Separate Step and Sidecar types

.gitignore

@@ -33,6 +33,9 @@
 # Emacs garbage
 *~
 
+# Vim garbage
+*.swp
+
 # VSCode config
 .vscode
 
@@ -49,4 +52,4 @@ cmd/*/kodata/source.tar.gz
 # binaries
 test/pullrequest/pullrequest-init
 /.bin/
-/bin/
+/bin/

pkg/apis/pipeline/v1beta1/task_types.go

@@ -125,8 +125,16 @@ type Step struct {
 	Script string `json:"script,omitempty"`
 }
 
-// A sidecar has the same data structure as a Step, consisting of a Container, and optional Script.
-type Sidecar = Step
+// Sidecar embeds the Container type, which allows it to include fields not
+// provided by Container.
+type Sidecar struct {
+	corev1.Container `json:",inline"`
+
+	// Script is the contents of an executable file to execute.
+	//
+	// If Script is not empty, the Step cannot have an Command or Args.
+	Script string `json:"script,omitempty"`
+}
 
 // +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
 // TaskList contains a list of Task

pkg/pod/script.go

@@ -62,7 +62,17 @@ func convertScripts(shellImage string, steps []v1beta1.Step, sidecars []v1beta1.
 	}
 
 	convertedStepContainers := convertListOfSteps(steps, &placeScriptsInit, &placeScripts, "script")
-	sidecarContainers := convertListOfSteps(sidecars, &placeScriptsInit, &placeScripts, "sidecar-script")
+	// convertListOfSteps operates on overlapping fields across Step and Sidecar, hence a conversion
+	// from Sidecar into Step
+	sideCarSteps := []v1beta1.Step{}
+	for _, step := range sidecars {
+		sidecarStep := v1beta1.Step{
+			step.Container,
+			step.Script,
+		}
+		sideCarSteps = append(sideCarSteps, sidecarStep)
+	}
+	sidecarContainers := convertListOfSteps(sideCarSteps, &placeScriptsInit, &placeScripts, "sidecar-script")
 
 	if placeScripts {
 		return &placeScriptsInit, convertedStepContainers, sidecarContainers

pkg/pod/script_test.go

@@ -35,7 +35,7 @@ func TestConvertScripts_NothingToConvert_EmptySidecars(t *testing.T) {
 		Container: corev1.Container{
 			Image: "step-2",
 		},
-	}}, []v1alpha1.Step{})
+	}}, []v1alpha1.Sidecar{})
 	want := []corev1.Container{{
 		Image: "step-1",
 	}, {
@@ -89,7 +89,7 @@ func TestConvertScripts_NothingToConvert_WithSidecar(t *testing.T) {
 		Container: corev1.Container{
 			Image: "step-2",
 		},
-	}}, []v1alpha1.Step{{
+	}}, []v1alpha1.Sidecar{{
 		Container: corev1.Container{
 			Image: "sidecar-1",
 		},
@@ -153,7 +153,7 @@ script-3`,
 			VolumeMounts: preExistingVolumeMounts,
 			Args:         []string{"my", "args"},
 		},
-	}}, []v1alpha1.Step{})
+	}}, []v1alpha1.Sidecar{})
 	wantInit := &corev1.Container{
 		Name:    "place-scripts",
 		Image:   images.ShellImage,
@@ -241,7 +241,7 @@ script-3`,
 			VolumeMounts: preExistingVolumeMounts,
 			Args:         []string{"my", "args"},
 		},
-	}}, []v1alpha1.Step{{
+	}}, []v1alpha1.Sidecar{{
 		Script: `#!/bin/sh
 sidecar-1`,
 		Container: corev1.Container{Image: "sidecar-1"},