README.md

Clipper - circuit breaker

Lightweight circuit breaker tool, inspired in hystrix from Netflix.

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This is a simple, dependency free, circuit breaker library. Super easy to use. You could find also some basic statistics and a handler according to the std lib to expose, given the name of the command.

clipper.Do(&clipper.Configs{Name: "my_command"}, func() error {
		_, err := http.Get("http://www.google.com/robots.txt")
		return err
	}, nil)

Do use 3 args,

1. The Config
2. Operational function
3. Fallback function

And in this case you also have 2 different ways to call the clipper , sync and async, could check out in the examples folder.

The config should have the name and the max duration expressed in seconds. The Function to operate,. The fallback function, is not necessary at all.

Wait the response

out := make(chan bool, 1)
	var res *http.Response
	valChan := clipper.Do(&clipper.Configs{Name: "my_command"}, func() error {
		r, err := http.Get("http://www.google.com/robots.txt")
		res = r
		out <- true
		return err
	}, nil)

	select {
	case <-out:
		value := <-valChan
		if value == 0 {
			fmt.Println("no errors")
		} else {
			fmt.Println("some errors here")
		}
	}
	fmt.Println(res)

No wait to the response

clipper.Do(&clipper.Configs{Name: "my_command"}, func() error {
		r, err := http.Get("http://www.google.com/robots.txt")
		res = r
		return err
	}, nil)

	clipper.FillStats("my_command", true)

Web

Check the function ExposeMetrics() and get all the metrics info. You must provide a valid command name. In the URL like: localhost:8080/metrics?c=my_command

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Tests

go test -v .