feat: Support for StatefulSets, DaemonSets and Headless Services

README.md

@@ -2,7 +2,7 @@
 
 # Application
 
-Generic Helm chart for deploying stateless applications on Kubernetes. Supports Deployments, Jobs, and CronJobs along with common companion resources (Services, Ingress, RBAC, autoscaling, monitoring, certificates, and more).
+Generic Helm chart for deploying applications on Kubernetes. Supports Deployments, StatefulSets, DaemonSets, Jobs, and CronJobs along with common companion resources (Services, Ingress, RBAC, autoscaling, monitoring, certificates, and more).
 
 ## Installing the Chart
 
@@ -82,11 +82,14 @@ Please refer to the [Contributing Guide](CONTRIBUTING.md) for details on how to
 | Key | Type | Default | Description |
 |-----|------|---------|-------------|
 | deployment.enabled | bool | `true` | Enable Deployment. |
+| deployment.kind | string | `"Deployment"` | Define the kind of workload. Must specify either one of the following field when enabled: Deployment, StatefulSet, DaemonSet |
 | deployment.additionalLabels | object, null | `nil` | Additional labels for Deployment. |
 | deployment.podLabels | object, null | `nil` | Additional pod labels which are used in Service's Label Selector. |
 | deployment.annotations | object, null | `nil` | Annotations for Deployment. |
 | deployment.additionalPodAnnotations | object, null | `nil` | Additional pod annotations. |
-| deployment.strategy.type | string | `"RollingUpdate"` | Type of deployment strategy. |
+| deployment.strategy.type | string | `"RollingUpdate"` | Type of deployment strategy. Only for Deployments. |
+| deployment.updateStrategy.type | string | `"RollingUpdate"` | Type of deployment.updateStrategy. Only works for StatefulSets and DaemonSets |
+| deployment.podManagementPolicy | string | `"OrderedReady"` | Type of deployment.podManagementPolicy. Only works for StatefulSets. One of OrderedReady or Parallel |
 | deployment.reloadOnChange | bool | `true` | Reload deployment if attached Secret/ConfigMap changes. |
 | deployment.nodeSelector | object, null | `nil` | Select the node where the pods should be scheduled. |
 | deployment.hostAliases | list, null | `nil` | Mapping between IP and hostnames that will be injected as entries in the pod's hosts files. |
@@ -97,7 +100,9 @@ Please refer to the [Contributing Guide](CONTRIBUTING.md) for details on how to
 | deployment.envFrom | object, null | `nil` | Mount environment variables from ConfigMap or Secret to the pod. Use `nameSuffix` for resources managed by this chart (name will be prefixed with application name), or `name` to reference an existing external ConfigMap or Secret not managed by this chart. See the README "Consuming environment variable in application chart" section for more details. |
 | deployment.env | object, null | `nil` | Environment variables to be added to the pod. See the README "Consuming environment variable in application chart" section for more details. |
 | deployment.volumes | object, null | `nil` | Volumes to be added to the pod. Key is the name of the volume. Value is the volume definition. |
+| deployment.volumeClaimTemplates | object, null | `nil` | VolumeClaimTemplates to be added to the pods. Key is the name of the volume. Value is the spec for volumeClaimTemplate. Use only for StatefulSets. |
 | deployment.volumeMounts | object, null | `nil` | Mount path for Volumes. Key is the name of the volume. Value is the volume mount definition. |
+| deployment.persistentVolumeClaimRetentionPolicy | object, null | `nil` | Rules on what to do with residual PVCs for StatefulSets. No-op for Deployments or DaemonSets. |
 | deployment.priorityClassName | string, null | `""` | Define the priority class for the pod. |
 | deployment.runtimeClassName | string, null | `""` | Set the runtimeClassName for the deployment's pods. |
 | deployment.tolerations | list, null | `nil` | Taint tolerations for the pods. |
@@ -182,6 +187,18 @@ Please refer to the [Contributing Guide](CONTRIBUTING.md) for details on how to
 | service.type | string | `"ClusterIP"` | Type of service. |
 | service.clusterIP | string, null | `nil` | Fixed IP for a ClusterIP service. Set to `None` for an headless service |
 | service.loadBalancerClass | string, null | `nil` | LoadBalancer class name for LoadBalancer type services. |
+| headlessService.name | string, null | `nil` | Optional override for service name Defaults to application.name-headless |
+
+### Headless Service Parameters
+
+| Key | Type | Default | Description |
+|-----|------|---------|-------------|
+| headlessService.enabled | bool | `false` | Enable Headless Service for StatefulSet. |
+| headlessService.additionalLabels | object, null | `nil` | Additional labels for headless service. |
+| headlessService.annotations | object, null | `nil` | Annotations for headless service. |
+| headlessService.ports | list | `[{"name":"http","port":8080,"protocol":"TCP","targetPort":8080}]` | Ports for applications service. |
+| headlessService.ports[0].targetPort | int, string, null | `8080` | Target port on pods. Accepts port number or port name (IANA_SVC_NAME). |
+| headlessService.publishNotReadyAddresses | bool, null | `nil` | Propagate SRV DNS records for Pods to enable peer discovery, by disregarding any indications of ready/not-ready for Pods. |
 
