With go installed you can build it with:
make build
And you can run it with:
./notify -dummyserver --interval=1s --url http://localhost:8080/notify < messages.txt
If you prefer you can use docker to run it:
docker build -t notifier .
docker run -it notifier /bin/bash -c "./notify -dummyserver --interval=1s --url http://localhost:8080/notify < messages.txt"
You can tun test with: make test and with the flag -dummyserver it will start a test server on port 8080 and receives requests to /notify and returns a dummy response containing the request body.