Simple HTTP and REST client library for Go (inspired by Ruby rest-client)
Features section describes in detail about Resty capabilities
- v2.3.0 released and tagged on May 20, 2020.
- v2.0.0 released and tagged on Jul 16, 2019.
- v1.12.0 released and tagged on Feb 27, 2019.
- v1.0 released and tagged on Sep 25, 2017. - Resty's first version was released on Sep 15, 2015 then it grew gradually as a very handy and helpful library. Its been a two years since first release. I'm very thankful to Resty users and its contributors.
- GET, POST, PUT, DELETE, HEAD, PATCH, OPTIONS, etc.
- Simple and chainable methods for settings and request
- Request Body can be
string
,[]byte
,struct
,map
,slice
andio.Reader
too- Auto detects
Content-Type
- Buffer less processing for
io.Reader
- Request Body can be read multiple times via
Request.RawRequest.GetBody()
- Auto detects
- Response object gives you more possibility
- Access as
[]byte
array -response.Body()
OR Access asstring
-response.String()
- Know your
response.Time()
and when weresponse.ReceivedAt()
- Access as
- Automatic marshal and unmarshal for
JSON
andXML
content type- Default is
JSON
, if you supplystruct/map
without headerContent-Type
- For auto-unmarshal, refer to -
- Success scenario Request.SetResult() and Response.Result().
- Error scenario Request.SetError() and Response.Error().
- Supports RFC7807 -
application/problem+json
&application/problem+xml
- Default is
- Easy to upload one or more file(s) via
multipart/form-data
- Auto detects file content type
- Request URL Path Params (aka URI Params)
- Backoff Retry Mechanism with retry condition function reference
- Resty client HTTP & REST Request and Response middlewares
Request.SetContext
supported- Authorization option of
BasicAuth
andBearer
token - Set request
ContentLength
value for all request or particular request - Custom Root Certificates and Client Certificates
- Download/Save HTTP response directly into File, like
curl -o
flag. See SetOutputDirectory & SetOutput. - Cookies for your request and CookieJar support
- SRV Record based request instead of Host URL
- Client settings like
Timeout
,RedirectPolicy
,Proxy
,TLSClientConfig
,Transport
, etc. - Optionally allows GET request with payload, see SetAllowGetMethodPayload
- Supports registering external JSON library into resty, see how to use
- Exposes Response reader without reading response (no auto-unmarshaling) if need be, see how to use
- Option to specify expected
Content-Type
when responseContent-Type
header missing. Refer to #92 - Resty design
- Have client level settings & options and also override at Request level if you want to
- Request and Response middlewares
- Create Multiple clients if you want to
resty.New()
- Supports
http.RoundTripper
implementation, see SetTransport - goroutine concurrent safe
- Resty Client trace, see Client.EnableTrace and Request.EnableTrace
- Debug mode - clean and informative logging presentation
- Gzip - Go does it automatically also resty has fallback handling too
- Works fine with
HTTP/2
andHTTP/1.1
- Bazel support
- Easily mock Resty for testing, for e.g.
- Well tested client library
- Redirect Policies - see how to use
- NoRedirectPolicy
- FlexibleRedirectPolicy
- DomainCheckRedirectPolicy
- etc. more info
- Retry Mechanism how to use
- Backoff Retry
- Conditional Retry
- SRV Record based request instead of Host URL how to use
- etc (upcoming - throw your idea's here).
Initially Resty started supporting go modules
since v1.10.0
release.
Starting Resty v2 and higher versions, it fully embraces go modules package release. It requires a Go version capable of understanding /vN
suffixed imports:
- 1.9.7+
- 1.10.3+
- 1.11+
Resty author also published following projects for Go Community.
- aah framework - A secure, flexible, rapid Go web framework.
- THUMBAI - Go Mod Repository, Go Vanity Service and Simple Proxy Server.
- go-model - Robust & Easy to use model mapper and utility methods for Go
struct
.
# Go Modules
require github.com/go-resty/resty/v2 v2.3.0
The following samples will assist you to become as comfortable as possible with resty library.
// Import resty into your code and refer it as `resty`.
import "github.com/go-resty/resty/v2"
// Create a Resty Client
client := resty.New()
resp, err := client.R().
