Add a topologySpreadConstraints for the queue-worker

The new default topologySpreadConstraints for the queue-worker
will spread pods out, which should happen by default, but is
a mechanism that can help if that isn't what you are seeing
already.

Set this to whenUnsatisfiable: DoNotSchedule if you need a
strict policy.

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alexellis2@gmail.com>

Author: alexellis

chart/openfaas/Chart.yaml

@@ -2,7 +2,7 @@ apiVersion: v2
 type: application
 description: OpenFaaS - Serverless Functions Made Simple
 name: openfaas
-version: 14.2.73
+version: 14.2.74
 sources:
 - https://github.com/openfaas/faas
 - https://github.com/openfaas/faas-netes

chart/openfaas/templates/jetstream-queueworker-dep.yaml

@@ -23,6 +23,10 @@ spec:
       labels:
         app: queue-worker
     spec:
+      {{- if and .Values.jetstreamQueueWorker.topologySpreadConstraints .Values.openfaasPro }}
+      topologySpreadConstraints:
+      {{- toYaml .Values.jetstreamQueueWorker.topologySpreadConstraints | nindent 8 }}
+      {{- end }}
       volumes:
       {{- if .Values.openfaasPro }}
       - name: license

chart/openfaas/values.yaml

@@ -226,6 +226,15 @@ jetstreamQueueWorker:
   # Set pprof to listen on port 6000 to debug issues
   pprof: false
 
+  topologySpreadConstraints:
+    - maxSkew: 1
+      topologyKey: "kubernetes.io/hostname"
+      # Set to "DoNotSchedule" if you need a strict enforcement
+      whenUnsatisfiable: ScheduleAnyway
+      labelSelector:
+        matchLabels:
+          app: queue-worker
+
 # OpenFaaS Pro
 # The values for queueWorkerPro are merged with those under
 # the "queueWorker" section