#!/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/router}
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 /deis/services >/dev/null 2>&1; then
	etcdctl --no-sync -C $ETCD mkdir /deis/services || true >/dev/null 2>&1
	etcdctl --no-sync -C $ETCD set $ETCD_PATH/port ${PORT:-80} >/dev/null
fi

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

# spawn the service in the background
echo "Starting Nginx..."
/usr/sbin/nginx &
SERVICE_PID=$!

# smart shutdown on SIGINT and SIGTERM
function on_exit() {
    kill -TERM $SERVICE_PID
    wait $SERVICE_PID 2>/dev/null
}
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-router running...

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

	# configure service discovery
	PORT=${PORT:-80}
	PROTO=${PROTO:-tcp}

	# 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