#+title: gitbay admin guide

One static binary (=gitbayd=), one SQLite file, bare repositories on
disk, and the system =git=. Schema migrations run automatically on
startup and on every admin command.

* Install

Build from source (=go build ./cmd/gitbayd=), install via the vanity
module path (=go install gitbay.org/gitbay/cmd/gitbayd@latest=), or use
a release build: =deploy/release.sh <tag>= cross-compiles reproducible
linux/amd64, linux/arm64, and darwin/arm64 binaries with a SHA256SUMS
manifest (CGO off, trimpath, stripped — byte-identical per commit and
toolchain).

#+begin_src sh
install -m 755 gitbayd /usr/local/bin/
adduser --system --group --home /var/lib/gitbay --shell /usr/sbin/nologin gitbay
install -d -o gitbay -g gitbay -m 750 /var/lib/gitbay
gitbayd --config /etc/gitbay/config.toml check-config
#+end_src

=deploy/= in the source tree has a cloud-init file, a hardened systemd
unit, and a nightly backup timer. Run as the unprivileged =gitbay= user;
the unit's =AmbientCapabilities=CAP_NET_BIND_SERVICE= covers ports
22/80/443 without root.

** The SSH port decision

- =ssh.mode = "embedded"= (default): gitbayd itself listens, normally on
  22 — move the host's admin sshd to another port. Remotes read
  =git@host:owner/repo= with no port gymnastics.
- =ssh.mode = "system"=: the host sshd owns 22 and invokes gitbayd via
  =AuthorizedKeysCommand=:
  #+begin_example
  AuthorizedKeysCommand /usr/local/bin/gitbayd --config /etc/gitbay/config.toml authorized-keys %t %k
  AuthorizedKeysCommandUser gitbay
  #+end_example
  sshd requires that binary to be root-owned and not group/world
  writable. Unknown keys fail authentication inside sshd, so system mode
  requires =registration.mode = "closed"= (check-config enforces this).

* Configuration reference

=/etc/gitbay/config.toml=. =check-config= validates and names every
contradiction; =--no-host-checks= skips port/path probes.
=gitbayd admin config show= prints the configuration in effect as TOML,
every default filled in and =smtp_pass= redacted. A file that fails
validation still prints, followed by the contradiction.

** [server]
- =root= (default =/var/lib/gitbay=) — repositories, database, host
  keys, ACME cache all live here.
- =site_url= (required) — canonical =https://host=; drives ACME, clone
  URLs, mail links.
- =source_repo= (optional, =owner/name=) — the repository this instance
  develops itself in. Startup warns when the running build's commit is
  not on that repository's default branch, which is how a binary built
  from an unmerged branch stops being invisible. Leave it unset unless
  the instance hosts its own source.

** [ssh]
- =mode= — =embedded= | =system= (above).
- =port= (22) — embedded listener port.
- =host_keys= — list of private key paths; empty generates an ed25519
  key at =<root>/ssh/host_ed25519=.

** [http]
- =addr= (=:443=), =tls= — =acme= | =files= | =off=.
- =acme=: certificates via TLS-ALPN-01 on the HTTPS port, cached at
  =<root>/acme=; =acme_email= for the CA account; =acme_http_addr=
  (=:80=, ="off"= to disable) adds HTTP-01 and an https redirect —
  failing to bind it is a warning, not fatal. Requires an =https://=
  site_url with a public DNS name.
- =files=: =cert_file= + =key_file=.
- =off=: plain HTTP — development, or behind a TLS-terminating proxy.

=trusted_proxies= lists the addresses or CIDRs of reverse proxies in
front of the daemon. A request from one of them is attributed, for API
rate limiting, to the last =X-Forwarded-For= hop that is not itself a
trusted proxy; from anyone else the header is ignored. Empty, the
default, is right when gitbayd terminates TLS itself.

** [web]
- =mode= — =view_only= (default) | =accounts=. In view_only the mutating
  web routes are never registered; in accounts, browser sessions are
  minted over SSH (=web login=), and users with write access can create
  repos, comment, and make simple file edits (which commit unsigned,
  honestly). =password_auth= is reserved and currently rejected.

** [registration]
- =mode= — =closed= (default) | =invite= | =open=. invite/open require
  [mail]. See the user guide for the flows.

