cassandra-configurator.sh

#!/bin/bash
set -e

# first arg is `-f` or `--some-option`
if [ "${1:0:1}" = '-' ]; then
	set -- cassandra -f "$@"
fi

if [ "$1" = '/usr/bin/supervisord' ]; then
	# TODO detect if this is a restart if necessary
	: ${CASSANDRA_LISTEN_ADDRESS='auto'}
	if [ "$CASSANDRA_LISTEN_ADDRESS" = 'auto' ]; then
		CASSANDRA_LISTEN_ADDRESS="$(hostname --ip-address)"
	fi

	: ${CASSANDRA_BROADCAST_ADDRESS="$CASSANDRA_LISTEN_ADDRESS"}

	if [ "$CASSANDRA_BROADCAST_ADDRESS" = 'auto' ]; then
		CASSANDRA_BROADCAST_ADDRESS="$(hostname --ip-address)"
	fi
	: ${CASSANDRA_BROADCAST_RPC_ADDRESS:=$CASSANDRA_BROADCAST_ADDRESS}

	: ${CASSANDRA_SEEDS:="$CASSANDRA_PORT_9042_TCP_ADDR"}
	: ${CASSANDRA_SEEDS:="$CASSANDRA_BROADCAST_ADDRESS"}
	
	sed -ri 's/(- seeds:) "127.0.0.1"/\1 "'"$CASSANDRA_SEEDS"'"/' "$CASSANDRA_CONFIG/cassandra.yaml"

	for yaml in \
		broadcast_address \
		broadcast_rpc_address \
		cluster_name \
		endpoint_snitch \
		listen_address \
		num_tokens \
	; do
		var="CASSANDRA_${yaml^^}"
		val="${!var}"
		if [ "$val" ]; then
			sed -ri 's/^(# )?('"$yaml"':).*/\2 '"$val"'/' "$CASSANDRA_CONFIG/cassandra.yaml"
		fi
	done

	for rackdc in dc rack; do
		var="CASSANDRA_${rackdc^^}"
		val="${!var}"
		if [ "$val" ]; then
			sed -ri 's/^('"$rackdc"'=).*/\1 '"$val"'/' "$CASSANDRA_CONFIG/cassandra-rackdc.properties"
		fi
	done
fi

exec "$@"