restart plugin: support binary log uri

Introduce LogURIGenerator helper function in cio package. It is used in
the restart options, like WithBinaryLogURI and WithFileLogURI.

And restart.LogPathLabel might be used in production and work well. In
order to reduce breaking change, the LogPathLabel is still recognized if
new LogURILabel is not set. In next release 1.5, the LogPathLabel will
be removed.

Signed-off-by: Wei Fu <fuweid89@gmail.com>

cio/io.go

@@ -245,19 +245,11 @@ func LogURI(uri *url.URL) Creator {
 // BinaryIO forwards container STDOUT|STDERR directly to a logging binary
 func BinaryIO(binary string, args map[string]string) Creator {
 	return func(_ string) (IO, error) {
-		binary = filepath.Clean(binary)
-		if !strings.HasPrefix(binary, "/") {
-			return nil, errors.New("absolute path needed")
+		uri, err := LogURIGenerator("binary", binary, args)
+		if err != nil {
+			return nil, err
 		}
-		uri := &url.URL{
-			Scheme: "binary",
-			Path:   binary,
-		}
-		q := uri.Query()
-		for k, v := range args {
-			q.Set(k, v)
-		}
-		uri.RawQuery = q.Encode()
+
 		res := uri.String()
 		return &logURI{
 			config: Config{
@@ -272,14 +264,11 @@ func BinaryIO(binary string, args map[string]string) Creator {
 // If the log file already exists, the logs will be appended to the file.
 func LogFile(path string) Creator {
 	return func(_ string) (IO, error) {
-		path = filepath.Clean(path)
-		if !strings.HasPrefix(path, "/") {
-			return nil, errors.New("absolute path needed")
-		}
-		uri := &url.URL{
-			Scheme: "file",
-			Path:   path,
+		uri, err := LogURIGenerator("file", path, nil)
+		if err != nil {
+			return nil, err
 		}
+
 		res := uri.String()
 		return &logURI{
 			config: Config{
@@ -290,6 +279,30 @@ func LogFile(path string) Creator {
 	}
 }
 
+// LogURIGenerator is the helper to generate log uri with specific scheme.
+func LogURIGenerator(scheme string, path string, args map[string]string) (*url.URL, error) {
+	path = filepath.Clean(path)
+	if !strings.HasPrefix(path, "/") {
+		return nil, errors.New("absolute path needed")
+	}
+
+	uri := &url.URL{
+		Scheme: scheme,
+		Path:   path,
+	}
+
+	if len(args) == 0 {
+		return uri, nil
+	}
+
+	q := uri.Query()
+	for k, v := range args {
+		q.Set(k, v)
+	}
+	uri.RawQuery = q.Encode()
+	return uri, nil
+}
+
 type logURI struct {
 	config Config
 }

cio/io_test.go

@@ -195,3 +195,47 @@ func TestLogFileFailOnRelativePath(t *testing.T) {
 	_, err := LogFile("./file.txt")("!")
 	assert.Error(t, err, "absolute path needed")
 }
+
+func TestLogURIGenerator(t *testing.T) {
+	for _, tc := range []struct {
+		scheme   string
+		path     string
+		args     map[string]string
+		expected string
+		err      string
+	}{
+		{
+			scheme:   "fifo",
+			path:     "/full/path/pipe.fifo",
+			expected: "fifo:///full/path/pipe.fifo",
+		},
+		{
+			scheme: "file",
+			path:   "/full/path/file.txt",
+			args: map[string]string{
+				"maxSize": "100MB",
+			},
+			expected: "file:///full/path/file.txt?maxSize=100MB",
+		},
+		{
+			scheme: "binary",
+			path:   "/full/path/bin",
+			args: map[string]string{
+				"id": "testing",
+			},
+			expected: "binary:///full/path/bin?id=testing",
+		},
+		{
+			scheme: "unknown",
+			path:   "nowhere",
+			err:    "absolute path needed",
+		},
+	} {
+		uri, err := LogURIGenerator(tc.scheme, tc.path, tc.args)
+		if err != nil {
+			assert.Error(t, err, tc.err)
+			continue
+		}
+		assert.Equal(t, tc.expected, uri.String())
+	}
+}

runtime/restart/monitor/change.go

@@ -18,10 +18,13 @@ package monitor
 
 import (
 	"context"
+	"net/url"
 	"syscall"
 