- =pending_expiry= (empty, never) — a duration such as ="168h"=; a
  self-registered account still unverified after that long is removed,
  hourly and at start, audited as =pending.expired=.

** [mail]
- =smtp_host= (host:port, 587 assumed), =from=, optional =smtp_user= /
  =smtp_pass=. STARTTLS when offered. Required for invite/open
  registration and self-service =email add=; in closed mode you may omit
  it entirely and assert addresses by hand (below).

** [api]
- =enabled= (false) — the JSON API surface; see [[API]]. Off
  means no credential-bearing HTTP endpoint exists at all.

** [webhooks]
- =allow_local= (false) — permit webhook targets on loopback/private
  addresses. Leave off unless you know why you need it (SSRF).

** [limits]
- =clone_timeout= (3600s) — cap on =repo import= fetches.
- =max_blob_bytes= (100MB) — cap on raw file serving over the web.
- =max_asset_bytes= (512MB) — cap per uploaded release asset.
- =max_repos_per_user= (0, unlimited) — repositories an account may own
  directly; =repo create=, =fork= and =import= refuse past it.
  Organizations are not capped.
- =max_bytes_per_user= (0, unlimited) — disk the account's own
  repositories may take; a push may be no larger than what is left.
- =max_pack_bytes=, =ssh_auth_rate= — reserved, not yet enforced.

** [git_daemon]
- =enabled= (false), =port= (9418) — the anonymous =git://= listener.
  Serves only public repositories that additionally ran
  =repo settings git-daemon <repo> on=.

** [mirrors]
- =pull_interval_minutes= (15) — how often pull mirrors fetch their
  upstream. Push mirrors sync shortly after each local ref update.
  Mirror URLs pass the same SSRF rules as webhook targets.

** [go_import]
Vanity Go module paths, one per line: ="host/module" = "owner/repo"=.
Requests with =?go-get=1= at or under the module path answer with the
go-import meta tag pointing at the repository's HTTPS clone URL, so
=go install host/module/cmd/...@latest= resolves. The repository should
be public (the module path itself confirms it exists).

* Users, email, invites

Every =gitbayd admin= subcommand except =backup=, =gc= and the one-shot
backfills is a wrapper that dispatches the registry command of the same
name as the host: an admin context with no account behind it, so its
audit rows carry no actor and =source: host=. The same commands run in an
instance admin's SSH session (=ssh git@<host> admin ...=) and write the
same rows with the key fingerprint as source. One implementation, two
credentials.

#+begin_src sh
gitbayd admin user create alice --key alice.pub --email a@example.org --verified [--admin]
gitbayd admin email verify alice a@example.org   # admin assertion, no SMTP needed
gitbayd admin invite --email b@example.org       # mails a code; prints it if no SMTP
#+end_src

"Verified" means SMTP-confirmed or host-admin-asserted; the database
records which. Verified emails are what make commit signatures
meaningful — an unverified address never produces a =verified= badge.

* Audit and account control

The audit log is the security feed (events are the product feed): every
successful mutating command with its argv and source credential (SSH key
fingerprint or API), registrations, admin actions, force-pushes, and
auth failures/throttling. Secrets never appear — they travel on stdin,
never in argv.

#+begin_src sh
gitbayd admin audit [--actor u|-] [--action prefix] [--since 24h|7d|date] [--limit n] [--json]
ssh git@<host> audit ...             # the same, from an admin session (SSH only)
ssh git@<host> admin user list [--state active|pending|disabled|admin]
ssh git@<host> admin user show <name>   # keys, emails, orgs, tokens, sessions
ssh git@<host> admin user limits <name> [--repos n|default] [--bytes n|default]   # per-account caps
ssh git@<host> admin user promote <name>   # grant instance admin
ssh git@<host> admin user demote <name>    # remove it; the last admin is refused
gitbayd admin user promote <name>    # host-local: recovery when no admin key is reachable
gitbayd admin user disable <name>    # suspend: SSH, web, API all refused;
gitbayd admin user enable <name>     #   sessions dropped, nothing deleted
gitbayd admin user delete <name> --yes  # only for accounts anchoring nothing:
                                     #   refused (with each blocker named) while
                                     #   the account owns repos, authored
                                     #   issues/MRs/comments/reviews, or is an
                                     #   org's only admin
#+end_src

=--actor= takes a username, or =-= for rows with no actor: host commands
and auth failures. =--action= is a prefix, so =cmd repo= catches every
repository command and =admin= every host or admin-session action.
=--since= is a duration back from now (=30m=, =24h=, =7d=) or a date.

