Per mara: a general fix, not one name in one container.
Every container inherits a COPY of the host's /etc/resolv.conf at start
(nixos-containers.nix: cp --remove-destination, one shot, not a
bind-mount), so the address written there is the address every container
tries - in its own netns. That makes the value load-bearing:
value host host-netns containers bridged containers
127.0.0.1 ok ok THEIR OWN loopback
bridge IP ok ok ok
dnsmasq binds lo and the bridge, so the bridge IP works for the host
too. It is the only value correct on both sides of a netns boundary.
resolveLocalQueries goes ON for its plumbing, not its address: it points
dnsmasq's own upstreams at a separate resolv-file, without which
dnsmasq reads /etc/resolv.conf and every non-hive query loops the moment
the host is pointed at dnsmasq. Its two loopback-publishing effects
(networking.nameservers and resolvconf.useLocalResolver) are overridden.
Cost: the host's DNS now depends on dnsmasq being up. Every container
already did.
The forge container keeps its hosts entry from the previous commit -
not redundancy, a fallback in a different failure domain: it works with
no DNS at all, so SSO does not ride on a host-wide resolver change.
Four wiring sites, same as forge/matrix/authelia: vhost, cert name, DNS,
local-dev hosts. This commit is the last two.
The apex is a SIBLING of forge./chat./auth., not a child of anything
dnsmasq already answers for, so the /<hive domain>/ rule does not cover
it - without an explicit record the name is unresolvable from every
agent netns while working fine from the host, which is the shape that
nearly shipped when authelia's name moved.
Published to agents deliberately (mara: publishing it is fine).
Reachability is not the access control: the vhost's auth_request plus
authelia's group:operators rule are, and an agent that resolves the name
still cannot open the page.
Per mara on the PR: how a thing used to be deployed stops being
relevant the moment this is merged and the hives are rebuilt, so the
comments state the current constraint and nothing about the container
that used to hold it.
Removes the two ⚠️ blocks this PR added (hive-tls-ca's ordering, the
resign propagation), the matrix ordering's, dnsmasq's resolv.conf
paragraph, and the pre-existing 'REMOVED WITH THE CONTAINER' inventory
in the gateway module. The 🚨 do-not-simplify warning on the cert-copy
unit keeps both its reasons and loses the container framing.
Kept deliberately: the two operator-facing 'this used to default to
true' option notes (migration information for someone upgrading), and
the SupplementaryGroups block, which documents why an absence is
load-bearing rather than how a deployment used to look.
Prose-only sweep of every remaining claim that nginx or dnsmasq lives
in a container: the port comment (root in a container -> root on the
host), upstreamHost's netns rationale, the ACME state dir, the store
path reachability note, the vhost tree header, dnsmasq's resolv.conf
paragraph (there is no copy and no path unit watching it any more),
the two hive-network bridge comments, and swarm-controller's socket
access-control note, which described a bind-mount that no longer
exists.
No behaviour change; all of it was describing a mechanism that was
deleted.
authelia has listened on 127.0.0.1:9091 since it was stood up, with
nothing proxying to it — so `auth.<swarm.domain>` resolved and then
refused the connection. This is the vhost that was never written.
Follows forge and matrix exactly: one `optionalAttrs` attrset merged into
`virtualHosts`, TLS chosen by `vhostTlsFor` (the swarm-services leaf
already names it, since `swarm.serviceDomains` includes
`authelia.domain`), and the same four wiring sites those two occupy —
vhost, dnsmasq address, local-dev `/etc/hosts`, and the arg lists that
feed both files.
Gated on this host running the container, not on authelia being
configured: every hive knows the swarm's `authelia.url`, but only the one
serving it may claim the name. A client hive declaring this vhost would
answer for a service it does not run.
Two things that are deliberate rather than incidental:
`X-Forwarded-{Proto,Host,Uri,For}` are set because authelia decides by
the *original* request — the login redirect and the session cookie's
domain both derive from them. Without them every request looks like it
arrived at 127.0.0.1 over plain http.
And no `auth_basic`. Applying the gateway's basic-auth block to the SSO
provider would put the login page behind the login mechanism it exists to
replace.
localHostsEntry's 127.0.0.1 rows leak into the address= answers dnsmasq
gives agent containers now that it runs on the host, sending every
agent back to itself instead of the bridge IP.
The gateway container's /etc/resolv.conf is a one-shot copy: nixos-container
cps it in from the host in its start script, and nspawn's --resolv-conf=auto
copies (not binds) for a writable host-netns container. systemd-nspawn(1)
states the consequence outright — "no further propagation of configuration is
generally done after the one-time early initialization (this is because the
file is usually updated through copying and renaming)".
dnsmasq has no explicit upstream and follows that file, so a host network
change strands it on a resolver that no longer answers and every non-hive
lookup from every agent hangs. Agents' own resolvers point at the static
bridge IP and never go stale, which is why the symptom presents as "the
gateway needs a kick".
Add a host-side hive-gateway-resolv path unit watching /etc/resolv.conf.
On change it machinectl copy-to's the file into the container and reloads
dnsmasq — ExecReload is kill -HUP, so upstreams are re-read and the cache
flushed without dropping anything; nginx never notices.
- watched from the HOST: a rename on the host doesn't cross the nspawn mount
namespace, so an in-container path unit can't see it (same reason c0re
reloads nginx from the host side)
- copy, not a file bind-mount: openresolv renames over the file, so a bind
would pin the first inode forever — strictly worse than today
- machinectl copy-to writes through the container's own mount namespace, so
this holds regardless of how the container assembles /etc
- armed Before=network-pre.target so the boot's first DHCP write is caught,
and re-run on gateway start for changes made while it was down
- a host file with no nameserver line is skipped, not pushed, so a
mid-rewrite snapshot can't blank hive DNS
- deliberately no fallback server=: dnsmasq queries all known upstreams in
parallel, so a hardcoded public resolver would take a share of normal
traffic rather than only covering the gap
