ts-load-balancer

Basic zero dependency L7 load balancer written as Coding Challenge. HTTPS included.

Install

Install ts-load-balancer:

npm i -g ts-load-balancer

Now you have command tslb available.

Usage

To start load balancer you need to specify port and list of backend hosts:

tslb -p 8080 -s=localhost:8081,localhost:8082

All options:

• --servers -s: required, list of hosts. Format: ${hostname}:${port}, f.e. example.com:8081, localhost:8282
• --port -p: default 80, specify port for load balancer server
• --strategy: rrobin by default. (TODO: implement more startegies)
• --check-interval -hc: default 10_000, interval in ms between health checks
• --protocol: default http. If https is chosen than --cert and --key is required
• --cert: required for https. Path to SSL certificate in file system
• --key: required for https. Path to SSL key in file system

Developing

npm install
npm start

Will run balancer on the port :8080. You can edit CLI parameters in the package.json.

npm start:https

Start balancer using https and certificate from ./stub directory.

Stub

For integration testing there is a stub for backend server.

node ./stub/server.mjs 8081 true

Command starts simple server with only one api handler on port 8081 and makes this server available (server will return 200 OK on GET /health).

Testing

For unit testing run

npm test

Integration tests

Integration test is located in /test.

npm run integrations

It will run stub servers on ports 8081,8082,8083. And balancer on port 8080.