feat: support runs-on labels and group (#2062)

Signed-off-by: Raffael Sahli <raffael.sahli@doodle.com>
Co-authored-by: ChristopherHX <christopher.homberger@web.de>

pkg/model/workflow.go

@@ -275,15 +275,39 @@ func (j *Job) Needs() []string {
 // RunsOn list for Job
 func (j *Job) RunsOn() []string {
 	switch j.RawRunsOn.Kind {
+	case yaml.MappingNode:
+		var val struct {
+			Group  string
+			Labels yaml.Node
+		}
+
+		if !decodeNode(j.RawRunsOn, &val) {
+			return nil
+		}
+
+		labels := nodeAsStringSlice(val.Labels)
+
+		if val.Group != "" {
+			labels = append(labels, val.Group)
+		}
+
+		return labels
+	default:
+		return nodeAsStringSlice(j.RawRunsOn)
+	}
+}
+
+func nodeAsStringSlice(node yaml.Node) []string {
+	switch node.Kind {
 	case yaml.ScalarNode:
 		var val string
-		if !decodeNode(j.RawRunsOn, &val) {
+		if !decodeNode(node, &val) {
 			return nil
 		}
 		return []string{val}
 	case yaml.SequenceNode:
 		var val []string
-		if !decodeNode(j.RawRunsOn, &val) {
+		if !decodeNode(node, &val) {
 			return nil
 		}
 		return val

pkg/model/workflow_test.go

@@ -71,6 +71,41 @@ jobs:
 	assert.Contains(t, workflow.On(), "pull_request")
 }
 
+func TestReadWorkflow_RunsOnLabels(t *testing.T) {
+	yaml := `
+name: local-action-docker-url
+
+jobs:
+  test:
+    container: nginx:latest
+    runs-on:
+      labels: ubuntu-latest
+    steps:
+    - uses: ./actions/docker-url`
+
+	workflow, err := ReadWorkflow(strings.NewReader(yaml))
+	assert.NoError(t, err, "read workflow should succeed")
+	assert.Equal(t, workflow.Jobs["test"].RunsOn(), []string{"ubuntu-latest"})
+}
+
+func TestReadWorkflow_RunsOnLabelsWithGroup(t *testing.T) {
+	yaml := `
+name: local-action-docker-url
+
+jobs:
+  test:
+    container: nginx:latest
+    runs-on:
+      labels: [ubuntu-latest]
+      group: linux
+    steps:
+    - uses: ./actions/docker-url`
+
+	workflow, err := ReadWorkflow(strings.NewReader(yaml))
+	assert.NoError(t, err, "read workflow should succeed")
+	assert.Equal(t, workflow.Jobs["test"].RunsOn(), []string{"ubuntu-latest", "linux"})
+}
+
 func TestReadWorkflow_StringContainer(t *testing.T) {
 	yaml := `
 name: local-action-docker-url