I am working in a Go project, and I need to perform some operations over an external API: GET, PUT, POST and DELETE. Currently I am using net/http, and I created a &http.Client{} to make GET and PUT. That is working as expected.
Now I need to perform a DELETE and I cannot find anything about it. Is it supported? Basically, I need to call a URL like this:
somedomain.com/theresource/:id
Method: DELETE
How can I perform that?
Here is a small example of how to do it:
package main
import (
"fmt"
"io/ioutil"
"net/http"
)
func sendRequest() {
// Request (DELETE http://www.example.com/bucket/sample)
// Create client
client := &http.Client{}
// Create request
req, err := http.NewRequest("DELETE", "http://www.example.com/bucket/sample", nil)
if err != nil {
fmt.Println(err)
return
}
// Fetch Request
resp, err := client.Do(req)
if err != nil {
fmt.Println(err)
return
}
defer resp.Body.Close()
// Read Response Body
respBody, err := ioutil.ReadAll(resp.Body)
if err != nil {
fmt.Println(err)
return
}
// Display Results
fmt.Println("response Status : ", resp.Status)
fmt.Println("response Headers : ", resp.Header)
fmt.Println("response Body : ", string(respBody))
}
Related
I am writing a code in GoLang to get data from a url but when I make http.Get() request, the response I get is as per the following.
"compile_output": "# command-line-arguments\n/usr/local/go-1.13.5/pkg/tool/linux_amd64/link: resize output file failed: truncate $WORK/b001/exe/a.out: file too large\n",
Please suggest me how to tackle this.
Code is as per the following:
import (
"fmt"
"io/ioutil"
"net/http"
)
func main() {
// define the URL to get data from
url := "my_example_url"
// use http.Get() to make a GET request to the URL
resp, err := http.Get(url)
if err != nil {
fmt.Println("Error getting data:", err)
return
}
defer resp.Body.Close()
// read the response body
body, err := ioutil.ReadAll(resp.Body)
if err != nil {
fmt.Println("Error reading response:", err)
return
}
// print the response body
fmt.Println(string(body))
}
I tried reading through GoLang URl Documentations, but didn't help.
I've written a simple Fetch Go function which calls an API, and generates a response.
When called, it successfully logs the data to the console which is pulled from the API.
What I want to do though is take the final 'respBody' variable generated from reading the response body, and then return it back to my frontend client - but I can't figure out how.
All the examples just use Println, and I've searched the docs but can't find anything.
Can anyone tell me how to change my code so I can return the respBody back to the client?
Here's my function:
func Fetch(w http.ResponseWriter, r *http.Request) {
client := &http.Client{}
req, err := http.NewRequest("GET", "https://pro-api.coinmarketcap.com/v1/cryptocurrency/listings/latest", nil)
if err != nil {
log.Print(err)
os.Exit(1)
}
resp, err := client.Do(req)
if err != nil {
fmt.Println("Error sending request to server")
os.Exit(1)
}
respBody, _ := ioutil.ReadAll(resp.Body)
fmt.Println(string(respBody)) // This is the final bit where I want to send this back to the client.
}
Your function is a HandlerFunc, which contains the ResponseWriter interface, in your case it's w.
So, you can write data using http.ResponseWriter:
func Fetch(w http.ResponseWriter, r *http.Request) {
client := &http.Client{}
req, err := http.NewRequest("GET", "https://pro-api.coinmarketcap.com/v1/cryptocurrency/listings/latest", nil)
if err != nil {
log.Print(err)
os.Exit(1)
}
resp, err := client.Do(req)
if err != nil {
fmt.Println("Error sending request to server")
os.Exit(1)
}
respBody, _ := ioutil.ReadAll(resp.Body)
// Here:
w.WriteHeader(resp.StatusCode)
w.Write(respBody)
}
You can use use io.Copy(w, resp.Body) instead, remember to close body using defer resp.Body.Close().
