Merge pull request #2224 from consideRatio/pr/add-hub.lifecycle-configuration

Add hub.lifecycle configuration (for postStart/preStop lifecycle hooks in hub pod)

Author: minrk

jupyterhub/schema.yaml

@@ -1092,6 +1092,19 @@ properties:
         description: |
           A k8s native specification of resources, see [the
           documentation](https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.20/#resourcerequirements-v1-core).
+      lifecycle: &lifecycle-spec
+        type: object
+        additionalProperties: false
+        description: |
+          A k8s native specification of lifecycle hooks on the container, see [the
+          documentation](https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.20/#lifecycle-v1-core).
+        properties:
+          postStart:
+            type: object
+            additionalProperties: true
+          preStop:
+            type: object
+            additionalProperties: true
       services:
         type: object
         additionalProperties: true
@@ -1855,6 +1868,13 @@ properties:
         type: object
         additionalProperties: false
         description: *kubespawner-native-config-description
+        properties:
+          postStart:
+            type: object
+            additionalProperties: true
+          preStop:
+            type: object
+            additionalProperties: true
       networkTools:
         type: object
         additionalProperties: false

jupyterhub/templates/hub/deployment.yaml

@@ -23,7 +23,7 @@ spec:
         {{- . | toYaml | trimSuffix "\n" | nindent 8 }}
         {{- end }}
       annotations:
-        # This lets us autorestart when the secret changes!
+        {{- /* This lets us autorestart when the secret changes! */}}
         checksum/config-map: {{ include (print .Template.BasePath "/hub/configmap.yaml") . | sha256sum }}
         checksum/secret: {{ include (print .Template.BasePath "/hub/secret.yaml") . | sha256sum }}
         {{- with .Values.hub.annotations }}
@@ -111,13 +111,13 @@ spec:
             {{- if .Values.debug.enabled }}
             - --debug
             {{- end }}
-            {{- /*
-            We want to do automatic upgrades for sqlite-pvc by default, but
-            allow users to opt out of that if they want. Users using their own
-            db need to 'opt in' Go Templates treat nil and "" and false as
-            'false', making this code complex. We can probably make this a
-            one-liner, but doing combinations of boolean vars in go templates is
-            very inelegant & hard to reason about.
+            {{- /* NOTE:
+              We want to do automatic upgrades for sqlite-pvc by default, but
+              allow users to opt out of that if they want. Users using their own
+              db need to 'opt in' Go Templates treat nil and "" and false as
+              'false', making this code complex. We can probably make this a
+              one-liner, but doing combinations of boolean vars in go templates
+              is very inelegant & hard to reason about.
             */}}
             {{- $upgradeType := typeOf .Values.hub.db.upgrade }}
             {{- if eq $upgradeType "bool" }}
@@ -179,6 +179,10 @@ spec:
           securityContext:
             {{- $securityContext | toYaml | trimSuffix "\n" | nindent 12 }}
           {{- end }}
+          {{- with .Values.hub.lifecycle }}
+          lifecycle:
+            {{- . | toYaml | trimSuffix "\n" | nindent 12 }}
+          {{- end }}
           env:
             - name: PYTHONUNBUFFERED
               value: "1"
@@ -191,9 +195,12 @@ spec:
             - name: CONFIGPROXY_AUTH_TOKEN
               valueFrom:
                 secretKeyRef:
-                  # NOTE: References the chart managed k8s Secret even if
-                  #       hub.existingSecret is specified to avoid using the
-                  #       lookup function on the user managed k8s Secret.
+                  {{- /* NOTE:
+                    References the chart managed k8s Secret even if
+                    hub.existingSecret is specified to avoid using the lookup
+                    function on the user managed k8s Secret which is assumed to
+                    not be possible.
+                  */}}
                   name: {{ include "jupyterhub.hub.fullname" . }}
                   key: hub.config.ConfigurableHTTPProxy.auth_token
             {{- with .Values.hub.extraEnv }}
@@ -203,13 +210,13 @@ spec:
             - name: http
               containerPort: 8081
           {{- if .Values.hub.livenessProbe.enabled }}
-          # livenessProbe notes:
-          # We don't know how long hub database upgrades could take
-          # so having a liveness probe could be a bit risky unless we put
-          # a initialDelaySeconds value with long enough margin for that
-          # to not be an issue. If it is too short, we could end up aborting
-          # database upgrades midway or ending up in an infinite restart
-          # loop.
+          {{- /* NOTE:
+            We don't know how long hub database upgrades could take so having a
+            liveness probe could be a bit risky unless we put a
+            initialDelaySeconds value with long enough margin for that to not be
+            an issue. If it is too short, we could end up aborting database
+            upgrades midway or ending up in an infinite restart loop.
+          */}}
           livenessProbe:
             initialDelaySeconds: {{ .Values.hub.livenessProbe.initialDelaySeconds }}
             periodSeconds: {{ .Values.hub.livenessProbe.periodSeconds }}

jupyterhub/values.yaml

@@ -88,6 +88,7 @@ hub:
     runAsUser: 1000
     runAsGroup: 1000
     allowPrivilegeEscalation: false
+  lifecycle: {}
   services: {}
   pdb:
     enabled: false

