Edge Cluster Frontend

The Edge Cluster Frontend is the entrypoint for offloading functions from the Device Client in each Edge Cluster. It acts as a load balancer, to handle the redirection to the correct Serverless Runtime running within the particular Edge Cluster where it is located.

Install

The Application needs to reach the OpenNebula XMLRPC endpoint and the oneflow endpoint. Configure options at /etc/cognit-edge_cluster_frontend.conf.

host: 0.0.0.0
port: 1339
oneflow: "http://opennebula_frontend:2474"
one_xmlrpc: https://opennebula_frontend/RPC2
cognit_frontend: 'http://localhost:1338'
log_level: debug

The COGNIT admin user credentials will be loaded from ~/.one/one_auth. These are the credentials from the user that will own the Serverless Runtime instances.

The application was developed with python 3.10. Check the dependencies. It is recommended to install it with a virtual environment.

Install virtualenv

pip install virtualenv

Create virtualenv

cd /path/to/cognit-frontend-repo
python -m venv venv
source venv/bin/activate
pip install -r requirements.txt

Run the application

./src/main.py

It should result in uvicorn starting the web server and logging requests

(venv)  ◰³ venv  ~/P/C/edgecluster-frontend   v1 *  ./src/main.py                                                                                                        53s
INFO:     Started server process [27235]
INFO:     Waiting for application startup.
INFO:     Application startup complete.
INFO:     Uvicorn running on http://0.0.0.0:1339 (Press CTRL+C to quit)
INFO:     127.0.0.1:56536 - "GET /docs HTTP/1.1" 200 OK
INFO:     127.0.0.1:56536 - "GET /openapi.json HTTP/1.1" 200 OK
32
INFO:     127.0.0.1:56548 - "POST /v1/functions/32/execute?app_req_id=28&mode=sync HTTP/1.1" 200 OK

Unload the virtual env after stopping the application

deactivate

Use

The API documentation is available where the api is running, by default at http://localhost:1338/docs.

The App client must previously get an auth token issued by the cognit frontend and send it on the requests header.