add var to simplify redis init checks

Signed-off-by: cabrinha <yuppie@hey.com>

Author: cabrinha

dist/chart/templates/gateway-plugin/deployment.yaml

@@ -1,4 +1,5 @@
 {{- if .Values.gateway.enable }}
+{{- $redisHost := default (printf "%s-redis-master" (include "aibrix.fullname" .)) .Values.gatewayPlugin.dependencies.redis.host }}
 apiVersion: apps/v1
 kind: Deployment
 metadata:
@@ -63,9 +64,9 @@ spec:
                 secretKeyRef:
                   name: {{ include "aibrix.fullname" . }}-redis
                   key: redis-password
-          command: ['sh', '-c', 'until printf ''AUTH %s\nping\n'' "$REDIS_PASSWORD" | nc {{ .Values.gatewayPlugin.dependencies.redis.host }} {{ .Values.gatewayPlugin.dependencies.redis.port }} -w 1 | grep -c PONG; do echo waiting for redis; sleep 2; done']
+          command: ['sh', '-c', 'until printf ''AUTH %s\nping\n'' "$REDIS_PASSWORD" | nc {{ $redisHost }} {{ .Values.gatewayPlugin.dependencies.redis.port }} -w 1 | grep -c PONG; do echo waiting for redis; sleep 2; done']
           {{- else }}
-          command: ['sh', '-c', 'until echo "ping" | nc {{ .Values.gatewayPlugin.dependencies.redis.host }} {{ .Values.gatewayPlugin.dependencies.redis.port }} -w 1 | grep -c PONG; do echo waiting for redis; sleep 2; done']
+          command: ['sh', '-c', 'until echo "ping" | nc {{ $redisHost }} {{ .Values.gatewayPlugin.dependencies.redis.port }} -w 1 | grep -c PONG; do echo waiting for redis; sleep 2; done']
           {{- end }}
       containers:
         - name: gateway-plugin

dist/chart/templates/metadata-service/deployment.yaml

@@ -1,3 +1,4 @@
+{{- $redisHost := default (printf "%s-redis-master" (include "aibrix.fullname" .)) .Values.metadata.service.redis.host }}
 apiVersion: apps/v1
 kind: Deployment
 metadata:
@@ -29,9 +30,9 @@ spec:
                 secretKeyRef:
                   name: {{ include "aibrix.fullname" . }}-redis
                   key: redis-password
-          command: ['sh', '-c', 'until printf ''AUTH %s\nping\n'' "$REDIS_PASSWORD" | nc {{ .Values.metadata.service.redis.host }} {{ .Values.metadata.service.redis.port }} -w 1 | grep -c PONG; do echo waiting for redis; sleep 2; done']
+          command: ['sh', '-c', 'until printf ''AUTH %s\nping\n'' "$REDIS_PASSWORD" | nc {{ $redisHost }} {{ .Values.metadata.service.redis.port }} -w 1 | grep -c PONG; do echo waiting for redis; sleep 2; done']
           {{- else }}
-          command: ['sh', '-c', 'until echo "ping" | nc {{ .Values.metadata.service.redis.host }} {{ .Values.metadata.service.redis.port }} -w 1 | grep -c PONG; do echo waiting for redis; sleep 2; done']
+          command: ['sh', '-c', 'until echo "ping" | nc {{ $redisHost }} {{ .Values.metadata.service.redis.port }} -w 1 | grep -c PONG; do echo waiting for redis; sleep 2; done']
           {{- end }}
       containers:
         - name: metadata-service
@@ -60,7 +61,7 @@ spec:
             periodSeconds: 5
           env:
             - name: REDIS_HOST
-              value: {{ default (printf "%s-redis-master" (include "aibrix.fullname" .)) .Values.metadata.service.redis.host }}
+              value: {{ $redisHost }}
             - name: REDIS_PORT
               value: "{{ .Values.metadata.service.redis.port }}"
             {{- if .Values.metadata.redis.enablePassword }}