tools/templates/lint-and-validate-values.yaml

@@ -74,25 +74,23 @@ hub:
   deploymentStrategy:
     type: Recreate
     rollingUpdate:
+  labels: &labels
+    mock-label1-key: mock-label1-value
+    mock-label2-key: mock-label2-value
+  annotations: &annotations
+    mock-annotation1-key: mock-annotation1-value
+    mock-annotation2-key: mock-annotation2-value
   db:
     type: sqlite-pvc
     upgrade:
     pvc:
-      annotations:
-        mock-annotation: mock
-      selector:
-        matchLabels:
-          mock-selector: mock
+      annotations: *annotations
       accessModes:
         - ReadWriteOnce
       storage: 1Gi
       subPath: /mock
       storageClassName: custom-storage-class
     url: custom-db-url
-  labels:
-    mock: mock
-  annotations:
-    mock: mock
   image:
     name: dummy-name
     tag: dummy-tag
@@ -111,7 +109,7 @@ hub:
       c.Spawner.cmd = 'mock'
   extraConfigMap:
     mock.entry: mock-config-map-entry
-  extraEnv:
+  extraEnv: &extraEnv
     IGNORED_KEY_NAME:
       name: MOCK_ENV_VAR_NAME1
       value: MOCK_ENV_VAR_VALUE1
@@ -120,10 +118,26 @@ hub:
   extraContainers: []
   extraVolumes: []
   extraVolumeMounts: []
-  resources:
+  resources: &resources
     requests:
       cpu: 100m
       memory: 512Mi
+    limits:
+      cpu: 200m
+      memory: 1Gi
+  lifecycle: &lifecycle
+    postStart:
+      exec:
+        command:
+          - "/bin/sh"
+          - "-c"
+          - "echo Hello from the postStart handler >> /usr/share/message"
+    preStop:
+      exec:
+        command:
+          - "/bin/sh"
+          - "-c"
+          - "echo Hello from the preStart handler >> /usr/share/message"
   services:
     tests:
       apiToken: mocked-api-token
@@ -158,25 +172,19 @@ proxy:
         port: 22
         targetPort: ssh
     type: LoadBalancer
-    labels:
-      MOCK_PROXY_ENV: mock
-    annotations:
-      hub.jupyter.org/mock-proxy-annotation: mock
+    labels: *labels
+    annotations: *annotations
     nodePorts:
       http:
       https:
   chp:
     extraCommandLineFlags:
       - "--auto-rewrite"
       - "--mock-flag {{ .Values.proxy.chp.resources.requests.memory }}"
-    resources:
-      requests:
-        cpu: 100m
-        memory: 512Mi
+    resources: *resources
     defaultTarget: http://dummy.local/hello
     errorTarget: http://dummy.local/error
-    extraEnv:
-      MOCK_ENV: mock
+    extraEnv: *extraEnv
     nodeSelector:
       node-type: mock
     tolerations:
@@ -200,17 +208,9 @@ proxy:
     extraPorts:
       - name: ssh
         containerPort: 8022
-    labels:
-      hub.jupyter.org/test-label: mock
-    resources:
-      requests:
-        cpu: 200m
-        memory: 512Mi
-      limits:
-        cpu: 200m
-        memory: 1Gi
-    extraEnv:
-      LEGO_CA_CERTIFICATES: /etc/pebble/root-cert.pem
+    labels: *labels
+    resources: *resources
+    extraEnv: *extraEnv
     nodeSelector:
       node-type: mock
     tolerations:
@@ -231,15 +231,8 @@ proxy:
       maxUnavailable: null
       minAvailable: 1
   secretSync:
-    resources:
-      requests:
-        cpu: 100m
-        memory: 128Mi
-      limits:
-        cpu: 200m
-        memory: 1Gi
-  labels:
-    mock-proxy-label: mock
+    resources: *resources
+  labels: *labels
   https:
     enabled: true
     type: letsencrypt
@@ -334,9 +327,9 @@ singleuser:
     interNamespaceAccessLabels: ignore
     allowedIngressPorts: []
   events: true
-  extraLabels: {}
-  extraEnv: {}
-  lifecycleHooks: {}
+  extraLabels: *labels
+  extraEnv: *extraEnv
+  lifecycleHooks: *lifecycle
   initContainers:
     - name: mock-init-container-name
       image: mock-init-container-image
@@ -350,8 +343,7 @@ singleuser:
   serviceAccountName:
   storage:
     type: dynamic
-    extraLabels:
-      mock-label: mock-value
+    extraLabels: *labels
     extraVolumes: []
     extraVolumeMounts: []
     static:
@@ -407,7 +399,7 @@ scheduling:
   userPlaceholder:
     enabled: true
     replicas: 1
-    resources: {}
+    resources: *resources
   corePods:
     tolerations:
       - key: mock-taint-key-corePods
@@ -452,8 +444,7 @@ prePuller:
 
 ingress:
   enabled: true
-  annotations:
-    mock: mock
+  annotations: *annotations
   hosts:
     - mocked1.domain.name
     - mocked2.domain.name
@@ -474,7 +465,9 @@ cull:
 debug:
   enabled: true
 
-global: {}
+global:
+  whatever:
+    this-should-be-accepted: true
 
 custom:
   myCustomStuff: [hello]