Source: ctxhttp.go in package golang.org/x/net/context/ctxhttp

Package ctxhttp provides helper functions for performing context-aware HTTP requests.

package ctxhttp // import "golang.org/x/net/context/ctxhttp"

import (
	"context"
	"io"
	"net/http"
	"net/url"
	"strings"
)

Do sends an HTTP request with the provided http.Client and returns an HTTP response. If the client is nil, http.DefaultClient is used. The provided ctx must be non-nil. If it is canceled or times out, ctx.Err() will be returned.

func Do(ctx context.Context, client *http.Client, req *http.Request) (*http.Response, error) {
	if client == nil {
		client = http.DefaultClient
	}

If we got an error, and the context has been canceled, the context's error is probably more useful.

	if err != nil {
		select {
		case <-ctx.Done():
			err = ctx.Err()
		default:
		}
	}
	return resp, err
}

Get issues a GET request via the Do function.

func Get(ctx context.Context, client *http.Client, url string) (*http.Response, error) {
	req, err := http.NewRequest("GET", url, nil)
	if err != nil {
		return nil, err
	}
	return Do(ctx, client, req)
}

Head issues a HEAD request via the Do function.

func Head(ctx context.Context, client *http.Client, url string) (*http.Response, error) {
	req, err := http.NewRequest("HEAD", url, nil)
	if err != nil {
		return nil, err
	}
	return Do(ctx, client, req)
}

Post issues a POST request via the Do function.

func Post(ctx context.Context, client *http.Client, url string, bodyType string, body io.Reader) (*http.Response, error) {
	req, err := http.NewRequest("POST", url, body)
	if err != nil {
		return nil, err
	}
	req.Header.Set("Content-Type", bodyType)
	return Do(ctx, client, req)
}

PostForm issues a POST request via the Do function.

func PostForm(ctx context.Context, client *http.Client, url string, data url.Values) (*http.Response, error) {
	return Post(ctx, client, url, "application/x-www-form-urlencoded", strings.NewReader(data.Encode()))