The fly.io docs suggest to set a static cookie with a mix release configuration: Clustering Your Application · Fly Docs
I don’t understand why that is suggested, as it makes things quite difficult, especially if multiple release configs need to be created for different environments (each with their own cookie). In that case you also need to change your Dockerfile
to accommodate for the RELEASE_NAME
(the mix release
command needs the name as input, and the release scripts in bin
are also dependent on the RELEASE_NAME
).
To me it seems way simpler to set the RELEASE_COOKIE
environment variable, and be done with it. It takes precedence over the generated releases/COOKIE
file. It’s documented here, when explaining the :cookie
option. And in most cases it’s simple to specify a regular environment variable at runtime (or a fly.io secret, in my specific case).
Am I missing something, or is the suggestion on the fly.io documentation needlessly complicated?