Add optional user provided zookeeper as metadata store for other components (#38)

## Motivation
### Case
I have a physical zk cluster and want configure bookkeeper & broker & proxy to use it.
So I set components.zookeeper as false, and only found pulsar.zookeeper.connect to set my physical zk address.
But deploy stage was stucked in bookkeeper wait-zookeeper-ready container.

### Issue
The wait-zookeeper-ready initContainer in bookkeeper-cluster-initialize Job used spliced zk Service hosts to detect zk ready or not, other component init Job initContainer do the same thing. Actually, zk service are unreachable because I disabled zk component.

## Modifications
- Add optional pulsar_metadata.userProvidedZookeepers config for this case, and make component's init Job use user zk to detect liveness, instead of spliced Service hosts.

- Delete redundant image reference in bookkeeper init Job.

charts/pulsar/templates/_zookeeper.tpl

@@ -9,6 +9,10 @@ Define the pulsar zookeeper
 Define the pulsar zookeeper
 */}}
 {{- define "pulsar.zookeeper.connect" -}}
+{{$zk:=.Values.pulsar_metadata.userProvidedZookeepers}}
+{{- if and (not .Values.components.zookeeper) $zk }}
+{{- $zk -}}
+{{ else }}
 {{- if not (and .Values.tls.enabled .Values.tls.zookeeper.enabled) -}}
 {{ template "pulsar.zookeeper.service" . }}:{{ .Values.zookeeper.ports.client }}
 {{- end -}}
@@ -16,6 +20,7 @@ Define the pulsar zookeeper
 {{ template "pulsar.zookeeper.service" . }}:{{ .Values.zookeeper.ports.clientTls }}
 {{- end -}}
 {{- end -}}
+{{- end -}}
 
 {{/*
 Define the zookeeper hostname

charts/pulsar/templates/bookkeeper-cluster-initialize.yaml

@@ -31,18 +31,24 @@ spec:
     spec:
       initContainers:
       - name: wait-zookeeper-ready
-        image: "{{ .Values.bookkeeper.metadata.image.repository }}:{{ .Values.bookkeeper.metadata.image.tag }}"
-        imagePullPolicy: {{ .Values.bookkeeper.metadata.image.pullPolicy }}
+        image: "{{ .Values.images.bookie.repository }}:{{ .Values.images.bookie.tag }}"
+        imagePullPolicy: {{ .Values.images.bookie.pullPolicy }}
         command: ["sh", "-c"]
         args:
           - >-
+            {{- if $zk:=.Values.pulsar_metadata.userProvidedZookeepers }}
+            until bin/pulsar zookeeper-shell -server {{ $zk }} ls {{ or .Values.metadataPrefix "/" }}; do
+              echo "user provided zookeepers {{ $zk }} are unreachable... check in 3 seconds ..." && sleep 3;
+            done;
+            {{ else }}
             until nslookup {{ template "pulsar.fullname" . }}-{{ .Values.zookeeper.component }}-{{ add (.Values.zookeeper.replicaCount | int) -1 }}.{{ template "pulsar.fullname" . }}-{{ .Values.zookeeper.component }}.{{ .Values.namespace }}; do
               sleep 3;
             done;
+            {{- end}}
       containers:
       - name: "{{ template "pulsar.fullname" . }}-{{ .Values.bookkeeper.component }}-init"
-        image: "{{ .Values.bookkeeper.metadata.image.repository }}:{{ .Values.bookkeeper.metadata.image.tag }}"
-        imagePullPolicy: {{ .Values.bookkeeper.metadata.image.pullPolicy }}
+        image: "{{ .Values.images.bookie.repository }}:{{ .Values.images.bookie.tag }}"
+        imagePullPolicy: {{ .Values.images.bookie.pullPolicy }}
       {{- if .Values.bookkeeper.metadata.resources }}
         resources:
 {{ toYaml .Values.bookkeeper.metadata.resources | indent 10 }}

charts/pulsar/templates/proxy-statefulset.yaml

@@ -86,9 +86,15 @@ spec:
         command: ["sh", "-c"]
         args:
           - >-
+            {{- if $zk:=.Values.pulsar_metadata.userProvidedZookeepers }}
+            until bin/pulsar zookeeper-shell -server {{ $zk }} ls {{ or .Values.metadataPrefix "/" }}; do
+              echo "user provided zookeepers {{ $zk }} are unreachable... check in 3 seconds ..." && sleep 3;
+            done;
+            {{ else }}
             until bin/pulsar zookeeper-shell -server {{ template "pulsar.fullname" . }}-{{ .Values.zookeeper.component }} get {{ .Values.metadataPrefix }}/admin/clusters/{{ template "pulsar.fullname" . }}; do
               sleep 3;
             done;
+            {{- end}}
       # This init container will wait for at least one broker to be ready before
       # deploying the proxy
       - name: wait-broker-ready

charts/pulsar/templates/pulsar-cluster-initialize.yaml

@@ -48,9 +48,15 @@ spec:
         command: ["sh", "-c"]
         args:
           - >-
+            {{- if $zk:=.Values.pulsar_metadata.userProvidedZookeepers }}
+            until bin/pulsar zookeeper-shell -server {{ $zk }} ls {{ or .Values.metadataPrefix "/" }}; do
+              echo "user provided zookeepers {{ $zk }} are unreachable... check in 3 seconds ..." && sleep 3;
+            done;
+            {{ else }}
             until nslookup {{ template "pulsar.fullname" . }}-{{ .Values.zookeeper.component }}-{{ add (.Values.zookeeper.replicaCount | int) -1 }}.{{ template "pulsar.fullname" . }}-{{ .Values.zookeeper.component }}.{{ .Values.namespace }}; do
               sleep 3;
             done;
+            {{- end}}
       # This initContainer will wait for bookkeeper initnewcluster to complete
       # before initializing pulsar metadata
       - name: pulsar-bookkeeper-verify-clusterid

charts/pulsar/values.yaml

@@ -345,11 +345,6 @@ bookkeeper:
   ## BookKeeper Cluster Initialize
   ## templates/bookkeeper-cluster-initialize.yaml
   metadata:
-    image:
-      # the image used for running `bookkeeper-cluster-initialize` job
-      repository: apachepulsar/pulsar-all
-      tag: 2.6.0
-      pullPolicy: IfNotPresent
     ## Set the resources used for running `bin/bookkeeper shell initnewcluster`
     ##
     resources:
@@ -515,6 +510,11 @@ pulsar_metadata:
   # configurationStore:
   configurationStoreMetadataPrefix: ""
 
+  ## optional, you can provide your own zookeeper metadata store for other components
+  # to use this, you should explicit set components.zookeeper to false
+  #
+  # userProvidedZookeepers: "zk01.example.com:2181,zk02.example.com:2181"
+
 ## Pulsar: Broker cluster
 ## templates/broker-statefulset.yaml
 ##