You can simply copy the contents of the response body to the response writer:
io.Copy(w,resp.Body)
Since you can only read the body once, the solution above will not allow you to get the body. If you also want to log it, or process it somehow, you can read it and then write it to the response writer.
respBody, _ := ioutil.ReadAll(resp.Body)
fmt.Println(string(respBody))
w.Write(respBody)
I am trying to implement a python code from the JIRA REST API examples:
https://developer.atlassian.com/cloud/jira/platform/rest/v3/api-group-jql/#api-rest-api-3-jql-parse-post
My python code (which works as expected):
import requests
from requests.auth import HTTPBasicAuth
import json
url = "https://my-url.com/rest/api/2/search"
auth = HTTPBasicAuth("user1", "pwd1")
headers = {
"Accept": "application/json",
"Content-Type": "application/json"
}
payload = json.dumps( {
"jql": "my-query-string"
}
response = requests.request("POST", url, data=payload, headers=headers, auth=auth, verify=False)
print(json.dumps(json.loads(response.text), sort_keys=True, indent=4, separators=(",", ": ")))
I'm trying to transform this to a golang code as below:
package main
import (
"io/ioutil"
"fmt"
"log"
"time"
"net/http"
"net/url"
}
func main() {
timeout := time.Duration(500 * time.Second)
client := http.Client{
Timeout: timeout,
}
req, err := http.NewRequest("POST", "https://my-url.com/rest/api/2/search", nil)
if err != nil {
log.Fatalln(err)
}
req.SetBasicAuth("user1", "pwd1")
req.Header.Set("Content-Type", "application/json")
q := url.Values{}
q.Add("jql", "my-query-string")
req.URL.RawQuery = q.Encode()
fmt.Println(req.URL.String())
resp, err := client.Do(req)
if err != nil {
log.Fatalln(err)
}
defer resp.Body.Close()
data, err := ioutil.ReadAll(resp.Body)
if err != nil {
log.Fatalln(err)
}
log.Println(string(data))
The code builds with no issues. When I run the go code, I get this error:
2021/04/17 19:36:31 {"errorMessages":["No content to map to Object due to end of input"]}
I have 2 questions :
a. How can I fix the above error ?
b. I also want to include concurrency in the same code, i.e the same POST request will actually be executed for 5 different query strings (concurrently) and fetch the results, how can i achieve that ?
For POST requests you need to send the data as json. Note that in Go setting a request's Content-Type header does not automagically convert whatever you give it to the specified type.
An example sending json.
package main
import (
"strings"
"net/http"
"io/ioutil"
"fmt"
)
func main() {
body := strings.NewReader(`{"jql": "project = HSP"}`)
req, err := http.NewRequest("POST", "https://your-domain.atlassian.com/rest/api/2/search", body)
if err != nil {
panic(err)
}
req.SetBasicAuth("email#example.com", "<api_token>")
req.Header.Set("Accept", "application/json")
req.Header.Set("Content-Type", "application/json")
resp, err := http.DefaultClient.Do(req)
if err != nil {
panic(err)
}
defer resp.Body.Close()
out, err := ioutil.ReadAll(resp.Body)
if err != nil {
panic(err)
}
fmt.Println(string(out))
}
If you want to use query parameters you should use the endpoint with the GET method.
package main
import (
"net/http"
"net/url"
"io/ioutil"
"fmt"
)
func main() {
query := url.Values{"jql": {"project = HSP"}}
req, err := http.NewRequest("GET", "https://your-domain.atlassian.com/rest/api/2/search?" + query.Encode(), nil)
if err != nil {
panic(err)
}
req.SetBasicAuth("email#example.com", "<api_token>")
req.Header.Set("Accept", "application/json")
resp, err := http.DefaultClient.Do(req)
if err != nil {
panic(err)
}
defer resp.Body.Close()
out, err := ioutil.ReadAll(resp.Body)
if err != nil {
panic(err)
}
fmt.Println(string(out))
}
Is this not the right way to set POST request body?
