Send a login request to get an authorization token for the rest of your test
Below is a partial test (just the on_start section) that shows how to set an authorization (or really any) header based on response content at launch with your load test.
from locust import HttpLocust, TaskSet, task
import requests
class UserBehavior(TaskSet):
def on_start(self):
# Send login request
response = requests.post("http://mysite.com/login", {"username": "user", "password": "pass"})
# set "token" from response header
self.client.headers.update({'Authorization': response.headers.get('token')})
# OR set "token" from response cookies
self.client.cookies.set('Authorization', response.cookies.get('token'))
# OR set "token" from response body
self.client.headers.update({'Authorization': str(response.content.decode().find('token'))})