docker-entrypoint.sh

#!/bin/bash

NUM_REDIS_REPLICAS=${NUM_REDIS_REPLICAS:-3}
KUBERNETES_CLUSTER_DOMAIN=${KUBERNETES_CLUSTER_DOMAIN:-"cluster.local"}

declare -a podList
replicaCount=0
while [[ ${replicaCount} -lt ${NUM_REDIS_REPLICAS} ]]; do
        podName="redis-server-${replicaCount}"
        podList+=($podName)
        let replicaCount=replicaCount+1
done

bkRedisFile="/usr/local/etc/haproxy/bk_redis.txt"
if [ -f $bkRedisFile ] ; then
    rm $bkRedisFile
fi
echo " " | tee ${bkRedisFile} > /dev/null
echo "backend bk_redis1" | tee -a ${bkRedisFile} > /dev/null
echo "  log global" | tee -a ${bkRedisFile} > /dev/null
echo "  option tcp-check" | tee -a ${bkRedisFile} > /dev/null
# echo "  option tcplog" | tee -a ${bkRedisFile} > /dev/null
echo "  option log-health-checks" | tee -a ${bkRedisFile} > /dev/null
echo "  errorfile 503 /usr/local/etc/haproxy/errors/503.http" | tee -a ${bkRedisFile} > /dev/null
echo "  tcp-check comment PING\ phase" | tee -a ${bkRedisFile} > /dev/null
echo "  tcp-check send PING\r\n" | tee -a ${bkRedisFile} > /dev/null
echo "  tcp-check expect string +PONG" | tee -a ${bkRedisFile} > /dev/null
echo "  tcp-check comment role\ check" | tee -a ${bkRedisFile} > /dev/null
echo "  tcp-check send info\ replication\r\n" | tee -a ${bkRedisFile} > /dev/null
echo "  tcp-check expect string role:master" | tee -a ${bkRedisFile} > /dev/null
echo "  tcp-check comment QUIT\ phase" | tee -a ${bkRedisFile} > /dev/null
echo "  tcp-check send QUIT\r\n" | tee -a ${bkRedisFile} > /dev/null
echo "  tcp-check expect string +OK" | tee -a ${bkRedisFile} > /dev/null

for ((i = 0; i < ${#podList[@]}; ++i)); do
        echo "  server redis_$i ${podList[i]}.redis-server.default.svc.${KUBERNETES_CLUSTER_DOMAIN}:6379 check resolvers kubernetes init-addr last,libc,none inter 1s rise 1 fall 180" | tee -a ${bkRedisFile} > /dev/null
done

sed -i "\$r /usr/local/etc/haproxy/bk_redis.txt" /usr/local/etc/haproxy/haproxy.cfg

if [ -f $bkRedisFile ] ; then
    rm $bkRedisFile
fi

## Enable Redis Auth if flag is set to true.
if [ "$REDIS_AUTH_ENABLED" = "true" ]; then
        redissecret=`cat /etc/redis/redis-secret/secret`

        ##set passwords to redis secret
        sed -i "s/passwordhere/$redissecret/" /usr/local/etc/haproxy/haproxy.cfg

  ## Set auth to redis
        sed -i "/log-health-checks/a\\  tcp-check send AUTH\\\ $redissecret\\\r\\\n" /usr/local/etc/haproxy/haproxy.cfg
        sed -i "/tcp-check send AUTH/a\\  tcp-check expect string +OK" /usr/local/etc/haproxy/haproxy.cfg
fi


# get the namespace and include in the ordinal hostname for redis
k8s_namespace=$(cat /var/run/secrets/kubernetes.io/serviceaccount/namespace)
sed -i -E "s/(redis-server-[[:digit:]].redis-server.)default(.svc.${KUBERNETES_CLUSTER_DOMAIN})/\1${k8s_namespace}\2/" /usr/local/etc/haproxy/haproxy.cfg

## If DNS_RESOLVER is empty than take namespaces from /etc/resolv.conf
[ -z "${DNS_RESOLVER}" ] && export DNS_RESOLVER=$(cat /etc/resolv.conf | grep nameserver | awk '{ print $2 }')

sed -i "/^resolvers kubernetes/a\\  nameserver dns $DNS_RESOLVER:53" /usr/local/etc/haproxy/haproxy.cfg

## loop through all namespaces and add to haproxy.cfg
#for ((i=0; i<${#DNS_RESOLVER[*]}; i++));
#do
   ##sed -i "/^resolvers kubernetes/a\\  nameserver dns${i} ${DNS_RESOLVER[$i]}:53" /usr/local/etc/haproxy/haproxy.cfg
#done

# first arg is `-f` or `--some-option`
if [ "${1#-}" != "$1" ]; then
	set -- haproxy "$@"
fi

if [ "$1" = 'haproxy' ]; then
	shift # "haproxy"
	# if the user wants "haproxy", let's add a couple useful flags
	#   -W  -- "master-worker mode" (similar to the old "haproxy-systemd-wrapper"; allows for reload via "SIGUSR2")
	#   -db -- disables background mode
	set -- haproxy -W -db "$@"
fi

exec "$@"