Use map for stream processors

Signed-off-by: Maksym Pavlenko <makpav@amazon.com>

docs/stream_processors.md

@@ -21,20 +21,20 @@ pipe's path set as the value of the environment variable `STREAM_PROCESSOR_PIPE`
 ## Configuration
 
 To configure stream processors for containerd, entries in the config file need to be made.
-The `stream_processors` field is an array so that users can chain together multiple processors
+The `stream_processors` field is a map so that users can chain together multiple processors
 to mutate content streams.
 
 Processor Fields:
 
-* `id` - ID of the processor, used for passing a specific payload to the processor.
+* Key - ID of the processor, used for passing a specific payload to the processor.
 * `accepts` - Accepted media-types for the processor that it can handle.
 * `returns` - The media-type that the processor returns.
 * `path` - Path to the processor binary.
 * `args` - Arguments passed to the processor binary.
 
 ```toml
-[[stream_processors]]
-	id = "io.containerd.processor.v1.pigz"
+[stream_processors]
+  [stream_processors."io.containerd.processor.v1.pigz"]
 	accepts = ["application/vnd.docker.image.rootfs.diff.tar.gzip"]
 	returns = "application/vnd.oci.image.layer.v1.tar"
 	path = "unpigz"

services/server/config/config.go

@@ -63,13 +63,11 @@ type Config struct {
 	// Imports are additional file path list to config files that can overwrite main config file fields
 	Imports []string `toml:"imports"`
 
-	StreamProcessors []StreamProcessor `toml:"stream_processors"`
+	StreamProcessors map[string]StreamProcessor `toml:"stream_processors"`
 }
 
 // StreamProcessor provides configuration for diff content processors
 type StreamProcessor struct {
-	// ID of the processor, also used to fetch the specific payload
-	ID string `toml:"id"`
 	// Accepts specific media-types
 	Accepts []string `toml:"accepts"`
 	// Returns the media-type

services/server/config/config_test.go

@@ -86,6 +86,11 @@ func TestLoadSingleConfig(t *testing.T) {
 	data := `
 version = 2
 root = "/var/lib/containerd"
+
+[stream_processors]
+  [stream_processors."io.containerd.processor.v1.pigz"]
+	accepts = ["application/vnd.docker.image.rootfs.diff.tar.gzip"]
+	path = "unpigz"
 `
 	tempDir, err := ioutil.TempDir("", "containerd_")
 	assert.NilError(t, err)
@@ -100,6 +105,12 @@ root = "/var/lib/containerd"
 	assert.NilError(t, err)
 	assert.Equal(t, 2, out.Version)
 	assert.Equal(t, "/var/lib/containerd", out.Root)
+	assert.DeepEqual(t, map[string]StreamProcessor{
+		"io.containerd.processor.v1.pigz": {
+			Accepts: []string{"application/vnd.docker.image.rootfs.diff.tar.gzip"},
+			Path:    "unpigz",
+		},
+	}, out.StreamProcessors)
 }
 
 func TestLoadConfigWithImports(t *testing.T) {

services/server/server.go

@@ -89,8 +89,8 @@ func New(ctx context.Context, config *srvconfig.Config) (*Server, error) {
 	if err != nil {
 		return nil, err
 	}
-	for _, p := range config.StreamProcessors {
-		diff.RegisterProcessor(diff.BinaryHandler(p.ID, p.Returns, p.Accepts, p.Path, p.Args))
+	for id, p := range config.StreamProcessors {
+		diff.RegisterProcessor(diff.BinaryHandler(id, p.Returns, p.Accepts, p.Path, p.Args))
 	}
 
 	serverOpts := []grpc.ServerOption{