CF RSS

This version has a scheduler that makes an API request to Codeforces at fixed interval, retrieves the batch result, and stores it in MongoDB. This can retain the recent action history forever.

It also has a method to retrieves all the actions that happened after a fixed timestamp.

Local Development

Make sure that you have go 1.18 installed. Also, MongoDB should be running on port 27017.

If you don't have MongoDB running yet, use a docker image for experiments.

docker run -p 27017:27017 mongo

Or, if you want to run it as background service.

docker run -d -p 27017:27017 mongo

Now, from the application root, run

go run cmd/web/main.go

This should give you a fully configured environment, with the default flags. In case you want to customize it further, pass your own flags.

Flags

• --environment=dev : If set to anything other than dev, the Zap logger would be created in production mode.
• --mongo-addr=mongodb://localhost:27017 : Use this flag to provide the port on which MongoDB is running locally. If you want to connect to MongoDB Atlas (say, in production), use the format mongodb+srv://admin:password@cluster0.s0g4l.mongodb.net/test
• --database-name=cfrss-local : The database which stores the data. In production, set it to cfrss.
• --cooldown-minutes=5 : The amount of time (in minutes) between successive Codeforces API calls.
• --cf-batch-size=100 : The number of recent actions to retrieve in each Codeforces API call.

Docker

First, build the image using

docker build --tag cfrss:latest .

To run the docker image, you need to pass the MongoDB address as a flag. If you want to use the local instance of MongoDB, expose the network stack.

docker run --network=host cfrss:latest 

If you want to use the cloud version, pass the flags like so

docker run -d --restart always -p 5000:5000 --name cfrss cfrss:latest --mongo-addr=mongodb+srv://admin:enterCorrectValue@cluster0.s0g4l.mongodb.net/test --database-name=cfrss-local --enable-cf-scheduler=false --environment=dev

In production, you need to change 3 things:

1. Enter the correct MongoDB credentials.
2. Enter the correct DB name: cfrss.
3. Set enable-cf-scheduler to true.
4. Set environment to prod.

To view the logs,

docker logs cfrss

To stop the container

docker stop cfrss

It can be restarted via

docker start cfrss

To remove the container

docker rm cfrss