Specify instance-id in fly-replay header

Questions / Help
6

Is running the primary on one port and secondaries (read replicas) on another an option? If so, traffic sent to that port should always end up with primary?

# litestream.primary.yml
addr: ":7770"
dbs:
  - path: /to/dB


# litestream.replica.yml
addr: ":7771"
dbs:
  - path: /to/db
    upstream:
      url: http://$PRIMARY_HOSTNAME:7770

ref: github/fly-apps/litestream-base.