How can I make a request with a bearer token in Go - http

Question

I need to make a GET request to an API with a bearer token in the authorization request. How can I do this in Go? I have the following code, but I haven't had success.
package main
import (
"io/ioutil"
"log"
"net/http"
)
func main() {
url := "https://api.globalcode.com.br/v1/publico/eventos"
resp, err := http.Get(url)
resp.Header.Add("Bearer", "token")
if err != nil {
log.Println("Erro ao realizar request.\n[ERRO] -", err)
}
body, _ := ioutil.ReadAll(resp.Body)
log.Println(string([]byte(body)))
}

Answer 1

For control over HTTP client headers, redirect policy, and other settings, create a Client:
package main
import (
"io/ioutil"
"log"
"net/http"
)
func main() {
url := "https://api.globalcode.com.br/v1/publico/eventos"
// Create a Bearer string by appending string access token
var bearer = "Bearer " + <ACCESS TOKEN HERE>
// Create a new request using http
req, err := http.NewRequest("GET", url, nil)
// add authorization header to the req
req.Header.Add("Authorization", bearer)
// Send req using http Client
client := &http.Client{}
resp, err := client.Do(req)
if err != nil {
log.Println("Error on response.\n[ERROR] -", err)
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
if err != nil {
log.Println("Error while reading the response bytes:", err)
}
log.Println(string([]byte(body)))
}
The Client's Transport typically has internal state (cached TCP
connections), so Clients should be reused instead of created as
needed. Clients are safe for concurrent use by multiple goroutines.
A Client is higher-level than a RoundTripper (such as Transport) and
additionally handles HTTP details such as cookies and redirects.
For more information on Client and Transport check golang spec for net/http package

Answer 2

I had to add a client.CheckRedirect Function(seen below) in order to pass the Bearer token to the API.
bearer := "Bearer " + token
req, err := http.NewRequest("GET", url, bytes.NewBuffer(nil))
req.Header.Set("Authorization", bearer)
req.Header.Add("Accept", "application/json")
client := &http.Client{}
client.CheckRedirect = func(req *http.Request, via []*http.Request) error {
for key, val := range via[0].Header {
req.Header[key] = val
}
return err
}
resp, err := client.Do(req)
if err != nil {
log.Println("Error on response.\n[ERRO] -", err)
} else {
defer resp.Body.Close()
data, _ := ioutil.ReadAll(resp.Body)
fmt.Println(string(data))
}
}

Answer 3

I made a super-little-basic library for execute basic request like:
package main
import (
request "github.com/alessiosavi/Requests"
)
func main(){
// Create a key-value list of headers
headers := request.CreateHeaderList(`Accept`, `application/json`, "Authorization", "Bearer "+IAMToken)
resp :=request.SendRequest(`http://your_site.com`, `GET`, headers, nil))
}
Here you can find the request implementation:
https://github.com/alessiosavi/Requests/blob/e7ca66bde738b6224fba2b6f146a8dbee67d3323/Requests.go
Here you can find how i use the library for Bearer Auth and other auth type:
https://github.com/alessiosavi/GoCloudant/blob/a8ad3a7990f04ea728bb327d6faea6af3e5455ca/cloudant.go