GDB-10410: Added default podAntiAffinity configurations

CHANGELOG.md

@@ -1,5 +1,13 @@
 # GraphDB Helm chart release notes
 
+## Version 11.1.0
+
+### New
+
+- Added `podAntiAffinity` and `proxy.podAntiAffinity` for configuring a default podAntiAffinity for the GraphDB pods and
+  GraphDB proxy pods. The default values configure a "soft" podAntiAffinity that tries to schedule GraphDB pods across
+  different Kubernetes hosts but does not enforce it.
+
 ## Version 11.0.1
 
 GraphDB Helm 11.0.1 is a patch release that includes bug fixes.

README.md

@@ -434,6 +434,9 @@ IMPORTANT: This is generated by helm-docs, do not attempt modifying it on hand a
 | persistence.volumeClaimTemplate.spec.accessModes[0] | string | `"ReadWriteOnce"` |  |
 | persistence.volumeClaimTemplate.spec.resources.requests.storage | string | `"5Gi"` |  |
 | podAnnotations | object | `{}` |  |
+| podAntiAffinity.enabled | bool | `true` |  |
+| podAntiAffinity.preset | string | `"soft"` |  |
+| podAntiAffinity.topology | string | `"kubernetes.io/hostname"` |  |
 | podDisruptionBudget.enabled | bool | `true` |  |
 | podDisruptionBudget.maxUnavailable | string | `""` |  |
 | podDisruptionBudget.minAvailable | string | `"51%"` |  |
@@ -506,6 +509,9 @@ IMPORTANT: This is generated by helm-docs, do not attempt modifying it on hand a
 | proxy.persistence.volumeClaimTemplate.spec.accessModes[0] | string | `"ReadWriteOnce"` |  |
 | proxy.persistence.volumeClaimTemplate.spec.resources.requests.storage | string | `"500Mi"` |  |
 | proxy.podAnnotations | object | `{}` |  |
+| proxy.podAntiAffinity.enabled | bool | `true` |  |
+| proxy.podAntiAffinity.preset | string | `"soft"` |  |
+| proxy.podAntiAffinity.topology | string | `"kubernetes.io/hostname"` |  |
 | proxy.podDisruptionBudget.enabled | bool | `true` |  |
 | proxy.podDisruptionBudget.maxUnavailable | string | `""` |  |
 | proxy.podDisruptionBudget.minAvailable | string | `"51%"` |  |

templates/graphdb/statefulset.yaml

@@ -129,8 +129,31 @@ spec:
       {{- with .Values.nodeSelector }}
       nodeSelector: {{- tpl (toYaml .) $ | nindent 8 }}
       {{- end }}
-      {{- with .Values.affinity }}
-      affinity: {{- tpl (toYaml .) $ | nindent 8 }}
+      {{- if or .Values.affinity .Values.podAntiAffinity.enabled }}
+      affinity:
+        {{- if .Values.affinity  }}
+          {{- tpl (toYaml .Values.affinity) $ | nindent 8 }}
+        {{- end }}
+        {{- if and .Values.podAntiAffinity.enabled (not .Values.affinity.podAntiAffinity) }}
+        podAntiAffinity:
+          {{- if eq .Values.podAntiAffinity.preset "soft" }}
+          preferredDuringSchedulingIgnoredDuringExecution:
+            - weight: 1
+              podAffinityTerm:
+                topologyKey: {{ .Values.podAntiAffinity.topology }}
+                labelSelector:
+                  matchLabels:
+                    {{- include "graphdb.selectorLabels" . | nindent 20 }}
+          {{- else if eq .Values.podAntiAffinity.preset "hard" }}
+          requiredDuringSchedulingIgnoredDuringExecution:
+            - topologyKey: {{ .Values.podAntiAffinity.topology }}
+              labelSelector:
+                matchLabels:
+                  {{- include "graphdb.selectorLabels" . | nindent 18 }}
+          {{- else }}
+            {{- fail (printf "Unknown podAntiAffinity preset '%s'" .Values.podAntiAffinity.preset) }}
+          {{- end }}
+        {{- end }}
       {{- end }}
       {{- with .Values.tolerations }}
       tolerations: {{- tpl (toYaml .) $ | nindent 8 }}