 ### Ingress Parameters
 

README.md.gotmpl

@@ -2,7 +2,7 @@
 
 # Application
 
-Generic Helm chart for deploying stateless applications on Kubernetes. Supports Deployments, Jobs, and CronJobs along with common companion resources (Services, Ingress, RBAC, autoscaling, monitoring, certificates, and more).
+Generic Helm chart for deploying applications on Kubernetes. Supports Deployments, StatefulSets, DaemonSets, Jobs, and CronJobs along with common companion resources (Services, Ingress, RBAC, autoscaling, monitoring, certificates, and more).
 
 ## Installing the Chart
 

application/Chart.yaml

@@ -1,6 +1,6 @@
 apiVersion: v2
 name: application
-description: Generic Helm chart for deploying stateless applications on Kubernetes
+description: Generic Helm chart for deploying applications on Kubernetes
 type: application
 version: 9.3.1
 keywords:

application/ci/values.yaml

@@ -6,15 +6,16 @@ additionalLabels:
   team: stakater
 
 deployment:
+  kind: StatefulSet
   dnsConfig:
     options:
       - name: ndots
         value: "1"
   dnsPolicy: ClusterFirst
-  strategy:
+  updateStrategy:
     type: RollingUpdate
     rollingUpdate:
-      maxSurge: 25%
+      # maxSurge: 25%
       maxUnavailable: 25%
   reloadOnChange: true
   hostAliases:
@@ -99,6 +100,17 @@ deployment:
   volumeMounts:
     volume-name:
       mountPath: /path1
+    volume-claim-template-name:
+      mountPath: /path2
+  volumeClaimTemplates:
+    volume-claim-template-name:
+      accessModes: [ "ReadWriteOnce" ]
+      resources:
+        requests:
+          storage: 1Gi
+  persistentVolumeClaimRetentionPolicy:
+    whenDeleted: Delete
+    whenScaled: Retain
   tolerations:
     - key: dedicated
       operator: Equal

