Add topology spread constraint snippet to all deployments

charts/posthog/Chart.yaml

@@ -11,7 +11,7 @@ type: application
 
 # This is the chart version. This version number should be incremented each time you make changes
 # to the chart and its templates, including the app version.
-version: 30.32.0
+version: 30.33.0
 
 # This is the version number of the application being deployed. This version number should be
 # incremented each time you make changes to the application.

charts/posthog/templates/_snippet-plugins-deployment.tpl

@@ -44,6 +44,7 @@ spec:
         {{- end }}
     spec:
       serviceAccountName: {{ template "posthog.serviceAccountName" .root }}
+      {{- include "_snippet-topologySpreadConstraints" .root | nindent 6 }}
 
       {{- if .params.affinity }}
       affinity:

charts/posthog/templates/_snippet-topologySpreadConstraints.tpl

@@ -0,0 +1,35 @@
+{{/* Common topologySpreadConstraints definition */}}
+{{/*
+  matchLabelsKeys are the set of unique pod labels for which the constraints are applied
+  any missing labels are ignored.
+
+  pod-template-hash is added automatically by deployments and is unique for each rollout.
+  Including this means we don't get out of sync on rollouts as it ignores the locations
+  of existing pods that will be terminated after the rollout is finished.
+   */}}
+{{- define "_snippet-selectors" -}}
+labelSelector:
+  matchLabels: {}
+matchLabelKeys:
+- pod-template-hash
+- app
+- release
+- role
+- app.kubernetes.io/name
+- app.kubernetes.io/instance
+{{- end }}
+{{- define "_snippet-topologySpreadConstraints" }}
+{{- if (.Values.includeDefaultTopologySpreadConstraints | default false) }}
+topologySpreadConstraints:
+- maxSkew: 1
+  topologyKey: topology.kubernetes.io/zone
+  whenUnsatisfiable: ScheduleAnyway
+  nodeTaintsPolicy: Honor
+  {{- include "_snippet-selectors" . | nindent 2 }}
+- maxSkew: 3
+  topologyKey: kubernetes.io/hostname
+  whenUnsatisfiable: ScheduleAnyway
+  nodeTaintsPolicy: Honor
+  {{- include "_snippet-selectors" . | nindent 2 }}
+{{- end }}
+{{- end }}

charts/posthog/templates/decide-deployment.yaml

@@ -41,6 +41,7 @@ spec:
     spec:
       terminationGracePeriodSeconds: {{ include "snippet.web-deployments.terminationGracePeriodSeconds" . }}
       serviceAccountName: {{ template "posthog.serviceAccountName" . }}
+      {{- include "_snippet-topologySpreadConstraints" . | nindent 6 }}
 
       {{- if .Values.web.affinity }}
       affinity:

charts/posthog/templates/events-deployment.yaml

@@ -41,6 +41,7 @@ spec:
     spec:
       terminationGracePeriodSeconds: {{ include "snippet.web-deployments.terminationGracePeriodSeconds" . }}
       serviceAccountName: {{ template "posthog.serviceAccountName" . }}
+      {{- include "_snippet-topologySpreadConstraints" . | nindent 6 }}
 
       {{- if .Values.web.affinity }}
       affinity:

charts/posthog/templates/pgbouncer-deployment.yaml

@@ -42,6 +42,7 @@ spec:
       terminationGracePeriodSeconds: 65
 
       serviceAccountName: {{ template "posthog.serviceAccountName" . }}
+      {{- include "_snippet-topologySpreadConstraints" . | nindent 6 }}
 
       {{- if .Values.pgbouncer.affinity }}
       affinity: {{ toYaml .Values.pgbouncer.affinity | nindent 8 }}

charts/posthog/templates/pgbouncer-read-deployment.yaml

@@ -42,6 +42,7 @@ spec:
       terminationGracePeriodSeconds: 65
 
       serviceAccountName: {{ template "posthog.serviceAccountName" . }}
+      {{- include "_snippet-topologySpreadConstraints" . | nindent 6 }}
 
