options.md

Options

retryhttp.Transport can be customized with several options. In general, each option that can be specified at creation time has an equivalent helper function for overriding the option using the request Context. An option set on the Context takes precedence over an option set on the Transport.

Option	Context Equivalent	Default Value	Description
WithTransport	none	http.DefaultTransport	The internal http.RoundTripper to use for requests.
WithShouldRetryFn	SetShouldRetryFn	DefaultShouldRetryFn	The ShouldRetryFn that determines if a request should be retried. DefaultShouldRetryFn is a good starting point. If you're only looking to make minor tweaks, CustomizedShouldRetryFn may be appropriate.
WithDelayFn	SetDelayFn	DefaultDelayFn	The DelayFn that determines how long to delay between retries. If DefaultDelayFn doesn't solve your use-case, CustomizedDelayFn may be appropriate.
WithMaxRetries	SetMaxRetries	3	The maximum number of retries to make. Note that this is the number of retries not attempts, so a MaxRetries of 3 means up to 4 total attempts: 1 initial attempt and 3 retries. Note also that if your ShouldRetryFn returns false, a retry will not be made even if MaxRetries has not been exhausted.
WithPreventRetryWithBody	SetPreventRetryWithBody	false	Whether to prevent retrying requests that have a HTTP body. Any request that has any chance of needing a retry must buffer its body into memory so that it can be replayed in subsequent attempts. This may or may not be appropriate for certain use-cases, which is why this option is provided.
WithAttemptTimeout	SetAttemptTimeout	No timeout	A per-attempt timeout to be used. This differs from an overall timeout in that the timeout is reset for each attempt. Without a per-attempt timeout, the overall timeout could be exhausted in a single attempt with no time left for subsequent retries. Providing time.Duration(0) here removes the timeout.

Example

client := http.Client{
    Transport: retryhttp.New(
        retryhttp.WithShouldRetryFn(attempt retryhttp.Attempt) bool {
            // only retry HTTP 418 statuses
            if attempt.Res != nil && attempt.Res.StatusCode == http.StatusTeapot {
                return true
            }
            return false
        },
        retryhttp.WithMaxRetries(2),
        retryhttp.WithAttemptTimeout(time.Second * 10),
    ),
}

ctx := context.TODO
ctx = retryhttp.SetShouldRetryFn(ctx, func(attempt retryhttp.Attempt) bool {
    // retry any error
    if attempt.Err != nil {
        return true
    }
    return false
})
ctx = retryhttp.SetMaxRetries(ctx, 1) // only 1 retry
ctx = retryhttp.SetAttemptTimeout(ctx, 0) // remove attempt timeout

req, err := http.NewRequest(http.MethodGet, "example.com", nil)
...

// add augmented context to the request: retries will abide by the overrides
// instead of the orginial configurations
res, err := client.Do(req.WithContext(ctx))
...