Per the operator's call on #3372: rather than moving Grafana off the
forge's 3000 to another number, take it off TCP entirely.
The collision was possible because every swarm service container shares
the host's network namespace, which makes a port a swarm-wide resource
two modules can each claim believing it free — Grafana took upstream's
3000, so does the forge, and `grafana.<swarm-domain>` served the forge
with no bind error and nothing in any log. A socket has a path, and a
path collision is a build-time conflict rather than a runtime coin toss.
Three parts, none of which works alone:
- `protocol = "socket"` with `socket_gid` = nginx's static gid 60.
- Grafana joins that gid inside the container. A non-root process may
only chgrp to a group it belongs to, and a container has its own user
database — without the membership Grafana starts, the chown fails, and
the socket is simply unreachable.
- The socket dir is created host-side by tmpfiles and bind-mounted in. A
container's /run is an nspawn tmpfs, so it is not visible from the host
at /var/lib/nixos-containers/<name>/run; the same shape the per-agent
web.sock already uses.
The `port` option is gone rather than deprecated — nothing can set it to
a colliding value if it does not exist.
nixpkgs dropped the default for `services.grafana.settings.security.secret_key`
and asserts on null, so the module I merged an hour ago fails the build on any
host that enables it. That is a broken deploy, not a warning.
Generated in-container like authelia's own keys and for the same reason:
nothing outside the container ever reads it. Generated ONCE and kept — the
key signs Grafana's stored datasource secrets, and rotating it does not
re-encrypt what it already encrypted, so a fresh key per boot would leave
Grafana unable to read its own database. Delivered as `$__file{}`, so it
never enters the store.
The gate missed this because a container is a separate NixOS evaluation with
its own assertions: forcing the host's `config.assertions` never touched the
container's. `state/eval-3265.sh` now forces
`containers.swarm-grafana.config.assertions` and reports any that fail.
Second half of the metrics pair: a `swarm-grafana` container beside the
VictoriaMetrics store, provisioned with it as the default datasource and
fronted by the gateway on its own swarm-sibling name.
Behind swarm SSO, per the operator's call on #3265. The authelia client
and Grafana's callback URL both derive from `domain`, so the exact-match
string authelia checks cannot drift from the one Grafana sends. The
minted secret is delivered host-side (both container trees are only
addressable there) and reaches Grafana as a `$__file{}` reference rather
than a value, so it never enters the store.
The login form is disabled whenever SSO is configured: Grafana ships an
`admin`/`admin` account and this vhost is on the public gateway.