application/templates/deployment.yaml

@@ -1,7 +1,13 @@
 {{- if .Values.deployment.enabled }}
+{{- $kindsWithHeadlessService := list "StatefulSet" -}}
+{{- $kindsWithPodManagementPolicy := list "StatefulSet" -}}
+{{- $kindsWithReplicas := list "Deployment" "StatefulSet" -}}
+{{- $kindsWithStrategy := list "Deployment" -}}
+{{- $kindsWithUpdateStrategy := list "DaemonSet" "StatefulSet" -}}
+{{- $kindsWithVolumeClaimTemplates := list "StatefulSet" -}}
 ---
 apiVersion: apps/v1
-kind: Deployment
+kind: {{ .Values.deployment.kind  | default "Deployment" }}
 metadata:
   labels:
   {{- include "application.labels" $ | nindent 4 }}
@@ -20,13 +26,26 @@ metadata:
   name: {{ template "application.name" . }}
   namespace: {{ include "application.namespace" . }}
 spec:
+{{- if and (has .Values.deployment.kind $kindsWithHeadlessService) ((.Values.headlessService).enabled) }}
+  serviceName: {{ .Values.headlessService.name | default (printf "%s-headless" (include "application.name" .)) }}
+{{- end }}
+{{- if has .Values.deployment.kind $kindsWithReplicas }}
 {{- if not (eq .Values.deployment.replicas nil) }}
   replicas: {{ .Values.deployment.replicas }}
+{{- end }}
 {{- end }}
   selector:
     matchLabels:
 {{ include "application.selectorLabels" . | indent 6 }}
-  {{- if .Values.deployment.strategy }}
+  {{- if has .Values.deployment.kind $kindsWithPodManagementPolicy }}
+  {{- with .Values.deployment.podManagementPolicy }}
+  podManagementPolicy: {{ . }}
+  {{- end }}
+  {{- end }}
+  {{- if and (has .Values.deployment.kind $kindsWithUpdateStrategy) .Values.deployment.updateStrategy }}
+  updateStrategy:
+{{ toYaml .Values.deployment.updateStrategy | indent 4 }}
+  {{- else if and (has .Values.deployment.kind $kindsWithStrategy) .Values.deployment.strategy }}
   strategy:
 {{ toYaml .Values.deployment.strategy | indent 4 }}
   {{- end }}
@@ -344,4 +363,17 @@ spec:
       {{- if not (kindIs "invalid" .Values.deployment.minReadySeconds) }}
       minReadySeconds: {{ .Values.deployment.minReadySeconds }}
       {{- end }}
+  {{- if and (has .Values.deployment.kind $kindsWithVolumeClaimTemplates) .Values.deployment.volumeClaimTemplates }}
+  volumeClaimTemplates:
+    {{- range $key, $value := .Values.deployment.volumeClaimTemplates }}
+  - metadata:
+      name: {{ $key }}
+    spec:
+{{ include "application.tplvalues.render" ( dict "value" $value "context" $ ) | indent 6 }}
+    {{- end }}
+    {{- if .Values.deployment.persistentVolumeClaimRetentionPolicy }}
+  persistentVolumeClaimRetentionPolicy:
+{{ toYaml .Values.deployment.persistentVolumeClaimRetentionPolicy | indent 4 }}
+    {{- end }}
+  {{- end }}
 {{- end }}

application/templates/headlessservice.yaml

@@ -0,0 +1,27 @@
+{{- if (.Values.headlessService).enabled }}
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: {{ .Values.headlessService.name | default (printf "%s-headless" (include "application.name" .)) }}
+  namespace: {{ template "application.namespace" $ }}
+  labels:
+  {{- include "application.labels" $ | nindent 4 }}
+  {{- if .Values.headlessService.additionalLabels }}
+    {{- toYaml .Values.headlessService.additionalLabels | nindent 4 }}
+  {{- end }}
+  {{- if .Values.headlessService.annotations }}
+  annotations:
+    {{- include "application.tplvalues.render" ( dict "value" .Values.headlessService.annotations  "context" $ ) | nindent 4 }}
+{{- end }}
+spec:
+  clusterIP: None
+  type: ClusterIP
+  {{- if .Values.headlessService.publishNotReadyAddresses }}
+  publishNotReadyAddresses: {{ .Values.headlessService.publishNotReadyAddresses | default false }}
+  {{- end }}
+  selector:
+{{ include "application.selectorLabels" . | indent 4 }}
+  ports:
+{{ toYaml .Values.headlessService.ports | indent 4 }}
+{{- end }}

