Introduction

This is going to be a grab bag of docker-compose tips and snippets for things that I do commonly enough that I want to write them down but not commonly enough that I remember the syntax offhand.

Different file names

By default docker-compose wants the compose file to be docker-compose.yml in the same directory as the command is being run. Generally you want to stick with that, but I did come up with a situation where I wanted to give them different names. You can do docker-compose -f <file name> <rest of your commands> to get around this. Note that the -f <file name> has to be at the start, you can’t just put it in like any other flag.

.env files

One of the reasons I was trying to have different file names was because I wanted a bunch of different compose files to share a .env file. My new solution is to have a .env file in the root directory of where I keep my compose files and then use symbolic links to make a link to that master file in each directory. Depending on how I created the link though I would run into a too many levels of symbolic links error. A clean way to solve this is to navigate to the subdirectory and run ln -s ../.env .env. Whatever you put after -s is literally what’s included in the link, so as long as there’s a .env file in the parent folder this will work, regardless of where in your file system you move these directories.

Conclusion

That’s it for now. I’ll come back and update this document if anything else comes up.