Docker和PM2：基于字符串的CMD和环境变量

Question

I'm currently using the shell -form of CMD in Docker for launching my node app:

CMD /usr/src/app/node_modules/.bin/trifid --config $TRIFID_CONFIG

The env-var TRIFID_CONFIG is set to a default in the Dockerfile :

ENV TRIFID_CONFIG config.customer.json

This makes it easy to pass another config file for dev-environments for example.

Now I try to switch this to PM2 for production. However it looks like all PM2 samples are using the "exec" form which from what I understood does not evaluate ENV-vars. I tried the shell-form with PM2:

CMD pm2-docker /usr/src/app/node_modules/trifid/server.js --config $TRIFID_CONFIG

But it looks like the variable is not evaluated like this, it fails back to default on execution.

What would be the proper way to handle this with PM2 inside a Docker image?

Answer 1

I had a discussion on Github and meanwhile figured it out:

CMD pm2-docker /usr/src/app/node_modules/.bin/trifid -- --config $TRIFID_CONFIG

So the trick is to use -- after the command and the rest will be passed as argument. If I use the shell form env-vars do seem to get evaluated properly.