application/templates/hpa.yaml

@@ -21,7 +21,7 @@ metadata:
 spec:
   scaleTargetRef:
     apiVersion: apps/v1
-    kind: Deployment
+    kind: {{ .Values.deployment.kind }}
     name: {{ template "application.name" . }}
   minReplicas: {{ .Values.autoscaling.minReplicas }}
   maxReplicas: {{ .Values.autoscaling.maxReplicas }}

application/templates/vpa.yaml

@@ -20,7 +20,7 @@ metadata:
 spec:
   targetRef:
     apiVersion: apps/v1
-    kind: Deployment
+    kind: {{ .Values.deployment.kind }}
     name: {{ template "application.name" . }}
   resourcePolicy:
     containerPolicies:

application/tests/__snapshot__/common_test.yaml.snap

@@ -318,7 +318,7 @@ should match snapshot:
       schedule: '* * * 8 *'
   11: |
     apiVersion: apps/v1
-    kind: Deployment
+    kind: StatefulSet
     metadata:
       annotations:
         reloader.stakater.com/auto: "true"
@@ -334,17 +334,16 @@ should match snapshot:
       name: application
       namespace: NAMESPACE
     spec:
+      persistentVolumeClaimRetentionPolicy:
+        whenDeleted: Delete
+        whenScaled: Retain
+      podManagementPolicy: OrderedReady
       replicas: 2
       revisionHistoryLimit: 2
       selector:
         matchLabels:
           app.kubernetes.io/name: application
           application.stakater.com/workload-class: serving
-      strategy:
-        rollingUpdate:
-          maxSurge: 25%
-          maxUnavailable: 25%
-        type: RollingUpdate
       template:
         metadata:
           annotations:
@@ -486,6 +485,8 @@ should match snapshot:
                 successThreshold: 1
                 timeoutSeconds: 1
               volumeMounts:
+                - mountPath: /path2
+                  name: volume-claim-template-name
                 - mountPath: /path1
                   name: volume-name
             - command:
@@ -589,6 +590,19 @@ should match snapshot:
                 secretName: secret-name
             - emptyDir: {}
               name: volume-name
+      updateStrategy:
+        rollingUpdate:
+          maxUnavailable: 25%
+        type: RollingUpdate
+      volumeClaimTemplates:
+        - metadata:
+            name: volume-claim-template-name
+          spec:
+            accessModes:
+              - ReadWriteOnce
+            resources:
+              requests:
+                storage: 1Gi
   12: |
     apiVersion: endpointmonitor.stakater.com/v1alpha1
     kind: EndpointMonitor
@@ -1302,7 +1316,7 @@ should match snapshot:
       minReplicas: 1
       scaleTargetRef:
         apiVersion: apps/v1
-        kind: Deployment
+        kind: StatefulSet
         name: application
   21: |
     apiVersion: networking.k8s.io/v1
@@ -1855,7 +1869,7 @@ should match snapshot:
               memory: 1Gi
       targetRef:
         apiVersion: apps/v1
-        kind: Deployment
+        kind: StatefulSet
         name: application
       updatePolicy:
         updateMode: Auto

application/tests/common_test.yaml

@@ -10,6 +10,7 @@ values:
 capabilities:
   apiVersions:
     # TODO: auto add all/used apiVersions
+    - apps/v1
     - batch/v1
     - batch/v1/CronJob
     - policy/v1

application/tests/deployment_test.yaml

@@ -390,4 +390,18 @@ tests:
           path: spec.template.spec.containers
           content:
             name: sidecar
-          any: true
+          any: true
+
+  - it: workload type defaults to Deployment if not set
+    asserts:
+      - equal:
+          path: kind
+          value: Deployment
+
+  - it: sets correct workload type if given
+    set:
+      deployment.kind: StatefulSet
+    asserts:
+      - equal:
+          path: kind
+          value: StatefulSet