=admin user list= pages by username (=--limit=, =--cursor=) and carries
each account's state and =last_seen=, the newest use of any of its SSH
keys or API tokens. =admin user show= adds the keys with their last use,
each address with how it was verified, PGP keys, org roles, the owned
repository count, API token names, and live browser sessions. Both are
SSH-only and refused to non-admins, like =audit=.

Promotion needs an active account: a pending or disabled one is refused.
Demotion is refused when it would leave no admin, over SSH and on the
host alike, so the host-local =promote= is the way back in when the only
admin key is lost.

Instance admin carries no right on anyone's repository: policy does not
consult it, and a private repository still answers not-found to an
admin. Moderation goes through explicit overrides that skip the access
check and write their own audit row:

#+begin_src sh
ssh git@<host> admin repo list [--owner o] [--visibility public|private]  # size, last push
ssh git@<host> admin repo archive|unarchive <owner/name>
ssh git@<host> admin repo visibility <owner/name> public|private
ssh git@<host> admin repo delete <owner/name> --yes
#+end_src

Each lands in the audit log as =admin repo.<action>= naming the
repository, on top of the =cmd= row every mutating command gets.

=limits.ssh_auth_rate= (10) throttles per-IP authentication *failures*
per minute — successful auths never count and clear the slate.
=limits.max_pack_bytes= is enforced as =receive.maxInputSize= on every
push.

=limits.write_rate= (60) bounds *mutating commands per account per
minute*. It is counted in the dispatcher, so SSH, the JSON API and the
web spend one budget and a caller cannot refresh it by changing surface;
=limits.api_rate= stays in front of it, bounding a network source rather
than an account. A command is one token whatever it writes, so a bundle
import costs one and only a loop of separate commands spends the budget.
Read-only commands, the runner protocol (a build streams its log in many
small writes) and the host CLI are exempt. Refusals exit 4 and say when
to retry. A negative value turns the limit off; it matters most with
=registration = "open"=, where every write also queues notification mail
and webhook deliveries.

* Queues

Every background worker keeps a backlog and a failure state. An instance
admin reads them all in one place:

#+begin_src sh
gitbay dashboard --json | jq .queues   # webhooks, mail, mirrors, builds, deps
#+end_src

Per worker: pending, retrying (pending with a failed attempt) and
dead-lettered counts with the oldest pending age, and the retrying or
failed rows themselves, capped at twenty each. Builds list what is
running and then what is pending, each since when, so a build no runner
is scoped to claim is visible here rather than only in its repository;
mirrors list the ones whose last sync failed;
dependency checks list the ones whose last check errored. Non-admins get
no =queues= key at all.

In accounts mode the same read renders at =/admin=, linked from the rail
for admins. Anyone else gets a 404 there.

A dead-lettered mail is logged as =notification dead-lettered mail=<id>=,
with the address redacted out of the relay's error. The id is the queue
row: find it in the Mail table on =/admin=, or in =dashboard --json=,
where the recipient and the unredacted error are. That is deliberate —
see the Threat-Model page.

* Maintenance

#+begin_src sh
gitbayd admin stats [--json]         # counts, database size, per-repo disk
ssh git@<host> admin stats [--json]  # the same, from an admin session
gitbayd admin gc [--repo owner/name] # git gc: repack and prune; per-repo sizes
gitbayd admin gc --aggressive        # thorough repack; slow, rarely needed
gitbayd admin gc --lfs               # also drop LFS objects no pointer names (older than a day)
#+end_src

=deploy/cloud-init.yaml= ships a =gitbay-gc.timer= that runs =admin gc=
weekly (Sunday 07:00 UTC). Imported repositories keep whatever pack
layout the source sent, so a first manual =admin gc= after a bulk
import is worthwhile.