templates/proxy/statefulset.yaml

@@ -98,8 +98,31 @@ spec:
       {{- with .Values.proxy.nodeSelector }}
       nodeSelector: {{- tpl (toYaml .) $ | nindent 8 }}
       {{- end }}
-      {{- with .Values.proxy.affinity }}
-      affinity: {{- tpl (toYaml .) $ | nindent 8 }}
+      {{- if or .Values.proxy.affinity .Values.proxy.podAntiAffinity.enabled }}
+      affinity:
+        {{- if .Values.proxy.affinity  }}
+          {{- tpl (toYaml .Values.proxy.affinity) $ | nindent 8 }}
+        {{- end }}
+        {{- if and .Values.proxy.podAntiAffinity.enabled (not .Values.proxy.affinity.podAntiAffinity) }}
+        podAntiAffinity:
+          {{- if eq .Values.proxy.podAntiAffinity.preset "soft" }}
+          preferredDuringSchedulingIgnoredDuringExecution:
+            - weight: 1
+              podAffinityTerm:
+                topologyKey: {{ .Values.proxy.podAntiAffinity.topology }}
+                labelSelector:
+                  matchLabels:
+                    {{- include "graphdb-proxy.selectorLabels" . | nindent 20 }}
+          {{- else if eq .Values.proxy.podAntiAffinity.preset "hard" }}
+          requiredDuringSchedulingIgnoredDuringExecution:
+            - topologyKey: {{ .Values.proxy.podAntiAffinity.topology }}
+              labelSelector:
+                matchLabels:
+                  {{- include "graphdb-proxy.selectorLabels" . | nindent 18 }}
+          {{- else }}
+            {{- fail (printf "Unknown podAntiAffinity preset '%s'" .Values.proxy.podAntiAffinity.preset) }}
+          {{- end }}
+        {{- end }}
       {{- end }}
       {{- with .Values.proxy.tolerations }}
       tolerations: {{- tpl (toYaml .) $ | nindent 8 }}

values.yaml

@@ -648,6 +648,18 @@ nodeSelector: {}
 # Ref: https://kubernetes.io/docs/concepts/scheduling-eviction/assign-pod-node/#affinity-and-anti-affinity
 affinity: {}
 
+# Default podAntiAffinity rule ensuring that GraphDB pods are scheduled on different Kubernetes nodes.
+# Note that this would take effect when GraphDB is deployed in a cluster.
+#
+# Possible values for .Values.podAntiAffinity.preset are:
+# - "soft" (default) - Configures a preferredDuringSchedulingIgnoredDuringExecution rule.
+# - "hard" - Configures a requiredDuringSchedulingIgnoredDuringExecution rule.
+# Ref: https://kubernetes.io/docs/concepts/scheduling-eviction/assign-pod-node/#affinity-and-anti-affinity
+podAntiAffinity:
+  enabled: true
+  preset: soft
+  topology: kubernetes.io/hostname
+
 # List of taint tolerations.
 # Values are processed as Helm templates.
 # Ref: https://kubernetes.io/docs/concepts/scheduling-eviction/taint-and-toleration/
@@ -1192,6 +1204,18 @@ proxy:
   # Ref: https://kubernetes.io/docs/concepts/scheduling-eviction/assign-pod-node/#affinity-and-anti-affinity
   affinity: {}
 
+  # Default podAntiAffinity rule ensuring that GraphDB pods are scheduled on different Kubernetes nodes.
+  # Note that this would take effect when GraphDB is deployed in a cluster.
+  #
+  # Possible values for .Values.podAntiAffinity.preset are:
+  # - "soft" (default) - Configures a preferredDuringSchedulingIgnoredDuringExecution rule.
+  # - "hard" - Configures a requiredDuringSchedulingIgnoredDuringExecution rule.
+  # Ref: https://kubernetes.io/docs/concepts/scheduling-eviction/assign-pod-node/#affinity-and-anti-affinity
+  podAntiAffinity:
+    enabled: true
+    preset: soft
+    topology: kubernetes.io/hostname
+
   # List of taint tolerations.
   # Values are processed as Helm templates.
   # Ref: https://kubernetes.io/docs/concepts/scheduling-eviction/taint-and-toleration/