+    - 1.14.x
+    - 1.15.x
 
 install:
   - go get -t ./...

console_test.go

@@ -33,6 +33,8 @@ func TestTempConsole(t *testing.T) {
 
 func TestTempConsoleWithXdgRuntimeDir(t *testing.T) {
 	tmpDir := "/tmp/foo"
+	// prevent interferring with other tests
+	defer os.Setenv("XDG_RUNTIME_DIR", os.Getenv("XDG_RUNTIME_DIR"))
 	if err := os.Setenv("XDG_RUNTIME_DIR", tmpDir); err != nil {
 		t.Fatal(err)
 	}

runc.go

@@ -160,7 +160,7 @@ func (r *Runc) Create(context context.Context, id, bundle string, opts *CreateOp
 	}
 	status, err := Monitor.Wait(cmd, ec)
 	if err == nil && status != 0 {
-		err = fmt.Errorf("%s did not terminate successfully", cmd.Args[0])
+		err = fmt.Errorf("%s did not terminate successfully: %w", cmd.Args[0], &ExitError{status})
 	}
 	return err
 }
@@ -194,7 +194,7 @@ func (o *ExecOpts) args() (out []string, err error) {
 	return out, nil
 }
 
-// Exec executres and additional process inside the container based on a full
+// Exec executes an additional process inside the container based on a full
 // OCI Process specification
 func (r *Runc) Exec(context context.Context, id string, spec specs.Process, opts *ExecOpts) error {
 	f, err := ioutil.TempFile(os.Getenv("XDG_RUNTIME_DIR"), "runc-process")
@@ -223,7 +223,7 @@ func (r *Runc) Exec(context context.Context, id string, spec specs.Process, opts
 		data, err := cmdOutput(cmd, true)
 		defer putBuf(data)
 		if err != nil {
-			return fmt.Errorf("%s: %s", err, data.String())
+			return fmt.Errorf("%w: %s", err, data.String())
 		}
 		return nil
 	}
@@ -240,7 +240,7 @@ func (r *Runc) Exec(context context.Context, id string, spec specs.Process, opts
 	}
 	status, err := Monitor.Wait(cmd, ec)
 	if err == nil && status != 0 {
-		err = fmt.Errorf("%s did not terminate successfully", cmd.Args[0])
+		err = fmt.Errorf("%s did not terminate successfully: %w", cmd.Args[0], &ExitError{status})
 	}
 	return err
 }
@@ -266,7 +266,7 @@ func (r *Runc) Run(context context.Context, id, bundle string, opts *CreateOpts)
 	}
 	status, err := Monitor.Wait(cmd, ec)
 	if err == nil && status != 0 {
-		err = fmt.Errorf("%s did not terminate successfully", cmd.Args[0])
+		err = fmt.Errorf("%s did not terminate successfully: %w", cmd.Args[0], &ExitError{status})
 	}
 	return status, err
 }
@@ -584,7 +584,7 @@ func (r *Runc) Restore(context context.Context, id, bundle string, opts *Restore
 	}
 	status, err := Monitor.Wait(cmd, ec)
 	if err == nil && status != 0 {
-		err = fmt.Errorf("%s did not terminate successfully", cmd.Args[0])
+		err = fmt.Errorf("%s did not terminate successfully: %w", cmd.Args[0], &ExitError{status})
 	}
 	return status, err
 }
@@ -681,7 +681,7 @@ func (r *Runc) runOrError(cmd *exec.Cmd) error {
 		}
 		status, err := Monitor.Wait(cmd, ec)
 		if err == nil && status != 0 {
-			err = fmt.Errorf("%s did not terminate successfully", cmd.Args[0])
+			err = fmt.Errorf("%s did not terminate successfully: %w", cmd.Args[0], &ExitError{status})
 		}
 		return err
 	}
@@ -709,8 +709,16 @@ func cmdOutput(cmd *exec.Cmd, combined bool) (*bytes.Buffer, error) {
 
 	status, err := Monitor.Wait(cmd, ec)
 	if err == nil && status != 0 {
-		err = fmt.Errorf("%s did not terminate successfully", cmd.Args[0])
+		err = fmt.Errorf("%s did not terminate successfully: %w", cmd.Args[0], &ExitError{status})
 	}
 
 	return b, err
 }
+
+type ExitError struct {
+	Status int
+}
+
+func (e *ExitError) Error() string {
+	return fmt.Sprintf("exit status %d", e.Status)
+}

runc_test.go

@@ -18,8 +18,11 @@ package runc
 
 import (
 	"context"
+	"errors"
 	"sync"
 	"testing"
+
+	specs "github.com/opencontainers/runtime-spec/specs-go"
 )
 
 func TestParseVersion(t *testing.T) {
@@ -104,3 +107,88 @@ func TestParallelCmds(t *testing.T) {
 	}
 	wg.Wait()
 }
+
+func TestRuncRunExit(t *testing.T) {
+	ctx := context.Background()
+	okRunc := &Runc{
+		Command: "/bin/true",
+	}
+
+	status, err := okRunc.Run(ctx, "fake-id", "fake-bundle", &CreateOpts{})
+	if err != nil {
+		t.Fatalf("Unexpected error from Run: %s", err)
+	}
+	if status != 0 {
+		t.Fatalf("Expected exit status 0 from Run, got %d", status)
+	}
+
+	failRunc := &Runc{
+		Command: "/bin/false",
+	}
+
+	status, err = failRunc.Run(ctx, "fake-id", "fake-bundle", &CreateOpts{})
+	if err == nil {
+		t.Fatal("Expected error from Run, but got nil")
+	}
+	if status != 1 {
+		t.Fatalf("Expected exit status 1 from Run, got %d", status)
+	}
+	extractedStatus := extractStatus(err)
+	if extractedStatus != status {
+		t.Fatalf("Expected extracted exit status %d from Run, got %d", status, extractedStatus)
+	}
+}
+
+func TestRuncExecExit(t *testing.T) {
+	ctx := context.Background()
+	okRunc := &Runc{
+		Command: "/bin/true",
+	}
+	err := okRunc.Exec(ctx, "fake-id", specs.Process{}, &ExecOpts{})
+	if err != nil {
+		t.Fatalf("Unexpected error from Exec: %s", err)
+	}
+	status := extractStatus(err)
+	if status != 0 {
+		t.Fatalf("Expected exit status 0 from Exec, got %d", status)
+	}
+
+	failRunc := &Runc{
+		Command: "/bin/false",
+	}
+
+	err = failRunc.Exec(ctx, "fake-id", specs.Process{}, &ExecOpts{})
+	if err == nil {
+		t.Fatal("Expected error from Exec, but got nil")
+	}
+	status = extractStatus(err)
+	if status != 1 {
+		t.Fatalf("Expected exit status 1 from Exec, got %d", status)
+	}
+
+	io, err := NewSTDIO()
+	if err != nil {
+		t.Fatalf("Unexpected error from NewSTDIO: %s", err)
+	}
+	err = failRunc.Exec(ctx, "fake-id", specs.Process{}, &ExecOpts{
+		IO: io,
+	})
+	if err == nil {
+		t.Fatal("Expected error from Exec, but got nil")
+	}
+	status = extractStatus(err)
+	if status != 1 {
+		t.Fatalf("Expected exit status 1 from Exec, got %d", status)
+	}
+}
+
+func extractStatus(err error) int {
+	if err == nil {
+		return 0
+	}
+	var exitError *ExitError
+	if errors.As(err, &exitError) {
+		return exitError.Status
+	}
+	return -1
+}