* Backup and restore

#+begin_src sh
gitbayd admin backup --out /var/backups/gitbay/backup.tar.gz
gitbayd admin backup --verify /var/backups/gitbay/backup.tar.gz   # read it back
#+end_src

One archive: a consistent SQLite snapshot (taken *before* the
repositories are read, so the database never references objects the
archive missed), every repository, and the SSH host keys. Excluded:
hook socket, regenerated hook scripts, WAL files. Safe to run against a
live daemon.

=--verify= reads an archive back: the snapshot must pass SQLite's
integrity check, and every repository the snapshot names must be in the
archive. A database-only archive is checked for integrity and says so.
Exit is non-zero on damage or a missing repository.

Restore: extract into an empty directory, point =server.root= at it,
start gitbayd. Host keys are preserved, so clients keep their
known_hosts entries; hooks regenerate at startup.

** Schedule and recovery point

Two timers, because the two halves of the data have different exposure.

- =gitbay-backup.timer=, nightly. The full archive above, last 7 kept.
- =gitbay-db-backup.timer=, hourly. =admin backup --db-only=, which
  writes the SQLite snapshot alone, last 48 kept. A few MB against the
  full archive's hundreds, which is what makes the frequency affordable.

The split follows what a loss would actually cost. Repositories are git,
so a mirror or any clone is a second copy; the database is the only copy
of issues, merge requests, comments and review state. So the recovery
point is about an hour for the data that exists nowhere else, and a day
for the data that does.

Continuous replication (litestream and similar) was considered and not
adopted. It would take the database's recovery point to seconds, but the
repositories would still be on the nightly archive, so a restore could
produce a database referencing commits the repository backup does not
have. Consistency between the two halves is worth more here than latency
on one of them. Revisit if repository replication becomes continuous
too.

* Upgrades

Replace the binary, restart the unit. Migrations apply automatically and
are transactional; hook scripts under =<root>/hooks= are rewritten at
startup to point at the current binary path.

* CI runner

=gitbay-runner= executes builds queued by pushes and merge requests. It
polls over SSH with a key added by =keys add --scope runner=, which
reaches only the runner protocol and read-only git (a runner executes
arbitrary repository code, so the key it holds must not do more), then
clones, runs the steps, streams the log back and resolves the commit
status. Run it as a dedicated unprivileged user on a non-admin account.
=admin user create --key= registers a full-scope key, so the runner key
is added afterwards through a bootstrap key that is then removed:

#+begin_src sh
useradd --system --create-home --home-dir /var/lib/gitbay-runner ci-runner
sudo -u ci-runner ssh-keygen -t ed25519 -N "" -f /var/lib/gitbay-runner/.ssh/id_ed25519
ssh-keygen -t ed25519 -N "" -f /tmp/ci-bootstrap
gitbayd --config /etc/gitbay/config.toml admin user create ci --key /tmp/ci-bootstrap.pub
ssh -i /tmp/ci-bootstrap git@127.0.0.1 keys add --scope runner < /var/lib/gitbay-runner/.ssh/id_ed25519.pub
ssh -i /tmp/ci-bootstrap git@127.0.0.1 keys remove "$(ssh-keygen -lf /tmp/ci-bootstrap.pub | awk '{print $2}')"
rm /tmp/ci-bootstrap /tmp/ci-bootstrap.pub
gitbay-runner -remote git@127.0.0.1 -workdir /var/lib/gitbay-runner/work
#+end_src

=-jobs N= runs N builds at once. Claiming is one transaction that
selects and updates, and each build works in its own =build-<id>=
directory, so workers do not collide; idle polls are staggered across
the interval so N of them do not wake together. The drop-in's weights
below are per service, not per build, so raising =-jobs= divides them
rather than multiplying the host's load.

=admin runners= shows which account each runner polls as, and what each
is scoped to. A runner with no scope claims builds for *any*
repository, which on an instance with open registration means running a
stranger's steps; scope one with =-repos owner/name=. An admin key
still works for the protocol during a rotation. A merge request head
from a fork is built in the target repository as untrusted: the claim
carries no secrets. Same-repository heads were built by their branch
push and are not built again.

