rek

An easy HTTP client for Go inspired by Requests, plus all the Go-specific goodies you'd hope for in a client. Here's an example:

// GET request
res, _ := rek.Get("https://httpbin.org/get")

fmt.Println(res.StatusCode())

body, _ := rek.BodyAsString(res.Body())

fmt.Println(body)

// POST request
type Comment struct {
    Username string `json:"username"`
    Body     string `json:"body"`
}

res, _ := rek.Post("https://httpbin.org/post",
    rek.Json(Comment{Username: "genesiskel", Body: "This movie sucked. Two thumbs down."}),
    rek.Headers(map[string]string{"My-Custom-Header": "foo,bar,baz"}),
    rek.BasicAuth("user", "pass"),
    rek.Timeout(5 * time.Second),
)

fmt.Println(res.StatusCode())

body, _ := rek.BodyAsString(res.Body())
fmt.Println(body)

Responses

The Response struct has the following methods:

Method	Description	Return type
StatusCode()	HTTP status code, e.g. 200, 400	int
Body()	The HTTP response body as a reader	io.ReadCloser
Headers()	The response headers	map[string]string
Encoding()	The content encoding of the response body, e.g. gzip	[]string
ContentType()	The value of the Content-Type header	string
Raw()	The unmodified *http.Response	*http.Response
Cookies()	The cookies attached to the response	[]*http.Cookie
ContentLength()	The length of the response	int64
Status()	The status of the response, e.g. 200 OK	string

HTTP response body

Keep in mind that the HTTP response body can only be read once. This is one area in which rek does not directly correspond to the Requests API. And so this, for example, won't work the way you might want:

res, _ := rek.Get("https://httpbin.org/get")

bs1, _ := ioutil.ReadAll(res.Body()) // Non-empty byte slice

bs2, _ := ioutil.ReadAll(res.Body()) // Empty byte slice

If you'd like to use the response body more than once, store it in a variable rather than re-accessing the body.

Helper methods

There are two simple helper methods for working with the response body:

Function	Return types
BodyAsString(io.ReadCloser)	(string, error)
BodyAsBytes(io.ReadCloser)	([]byte, error)

Bear in mind the caveat mentioned above, that the request body can only be read once, still holds. Here are some examples:

res, _ := rek.Get("https://httpbin.org/get")

s1, _ := rek.BodyAsString(res.Body()) // body is read here

s2, _ := rek.BodyAsString(res.Body()) // s2 is an empty string

Non-standard methods

rek natively supports the methods GET, POST, PUT, DELETE, PATCH, and HEAD. If you'd like to use a method that's not directly supported, you can use the Do function:

res, err := rek.Do("SOMEOTHERMETHOD", rek.Timeout(10 * time.Second))

Options

Headers

headers := map[string]string{
    "My-Custom-Header": "foo,bar,baz",
}

res, err := rek.Post("https://httpbin.org/post", rek.Headers(headers))

JSON

Pass in any struct:

type Comment struct {
    ID        int64     `json:"id"`
    Body      string    `json:"body"`
    Timestamp time.Time `json:"timestamp"`
}

comment := Comment{ID:47, Body:"Cool movie!", Timestamp: time.Now()}

res, err := rek.Post("https://httpbin.org/post", rek.Json(comment))

Request headers are automatically updated to include Content-Type as application/json;charset=utf-8.

Request timeout

res, err := rek.Get("https://httpbin.org/get", rek.Timeout(5 * time.Second))

Form data

form := map[string]string{
    "foo": "bar",
    "baq": "baz",
}

res, err := rek.Put("https://httpbin.org/put", rek.FormData(form))

Request headers are automatically updated to include Content-Type as application/x-www-form-urlencoded.

File upload

fieldName := "file"
filepath := "docs/README.md"
params := nil

res, err := rek.Post("https:/httpbin.org/post", rek.File(fieldName, filepath, params))

Request headers are automatically updated to include Content-Type as multipart/form-data; boundary=....

Basic auth

username, password := "user", "pass"

res, _ := rek.Get(fmt.Sprintf("https://httpbin.org/basic-auth/%s/%s", username, password),
    rek.BasicAuth(username, password))

fmt.Println(res.StatusCode()) // 200

res, _ := rek.Get(fmt.Sprintf("https://httpbin.org/basic-auth/%s/other", username, password),
    rek.BasicAuth(username, password))

fmt.Println(res.StatusCode()) // 401

Data

Takes any input and serializes it to a []byte:

data := map[string]interface{
    "age": 38,
    "name": "Luc",
}

res, err := rek.Post("https://httpbin.org/post", rek.Data(data))

Request headers are automatically updated to include Content-Type as application/octet-stream.

User agent

res, err := rek.Post("https://httpbin.org/post", rek.UserAgent("ThisGuy"))

Bearer (useful for JSON Web Tokens)

token := "... token ..."

res, err := rek.Post("https://httpbin.org/post", rek.Bearer(token))

Request modifier

Supply a function that modifies the *http.Request (after all other supplied options have been applied to the request):

modifier := func(r *http.Request) {
   // Do whatever you want with the request
}

res, err := rek.Get("https://httpbin.org/get", rek.RequestModifier(modifier))

Accept

Apply an Accept header to the request:

res, err := rek.Get("https://httpbin.org/get", rek.Accept("application/tar+gzip"))

API key

Add an API key to the request as an Authorization header (where the value is Basic ${KEY}):

res, err := rek.Get("https://some-secure-api.io", rek.ApiKey("a1b2c3..."))

Context

Supply a Context to the request:

ctx, cancel := context.WithCancel(context.Background())

res, err := rek.Get("https://long-winded-api.io", rek.Context(ctx))

// Ugh, I don't want this request to happen anymore

cancel()

OAuth2

You can add an OAuth2 configuration and token to your request:

conf := &oauth2.Config{
	ClientID:     "YOUR_CLIENT_ID",
	ClientSecret: "YOUR_CLIENT_SECRET",
	Scopes:       []string{"SCOPE1", "SCOPE2"},
	Endpoint: oauth2.Endpoint{
		AuthURL:  "https://provider.com/o/oauth2/auth",
		TokenURL: "https://provider.com/o/oauth2/token",
	},
}

tok, err := conf.Exchange(ctx, code)
// handle error

res, err := rek.Get("https://oauth2-protected-site.com", rek.OAuth2(conf, tok))

Custom client

You can pass in your own *http.Client as the basis for the request:

client := &http.Client{
    // Custom attributes
}

res, err := rek.Get("https://httpbin.org/get", rek.Client(client))

Validation

It's important to bear in mind that rek provides no validation for the options that you provide on a specific request and doesn't provide any constraints on which options can be used with which request method. Some options may not make sense for some methods, e.g. request JSON on a HEAD request, but I leave it up to the end user to supply their own constraints. One exception is that the request body can only be set once. If you attempt to set it more than once you'll get a ErrRequestBodySetMultipleTimes error. This, for example, will throw that error:

comment := Comment{Body: "This movie sucked"}

_, err := rek.Post("https://httpbin.org/post",
    rek.Json(comment),
    rek.FormData(map[string]string{"foo": "bar"}))

fmt.Println(errors.Is(err, rek.ErrRequestBodySetMultipleTimes)) // true