It is just docker file that can build basic emulators: auth, firestore. To access ui: https://localhost:4000
This repo represents the Dockerfile with docker.compose.yml which will run functions, firestore, auth and pubsub alltogether in docker.
So fork repo, add your functions to functions folder, and run docker compose up -d or docker-compose up -d
Use https://localhost:4000 to access emulator UI.
For functions unfortunatly you need to build docker locally because functions are packed during the build inside the container.
P.S.
I hope that Google eventually will set some official docker image, because it was nightmare to get piece by piece and make it work. Couple of days spent.
Inside the repo you might see functions folder, it contains code related to firebase functions.
There is alread simple http function handleRequest that just logs text query parameters. After your container is up - you can access it by navigating to
http://localhost:5001/dummy-project/us-central1/handleRequest?text=%22qqqqqqqqqqqq%22
dummy-project - is the project id you have set in .firebaserc file. I guess this needed for metadata.
us-central1 - region where you want your function to run, I put us-central as example. It does not matter it will be execute on your localhost
handleRequest is a function name defined in the functions js file.
Actually I was not able to see function logs from emulator ui, so you could just use logs from docker container:
docker logs <container id>
firebase-emulator | i functions: Beginning execution of "us-central1-handleRequest"
firebase-emulator | > [handleRequest] running inside the http method
firebase-emulator | > "qqqqqqqqqqqq"
firebase-emulator | i functions: Finished "us-central1-handleRequest" in 2.881127ms
In case you would like to change function behavior it will not automatically pick up your changes.
So for that you would need to rebuild the image and start container again with new image
docker compose up -d --build or docker-compose up -d --build