title: How can my cloud run service call other cloud run services?
body: <p>I have a service listening on 'https://myapp.a.run.app/dosomething', but I want to leverage the scalability features of Cloud Run, so in the controller for 'dosomething', I send off 10 requests to 'https://myapp.a.run.app/smalltask'; with my app configured to allow servicing of only one request per instance, I expect 10 instances to spin up, all do their smalltask, and return (all within the timeout period).</p>
  <p>But I don't know how to properly authenticate the request, so those 10 requests all result in 403's. For Cloud Run services, I manually pass in a bearer token with the initial request, though I expect to add some api proxy at some point. But without said API proxy, what's the right way to send the request such that it is accepted? The app is running as a user that does have permissions to access the endpoint.</p>