I am trying to pass an additional parameter in the request I am trying to send to the Go server -
websocket.create_connection("ws://<ip>:port/x/y?token="qwerty")
The Go server implementation is as follows -
func main() {
err := config.Parse()
if err != nil {
glog.Error(err)
os.Exit(1)
return
}
flag.Parse()
defer glog.Flush()
router := mux.NewRouter()
http.Handle("/", httpInterceptor(router))
router.Handle("/v1/x", common.ErrorHandler(stats.GetS)).Methods("GET")
router.Handle("/v1/x/y", common.ErrorHandler(stats.GetS)).Methods("GET")
var listen = fmt.Sprintf("%s:%d", config.Config.Ip, config.Config.Port)
err = http.ListenAndServe(listen, nil)
if err != nil {
glog.Error(err)
os.Exit(1)
}
}
func httpInterceptor(router http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
startTime := time.Now()
if !auth.Auth(w, req) {
http.Error(w, "Failed authentication", 401)
return
}
router.ServeHTTP(w, req)
finishTime := time.Now()
elapsedTime := finishTime.Sub(startTime)
switch req.Method {
case "GET":
case "POST":
}
})
}
How should I look and parse for the token in the Go server so that the authentication is successful?
Library function
func ParseFromRequest(req *http.Request, keyFunc Keyfunc) (token *Token, err error) {
// Look for an Authorization header
if ah := req.Header.Get("Authorization"); ah != "" {
// Should be a bearer token
if len(ah) > 6 && strings.ToUpper(ah[0:6]) == "BEARER" {
return Parse(ah[7:], keyFunc)
}
}
// Look for "access_token" parameter
req.ParseMultipartForm(10e6)
if tokStr := req.Form.Get("access_token"); tokStr != "" {
return Parse(tokStr, keyFunc)
}
return nil, ErrNoTokenInRequest
}
Call FormValue to get a query parameter:
token := req.FormValue("token")
req is a the *http.Request
An alternative is to call ParseForm and access req.Form directly:
if err := req.ParseForm(); err != nil {
// handle error
}
token := req.Form.Get("token")
The OP asks in a comment how to map "token" to "access_token" for an external package that's looking "access_token". Execute this code before calling the external package:
if err := req.ParseForm(); err != nil {
// handle error
}
req.Form["access_token"] = req.Form["token"]
When the external package calls req.Form.Get("access_token"), it will get the same value as the "token" parameter.
Depending on the way you want to parse the token , if its coming from the form or the URL.
The first answer can be used if the token is being sent from the form while in case of a URL, I would suggest using this. This works for me
token := req.URL.Query().Get("token")
For url query parameters:
mux.Vars(r)["token"]
Related
I have the following simple http.Client:
import (
"net/http"
"log"
)
...
func main() {
...
link = "http://example.com"
method = "GET"
req, _ := http.NewRequest(method, link, nil)
client := &http.Client{}
myZapLogger.Info("Sending a %s request to %s\n", method, link)
resp, err := client.Do(req)
if err != nil {
myZapLogger.Error(..., err) // I'm logging rather than fatal-ing or so
} else {
myZapLogger.Info("Received a %d on request X", resp.StatusCode)
}
...
}
...
I was looking for a way to do the above for each request through a hook (or so), so that it's triggered automatically each time. I can write a function the encloses all that, but in a case where I'm passing an http client to some other package, I wouldn't be able to control/log such requests that way (e.g. aws-go-sdk).
Is there a way to do this through contexts or attaching hooks to the client?
Thanks
eudore's comment answers the question; I'll just put it into code:
type MyRoundTripper struct {}
func (t MyRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
// Do work before the request is sent
resp, err := http.DefaultTransport.RoundTrip(req)
if err != nil {
return resp, err
}
// Do work after the response is received
return resp, err
}
To use it, you'll just pass it to your HTTP Client:
rt := MyRoundTripper{}
client := http.Client{Transport: rt}
I am writing an API whichs has to redirect incoming requests to another service, the response must be forwarded to the original requester.
I figured a simple function like below should do the trick, but I was wrong.
