Sending your deploy markers to Appsignal from a Phoenix app.

AppSignal deploy markers are a way to keep track of what git commit the bug happened, or when the slowdown started appearing in your app.

https://docs.appsignal.com/application/markers/deploy-markers.html

As long as you have an APP_REVISION environment variable set, you will send it to Appsignal through the integration library.

In the case of Railway you can quite easily add the variable to your Dockerfile and have everything work out nicely in 2 lines.

Railway even provides the variable automatically for you.

# At the very end of your Dockerfile:

# This is a variable Railway automatically exposes.
# Add the variable.
ARG RAILWAY_GIT_COMMIT_SHA 

# Use the variable
ENV APP_REVISION=$RAILWAY_GIT_COMMIT_SHA

CMD ["/app/bin/server"]

And that's it. Deploy markers will now work for you.