Thanks @CrashyBang! I just tested your fork and this is a helpful improvement for getting a smooth, errorless run the 1st time.

Per the question you raise in the issue, I think this is a good stopgap for avoiding an obvious error. However, it also reveals a deeper issue that should be addressed at some point, which is that the server should attempt to retry its connection to the database when it catches a SequelizeConnectionRefusedError. That connection is made using the Sequelize library, and there's an open issue for this exact problem.

I'll definitely accept this PR, but I also wonder if you have any thoughts on improving the resilience of the DB connection?

Hey @allanlasser yeah I totally agree with that, it is not just Sequelize either Knex.js has a similar problem.

As far as making it more resilient we could try and catch the error ourselves, or wait on the outstanding issue.

Also if you don't want to add the wait-for-it.sh to the source I ended doing the following in my own project, because like you say this is a work around and it would be better if we could address the core issue:

RUN curl -o ~/wait-for-it.sh https://raw.githubusercontent.com/vishnubob/wait-for-it/master/wait-for-it.sh \
    && chmod +x ~/wait-for-it.sh

ENTRYPOINT ~/wait-for-it.sh postgres:5432 -- npm run start

Thoughts?