EnableTrace().
Get("https://httpbin.org/get")
// Explore response object
fmt.Println("Response Info:")
fmt.Println("Error :", err)
fmt.Println("Status Code:", resp.StatusCode())
fmt.Println("Status :", resp.Status())
fmt.Println("Proto :", resp.Proto())
fmt.Println("Time :", resp.Time())
fmt.Println("Received At:", resp.ReceivedAt())
fmt.Println("Body :\n", resp)
fmt.Println()
// Explore trace info
fmt.Println("Request Trace Info:")
ti := resp.Request.TraceInfo()
fmt.Println("DNSLookup :", ti.DNSLookup)
fmt.Println("ConnTime :", ti.ConnTime)
fmt.Println("TCPConnTime :", ti.TCPConnTime)
fmt.Println("TLSHandshake :", ti.TLSHandshake)
fmt.Println("ServerTime :", ti.ServerTime)
fmt.Println("ResponseTime :", ti.ResponseTime)
fmt.Println("TotalTime :", ti.TotalTime)
fmt.Println("IsConnReused :", ti.IsConnReused)
fmt.Println("IsConnWasIdle:", ti.IsConnWasIdle)
fmt.Println("ConnIdleTime :", ti.ConnIdleTime)
/* Output
Response Info:
Error : <nil>
Status Code: 200
Status : 200 OK
Proto : HTTP/2.0
Time : 475.611189ms
Received At: 2020-05-19 00:11:06.828188 -0700 PDT m=+0.476510773
Body :
{
"args": {},
"headers": {
"Accept-Encoding": "gzip",
"Host": "httpbin.org",
"User-Agent": "go-resty/2.3.0 (https://github.com/go-resty/resty)"
},
"origin": "0.0.0.0",
"url": "https://httpbin.org/get"
}
Request Trace Info:
DNSLookup : 4.870246ms
ConnTime : 393.95373ms
TCPConnTime : 78.360432ms
TLSHandshake : 310.032859ms
ServerTime : 81.648284ms
ResponseTime : 124.266µs
TotalTime : 475.611189ms
IsConnReused : false
IsConnWasIdle: false
ConnIdleTime : 0s
*/
// Create a Resty Client
client := resty.New()
resp, err := client.R().
SetQueryParams(map[string]string{
"page_no": "1",
"limit": "20",
"sort":"name",
"order": "asc",
"random":strconv.FormatInt(time.Now().Unix(), 10),
}).
SetHeader("Accept", "application/json").
SetAuthToken("BC594900518B4F7EAC75BD37F019E08FBC594900518B4F7EAC75BD37F019E08F").
Get("/search_result")
// Sample of using Request.SetQueryString method
resp, err := client.R().
SetQueryString("productId=232&template=fresh-sample&cat=resty&source=google&kw=buy a lot more").
SetHeader("Accept", "application/json").
SetAuthToken("BC594900518B4F7EAC75BD37F019E08FBC594900518B4F7EAC75BD37F019E08F").
Get("/show_product")
// Create a Resty Client
client := resty.New()
// POST JSON string
// No need to set content type, if you have client level setting
resp, err := client.R().
SetHeader("Content-Type", "application/json").
SetBody(`{"username":"testuser", "password":"testpass"}`).
SetResult(&AuthSuccess{}). // or SetResult(AuthSuccess{}).
Post("https://myapp.com/login")
// POST []byte array
// No need to set content type, if you have client level setting
resp, err := client.R().
SetHeader("Content-Type", "application/json").
SetBody([]byte(`{"username":"testuser", "password":"testpass"}`)).
SetResult(&AuthSuccess{}). // or SetResult(AuthSuccess{}).
Post("https://myapp.com/login")
// POST Struct, default is JSON content type. No need to set one
resp, err := client.R().
SetBody(User{Username: "testuser", Password: "testpass"}).
SetResult(&AuthSuccess{}). // or SetResult(AuthSuccess{}).
SetError(&AuthError{}). // or SetError(AuthError{}).
Post("https://myapp.com/login")
// POST Map, default is JSON content type. No need to set one
resp, err := client.R().
SetBody(map[string]interface{}{"username": "testuser", "password": "testpass"}).