I receive the data from my redirected response, however when I send it back to the initial request I receive this response without any data Could not get response. Error: socket hang up
If I try to execute the very same request using postman straight to the redirect URL it works perfectly fine.
func initialAssetsHandler(w http.ResponseWriter, r *http.Request) {
body, err := ioutil.ReadAll(r.Body)
if err != nil {
fmt.Println(err)
return
}
resp, err := http.Post(conf.redirectURL, "application/json", bytes.NewReader(body))
if err != nil {
log.Error(err)
}
defer resp.Body.Close()
buf := new(bytes.Buffer)
buf.ReadFrom(resp.Body)
log.Info(string(buf.Bytes()))
var data json.RawMessage
if err = json.NewDecoder(resp.Body).Decode(&data); err != nil {
fmt.Println(err)
return
}
helper.SendJsonRaw(w, 200, data)
}
Here is the SendJsonRaw function:
func SendJsonRaw(w http.ResponseWriter, status int, r json.RawMessage) error {
w.Header().Set(HeaderContentType, MimeApplicationJSON)
w.WriteHeader(status)
_, err := w.Write(r)
return err
}
The r.Body is read by the json decoder up to EOF, then when you pass it to the redirect request it looks empty to the http.Client and therefore it sends no body. You need to retain the content of the body.
For example you can do the following:
func initialAssetsHandler(w http.ResponseWriter, r *http.Request) {
body, err := ioutil.ReadAll(r.Body)
if err != nil {
fmt.Println(err)
return
}
var initialAssets TagAssets
if err := json.Unmarshal(&initialAssets, body); err != nil {
if !strings.Contains(err.Error(), "json: invalid use of ,string struct tag, trying to unmarshal") {
helper.SendJsonError(w, http.StatusBadRequest, err)
return
}
}
resp, err := http.Post(conf.redirectURL, "application/json", bytes.NewReader(body))
if err != nil {
log.Error(err)
}
defer resp.Body.Close()
log.Info(resp)
var data json.RawMessage
if err := json.NewDecoder(resp.Body).Decode(&data); err != nil {
fmt.Println(err)
return
}
helper.SendJsonOk(w, data)
}
I am trying to get the parameters made in a POST request, but I am not able to make it, my code is:
package main
import (
"fmt"
"log"
"net/http"
)
func main() {
http.HandleFunc("/", hello)
fmt.Printf("Starting server for testing HTTP POST...\n")
if err := http.ListenAndServe(":8080", nil); err != nil {
log.Fatal(err)
}
}
func hello(w http.ResponseWriter, r *http.Request) {
if r.URL.Path != "/" {
http.Error(w, "404 not found.", http.StatusNotFound)
return
}
switch r.Method {
case "POST":
// Call ParseForm() to parse the raw query and update r.PostForm and r.Form.
if err := r.ParseForm(); err != nil {
fmt.Fprintf(w, "ParseForm() err: %v", err)
return
}
name := r.Form.Get("name")
age := r.Form.Get("age")
fmt.Print("This have been received:")
fmt.Print("name: ", name)
fmt.Print("age: ", age)
default:
fmt.Fprintf(w, "Sorry, only POST methods are supported.")
}
}
I am making the POST request in the terminal as follows:
curl -X POST -d '{"name":"Alex","age":"50"}' localhost:8080
And then the output is:
This have been received:name: age:
Why it is not taking the parameters? What I am doing wrong?
As you pass your body as a json object, you better define a Go struct matching that object and decode the request body to the object.
type Info struct {
Name string
Age int
}
info := &Info{}
if err := json.NewDecoder(r.Body).Decode(info); err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
_ = json.NewEncoder(w).Encode(info)
You can find the whole working code here.
$ curl -X POST -d '{"name":"Alex","age":50}' localhost:8080
This POST request is working fine now.
You could modify the Go struct and also the response object as you like .
I'm working on some tests in Go and I have spent the past 2 days trying to make it work but I couldn't. My problem is that the test returns 400 even when the user does exist.