       {{- if .Values.pgbouncerRead.affinity }}
       affinity: {{ toYaml .Values.pgbouncerRead.affinity | nindent 8 }}

charts/posthog/templates/recordings-deployment.yaml

@@ -41,6 +41,7 @@ spec:
     spec:
       terminationGracePeriodSeconds: {{ include "snippet.web-deployments.terminationGracePeriodSeconds" . }}
       serviceAccountName: {{ template "posthog.serviceAccountName" . }}
+      {{- include "_snippet-topologySpreadConstraints" . | nindent 6 }}
 
       {{- if .Values.web.affinity }}
       affinity:

charts/posthog/templates/temporal-py-worker-deployment.yaml

@@ -35,6 +35,7 @@ spec:
     spec:
       terminationGracePeriodSeconds: {{ .Values.temporalPyWorker.terminationGracePeriodSeconds }}
       serviceAccountName: {{ template "posthog.serviceAccountName" . }}
+      {{- include "_snippet-topologySpreadConstraints" . | nindent 6 }}
 
       {{- if .Values.temporalPyWorker.affinity }}
       affinity:

charts/posthog/templates/web-deployment.yaml

@@ -41,6 +41,7 @@ spec:
     spec:
       terminationGracePeriodSeconds: {{ include "snippet.web-deployments.terminationGracePeriodSeconds" . }}
       serviceAccountName: {{ template "posthog.serviceAccountName" . }}
+      {{- include "_snippet-topologySpreadConstraints" . | nindent 6 }}
 
       {{- if .Values.web.affinity }}
       affinity:

charts/posthog/templates/worker-deployment.yaml

@@ -40,6 +40,7 @@ spec:
         {{- end }}
     spec:
       serviceAccountName: {{ template "posthog.serviceAccountName" . }}
+      {{- include "_snippet-topologySpreadConstraints" . | nindent 6 }}
 
       {{- if .Values.worker.affinity }}
       affinity:

charts/posthog/tests/_topologySpreadConstraints.yaml

@@ -0,0 +1,49 @@
+suite: _topologySpreadConstraints
+templates:
+  - templates/plugins-deployment.yaml
+  - templates/web-deployment.yaml
+  - templates/worker-deployment.yaml
+  # NOTE: we need to include this as it is required by the other templates
+  - templates/secrets.yaml
+tests:
+  - it: spec.template.spec.topologySpreadConstraints should be empty by default
+    templates:
+      - templates/plugins-deployment.yaml
+      - templates/web-deployment.yaml
+      - templates/worker-deployment.yaml
+    set:
+      cloud: local
+    asserts:
+      - hasDocuments:
+          count: 1
+      - isEmpty:
+          path: spec.template.spec.topologySpreadConstraints
+  - it: spec.template.spec.topologySpreadConstraints should exist if includeDefaultTopologySpreadConstraints is set
+    templates:
+      - templates/plugins-deployment.yaml
+      - templates/web-deployment.yaml
+      - templates/worker-deployment.yaml
+    set:
+      cloud: local
+      includeDefaultTopologySpreadConstraints: true
+    asserts:
+      - hasDocuments:
+          count: 1
+      - equal:
+          path: spec.template.spec.topologySpreadConstraints[0].topologyKey
+          value: topology.kubernetes.io/zone
+      - equal:
+          path: spec.template.spec.topologySpreadConstraints[0].maxSkew
+          value: 1
+      - equal:
+          path: spec.template.spec.topologySpreadConstraints[0].whenUnsatisfiable
+          value: ScheduleAnyway
+      - equal:
+          path: spec.template.spec.topologySpreadConstraints[1].topologyKey
+          value: kubernetes.io/hostname
+      - equal:
+          path: spec.template.spec.topologySpreadConstraints[1].maxSkew
+          value: 3
+      - equal:
+          path: spec.template.spec.topologySpreadConstraints[1].whenUnsatisfiable
+          value: ScheduleAnyway

charts/posthog/values.yaml

@@ -3396,3 +3396,7 @@ busybox:
 
 # -- Kubernetes cluster domain name
 clusterDomain: cluster.local
+
+# Whether to set a topologySpreadConstraint on all deployments
+# to balance pods between availability zones and nodes
+includeDefaultTopologySpreadConstraints: false