Merge pull request #9 from ripienaar/broker_affinity

support pod afinity for brokers
choria-io · Jun 19, 2020 · 3d3d9ac · 3d3d9ac
2 parents 59d95c5 + 92859e8
commit 3d3d9ac
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Showing 4 changed files with 40 additions and 2 deletions.
diff --git a/charts/broker/Chart.yaml b/charts/broker/Chart.yaml
@@ -1,6 +1,6 @@
 apiVersion: v1
 name: broker
-version: 0.0.4
+version: 0.0.5
 appVersion: 0.14.0
 description: Choria Network Broker
 keywords:

diff --git a/charts/broker/README.md b/charts/broker/README.md
@@ -8,6 +8,37 @@ At start the broker will auto enroll with a Cert Manager managed Certificate Aut
 Please follow the steps outlined in [README.md](../README.md) to create the initial environment
 and add the Choria Helm Repository.
 
+## Pod Affinity
+
+Generally you'd want to run more than one instance of the broker, it does not need to be an odd number,
+and if you do you'd want to ensure the brokers run on different underlying nodes. 
+
+```yaml
+broker:
+  clusterSize: 3
+
+podAffinity:
+  podAntiAffinity:
+    requiredDuringSchedulingIgnoredDuringExecution:
+    - labelSelector:
+        matchExpressions:
+        - key: app
+          operator: In
+          values:
+          - broker
+      topologyKey: "kubernetes.io/hostname"
+```
+
+Above will create 3 broker instances and spread them across your kubernetes nodes.
+
+```nohighlight
+$ kubectl get pod -o wide -n choria
+NAME                            READY   STATUS    RESTARTS   AGE     IP           NODE     NOMINATED NODE   READINESS GATES
+broker-0                        1/1     Running   0          2m22s   10.2.2.14    knode1   <none>           <none>
+broker-1                        1/1     Running   0          2m29s   10.2.0.244   knode2   <none>           <none>
+broker-2                        1/1     Running   0          2m43s   10.2.1.82    knode3   <none>           <none>
+```
+
 ## Values
 
 |Variable|Description|Default|

diff --git a/charts/broker/templates/statefulset.yaml b/charts/broker/templates/statefulset.yaml
@@ -43,10 +43,14 @@ spec:
       labels:
         app: broker
       {{- if .Values.podLabels }}
-      {{ toYaml .Values.podLabels | indent 8 }}
+{{ toYaml .Values.podLabels | indent 8 }}
     {{- end }}
 
     spec:
+    {{- if .Values.podAffinity }}
+      affinity:
+{{ toYaml .Values.podAffinity | indent 8 }}
+    {{- end }}
       serviceAccount: choria-csraccess
       serviceAccountName: choria-csraccess
       {{- if .Values.image.pullSecret }}

diff --git a/charts/broker/values.yaml b/charts/broker/values.yaml
@@ -18,6 +18,9 @@ securityContext:
 # additional annotations to apply to pods
 podAnnotations: {}
 
+# adds custom affinity rules to the pods
+podAffinity: {}
+
 # additional labels to apply to pods
 podLabels: {}