=make deploy-runner= also installs
=deploy/gitbay-runner.override.conf= as a systemd drop-in: =Nice=10=,
=CPUWeight=30=, =IOWeight=30=, so a build never starves the host's sshd,
the daemon or the backup timers, and =NoNewPrivileges=,
=ProtectSystem=full=, =ProtectKernelTunables=, =ProtectControlGroups=
and =RestrictSUIDSGID=, so a step cannot reach outside its workspace
and the runner's home. The e2e suite alone starts sixty
daemon instances; without the drop-in a deploy's copy over the admin
sshd stalled. Both deploy targets copy with =rsync --partial=, which
resumes a stalled transfer.

v1 runs steps directly on the host — no containers — so treat the
runner machine as executing whatever your users push. Install the
toolchains your builds need on it.

A runner claims the oldest pending build in the queue, whichever
repository it belongs to. =-repos= narrows that to named repositories,
which is what makes a runner outside the server practical — one on a
machine that should build a single project, or that holds credentials for
one deployment, no longer picks up a build belonging to someone else. With
open registration that someone need not be anyone you know.

#+begin_src sh
gitbay-runner -remote git@gitbay.org -repos krz/site,krz/docs \
  -workdir /var/lib/gitbay-runner/work
#+end_src

gitbay.org's runner is scoped: it builds the forge's own repositories
and the isolation canary, nothing else, because it shares the host with
the forge. A =.gitbay/ci.yml= in another repository there queues builds
no runner claims. Whether that changes is krz/gitbay#184.

Naming no repositories is the old behaviour and stays the right choice for
the runner on the server itself. The scoping is what the runner asks for,
not an ACL the server holds over it: a runner account is admin by
necessity, so the boundary is you choosing how to start it.

=gitbay dashboard= and =ssh git@<host> admin runners= list every account
that has polled as a runner: when it last polled, the =-repos= scope it
asked for, and the build it holds. A build a runner claimed and never
reported is failed by the scheduler's minute tick, whether or not any
runner is still alive: within about two minutes of its log stream ending
with no outcome reported — the runner reports right after closing the
stream, retrying for half a minute if gitbayd is unreachable — or, if no
stream was ever seen, at the deadline.

Instance admin on the runner account only authorizes the claim/report
protocol; it grants no repo access. A build that pushes back — a pages
deploy, an archive publish, an automated MR branch — needs an explicit
grant on that repo: =repo access grant <owner/name> ci write=. Private
repos likewise need at least read for the clone.

** Container isolation

Builds run in a rootless podman container, one per job, with the
workspace bind mounted and nothing else: the clone happens outside with
the runner's key, so a step cannot read it. =-isolation none= keeps the
old behaviour — steps on the host as the runner's user — for an instance
where every repository is trusted. There is no automatic fallback: a
runner started with =-isolation podman= that cannot find a working
podman exits rather than running a build unsandboxed.

gitbay's own jobs name =localhost/gitbay-ci:1=, built from
=deploy/Containerfile.ci= on the runner host. A job's image must carry
what its steps need: the suite drives real git, git-lfs, gpg and sshd and
asserts they exist before running, so the stock runner default would fail
it immediately. Build or rebuild it with:

#+begin_src sh
ssh -p 2222 root@<host> 'cat > /tmp/Containerfile.ci' < deploy/Containerfile.ci
ssh -p 2222 root@<host> 'su - ci-runner -s /bin/sh -c \
  "podman build -t localhost/gitbay-ci:1 -f /tmp/Containerfile.ci /tmp"'
#+end_src

The tag is deliberate rather than =:latest=: changing the file means
bumping the tag in =.gitbay/ci.yml=, so a running branch's image does not
change under it.

=-image= names the image a job runs in when it declares none, and is
required under =-isolation podman=: there is no built-in default,
because an image this host does not have would fail every build. A job
overrides it with =image:= in =.gitbay/ci.yml=, validated as a reference
so a config file cannot turn it into podman arguments.

