pre request script to update postman with new keycloak token if its expired

keycloak_postman_token.js

// refresh token if it's expired
var client_id = pm.collectionVariables.get("client_id")
var client_secret = pm.collectionVariables.get("client_secret")


const postRequest = {
	url: pm.collectionVariables.get("sandbox_auth_url") + "protocol/openid-connect/token",
	method: 'POST',
	header: 'Content-Type:application/x-www-form-urlencoded',
	body:{
		mode: 'raw',
		raw: `grant_type=client_credentials&client_id=${client_id}&client_secret=${client_secret}`
	}
}
var getToken = true;

if (!pm.environment.get('accessTokenExpiry') || 
	!pm.environment.get('token')) {
	console.log('Token or expiry date are missing')
} else if (pm.environment.get('accessTokenExpiry') <= (new Date()).getTime()) {
	console.log('Token is expired')
} else {
	getToken = false;
	console.log('Token and expiry date are all good');
}

if (getToken === true) {
	pm.sendRequest(postRequest, (error, response) => {
		console.log(error ? error : response.json())
		pm.environment.set('token', response.json().access_token)

		var expiryDate = new Date();
		expiryDate.setSeconds(expiryDate.getSeconds() + response.json().expires_in);
		pm.environment.set('accessTokenExpiry', expiryDate.getTime());
	});
}