Wait more smartly for mysql DB to be ready

We replace the custom script wait-for-greenlight by dockerize: it is a
generic tool that allows for different services to be up. Also, on day,
it will allow us to generate config files dynamically (maybe).

Makefile

@@ -22,11 +22,11 @@ update:
 	docker-compose pull
 
 provision:
-	$(DOCKER_COMPOSE_RUN) lms bash /openedx/config/provision.sh
+	$(DOCKER_COMPOSE_RUN) lms bash -c "dockerize -wait tcp://mysql:3306 && bash /openedx/config/provision.sh"
 
 migrate-openedx:
-	$(DOCKER_COMPOSE_RUN_OPENEDX) lms bash -c "wait-for-greenlight.sh && ./manage.py lms migrate"
-	$(DOCKER_COMPOSE_RUN_OPENEDX) cms bash -c "wait-for-greenlight.sh && ./manage.py cms migrate"
+	$(DOCKER_COMPOSE_RUN_OPENEDX) lms bash -c "dockerize -wait tcp://mysql:3306 && ./manage.py lms migrate"
+	$(DOCKER_COMPOSE_RUN_OPENEDX) cms bash -c "dockerize -wait tcp://mysql:3306 && ./manage.py cms migrate"
 
 migrate-forum:
 	$(DOCKER_COMPOSE_RUN) forum bash -c "bundle exec rake search:initialize && \

openedx/Dockerfile

@@ -49,8 +49,13 @@ RUN ln -s /openedx/config/lms.env.json /openedx/ \
   && ln -s /openedx/config/lms.auth.json /openedx/ \
   && ln -s /openedx/config/cms.auth.json /openedx/
 
+# Dockerize will be useful to wait for mysql DB availability
+ENV DOCKERIZE_VERSION v0.6.1
+RUN curl -L -o dockerize.tar.gz https://github.com/jwilder/dockerize/releases/download/$DOCKERIZE_VERSION/dockerize-linux-amd64-$DOCKERIZE_VERSION.tar.gz \
+    && tar -C /usr/local/bin -xzvf dockerize.tar.gz \
+    && rm dockerize.tar.gz
+
 # Copy convenient scripts
-COPY ./bin/wait-for-greenlight.sh /usr/local/bin/
 COPY ./bin/docker-entrypoint.sh /usr/local/bin/
 
 # service variant is "lms" or "cms"

openedx/bin/wait-for-greenlight.sh

@@ -1,10 +0,0 @@
-#!/bin/bash
-
-echo "Checking system..."
-until ./manage.py $SERVICE_VARIANT check
-do
-  printf "."
-  sleep 1
-done
-
-echo -e "\nSystem is ready \\o/"