=-cpus= and =-memory= cap one build's container (podman's own units,
e.g. =-cpus 2 -memory 4g=); unset means uncapped. They only take effect
where podman can create a cgroup for the container. Under rootless
podman with the cgroupfs manager, which is what a system service gets,
it cannot: the container runs inside the service's own cgroup and both
flags are accepted and ignored (krz/gitbay#188). Cap the unit instead.
bay1's drop-in sets =MemoryMax=6G= and =CPUQuota=300%= on a 7.7GB
four-core host with no swap: the memory cap is what keeps the forge
alive when a build allocates without bound, and it sits above the e2e
suite's 5GB peak rather than at a fair share. =OOMPolicy=continue= keeps
systemd from stopping the runner when a build is OOM-killed.

Each repository gets its own build home under the runner's workdir,
mounted into its containers as =HOME=. Caches persist between builds of
one repository and are never read by another's.

*Images are provisioned, never pulled by a build.* The runner passes
=--pull=never=. Two reasons, and the second is the better one: the
service runs with =RestrictSUIDSGID=yes= so podman cannot unpack a layer
holding a setuid file, which is nearly every distribution image; and on
an instance where anyone can push a =ci.yml=, =image:= would otherwise
mean "fetch and run anything from the internet". An operator pulls or
builds what is allowed and a build picks among those. A job naming an
image the host does not have fails with a message saying so.

#+begin_src sh
su - ci-runner -s /bin/sh -c "podman pull docker.io/library/alpine:3.20"
su - ci-runner -s /bin/sh -c "podman images"
#+end_src

Prepare a host before pointing an isolating runner at it:

#+begin_src sh
ssh -p 2222 root@<host> 'sh -s' < deploy/runner-podman-setup.sh
make deploy-runner
#+end_src

The script installs podman, delegates a subuid/subgid range to
=ci-runner=, checks that user namespaces are enabled rather than
assuming, enables lingering, and verifies rootless podman actually runs
as that user. It is idempotent.

The drop-in sets =NoNewPrivileges=no=, without which rootless podman
cannot call =newuidmap= and the runner refuses to start. That is a
considered trade, explained in the file and in the Threat-Model; if you
run with =-isolation none=, set it back to =yes=.

*Restarting the runner is safe.* On SIGTERM it stops claiming, finishes
the build in flight, reports it, and exits; the drop-in's
=TimeoutStopSec=50min= covers the longest build, and its =KillMode=mixed=
is what makes the signal reach the runner alone — under systemd's default
the build's container and the log session are signalled with it, and the
runner drains a build that is already dead. So =make deploy-runner=
waits for a running build rather than orphaning it, and a build's result
is retried for half a minute if gitbayd is restarting at that moment. A
second SIGTERM ends the runner at once, abandoning the build to the
reaper.

*Validate podman mode on a scratch repository before pointing the runner
at real ones.* Every deploy that switched the whole instance to
containers and failed took CI down with it. Instead: create a throwaway
repository the runner account can read (public, or granted read — a
private one is "not found" to the runner and the build stays pending),
give it one job that names the CI image, and deploy the runner with
=-repos= naming only that repository. The production unit, with its real
hardening, then claims nothing else; other repositories' builds queue
until =-repos= is switched back, which is a pause, not an outage.

#+begin_src sh
gitbay repo create cmc/ci-smoke          # then push a .gitbay/ci.yml naming the image
sed -i 's#-repos krz/gitbay #-repos cmc/ci-smoke #' /etc/systemd/system/gitbay-runner.service.d/override.conf
systemctl daemon-reload && systemctl restart gitbay-runner
gitbay build log cmc/ci-smoke 1         # green: switch -repos back, redeploy
#+end_src

*Do not deploy an isolating runner to a host that has not been
prepared.* The runner is specified to refuse to start without a working
podman rather than fall back to running builds unsandboxed — a fallback
that silently drops isolation is worse than a stopped runner, because
nothing surfaces it. On an unprepared host that refusal stops every
build on the instance.

The service drop-in carries =Delegate=yes= for rootless cgroup
management and =ReadWritePaths= for podman's store under
=/var/lib/gitbay-runner=, which =ProtectSystem=full= would otherwise
make read-only. Those paths are prefixed =-= so they are ignored when
absent: the drop-in installs on unprepared hosts too, and a unit that
refused to start would stop every build.
The nightly canary on =cmc/ci-smoke= only runs if the runner's =-repos=
names that repository too; a scoped runner claims nothing else.
=gitbay-runner-prune.timer= prunes unused images weekly, as the runner's
user: rootless storage belongs to that user, and root's prune would not
see it. An unpruned image store on a 40GB host is a slow outage.

