Return RuntimeConfig with Linux.CgroupDriver - backport release/0.3

core/docker_service.go

@@ -446,6 +446,26 @@ func (ds *dockerService) Status(
 	return resp, nil
 }
 
+// RuntimeConfig returns the config of the runtime.
+func (ds *dockerService) RuntimeConfig(
+	_ context.Context,
+	r *runtimeapi.RuntimeConfigRequest,
+) (*runtimeapi.RuntimeConfigResponse, error) {
+	resp := &runtimeapi.RuntimeConfigResponse{}
+	if runtime.GOOS == "linux" {
+		resp.Linux = &runtimeapi.LinuxRuntimeConfiguration{}
+		switch ds.cgroupDriver {
+		case "cgroupfs":
+			resp.Linux.CgroupDriver = runtimeapi.CgroupDriver_CGROUPFS
+		case "systemd":
+			resp.Linux.CgroupDriver = runtimeapi.CgroupDriver_SYSTEMD
+		default:
+			return nil, fmt.Errorf("unknown cgroup driver: %s", ds.cgroupDriver)
+		}
+	}
+	return resp, nil
+}
+
 func (ds *dockerService) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	if ds.streamingServer != nil {
 		ds.streamingServer.ServeHTTP(w, r)

core/docker_service_test.go

@@ -19,6 +19,7 @@ package core
 import (
 	"errors"
 	"math/rand"
+	"runtime"
 	"testing"
 	"time"
 
@@ -163,6 +164,18 @@ func TestStatus(t *testing.T) {
 	}, statusResp.Status)
 }
 
+// TestRuntimeConfig tests the runtime config logic.
+func TestRuntimeConfig(t *testing.T) {
+	ds, _, _ := newTestDockerService()
+	ds.cgroupDriver = "systemd"
+
+	configResp, err := ds.RuntimeConfig(getTestCTX(), &runtimeapi.RuntimeConfigRequest{})
+	require.NoError(t, err)
+	if runtime.GOOS == "linux" {
+		assert.Equal(t, runtimeapi.CgroupDriver_SYSTEMD, configResp.Linux.CgroupDriver)
+	}
+}
+
 func TestVersion(t *testing.T) {
 	ds, _, _ := newTestDockerService()