support RDS environment variables in our bin/start script

bin/start

@@ -19,4 +19,21 @@ if [ "$MAILGUN_SMTP_LOGIN" ]; then
     export MB_EMAIL_SMTP_PASSWORD="$MAILGUN_SMTP_PASSWORD"
 fi
 
+# AWS Elastic Beanstalk w/ RDS
+if [ ! -z "$RDS_HOSTNAME" ]; then
+    # EEK: this is a bit fragile.  if user picks a non-standard port for their db we are screwed :(
+    if [ "$RDS_PORT" == "3306" ]; then
+        export MB_DB_TYPE=mysql
+    else
+        export MB_DB_TYPE=postgres
+    fi
+
+    export MB_DB_DBNAME=$RDS_DB_NAME
+    export MB_DB_USER=$RDS_USERNAME
+    export MB_DB_PASS=$RDS_PASSWORD
+    export MB_DB_HOST=$RDS_HOSTNAME
+    export MB_DB_PORT=$RDS_PORT
+fi
+
+
 exec java $JAVA_OPTS -jar ./target/uberjar/metabase.jar