Triggered by investigating a several-hour >10Mbps traffic spike to
linode. HAProxy's own IPAccounting confirmed ~121GB moved over ~19.6h
before it crash-looped, but with 'option httplog' commented out and no
per-backend request logs, there was no way to attribute that traffic
to a specific backend, host, or client.
- linode: enable HAProxy httplog + defaults 'log global' (was
commented out) so every proxied HTTP request is now logged with
timing/status/bytes.
- linode: add a haproxy 'stats' listener on 127.0.0.1:8404 for live
per-backend/per-server connection and byte counters.
- linode: route nginx (Nextcloud's local vhost) access logs to
journald via syslog, since the read-only monitoring account has no
access to /var/log/nginx/*.
- linode: enable vnstat for historical per-interface bandwidth
tracking (5-min granularity) so a reported 'traffic was high for N
hours' can be confirmed/timestamped immediately instead of
reconstructed after the fact from journal timestamps.
- k3s manifests: enable Traefik access logging (JSON) — this is the
ingress layer HAProxy forwards :80 traffic to (git/matrix/immich),
and lacked any per-request visibility.
- hosts/baseline.nix (fleet-wide): add a journald rate limit
(2000 lines / 30s per unit). Found live while investigating that
uptime-kuma on 'kuma' was logging a Prometheus label-validation
error on every monitor beat (~100k lines/hour), which was itself
degrading journalctl responsiveness on that host during the
cross-host traffic scan.
Related but not otherwise addressed here: Nebula relay/handshake
churn on kuma's tunnel and the etcd read-latency warnings seen on
isaiah/zeke around the same incident window — noted for a future
investigation, not fixed by this PR.
Adds a new NixOS module (greg.monitoring-access) that provisions a
dedicated, SSH-key-only 'emily' user account across all managed hosts.
The account is intentionally minimal-privilege:
- No password set (SSH key auth only)
- Not a member of wheel, no sudo/sudo-rs rules
- Only extra group membership is systemd-journal, granting read access
to system logs for monitoring/analysis tasks
- Authorized key lives in home/ssh/emily_authorized_keys, mirroring the
existing pattern used for the greg account's authorized_keys
This lets the Hermes agent (emily) log in read-only to inspect logs and
system state when asked, without any ability to modify configuration,
escalate privileges, or run destructive commands.
Module is imported unconditionally in modules/nixos/default.nix like
the other nixos modules, and defaults to enabled; it can be disabled
per-host via greg.monitoring-access.enable = false if ever needed.
pve1 is a static/DHCP-reserved Proxmox host at 10.42.0.4 (previously
mislabeled 'joel' in some places). 10.42.1.1 is the UDM Pro gateway
IP, not pve1 -- OPNsense was retired in favor of Ubiquiti. Removes
the stale duplicate PVE1 DHCP reservation at 10.42.1.1 and drops the
now-redundant 'joel' entry from network.json (consolidated into
pve1).
* keepalived does not work with Nebula VPN
* update Genesis firewall to allow passing through local traffic
* target all traffic directly to the LAN IP using genesis's routing
* Consolidate Linode into a single file
* Convert gitea and matrix to using Nebula connections
* Have Linode proxy to Nebula connections instead of Tailscale
* Update Acme to use DNS-01
* Update Flake to pull from branch that supports ACME 5.x client
Zims update script has been slightly mangled since nix-prefetch stopped
working.
Now it is updated to use nix-prefetch-url and no longer pulls from the
Torrent sources. That script exports a regular SHA256 hash and not an
SRI signature, so we now convert that to SRI as a second step in the
pre-fetch pipline
Also adding a cron to run the tool every month on the first, in order to
keep it up to date.
greg
emily
Greg Hellings
klaatuandgreg