 	"github.com/containerd/containerd"
 	"github.com/containerd/containerd/cio"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
 )
 
 type stopChange struct {
@@ -34,14 +37,30 @@ func (s *stopChange) apply(ctx context.Context, client *containerd.Client) error
 
 type startChange struct {
 	container containerd.Container
-	logPath   string
+	logURI    string
+
+	// Deprecated(in release 1.5): but recognized now, prefer to use logURI
+	logPath string
 }
 
 func (s *startChange) apply(ctx context.Context, client *containerd.Client) error {
 	log := cio.NullIO
-	if s.logPath != "" {
+
+	if s.logURI != "" {
+		uri, err := url.Parse(s.logURI)
+		if err != nil {
+			return errors.Wrapf(err, "failed to parse %v into url", s.logURI)
+		}
+		log = cio.LogURI(uri)
+	} else if s.logPath != "" {
 		log = cio.LogFile(s.logPath)
 	}
+
+	if s.logURI != "" && s.logPath != "" {
+		logrus.Warnf("LogPathLabel=%v has been deprecated, using LogURILabel=%v",
+			s.logPath, s.logURI)
+	}
+
 	killTask(ctx, s.container)
 	task, err := s.container.NewTask(ctx, log)
 	if err != nil {

runtime/restart/monitor/monitor.go

@@ -200,6 +200,7 @@ func (m *monitor) monitor(ctx context.Context) ([]change, error) {
 			changes = append(changes, &startChange{
 				container: c,
 				logPath:   labels[restart.LogPathLabel],
+				logURI:    labels[restart.LogURILabel],
 			})
 		case containerd.Stopped:
 			changes = append(changes, &stopChange{

runtime/restart/restart.go

@@ -33,17 +33,53 @@ import (
 	"context"
 
 	"github.com/containerd/containerd"
+	"github.com/containerd/containerd/cio"
 	"github.com/containerd/containerd/containers"
 )
 
 const (
 	// StatusLabel sets the restart status label for a container
 	StatusLabel = "containerd.io/restart.status"
+	// LogURILabel sets the restart log uri label for a container
+	LogURILabel = "containerd.io/restart.loguri"
+
 	// LogPathLabel sets the restart log path label for a container
+	//
+	// Deprecated(in release 1.5): use LogURILabel
 	LogPathLabel = "containerd.io/restart.logpath"
 )
 
+// WithBinaryLogURI sets the binary-type log uri for a container.
+func WithBinaryLogURI(binary string, args map[string]string) func(context.Context, *containerd.Client, *containers.Container) error {
+	return func(_ context.Context, _ *containerd.Client, c *containers.Container) error {
+		uri, err := cio.LogURIGenerator("binary", binary, args)
+		if err != nil {
+			return err
+		}
+
+		ensureLabels(c)
+		c.Labels[LogURILabel] = uri.String()
+		return nil
+	}
+}
+
+// WithFileLogURI sets the file-type log uri for a container.
+func WithFileLogURI(path string) func(context.Context, *containerd.Client, *containers.Container) error {
+	return func(_ context.Context, _ *containerd.Client, c *containers.Container) error {
+		uri, err := cio.LogURIGenerator("file", path, nil)
+		if err != nil {
+			return err
+		}
+
+		ensureLabels(c)
+		c.Labels[LogURILabel] = uri.String()
+		return nil
+	}
+}
+
 // WithLogPath sets the log path for a container
+//
+// Deprecated(in release 1.5): use WithFileLogURI.
 func WithLogPath(path string) func(context.Context, *containerd.Client, *containers.Container) error {
 	return func(_ context.Context, _ *containerd.Client, c *containers.Container) error {
 		ensureLabels(c)
@@ -68,6 +104,7 @@ func WithNoRestarts(_ context.Context, _ *containerd.Client, c *containers.Conta
 	}
 	delete(c.Labels, StatusLabel)
 	delete(c.Labels, LogPathLabel)
+	delete(c.Labels, LogURILabel)
 	return nil
 }