SetResult(&AuthSuccess{}). // or SetResult(AuthSuccess{}).
SetError(&AuthError{}). // or SetError(AuthError{}).
Post("https://myapp.com/login")
// POST of raw bytes for file upload. For example: upload file to Dropbox
fileBytes, _ := ioutil.ReadFile("/Users/jeeva/mydocument.pdf")
// See we are not setting content-type header, since go-resty automatically detects Content-Type for you
resp, err := client.R().
SetBody(fileBytes).
SetContentLength(true). // Dropbox expects this value
SetAuthToken("<your-auth-token>").
SetError(&DropboxError{}). // or SetError(DropboxError{}).
Post("https://content.dropboxapi.com/1/files_put/auto/resty/mydocument.pdf") // for upload Dropbox supports PUT too
// Note: resty detects Content-Type for request body/payload if content type header is not set.
// * For struct and map data type defaults to 'application/json'
// * Fallback is plain text content type
You can use various combinations of PUT
method call like demonstrated for POST
.
// Note: This is one sample of PUT method usage, refer POST for more combination
// Create a Resty Client
client := resty.New()
// Request goes as JSON content type
// No need to set auth token, error, if you have client level settings
resp, err := client.R().
SetBody(Article{
Title: "go-resty",
Content: "This is my article content, oh ya!",
Author: "Jeevanandam M",
Tags: []string{"article", "sample", "resty"},
}).
SetAuthToken("C6A79608-782F-4ED0-A11D-BD82FAD829CD").
SetError(&Error{}). // or SetError(Error{}).
Put("https://myapp.com/article/1234")
You can use various combinations of PATCH
method call like demonstrated for POST
.
// Note: This is one sample of PUT method usage, refer POST for more combination
// Create a Resty Client
client := resty.New()
// Request goes as JSON content type
// No need to set auth token, error, if you have client level settings
resp, err := client.R().
SetBody(Article{
Tags: []string{"new tag1", "new tag2"},
}).
SetAuthToken("C6A79608-782F-4ED0-A11D-BD82FAD829CD").
SetError(&Error{}). // or SetError(Error{}).
Patch("https://myapp.com/articles/1234")
// Create a Resty Client
client := resty.New()
// DELETE a article
// No need to set auth token, error, if you have client level settings
resp, err := client.R().
SetAuthToken("C6A79608-782F-4ED0-A11D-BD82FAD829CD").
SetError(&Error{}). // or SetError(Error{}).
Delete("https://myapp.com/articles/1234")
// DELETE a articles with payload/body as a JSON string
// No need to set auth token, error, if you have client level settings
resp, err := client.R().
SetAuthToken("C6A79608-782F-4ED0-A11D-BD82FAD829CD").
SetError(&Error{}). // or SetError(Error{}).
SetHeader("Content-Type", "application/json").
SetBody(`{article_ids: [1002, 1006, 1007, 87683, 45432] }`).
Delete("https://myapp.com/articles")
// HEAD of resource
// No need to set auth token, if you have client level settings
resp, err := client.R().
SetAuthToken("C6A79608-782F-4ED0-A11D-BD82FAD829CD").
Head("https://myapp.com/videos/hi-res-video")
// OPTIONS of resource
// No need to set auth token, if you have client level settings
resp, err := client.R().
SetAuthToken("C6A79608-782F-4ED0-A11D-BD82FAD829CD").
Options("https://myapp.com/servers/nyc-dc-01")
profileImgBytes, _ := ioutil.ReadFile("/Users/jeeva/test-img.png")
notesBytes, _ := ioutil.ReadFile("/Users/jeeva/text-file.txt")
// Create a Resty Client
client := resty.New()
resp, err := client.R().
SetFileReader("profile_img", "test-img.png", bytes.NewReader(profileImgBytes)).
SetFileReader("notes", "text-file.txt", bytes.NewReader(notesBytes)).
SetFormData(map[string]string{
"first_name": "Jeevanandam",
"last_name": "M",
}).
Post("http://myapp.com/upload")
// Create a Resty Client
client := resty.New()
// Single file scenario
resp, err := client.R().
SetFile("profile_img", "/Users/jeeva/test-img.png").
