Merge pull request #1618 from weaveworks/memcached-srv

Use ClusterIP service name for connecting to memcached

chart/flux/CHANGELOG.md

@@ -1,3 +1,20 @@
+## 0.6.0 (TBA)
+
+**Note** To fix the connectivity problems between Flux and memcached we've changed the 
+memcached service from headless to ClusterIP. This change will make the Helm upgrade fail 
+with `ClusterIP field is immutable`. 
+
+Before upgrading to 0.6.0 you have to delete the memcached headless service:
+
+```bash
+kubectl -n flux delete svc flux-memcached
+```
+
+### Improvements
+
+ - Use ClusterIP service name for connecting to memcached
+   [weaveworks/flux#1618](https://github.com/weaveworks/flux/pull/1618)
+
 ## 0.5.2 (2018-12-20)
 
 ### Improvements

chart/flux/templates/deployment.yaml

@@ -76,6 +76,9 @@ spec:
           - --ssh-keygen-dir=/var/fluxd/keygen
           - --k8s-secret-name={{ template "flux.fullname" . }}-git-deploy
           - --memcached-hostname={{ template "flux.fullname" . }}-memcached
+          {{- if .Values.memcached.createClusterIP }}
+          - --memcached-service=
+          {{- end }}
           - --git-url={{ .Values.git.url }}
           - --git-branch={{ .Values.git.branch }}
           - --git-path={{ .Values.git.path }}

chart/flux/templates/memcached.yaml

@@ -60,7 +60,9 @@ metadata:
     release: {{ .Release.Name }}
     heritage: {{ .Release.Service }}
 spec:
+  {{- if eq .Values.memcached.createClusterIP false }}
   clusterIP: None
+  {{- end }}
   ports:
     - port: 11211
       targetPort: memcached

chart/flux/values.yaml

@@ -126,6 +126,7 @@ registry:
 memcached:
   repository: memcached
   tag: 1.4.25
+  createClusterIP: true
   verbose: false
   maxItemSize: 1m
   maxMemory: 64

cmd/fluxd/main.go

@@ -282,14 +282,24 @@ func main() {
 	{
 		// Cache client, for use by registry and cache warmer
 		var cacheClient cache.Client
-		memcacheClient := registryMemcache.NewMemcacheClient(registryMemcache.MemcacheConfig{
+		var memcacheClient *registryMemcache.MemcacheClient
+		memcacheConfig := registryMemcache.MemcacheConfig{
 			Host:           *memcachedHostname,
 			Service:        *memcachedService,
 			Timeout:        *memcachedTimeout,
 			UpdateInterval: 1 * time.Minute,
 			Logger:         log.With(logger, "component", "memcached"),
 			MaxIdleConns:   *registryBurst,
-		})
+		}
+
+		// if no memcached service is specified use the ClusterIP name instead of SRV records
+		if *memcachedService == "" {
+			memcacheClient = registryMemcache.NewFixedServerMemcacheClient(memcacheConfig,
+				fmt.Sprintf("%s:11211", *memcachedHostname))
+		} else {
+			memcacheClient = registryMemcache.NewMemcacheClient(memcacheConfig)
+		}
+
 		defer memcacheClient.Stop()
 		cacheClient = cache.InstrumentClient(memcacheClient)
 

deploy/flux-deployment.yaml

@@ -17,7 +17,7 @@ spec:
       labels:
         name: flux
     spec:
-      serviceAccount: flux
+      serviceAccountName: flux
       volumes:
       - name: git-key
         secret:
@@ -93,7 +93,10 @@ spec:
         # or with a different service name, you can supply these
         # following two arguments to tell fluxd how to connect to it.
         # - --memcached-hostname=memcached.default.svc.cluster.local
-        # - --memcached-service=memcached
+
+        # use the memcached ClusterIP service name by setting the
+        # memcached-service to string empty
+        - --memcached-service=
 
         # this must be supplied, and be in the tmpfs (emptyDir)
         # mounted above, for K8s >= 1.10

deploy/memcache-svc.yaml

@@ -4,9 +4,6 @@ kind: Service
 metadata:
   name: memcached
 spec:
-  # The memcache client uses DNS to get a list of memcached servers and then
-  # uses a consistent hash of the key to determine which server to pick.
-  clusterIP: None
   ports:
     - name: memcached
       port: 11211