DEPRECATED

This repository is to be considered DEPRECATED. No code should be added to this repository

• The rchttp client has been moved to a new repo dp-net/http. All imports should be updated accordingly, and dependencies with this library should be removed.

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rchttp

rchttp stands for robust contextual HTTP, and provides a default client that inherits the methods associated with the standard HTTP client, but with the addition of production-ready timeouts and context-sensitivity, and the ability to perform exponential backoff when calling another HTTP server.

How to use

rchttp should have a familiar feel to it when it is used - with an example given below:

import rchttp "github.com/ONSdigital/dp-rchttp"

func httpHandlerFunc(w http.ResponseWriter, req *http.Request) {
    client := rchttp.NewClient()

    resp, err := rcClient.Get(req.Context(), "https://www.google.com")
    if err != nil {
        fmt.Println(err)
        return
    }
}

In this case, in the unlikely event of https://www.google.com returning a status of 500 or above, the client will retry at exponentially-increasing intervals, until the max retries (10 by default is reached).

Also, if the inbound request is cancelled, for example, its context will be closed and this will be noticed by the client.

You also do not have to use the default client if you don't like the configured timeouts or do not wish to use exponential backoff. The following example shows how to configure your own rchttp client:

import rchttp "github.com/ONSdigital/dp-rchttp"

func main() {
    rcClient := &rchttp.Client{
        // MaxRetries is the maximum number of retries you wish to
        // wait for, the retry method implements exponential backoff
        MaxRetries:         10,
        // RetryTime is the gap before (any) first retry (increases for second retry, and so on)
        RetryTime:          1 * time.Second,
        // PathsWithNoRetries is a list of all paths that you do not wish to retry call on failure,
        // the path should be set to true (default client has empty map)
        PathsWithNoRetries: map[string]bool{
			"/health": true,
		},
        // Create your own http client with configured timeouts
        HTTPClient: &http.Client{
            Timeout: 10 * time.Second,
            Transport: &http.Transport{
                DialContext: (&net.Dialer{
                    Timeout: 5 * time.Second,
                }).DialContext,
                TLSHandshakeTimeout: 5 * time.Second,
                MaxIdleConns:        10,
                IdleConnTimeout:     30 * time.Second,
            },
        },
    }
}