Post("http://myapp.com/upload")
// Multiple files scenario
resp, err := client.R().
SetFiles(map[string]string{
"profile_img": "/Users/jeeva/test-img.png",
"notes": "/Users/jeeva/text-file.txt",
}).
Post("http://myapp.com/upload")
// Multipart of form fields and files
resp, err := client.R().
SetFiles(map[string]string{
"profile_img": "/Users/jeeva/test-img.png",
"notes": "/Users/jeeva/text-file.txt",
}).
SetFormData(map[string]string{
"first_name": "Jeevanandam",
"last_name": "M",
"zip_code": "00001",
"city": "my city",
"access_token": "C6A79608-782F-4ED0-A11D-BD82FAD829CD",
}).
Post("http://myapp.com/profile")
// Create a Resty Client
client := resty.New()
// just mentioning about POST as an example with simple flow
// User Login
resp, err := client.R().
SetFormData(map[string]string{
"username": "jeeva",
"password": "mypass",
}).
Post("http://myapp.com/login")
// Followed by profile update
resp, err := client.R().
SetFormData(map[string]string{
"first_name": "Jeevanandam",
"last_name": "M",
"zip_code": "00001",
"city": "new city update",
}).
Post("http://myapp.com/profile")
// Multi value form data
criteria := url.Values{
"search_criteria": []string{"book", "glass", "pencil"},
}
resp, err := client.R().
SetFormDataFromValues(criteria).
Post("http://myapp.com/search")
// Create a Resty Client
client := resty.New()
// Setting output directory path, If directory not exists then resty creates one!
// This is optional one, if you're planning using absoule path in
// `Request.SetOutput` and can used together.
client.SetOutputDirectory("/Users/jeeva/Downloads")
// HTTP response gets saved into file, similar to curl -o flag
_, err := client.R().
SetOutput("plugin/ReplyWithHeader-v5.1-beta.zip").
Get("http://bit.ly/1LouEKr")
// OR using absolute path
// Note: output directory path is not used for absolute path
_, err := client.R().
SetOutput("/MyDownloads/plugin/ReplyWithHeader-v5.1-beta.zip").
Get("http://bit.ly/1LouEKr")
Resty provides easy to use dynamic request URL path params. Params can be set at client and request level. Client level params value can be overridden at request level.
// Create a Resty Client
client := resty.New()
client.R().SetPathParams(map[string]string{
"userId": "[email protected]",
"subAccountId": "100002",
}).
Get("/v1/users/{userId}/{subAccountId}/details")
// Result:
// Composed URL - /v1/users/[email protected]/100002/details
Resty provides middleware ability to manipulate for Request and Response. It is more flexible than callback approach.
// Create a Resty Client
client := resty.New()
// Registering Request Middleware
client.OnBeforeRequest(func(c *resty.Client, req *resty.Request) error {
// Now you have access to Client and current Request object
// manipulate it as per your need
return nil // if its success otherwise return error
})
// Registering Response Middleware
client.OnAfterResponse(func(c *resty.Client, resp *resty.Response) error {
// Now you have access to Client and current Response object
// manipulate it as per your need
return nil // if its success otherwise return error
})
Resty provides few ready to use redirect policy(s) also it supports multiple policies together.
// Create a Resty Client
client := resty.New()
// Assign Client Redirect Policy. Create one as per you need
client.SetRedirectPolicy(resty.FlexibleRedirectPolicy(15))
// Wanna multiple policies such as redirect count, domain name check, etc
client.SetRedirectPolicy(resty.FlexibleRedirectPolicy(20),
resty.DomainCheckRedirectPolicy("host1.com", "host2.org", "host3.net"))
Implement RedirectPolicy interface and register it with resty client. Have a look redirect.go for more information.
