The Hydra admin API creates OAuth clients and introspects tokens without
authentication, relying on network isolation the same way Kratos does, but
so-hydra published 0.0.0.0:4445:4445 and sat on sobridge. With userland-proxy
left at its default of true, Docker ran a proxy listener on the host, so any
container reached the admin API through the manager IP or the bridge gateway
regardless of its docker network.
so-hydra now sits alone on soauth and no longer publishes 4445. 4444 is still
published, so the nginx proxy for /oauth2/token and the well-known endpoints is
unchanged. so-soc is already dual homed from the Kratos change and reaches the
admin API over soauth, so only its hostUrl moves. wait_for_hydra polls the
container address instead of the host port.
so-client reaches the admin API through docker exec, mirroring so-user. Exit
codes still propagate, so the --fail-with-body error handling is unchanged.
so-hydra is removed in up_to_3.4.0 alongside so-kratos and so-soc so the
highstate recreates it with the correct network membership. The auth network
range is already handled by set_soauth_range.