Ensure MY_POD_NAME, MY_POD_NAMESPACE, and K8S_SERVICE_NAME envVar defined first (#437)

* Ensure MY_POD_NAME, MY_POD_NAMESPACE, and K8S_SERVICE_NAME envVar defined first

- handle the rabbitmq container envVar list as a special case if it's overwritten by override
- we need to ensure that MY_POD_NAME, MY_POD_NAMESPACE, and K8S_SERVICE_NAME  are defined first so other envVars values can reference them

Co-authored-by: Michal Kuratczyk <[email protected]>

Author: ChunyiLyu

internal/resource/statefulset.go

@@ -233,9 +233,34 @@ func patchPodSpec(podSpec, podSpecOverride *corev1.PodSpec) (corev1.PodSpec, err
 	if err != nil {
 		return corev1.PodSpec{}, fmt.Errorf("error unmarshalling patched Stateful Set: %v", err)
 	}
+
+	// handle the rabbitmq container envVar list as a special case if it's overwritten
+	// we need to ensure that MY_POD_NAME, MY_POD_NAMESPACE and K8S_SERVICE_NAME are defined first so other envVars values can reference them
+	if rmqContainer := containerRabbitmq(podSpecOverride.Containers); rmqContainer.Env != nil {
+		sortEnvVar(patchedPodSpec.Containers[0].Env)
+	}
+
 	return patchedPodSpec, nil
 }
 
+// sortEnvVar ensures that 'MY_POD_NAME', 'MY_POD_NAMESPACE' and 'K8S_SERVICE_NAME' envVars are defined first in the list
+// this is to enable other envVars to reference them as variables successfully
+func sortEnvVar(envVar []corev1.EnvVar) {
+	for i, e := range envVar {
+		if e.Name == "MY_POD_NAME" {
+			envVar[0], envVar[i] = envVar[i], envVar[0]
+			continue
+		}
+		if e.Name == "MY_POD_NAMESPACE" {
+			envVar[1], envVar[i] = envVar[i], envVar[1]
+			continue
+		}
+		if e.Name == "K8S_SERVICE_NAME" {
+			envVar[2], envVar[i] = envVar[i], envVar[2]
+		}
+	}
+}
+
 func (builder *StatefulSetBuilder) podTemplateSpec(annotations, labels map[string]string) corev1.PodTemplateSpec {
 	//Init Container resources
 	cpuRequest := k8sresource.MustParse(initContainerCPU)
@@ -703,3 +728,12 @@ func mergeMap(base, override map[string]string) map[string]string {
 
 	return result
 }
+
+func containerRabbitmq(containers []corev1.Container) corev1.Container {
+	for _, container := range containers {
+		if container.Name == "rabbitmq" {
+			return container
+		}
+	}
+	return corev1.Container{}
+}

internal/resource/statefulset_test.go

@@ -1421,6 +1421,116 @@ var _ = Describe("StatefulSet", func() {
 						},
 					))
 				})
+				Context("Container EnvVar", func() {
+					It("Overrides the envVar list while making sure that 'MY_POD_NAME', 'MY_POD_NAMESPACE' and 'K8S_SERVICE_NAME' are always defined first", func() {
+						instance.Spec.Override.StatefulSet = &rabbitmqv1beta1.StatefulSet{
+							Spec: &rabbitmqv1beta1.StatefulSetSpec{
+								Template: &rabbitmqv1beta1.PodTemplateSpec{
+									Spec: &corev1.PodSpec{
+										Containers: []corev1.Container{
+											{
+												Name: "rabbitmq",
+												Env: []corev1.EnvVar{
+													{
+														Name:  "test1",
+														Value: "test1",
+													},
+													{
+														Name:  "RABBITMQ_USE_LONGNAME",
+														Value: "false",
+													},
+													{
+														Name:  "RABBITMQ_STREAM_ADVERTISED_HOST",
+														Value: "$(MY_POD_NAME).$(K8S_SERVICE_NAME).$(MY_POD_NAMESPACE)",
+													},
+												},
+											},
+										},
+									},
+								},
+							},
+						}
+
+						builder = &resource.RabbitmqResourceBuilder{
+							Instance: &instance,
+							Scheme:   scheme,
+						}
+						stsBuilder := builder.StatefulSet()
+						Expect(stsBuilder.Update(statefulSet)).To(Succeed())
+						Expect(extractContainer(statefulSet.Spec.Template.Spec.Containers, "rabbitmq").Env[0]).To(Equal(
+							corev1.EnvVar{
+								Name: "MY_POD_NAME",
+								ValueFrom: &corev1.EnvVarSource{
+									FieldRef: &corev1.ObjectFieldSelector{
+										FieldPath:  "metadata.name",
+										APIVersion: "v1",
+									},
+								},
+							}))
+						Expect(extractContainer(statefulSet.Spec.Template.Spec.Containers, "rabbitmq").Env[1]).To(Equal(
+							corev1.EnvVar{
+								Name: "MY_POD_NAMESPACE",
+								ValueFrom: &corev1.EnvVarSource{
+									FieldRef: &corev1.ObjectFieldSelector{
+										FieldPath:  "metadata.namespace",
+										APIVersion: "v1",
+									},
+								},
+							}))
+						Expect(extractContainer(statefulSet.Spec.Template.Spec.Containers, "rabbitmq").Env[2]).To(Equal(
+							corev1.EnvVar{
+								Name:  "K8S_SERVICE_NAME",
+								Value: "foo-rabbitmq-headless",
+							}))
+						Expect(extractContainer(statefulSet.Spec.Template.Spec.Containers, "rabbitmq").Env).To(ConsistOf(
+							corev1.EnvVar{
+								Name: "MY_POD_NAME",
+								ValueFrom: &corev1.EnvVarSource{
+									FieldRef: &corev1.ObjectFieldSelector{
+										FieldPath:  "metadata.name",
+										APIVersion: "v1",
+									},
+								},
+							},
+							corev1.EnvVar{
+								Name: "MY_POD_NAMESPACE",
+								ValueFrom: &corev1.EnvVarSource{
+									FieldRef: &corev1.ObjectFieldSelector{
+										FieldPath:  "metadata.namespace",
+										APIVersion: "v1",
+									},
+								},
+							},
+							corev1.EnvVar{
+								Name:  "test1",
+								Value: "test1",
+							},
+							corev1.EnvVar{
+								Name:  "K8S_SERVICE_NAME",
+								Value: instance.ChildResourceName("headless"),
+							},
+							corev1.EnvVar{
+								Name:  "RABBITMQ_USE_LONGNAME",
+								Value: "false",
+							},
+							corev1.EnvVar{
+								Name:  "RABBITMQ_ENABLED_PLUGINS_FILE",
+								Value: "/operator/enabled_plugins",
+							},
+							corev1.EnvVar{
+								Name:  "RABBITMQ_NODENAME",
+								Value: "rabbit@$(MY_POD_NAME).$(K8S_SERVICE_NAME).$(MY_POD_NAMESPACE)",
+							},
+							corev1.EnvVar{
+								Name:  "K8S_HOSTNAME_SUFFIX",
+								Value: ".$(K8S_SERVICE_NAME).$(MY_POD_NAMESPACE)",
+							},
+							corev1.EnvVar{
+								Name:  "RABBITMQ_STREAM_ADVERTISED_HOST",
+								Value: "$(MY_POD_NAME).$(K8S_SERVICE_NAME).$(MY_POD_NAMESPACE)",
+							}))
+					})
+				})
 			})
 
 			It("ensures override takes precedence when same property is set both at the top level and at the override level", func() {