* LFS storage

Objects live content-addressed under =[lfs] root= (default
=<server.root>/lfs=); =[lfs] max_object_bytes= caps a single object
(512MB default). Storage sits behind a small interface — an
S3-compatible backend is a drop-in with the server proxying, and
presigned URLs a later optimization. LFS objects do not travel with
push mirrors (mirrors move git refs only), and gc does not yet collect
orphaned objects.

* Pages

=[pages] domain = "example.site"= serves public repos' =pages= branches
on =<owner>.<domain>=. DNS needs a wildcard record =*.<domain>= to the
server; ACME issues per-subdomain certificates on demand (only for
owners that exist). The domain must not be the site host or a parent of
it — pages content runs its own scripts and must stay off the forge's
origin.

Users with repo admin claim custom domains with =repo domain add=.
Claims activate only after a DNS TXT challenge proves control of the
domain (=repo domain verify=, audit-logged); pending claims serve
nothing, get no certificates, and expire after 7 days. ACME issues
certificates only for verified hosts, so stray DNS pointed at the
server gets nothing.

* Security

The [[Threat-Model]] file is the reference for what the forge
trusts and refuses to do. Operational checklist:

- *Software checks.* =deploy/audit.sh= runs =go vet=, =govulncheck=
  (the module list is deliberately short — review it on each release),
  and a short fuzz pass over every attacker-facing parser (pkt-line,
  commit, SSHSIG armor, OpenPGP key, SSH tokenizer). Run it before
  tagging a release. CI's own =vuln= job runs =govulncheck= nightly
  against main rather than per push, because =@latest= scans today's
  advisory database and an advisory lands without anyone pushing;
  =build trigger krz/gitbay vuln= runs it on demand.
- *Web responses* carry a scripts-forbidden CSP, =X-Frame-Options:
  DENY=, =nosniff=, =no-referrer=, and HSTS when TLS is on — no
  configuration needed.
- *Host sandboxing.* The systemd unit in =deploy/cloud-init.yaml= runs
  gitbayd unprivileged with =ProtectSystem=strict=, =PrivateDevices=,
  =LockPersonality=, =MemoryDenyWriteExecute=,
  =SystemCallFilter=@system-service=, and =RestrictAddressFamilies= to
  INET/INET6/UNIX. It keeps =CAP_NET_BIND_SERVICE= only, to bind 22/80/443.
- *OS patches* apply via =unattended-upgrades= (security origins,
  auto-reboot 04:30 if required).
- *Admin sshd (2222)* is throttled by =MaxStartups=/=MaxAuthTries= and
  watched by =fail2ban=; gitbayd's own port 22 is throttled by
  =limits.ssh_auth_rate= (auth failures per IP per minute), and every
  account's writes by =limits.write_rate=.
- *Monitoring.* =gitbay-monitor.timer= writes a reading hourly to
journald and, when =/etc/gitbay/monitor.url= exists, posts it to that
webhook: disk, service, the daemon's own =/healthz= answer, certificate
expiry, and the age of the newest full backup and database snapshot.
It exits non-zero on an alert so the unit shows in =systemctl
--failed=: a stopped service, =/healthz= not answering =ok=, disk ≥ 85%,
a certificate under 21 days, a full backup over 25 hours old, or a
database snapshot over 2 hours old.

=GET /healthz= is unauthenticated and cache-free: whether the database
answers and which commit serves, 503 when it does not.
- *Database.* =gitbay.db= and its WAL live under =/var/lib/gitbay= (mode
  0750, owned by =gitbay=). The nightly archive plus provider snapshots
  are the recovery path; for tighter RPO, add continuous replication
  (litestream) against the same file — it coexists with the WAL.

* Odds and ends

- deleting a fork marks MRs sourced from it =source_gone=; their diffs
  remain viewable and mergeable because the target repo owns the
  objects.
- =refs/merge-requests/*= is server-owned and unpushable by clients.
- audit-relevant activity (issue/MR lifecycle, imports, pushes) lands in
  the =events= table, which also feeds webhooks.
- the daemon idles under 10MB RSS; the smallest VPS tier is adequate.