This is my getUser function
func (handler *UserHandler) getUser(w http.ResponseWriter, ID int) {
logfile, err := os.OpenFile("events.log", os.O_RDWR|os.O_CREATE|os.O_APPEND, 0666)
if err != nil {
log.Fatalf("Error opening file: %v", err)
}
defer logfile.Close()
log.SetOutput(logfile)
user := db.Fetch(ID)
userJSON, err := json.Marshal(user)
if err != nil {
log.Printf("Error while marshaling the user into JSON: %v", err)
return
}
w.Header().Set("Content-Type", "application/json")
w.WriteHeader(http.StatusOK)
// userJSON is sent as http Response
w.Write(userJSON)
}
This is my UserHandler
type UserHandler struct{}
func (handle *UserHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
var head string
head, r.URL.Path = ShiftPath(r.URL.Path)
id, err := strconv.Atoi(head)
if err != nil {
http.Error(w, fmt.Sprintf("Invalid user ID %q", head), http.StatusBadRequest)
return
}
switch r.Method {
case "GET":
handle.getUser(w, id)
default:
http.Error(w, "Only GET is allowed", http.StatusMethodNotAllowed)
}
}
func ShiftPath(p string) (head, tail string) {
p = path.Clean("/" + p)
i := strings.Index(p[1:], "/") + 1
if i <= 0 {
return p[1:], "/"
}
return p[1:i], p[i:]
}
And this is my test
func TestGetUser(t *testing.T) {
handler := new(UserHandler)
mux := http.NewServeMux()
mux.HandleFunc("/user/", handler.ServeHTTP)
writer := httptest.NewRecorder()
request, _ := http.NewRequest("GET", "/user/12", nil)
mux.ServeHTTP(writer, request)
if writer.Code != 200 {
t.Errorf("Response code is %v", writer.Code)
}
}
Issue with code ====> id, err := strconv.Atoi(head)
Due to error you see a return and hence you see 400 error.
Have your server code fully functional with valid logic.
Suggestion: Always print or debug line by line. You can find the issue and root cause.
Go version: go1.8.1 windows/amd64
Sample code for HTTP request is:
func (c *Client) RoundTripSoap12(action string, in, out Message) error {
fmt.Println("****************************************************************")
headerFunc := func(r *http.Request) {
r.Header.Add("Content-Type", fmt.Sprintf("text/xml; charset=utf-8"))
r.Header.Add("SOAPAction", fmt.Sprintf(action))
r.Cookies()
}
return doRoundTrip(c, headerFunc, in, out)
}
func doRoundTrip(c *Client, setHeaders func(*http.Request), in, out Message) error {
req := &Envelope{
EnvelopeAttr: c.Envelope,
NSAttr: c.Namespace,
Header: c.Header,
Body: Body{Message: in},
}
if req.EnvelopeAttr == "" {
req.EnvelopeAttr = "http://schemas.xmlsoap.org/soap/envelope/"
}
if req.NSAttr == "" {
req.NSAttr = c.URL
}
var b bytes.Buffer
err := xml.NewEncoder(&b).Encode(req)
if err != nil {
return err
}
cli := c.Config
if cli == nil {
cli = http.DefaultClient
}
r, err := http.NewRequest("POST", c.URL, &b)
if err != nil {
return err
}
setHeaders(r)
if c.Pre != nil {
c.Pre(r)
}
fmt.Println("*************", r)
resp, err := cli.Do(r)
if err != nil {
fmt.Println("error occured is as follows ", err)
return err
}
fmt.Println("response headers are: ", resp.Header.Get("sprequestguid"))
defer resp.Body.Close()
if resp.StatusCode != http.StatusOK {
// read only the first Mb of the body in error case
limReader := io.LimitReader(resp.Body, 1024*1024)
body, _ := ioutil.ReadAll(limReader)
return fmt.Errorf("%q: %q", resp.Status, body)
}
return xml.NewDecoder(resp.Body).Decode(out)
I will call the RoundTripSoap12 function on the corresponding HTTP client.
When I send a request for the first time I will be getting some headers in the HTTP response, so these HTTP response headers should be sent as-is in my next HTTP request.
You may be interested in the httputil package and the reverse proxy example provided if you wish to proxy requests transparently:
https://golang.org/src/net/http/httputil/reverseproxy.go
You can copy the headers from one request to another one fairly easily - the Header is a separate object, if r and rc are http.Requests and you don't mind them sharing a header (you may need to clone instead if you want independent requests):
rc.Header = r.Header // note shallow copy
fmt.Println("Headers", r.Header, rc.Header)
https://play.golang.org/p/q2KUHa_qiP
Or you can look through keys and values and only copy certain headers, and/or do a clone instead to ensure you share no memory. See the http util package here for examples of this - see the functions cloneHeader and copyHeader inside reverseproxy.go linked above.