Runtime.exs and


I have a quick question that doesn’t seem to be explicitly mentioned anywhere in the docs. Does runtime.exs have access to the environment variables declared as part of your when deploying a mix release? It feels like it should but again can’t find anything that explicitly states it does and nothing to the contrary either…


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I found this in the documentation:

rel/ and rel/env.bat.eex - template files that are copied into every release and are executed on every command to set up environment variables, including specific ones to the VM, and the general environment

So I believe so.

A Phoenix release with runtime.exs will also have access to all environment variables like:

PORT=4000 build/prod/rel/new_phoenix/bin/new_phoenix start

I talked about it in my latest post:

If you want to export all variables from an environment file that doesn’t come with the release, you can do the following in Bash:

set -o allexport
set +o allexport
build/prod/rel/new_phoenix/bin/new_phoenix start