data := url.Values{}
data.Set("url", "https://www.google.com/")
client := http.Client{}
r, err := http.NewRequest(http.MethodPost, apiURL, strings.NewReader(data.Encode()))
The code below when executed suggests that no url param was sent in the POST request.
package main
import (
"fmt"
"io/ioutil"
"net/http"
"net/url"
"strings"
)
func doAPICall() {
// curl -XPOST -d 'url=https://www.google.com/' 'https://cleanuri.com/api/v1/shorten'
apiURL := "https://cleanuri.com/api/v1/shorten"
data := url.Values{}
data.Set("url", "https://www.google.com/")
client := http.Client{}
r, err := http.NewRequest(http.MethodPost, apiURL, strings.NewReader(data.Encode()))
if err != nil {
panic(err)
}
resp, err := client.Do(r)
if err != nil {
panic(err)
}
body, err := ioutil.ReadAll(resp.Body)
if err != nil {
panic(err)
}
fmt.Println(string(body))
}
func main() {
doAPICall()
}
Output:-
$ go run .
{"error":"API Error: URL is empty"}
$
The server expects a valid value for the Content-Type request header.
r, err := http.NewRequest(http.MethodPost, apiURL, strings.NewReader(data.Encode()))
if err != nil {
panic(err)
}
r.Header.Set("Content-Type", "application/x-www-form-urlencoded") // <-- add this line
resp, err := client.Do(r)
The server also supports JSON request bodies:
r, err := http.NewRequest(http.MethodPost, apiURL, strings.NewReader(`{"url": "https://www.google.com/"}`))
if err != nil {
panic(err)
}
r.Header.Set("Content-Type", "application/json")
resp, err := http.DefaultClient.Do(r)
You can do something like this
package main
import (
"fmt"
"io/ioutil"
"net/http"
"strings"
)
func main() {
url := "https://cleanuri.com/api/v1/shorten"
payload := strings.NewReader("url=https://www.google.com/")
req, err := http.NewRequest("POST", url, payload)
if err != nil {
fmt.Println(err)
return
}
req.Header.Add("content-type", "application/x-www-form-urlencoded")
req.Header.Add("cache-control", "no-cache")
res, err := http.DefaultClient.Do(req)
if err != nil {
fmt.Println(err)
return
}
defer res.Body.Close()
body, _ := ioutil.ReadAll(res.Body)
fmt.Println(res)
fmt.Println(string(body))
}
I'm trying to access an API like this:
package main
import (
"bytes"
"fmt"
"io/ioutil"
"net/http"
"net/url"
)
func main() {
apiUrl := "https://example.com/api/"
data := url.Values{}
data.Set("api_token", "MY_KEY")
data.Add("action", "list_projects")
req, _ := http.NewRequest("POST", apiUrl, bytes.NewBufferString(data.Encode()))
client := &http.Client{}
resp, err := client.Do(req)
defer resp.Body.Close()
if err == nil {
body, _ := ioutil.ReadAll(resp.Body)
fmt.Println(resp.Status)
fmt.Println(string(body))
}
}
But the response from an API tells me there was no data in POST request.
If I do it like this with curl, it works:
$ curl -X POST "https://example.com/api/" -d "api_token=MY_KEY" -d "action=list_projects"
You may want to use this form of request
resp, err := http.PostForm("http://example.com/form",
url.Values{"key": {"Value"}, "id": {"123"}})
or use the right mime type :
req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
and encode data
strings.NewReader(data.Encode())
It's better if you test err != nil and return if necessary. This code may not work cause the request failed.
defer resp.Body.Close()
instead use this pattern:
client := &http.Client{}
resp, err := client.Do(req)
if err != nil {
fmt.Println(err)
return
}
defer resp.Body.Close()
body, _ := ioutil.ReadAll(resp.Body)
fmt.Println(resp.Status)
fmt.Println(string(body))
So you can see in the console if the request failed or not