FuncX Forwarder Service

The Forwarder service runs in a container on Flask behind uWSGI. uWSGI listens on port 3031.

This is a REST micro service that handles requests for initializing Forwarders to which endpoints will connect. This service will have the following routes:

/register

This route expects a POST with a json payload that identifies the endpoint info and responds with a json response.

For eg:

POST payload:

{
   'endpoint_id': '<ENDPOINT_ID>',
   'redis_url': '<REDIS_URL>',
}

Response payload:

{
   'endpoint_id': endpoint_id,
   'task_url': 'tcp://55.77.66.22:55001',
   'result_url': 'tcp://55.77.66.22:55002',
   'command_port': 'tcp://55.77.66.22:55003'
}

/list_endpoints

This route will list the endpoint mappings.

/ping

This route is for liveness checking. Will return "pong" string when you do a GET on this route.

Architecture and Notes

The endpoint registers and receives the information:

Endpoint / Forwarder Interaction
                                        TaskQ ResultQ
                                           |    |
REST       /register--> Forwarder----->Executor Client
              ^                            |    ^
              |                            |    |
              |                            v    |
              |          +-------------> Interchange
 User ----> Endpoint ----|
                         +--> Provider

Debugging

You can run the forwareder-service in debug mode on your local system and skip the web-service entirely. For this, make sure you have the redis package installed and running. You can check this by running:

>>> redis-cli

This should output a prompt that says : 127.0.0.1:6379. This string needs to match.

Now, you can start the forwarder service for testing:

>>> forwarder-service --address 127.0.0.1 --port 50005 --debug

Once you have this running, we can update the endpoint configs to point to this local service.

Docker Container

You can run the service inside a docker container. To build the container locally:

docker build -t funcx/forwarder:dev .

Then, run the container:

# Assumes that Redis and RabbitMQ are running locally in a container
docker run --rm -it -p 8080:8080 \
  -e "ADVERTISED_FORWARDER_ADDRESS=host.docker.internal" \
  -e "REDIS_HOST=host.docker.internal" \
  -e "REDIS_PORT=6379" \
  -e "FUNCX_RABBITMQ_SERVICE_HOST=host.docker.internal" \
  funcx/forwarder:dev

Once it's running, you can hit the forwarder's endpoints:

curl http://localhost:8080/version