Add request and response headers to apply on all frontends


We have a Azure Service Fabric cluster running Traefik as reverse proxy for many web roles.
For better troubleshooting and traceability, I would like Traefik to add headers both to the upstream requests going to the backends, and also on the downstream responses sent to the client.

The main thing here, is that I would like to apply these headers on every request and response going through Traefik, no matter what the Frontend was configured with.

So far, I find Frontend-level headers, which means every Frontend needs to take care of configuring that.

I'm using Traefik v1.7.20

Thank you!