run-pgcli script now accepts DB_URL based arguments

Dockerfile

@@ -3,5 +3,5 @@ MAINTAINER Dennis Coldwell <dennis.coldwell@gmail.com>
 RUN apt-get -y update && apt-get -y install libpq-dev build-essential
 RUN pip install pgcli==0.20.1
 ADD run-pgcli.sh /bin/run-pgcli.sh
-CMD ["run-pgcli.sh"]
+ENTRYPOINT ["run-pgcli.sh"]
 

run-pgcli.sh

@@ -3,10 +3,19 @@
 # Simple wrapper for the pgli tool. This script allows us to pull in linked
 # docker containers if the user decides to bring up the cli that way.
 
-if [ -z ${POSTGRES_PORT_5432_TCP_ADDR+x} ]; then
-    # POSTGRES linked variables aren't set, just call pgcli without params
-    pgcli
-else
+db_url=$1
+
+if [ -n "$db_url" ]; then
+    # 1st priority goes to any argument passed to the script
+    pgcli "$db_url"
+elif [ -n "$DB_URL" ]; then
+    # next, if a DB_URL environment variable is set, use that
+    pgcli "$DB_URL"
+elif [ -n "$POSTGRES_PORT_5432_TCP_ADDR" ]; then
+    # if nothing is set, we try to construct a db_url from the env vars that docker
+    # automatically sets for the postgres container
     pgcli postgres://$POSTGRES_ENV_POSTGRES_USER:$POSTGRES_ENV_POSTGRES_PASSWORD@$POSTGRES_PORT_5432_TCP_ADDR:$POSTGRES_PORT_5432_TCP_PORT
+else
+    echo "Database URL not provided, please try again."
 fi