rodrigodelmonte / httpeeve

Exponential backoff for HTTP Requests

HTTPeeve

HTTPeeve is a library for making HTTP requests with exponential backoff. It wraps around https://github.com/cenkalti/backoff and provides some helper functions.

Installation

go get github.com/motain/httpeeve

Usage

An example of how to use the library can be found in the helper function NewDefaultBackoffClient5XX:

func NewDefaultBackoffClient5XX(httpClient http.Client) Client {
	return NewBackoffClient(httpClient, backoff.NewExponentialBackOff(), func(resp *http.Response) (bool, error) {
		if resp.StatusCode >= 500 && resp.StatusCode < 600 {
			return RetriableErrorf("bad status code %d", resp.StatusCode)
		}

		if resp.StatusCode >= 200 && resp.StatusCode < 300 {
			return OK()
		}

		return PermanentErrorf("bad status code %d", resp.StatusCode)
	})
}

This function takes a "net/http".Client. It initializes a NewBackoffClient with this, as well as an instance of "cenkalti/backoff".Backoff and a Conditioner.

In the example, the Conditioner determines that 5XX status codes can be retried, 2XXs are OK, and everything else results in an unretriable error.

This library also provides a helper function to see how many attempts a request took:

resp, err := client.Do(req)
if err != nil {
    // something
}
fmt.Println(httpeeve.Attempts(resp))