jar-lid-archive: a staging deployment on its own box

Jar Lid Archive (Django + Postgres 18 + SeaweedFS) on jar-lid-archive-staging-box
(nodito VM 3300, 1 core / 1 GB / 10 GB), public at jars-staging.contrapeso.xyz
through vipy's Caddy. New role roles/jar_lid_archive; per-host values in
host_vars, so a production host is a new [jar_lid_archive] entry, not a new
playbook.

── Containers, following :master ──────────────────────────────────────────
The same three services as the app repo's compose.yaml, so staging rehearses
what dev and CI run. Every playbook run pulls :master and `up -d --wait`s;
compose recreates web only when the digest moved. --wait gates on web's
/health/, which checks the database and the bucket, so a green run means the
app serves. Upgrading is re-running the playbook.

── web is on the host network ─────────────────────────────────────────────
Docker's published ports are DNATed before UFW sees them, so `8000:8000` would
answer on the LAN whatever UFW says, and binding to the tailnet IP races
tailscaled at boot. On the host network gunicorn's port is an ordinary one: UFW
default-deny covers the LAN, tailscaled's ts-input accepts tailscale0 ahead of
UFW (checked on mempool-box), and the headscale ACL grants tag:prd-vipy exactly
:8000. db and storage publish on 127.0.0.1 only. Verified: LAN times out, vipy
gets 200.

That matters for HTTPS: the app trusts X-Forwarded-Proto
(DJANGO_BEHIND_TLS_PROXY=1), which is only safe while Caddy is the sole client.
Login POST through the public URL passes CSRF; cookies are Secure.

── Secrets ────────────────────────────────────────────────────────────────
Generated straight into host_vars/jar_lid_staging_local/vault.yml, never
printed: Django key, Postgres and S3 secrets, and seed passwords for the
fixture's alice/bob/admin usernames - never the fixture's published passwords,
since the site is public. The group vault gains one line, this host's Gatus push
token; decrypted, it differs from before by exactly that line.

── Backups, and the outage the first one caused ───────────────────────────
One uncompressed tar (pg_dump -Fc + the SeaweedFS data dir), age-encrypted on
the box at 02:20, pulled by small-backups-box; 3 days at both ends. Verified end
to end, including decrypting a pulled artefact on lapy.

The first test run stopped web AND storage and left the app down 26 minutes:
SeaweedFS outlasted its 150s healthcheck budget on this disk, compose marked it
unhealthy, and web's depends_on never started it. Now only web is stopped - it
is the only writer to both stores, so they are still captured at one instant -
and the healthchecks have start_periods sized for the disk.

Also inherited from the app's compose.yaml: storage writes /tmp/s3.json and
chowns it to seaweed, so on a RESTART of the same container root cannot
re-create it (sticky /tmp + protected_regular): "Permission denied". Fixed here
with rm -f first; the app repo needs the same line.

── The disk is the problem ────────────────────────────────────────────────
The VM disk is on proxmox-tank-1, the HDD mirror, which knots-box's random reads
(~6 MB/s) keep near saturation. Inside this VM: ~96% "full" I/O pressure while
idle, ~5 min to start web, sudo occasionally over 12s. Moving it to local-zfs
(NVMe) is the fix; noted in the README, not done.

── Also ───────────────────────────────────────────────────────────────────
- lan_ip read from the Proxmox guest agent; host key checked against the one
  the agent reads off the disk before it went into known_hosts.
- Monitoring: liveness + disk (400), probe_jar-lid-archive-staging (403), public
  /health/ + DNS (402), backup-dump/backup-store.
- tofu: the VM definition.
- Deployed v2026.10.03.1.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

ansible/roles/jar_lid_archive/templates/dump.sh.j2

@@ -0,0 +1,25 @@
+#!/usr/bin/env bash
+# Jar Lid Archive dump - managed by Ansible (roles/jar_lid_archive).
+#
+# Writes ONE uncompressed tar to STDOUT, for roles/backup_source to encrypt:
+#   db.dump      pg_dump custom format   -> pg_restore -d jarlid db.dump
+#   seaweedfs/   the photo store, as files
+#
+# Called with `web` stopped (the backup playbook arranges it). web is the only
+# writer to db and storage, so both are quiescent and agree with each other: no
+# row points at a photo the tar does not have. storage keeps running; with no
+# writes arriving its volume files do not change under tar.
+#
+# The pg_dump lands in a temp dir on the same disk as the live database, which
+# is already plaintext; it is gone before this script exits.
+#
+# tar, not tar.gz: the bulk is JPEGs, which do not compress, and gzip on one
+# core would only make the window longer.
+set -euo pipefail
+
+cd {{ jar_lid_archive_dir }}
+tmp=$(mktemp -d {{ jar_lid_archive_dir }}/.dump.XXXXXX)
+trap 'rm -rf "$tmp"' EXIT
+
+docker compose exec -T db pg_dump -U {{ jar_lid_archive_postgres_user }} -d {{ jar_lid_archive_postgres_db }} -Fc > "$tmp/db.dump"
+tar -cf - -C "$tmp" db.dump -C {{ jar_lid_archive_dir }} seaweedfs