Pre-request - Script to generate access_token automatically

[orafacomf]

Hi everyone,

I need to create a collection pre-script to retrieve the acccess_token automatically every time I execute a request within the collection.

My data is:

URL: https://api.url.com/oauth/token

I need to send the following parameters:

grant_type=client_credentials
client_id={{client_id}}
client_secret={{client_secret}}

So, the URL that I need to send is:

https://api.url.com/oauth/token?grant_type=client_credentials&client_id={{client_id}}&client_secret={{client_secret}}

The comment of the link below has almost what I need, but I was not able to modify it the way I need:

#765 (comment)

Does anyone know what I need to change? Below is the coding used in the link above from @n00o.

Method 2
The more difficult way but more convenient once set up would be to use the collection pre-script to do both authorization steps together. It can be found by going to the gear icon next to the environment selection dropdown. Here is the basic format for the script:

const axios = require("axios");
const url = require("url");
const btoa = require("btoa");

var path = bru.getEnvVar("ssoBaseUrl")+"/auth/realms/"+bru.getEnvVar("ssoRealm")+"/protocol/openid-connect/token";
var creds = btoa(bru.getEnvVar("Username")+":"+bru.getEnvVar("Password")); //set environment variable for username and password
var headers = {"Authorization": "Basic "+creds, "Content-Type": "application/x-www-form-urlencoded"};

var params = new url.URLSearchParams({grant_type: "client_credentials"});
const auth1 = await axios.post(path,
           params.toString(),
           {headers: headers}).then((response) => {
           bru.setVar("access_token_1",response.data.access_token); //save access_token_1 for use elsewhere
});

params = new url.URLSearchParams({
    grant_type: "urn:ietf:params:oauth:grant-type:token-exchange",
    audience: "some target audience",
    subject_token: bru.getVar("access_token_1")
});
const auth2 = await axios.post(path,
           params.toString(),
           {headers: headers}).then((response) => {
           bru.setVar("access_token_2",response.data.access_token);
});

Any help is appreciated.

[orafacomf]

Hi everyone,
I was able to make it work based on the coding from @n00o.

// constantes originais
const axios = require("axios");
const url   = require("url");
const btoa  = require("btoa");

// variantes 
var grant_type    = bru.getEnvVar("e_grant_type");
var client_id     = bru.getEnvVar("e_OAuthClientId");
var client_secret = bru.getEnvVar("e_OAuthSecret");
var token_url     = bru.getEnvVar("e_token_url");
var path          = bru.getEnvVar("e_token_url");
var headers       = {"Authorization": "Basic "+bru.getEnvVar("e_Base64EncodedClientandSecret"), "Content-Type": "application/x-www-form-urlencoded"};

var params = new url.URLSearchParams({grant_type: "client_credentials"});
const auth = await axios.post(path,
             params.toString(),
             {headers: headers}).then((response) => {
             bru.setEnvVar("e_access_token",response.data.access_token);
             bru.setEnvVar("e_refresh_token",response.data.refresh_token);
             bru.setEnvVar("e_token_type",response.data.token_type);
             bru.setEnvVar("e_token_expiry",response.data.expires_in);
});