[NYS2AWS-71] allow node anti-affinity for Solr pods

CHANGELOG.md

@@ -7,6 +7,9 @@ chronology things are added/fixed/changed and - where possible - links to the PR
 
 ### Changes
 
+[v0.8.2]
+* added solr.enforceHostnameAntiAffinity
+
 [v0.8.0]
 
 * **Potentially breaking change**: changed `alfresco-ingress` definition & default values to enable usage of `ingressClassName` property in favour of `kubernetes.io/ingress.class` annotation.

README.md

@@ -1330,6 +1330,14 @@ nginx rules to redirect the normal pages to a 503 maintenance page.
   ```
 * Description: With this list of parameters you can add 1 or multiple annotations to the Solr service
 
+#### `solr.enforceHostnameAntiAffinity`
+
+* Required: false
+* Default: false
+* Description: If true, this option enforces a pod anti-affinity on the Solr pods based on the hostnames.
+  I.e. if true, each Solr pod will require a unique node. Starting more pods than nodes will put the
+  remainder pods in a `Pending` state.
+
 #### `solr.serviceAccount`
 
 * Required: false

xenit-alfresco/templates/solr/solr-stateful-set.yaml

@@ -30,6 +30,18 @@ spec:
         {{ toYaml .Values.solr.podAnnotations | nindent 8 }}
         {{- end }}
     spec:
+      {{- if .Values.solr.enforceHostnameAntiAffinity }}
+      affinity:
+        podAntiAffinity:
+          requiredDuringSchedulingIgnoredDuringExecution:
+            - topologyKey: "kubernetes.io/hostname"
+              labelSelector:
+                matchExpressions:
+                  - key: "app"
+                    operator: "In"
+                    values:
+                      - solr
+      {{- end }}
       {{- if .Values.solr.serviceAccount }}
       serviceAccountName: {{ .Values.solr.serviceAccount }}
       {{- end }}

xenit-alfresco/values.yaml

@@ -151,6 +151,7 @@ postgresql:
 solr:
   enabled: true
   replicas: 2
+  enforceHostnameAntiAffinity: false
   podManagementPolicy: Parallel
   image:
     registry: 'docker.io'