// Create a Resty Client
client := resty.New()
// Using raw func into resty.SetRedirectPolicy
client.SetRedirectPolicy(resty.RedirectPolicyFunc(func(req *http.Request, via []*http.Request) error {
// Implement your logic here
// return nil for continue redirect otherwise return error to stop/prevent redirect
return nil
}))
//---------------------------------------------------
// Using struct create more flexible redirect policy
type CustomRedirectPolicy struct {
// variables goes here
}
func (c *CustomRedirectPolicy) Apply(req *http.Request, via []*http.Request) error {
// Implement your logic here
// return nil for continue redirect otherwise return error to stop/prevent redirect
return nil
}
// Registering in resty
client.SetRedirectPolicy(CustomRedirectPolicy{/* initialize variables */})
// Create a Resty Client
client := resty.New()
// Custom Root certificates, just supply .pem file.
// you can add one or more root certificates, its get appended
client.SetRootCertificate("/path/to/root/pemFile1.pem")
client.SetRootCertificate("/path/to/root/pemFile2.pem")
// ... and so on!
// Adding Client Certificates, you add one or more certificates
// Sample for creating certificate object
// Parsing public/private key pair from a pair of files. The files must contain PEM encoded data.
cert1, err := tls.LoadX509KeyPair("certs/client.pem", "certs/client.key")
if err != nil {
log.Fatalf("ERROR client certificate: %s", err)
}
// ...
// You add one or more certificates
client.SetCertificates(cert1, cert2, cert3)
// Custom Root certificates from string
// You can pass you certificates throught env variables as strings
// you can add one or more root certificates, its get appended
client.SetRootCertificateFromString("-----BEGIN CERTIFICATE-----content-----END CERTIFICATE-----")
client.SetRootCertificateFromString("-----BEGIN CERTIFICATE-----content-----END CERTIFICATE-----")
// ... and so on!
// Adding Client Certificates, you add one or more certificates
// Sample for creating certificate object
// Parsing public/private key pair from a pair of files. The files must contain PEM encoded data.
cert1, err := tls.X509KeyPair([]byte("-----BEGIN CERTIFICATE-----content-----END CERTIFICATE-----"), []byte("-----BEGIN CERTIFICATE-----content-----END CERTIFICATE-----"))
if err != nil {
log.Fatalf("ERROR client certificate: %s", err)
}
// ...
// You add one or more certificates
client.SetCertificates(cert1, cert2, cert3)
Default Go
supports Proxy via environment variable HTTP_PROXY
. Resty provides support via SetProxy
& RemoveProxy
.
Choose as per your need.
Client Level Proxy settings applied to all the request
// Create a Resty Client
client := resty.New()
// Setting a Proxy URL and Port
client.SetProxy("http://proxyserver:8888")
// Want to remove proxy setting
client.RemoveProxy()
Resty uses backoff to increase retry intervals after each attempt.
Usage example:
// Create a Resty Client
client := resty.New()
// Retries are configured per client
client.
// Set retry count to non zero to enable retries
SetRetryCount(3).
// You can override initial retry wait time.
// Default is 100 milliseconds.
SetRetryWaitTime(5 * time.Second).
// MaxWaitTime can be overridden as well.
// Default is 2 seconds.
SetRetryMaxWaitTime(20 * time.Second).
// SetRetryAfter sets callback to calculate wait time between retries.
// Default (nil) implies exponential backoff with jitter
SetRetryAfter(func(client *Client, resp *Response) (time.Duration, error) {
return 0, errors.New("quota exceeded")
})
Above setup will result in resty retrying requests returned non nil error up to 3 times with delay increased after each attempt.
You can optionally provide client with custom retry conditions:
// Create a Resty Client
client := resty.New()
client.AddRetryCondition(
// RetryConditionFunc type is for retry condition function
// input: non-nil Response OR request execution error
func(r *resty.Response, err error) bool {
return r.StatusCode() == http.StatusTooManyRequests
},
)
Above example will make resty retry requests ended with 429 Too Many Requests
status code.
Multiple retry conditions can be added.
It is also possible to use resty.Backoff(...)
to get arbitrary retry scenarios
implemented. Reference.
// Create a Resty Client
client := resty.New()
// Allow GET request with Payload. This is disabled by default.
client.SetAllowGetMethodPayload(true)
// Here you go!
// Client 1
client1 := resty.New()
client1.R().Get("http://httpbin.org")
// ...
// Client 2
client2 := resty.New()
client2.R().Head("http://httpbin.org")
// ...
// Bend it as per your need!!!
