Allow scale to zero (#943)

templates/_helpers.tpl

@@ -156,7 +156,11 @@ Set's the replica count based on the different modes configured by user
   {{ if eq .mode "standalone" }}
     {{- default 1 -}}
   {{ else if eq .mode "ha" }}
-    {{- .Values.server.ha.replicas | default 3 -}}
+    {{- if kindIs "int64" .Values.server.ha.replicas -}}
+      {{- .Values.server.ha.replicas -}}
+    {{ else }}
+      {{- 3 -}}
+    {{- end -}}
   {{ else }}
     {{- default 1 -}}
   {{ end }}

test/unit/server-ha-statefulset.bats

@@ -157,6 +157,28 @@ load _helpers
   [ "${actual}" = "10" ]
 }
 
+@test "server/ha-StatefulSet: zero replicas" {
+  cd `chart_dir`
+  local actual=$(helm template \
+      --show-only templates/server-statefulset.yaml  \
+      --set 'server.ha.enabled=true' \
+      --set 'server.ha.replicas=0' \
+      . | tee /dev/stderr |
+      yq -r '.spec.replicas' | tee /dev/stderr)
+  [ "${actual}" = "0" ]
+}
+
+@test "server/ha-StatefulSet: invalid value for replicas" {
+  cd `chart_dir`
+  local actual=$(helm template \
+      --show-only templates/server-statefulset.yaml  \
+      --set 'server.ha.enabled=true' \
+      --set 'server.ha.replicas=null' \
+      . | tee /dev/stderr |
+      yq -r '.spec.replicas' | tee /dev/stderr)
+  [ "${actual}" = "3" ]
+}
+
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 # resources