boot

#!/bin/bash
#
# This script is designed to be run inside the container
#

# fail hard and fast even on pipelines
set -eo pipefail

# set debug based on envvar
[[ $DEBUG ]] && set -x

# configure etcd
export ETCD_PORT=${ETCD_PORT:-4001}
export ETCD="$HOST:$ETCD_PORT"
export ETCD_PATH=${ETCD_PATH:-/deis/cache}
export ETCD_TTL=${ETCD_TTL:-10}

# wait for etcd to be available
until etcdctl --no-sync -C $ETCD ls >/dev/null; do
	echo "waiting for etcd at $ETCD..."
	sleep $(($ETCD_TTL/2))  # sleep for half the TTL
done

# wait until etcd has discarded potentially stale values
sleep $(($ETCD_TTL+1))

# seed initial service configuration if necessary
if ! etcdctl --no-sync -C $ETCD ls $ETCD_PATH >/dev/null 2>&1 ; then
	etcdctl --no-sync -C $ETCD mkdir $ETCD_PATH >/dev/null 2>&1 || true
fi

# wait for confd to run once and install initial templates
until confd -onetime -node $ETCD -config-file /app/confd.toml; do
	echo "cache: waiting for confd to write initial templates..."
	sleep $(($ETCD_TTL/2))  # sleep for half the TTL
done

# spawn the service in the background
cd /var/lib/redis
sudo -u redis /usr/bin/redis-server /etc/redis/redis.conf &
SERVICE_PID=$!

# smart shutdown on SIGINT and SIGTERM
function on_exit() {
	kill -TERM $SERVICE_PID
	wait $SERVICE_PID 2>/dev/null
	exit 0
}
trap on_exit INT TERM

# spawn confd in the background to update services based on etcd changes
confd -node $ETCD -config-file /app/confd.toml &
CONFD_PID=$!

echo deis-cache running...

# publish the service to etcd using the injected PORT
if [[ ! -z $PUBLISH ]]; then

	# configure service discovery
	PORT=${PORT:-6379}
	PROTO=${PROTO:-tcp}

	set +e

	# wait for the service to become available on PUBLISH port
	sleep 1 && while [[ -z $(netstat -lnt | awk "\$6 == \"LISTEN\" && \$4 ~ \".$PUBLISH\" && \$1 ~ \"$PROTO.?\"") ]] ; do sleep 1; done

	# while the port is listening, publish to etcd
	while [[ ! -z $(netstat -lnt | awk "\$6 == \"LISTEN\" && \$4 ~ \".$PUBLISH\" && \$1 ~ \"$PROTO.?\"") ]] ; do
		etcdctl --no-sync -C $ETCD set $ETCD_PATH/host $HOST --ttl $ETCD_TTL >/dev/null
		etcdctl --no-sync -C $ETCD set $ETCD_PATH/port $PORT --ttl $ETCD_TTL >/dev/null
		sleep $(($ETCD_TTL/2)) # sleep for half the TTL
	done

	# if the loop quits, something went wrong
	exit 1

fi

wait