// Create a Resty Client
client := resty.New()
// Unique settings at Client level
//--------------------------------
// Enable debug mode
client.SetDebug(true)
// Assign Client TLSClientConfig
// One can set custom root-certificate. Refer: http://golang.org/pkg/crypto/tls/#example_Dial
client.SetTLSClientConfig(&tls.Config{ RootCAs: roots })
// or One can disable security check (https)
client.SetTLSClientConfig(&tls.Config{ InsecureSkipVerify: true })
// Set client timeout as per your need
client.SetTimeout(1 * time.Minute)
// You can override all below settings and options at request level if you want to
//--------------------------------------------------------------------------------
// Host URL for all request. So you can use relative URL in the request
client.SetHostURL("http://httpbin.org")
// Headers for all request
client.SetHeader("Accept", "application/json")
client.SetHeaders(map[string]string{
"Content-Type": "application/json",
"User-Agent": "My custom User Agent String",
})
// Cookies for all request
client.SetCookie(&http.Cookie{
Name:"go-resty",
Value:"This is cookie value",
Path: "/",
Domain: "sample.com",
MaxAge: 36000,
HttpOnly: true,
Secure: false,
})
client.SetCookies(cookies)
// URL query parameters for all request
client.SetQueryParam("user_id", "00001")
client.SetQueryParams(map[string]string{ // sample of those who use this manner
"api_key": "api-key-here",
"api_secert": "api-secert",
})
client.R().SetQueryString("productId=232&template=fresh-sample&cat=resty&source=google&kw=buy a lot more")
// Form data for all request. Typically used with POST and PUT
client.SetFormData(map[string]string{
"access_token": "BC594900-518B-4F7E-AC75-BD37F019E08F",
})
// Basic Auth for all request
client.SetBasicAuth("myuser", "mypass")
// Bearer Auth Token for all request
client.SetAuthToken("BC594900518B4F7EAC75BD37F019E08FBC594900518B4F7EAC75BD37F019E08F")
// Enabling Content length value for all request
client.SetContentLength(true)
// Registering global Error object structure for JSON/XML request
client.SetError(&Error{}) // or resty.SetError(Error{})
unixSocket := "/var/run/my_socket.sock"
// Create a Go's http.Transport so we can set it in resty.
transport := http.Transport{
Dial: func(_, _ string) (net.Conn, error) {
return net.Dial("unix", unixSocket)
},
}
// Create a Resty Client
client := resty.New()
// Set the previous transport that we created, set the scheme of the communication to the
// socket and set the unixSocket as the HostURL.
client.SetTransport(&transport).SetScheme("http").SetHostURL(unixSocket)
// No need to write the host's URL on the request, just the path.
client.R().Get("/index.html")
Resty can be built, tested and depended upon via Bazel. For example, to run all tests:
bazel test :go_default_test
Mocking http requests using httpmock library
In order to mock the http requests when testing your application you
could use the httpmock
library.
When using the default resty client, you should pass the client to the library as follow:
// Create a Resty Client
client := resty.New()
// Get the underlying HTTP Client and set it to Mock
httpmock.ActivateNonDefault(client.GetClient())
More detailed example of mocking resty http requests using ginko could be found here.
Resty releases versions according to Semantic Versioning
- Resty v2 does not use
gopkg.in
service for library versioning. - Resty fully adapted to
go mod
capabilities sincev1.10.0
release. - Resty v1 series was using
gopkg.in
to provide versioning.gopkg.in/resty.vX
points to appropriate tagged versions;X
denotes version series number and it's a stable release for production use. For e.g.gopkg.in/resty.v0
. - Development takes place at the master branch. Although the code in master should always compile and test successfully, it might break API's. I aim to maintain backwards compatibility, but sometimes API's and behavior might be changed to fix a bug.
I would welcome your contribution! If you find any improvement or issue you want to fix, feel free to send a pull request, I like pull requests that include test cases for fix/enhancement. I have done my best to bring pretty good code coverage. Feel free to write tests.
BTW, I'd like to know what you think about Resty
. Kindly open an issue or send me an email; it'd mean a lot to me.
Jeevanandam M. ([email protected])
Have a look on Members page.
Have a look on Contributors page.
Resty released under MIT license, refer LICENSE file.