Added initial support for PodMetaData, handling Annotations only (#210)

Co-authored-by: Matt Schallert <[email protected]>

Author: xmcqueen

docs/api.md

@@ -65,6 +65,7 @@ ClusterSpec defines the desired state for a M3 cluster to be converge to.
 | externalCoordinatorSelector | Specify a \"controlling\" coordinator for the cluster It is expected that there is a separate standalone coordinator cluster It is externally managed - not managed by this operator It is expected to have a service endpoint Setup this db cluster, but do not assume a co-located coordinator Instead provide a selector here so we can point to a separate coordinator service Specify here the labels required for the selector | map[string]string | false |
 | initContainers | Custom setup for db nodes can be done via initContainers Provide the complete spec for the initContainer here If any storage volumes are needed in the initContainer see InitVolumes below | []corev1.Container | false |
 | initVolumes | If the InitContainers require any storage volumes Provide the complete specification for the required Volumes here | []corev1.Volume | false |
+| podMetadata | PodMetadata is for any Metadata that is unique to the pods, and does not belong on any other objects, such as Prometheus scrape tags | [metav1.ObjectMeta](https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.10/#objectmeta-v1-meta) | false |
 
 [Back to TOC](#table-of-contents)
 

pkg/apis/m3dboperator/v1alpha1/cluster.go

@@ -295,6 +295,10 @@ type ClusterSpec struct {
 	// If the InitContainers require any storage volumes
 	// Provide the complete specification for the required Volumes here
 	InitVolumes []corev1.Volume `json:"initVolumes,omitempty"`
+
+	// PodMetadata is for any Metadata that is unique to the pods, and does
+	// not belong on any other objects, such as Prometheus scrape tags
+	PodMetadata metav1.ObjectMeta `json:"podMetadata,omitempty"`
 }
 
 // NodeAffinityTerm represents a node label and a set of label values, any of

pkg/k8sops/annotations/annotations.go

@@ -51,3 +51,17 @@ func BaseAnnotations(cluster *myspec.M3DBCluster) map[string]string {
 
 	return base
 }
+
+// PodAnnotations is for specifying annotations that are only to be
+// applied to the pods such as prometheus scrape tags
+func PodAnnotations(cluster *myspec.M3DBCluster) map[string]string {
+	base := BaseAnnotations(cluster)
+	for k := range cluster.Spec.PodMetadata.Annotations {
+		// accept any user-specified annotations if its safe to do so
+		if _, found := base[k]; !found {
+			base[k] = cluster.Spec.PodMetadata.Annotations[k]
+		}
+	}
+
+	return base
+}

pkg/k8sops/annotations/annotations_test.go

@@ -51,3 +51,34 @@ func TestGenerateBaseAnnotations(t *testing.T) {
 
 	assert.Equal(t, expAnnotations, annotations)
 }
+
+func TestGeneratePodAnnotations(t *testing.T) {
+	cluster := &myspec.M3DBCluster{
+		ObjectMeta: metav1.ObjectMeta{
+			Name: "cluster-foo",
+		},
+		Spec: myspec.ClusterSpec{
+			PodMetadata: metav1.ObjectMeta{
+				Annotations: map[string]string{
+					"pod-annotation": "some-annotation",
+				},
+			},
+		},
+	}
+
+	annotations := PodAnnotations(cluster)
+	expAnnotations := map[string]string{
+		"operator.m3db.io/app":     "m3db",
+		"operator.m3db.io/cluster": "cluster-foo",
+		"pod-annotation":           "some-annotation",
+	}
+
+	assert.Equal(t, expAnnotations, annotations)
+
+	cluster.Spec.Annotations = map[string]string{"foo": "bar"}
+	annotations = PodAnnotations(cluster)
+	expAnnotations["foo"] = "bar"
+	expAnnotations["pod-annotation"] = "some-annotation"
+
+	assert.Equal(t, expAnnotations, annotations)
+}

pkg/k8sops/m3db/statefulset.go

@@ -63,7 +63,7 @@ func NewBaseStatefulSet(ssName, isolationGroup string, cluster *myspec.M3DBClust
 		objLabels[k] = v
 	}
 
-	objAnnotations := annotations.BaseAnnotations(cluster)
+	objAnnotations := annotations.PodAnnotations(cluster)
 
 	// TODO(schallert): we're currently using the health of the coordinator for
 	// liveness probes until https://github.com/m3db/m3/issues/996 is fixed. Move