docker: add entrypoint to sentinel

Author: dsame

docker/sentinel/Dockerfile

@@ -3,11 +3,13 @@ FROM alpine:3.7
 RUN addgroup -S redis && adduser -S -G redis redis
 RUN apk add --no-cache redis
 
-
 COPY sentinel.conf /etc/redis/sentinel.conf
+COPY entrypoint.sh /docker-entrypoint.sh
 
 ENV PORT=26379
 ENV REDIS_PORT=6379
 ENV REDIS_HOST=redis
+ENV QUORUM=2
 
+ENTRYPOINT ["/docker-entrypoint.sh"]
 CMD ["redis-server", "/etc/redis/sentinel.conf", "--sentinel"]

docker/sentinel/entrypoint.sh

@@ -0,0 +1,9 @@
+#!/bin/sh
+
+sed -i.bak "s/^port .*$/port ${PORT}/" /etc/redis/sentinel.conf
+sed -i.bak "s/^\(sentinel monitor [^ ]*\).*$/\1 ${REDIS_HOST} ${REDIS_PORT} ${QUORUM}/" /etc/redis/sentinel.conf
+rm /etc/redis/sentinel.conf.bak
+chown redis:redis /etc/redis/sentinel.conf
+cat /etc/redis/sentinel.conf
+echo $@
+exec $@