You have deployed version 1 (v1) of an application to Cloud Run. You just deployed version 2 (v2) and want to perform a canary release. You want 10% of user traffic to go to v2, while 90% remains on v1.

How should you configure this in Cloud Run?

Cloud Run natively supports traffic splitting. Every time you deploy an update to a Cloud Run service, it creates a new 'Revision'. You can easily configure the service (via the Console or gcloud) to split incoming traffic across multiple revisions by specifying percentages (e.g., 90% to the old revision, 10% to the new revision). This makes canary deployments and A/B testing very straightforward without needing external load balancers or complex service meshes.