diff --git a/documentation/runbooks/offsite-endpoint.md b/documentation/runbooks/offsite-endpoint.md new file mode 100644 index 0000000..3666fa5 --- /dev/null +++ b/documentation/runbooks/offsite-endpoint.md @@ -0,0 +1,215 @@ +# RUNBOOK — offsite endpoint provisioning (WG server + PBS + peersync surface) + +> **What this creates:** the Felhom offsite endpoint (doc 06 §5) on a blank Debian 13 VM — the +> WG server on **443/UDP**, the offsite PBS with a `/srv` datastore, a drop-everything-else +> firewall, and the hub-driven `felhom-peersync` reconcile surface. Re-running it on a fresh VM +> re-creates the endpoint from nothing (that is the DR story, step 8). +> +> **Validated:** 2026-07-03 on the dev/test endpoint `felhom-hetzner` (Hetzner CX23, Debian 13, +> `167.233.158.164` / `2a01:4f8:1c16:7aa1::1`) with hub v0.32.0. The production endpoint is a +> later re-run of this runbook on a production VM. +> +> Companion piece: the hub side (env + Secret) is `manifests/hub.yaml` + step 6/7 below. +> The peersync script's source of truth is `scripts/felhom-peersync.sh` (v1.0.0). + +Parameters used throughout (adjust for a new endpoint): + +| Param | Dev value | +|---|---| +| VM | `felhom-hetzner`, `167.233.158.164` (**NOT the live jarrs.eu box** — different server) | +| DNS name | `ep0.felhom.eu` (A + AAAA, **DNS-only / grey-cloud** — proxying breaks WG/UDP + PBS) | +| WG port | **443/udp** (spike P4: handshakes + carries identically to 51820) | +| Tunnel subnet | `10.77.0.0/24`; endpoint in-tunnel IP `10.77.0.1` | +| PBS datastore | `felhom-offsite` at `/srv/pbs-felhom` (**never under `/root`** — the `backup` user cannot traverse it; spike gotcha) | + +## 0. Preconditions (operator) + +- [ ] The VM is powered on and root-SSH-reachable. +- [ ] DNS `ep0.felhom.eu` → A `167.233.158.164` + AAAA `2a01:4f8:1c16:7aa1::1`, **grey-cloud**. + Verify: `nslookup ep0.felhom.eu 1.1.1.1` returns the A record. **The AAAA must be the + box's full `::1` address** — a bare `...:7aa1::` (the subnet zero address) resolves but + points at nothing (live-run finding). Home-resolver propagation can lag public DNS by + minutes — a client-side `wg-quick up` that fails to resolve right after record creation + just needs a retry. +- [ ] Sanity: `ssh root@167.233.158.164 hostname` → `felhom-hetzner` (the throwaway CX23), not + any production box. + +## 1. Base (on the box, as root) + +```sh +apt update && DEBIAN_FRONTEND=noninteractive apt full-upgrade -y +printf 'PasswordAuthentication no\n' > /etc/ssh/sshd_config.d/90-felhom.conf && systemctl reload ssh +sshd -T | grep -i '^passwordauthentication' # must print: passwordauthentication no +``` +(The explicit drop-in beats auditing defaults — Hetzner images have no explicit line at all.) + +## 2. WG server + +```sh +apt install -y wireguard-tools # module ships in the stock Debian 13 kernel +umask 077 +wg genkey > /etc/wireguard/wg0.key # server private key — NEVER displayed/copied anywhere +wg pubkey < /etc/wireguard/wg0.key # RECORD this pubkey → hub registration (step 7) +cat > /etc/wireguard/wg0.conf.head < **NEVER run `wg show dump` in a logged/shared session** — field 1 of its interface line +> is the **private key**. Plain `wg show` prints only the public key. (Live-run lesson: a +> `dump | cut` leaked the first server key into a session log → the key was rotated on the +> spot. If it happens to you: regenerate the keypair, rebuild `wg0.conf.head` + `wg0.conf`, +> restart `wg-quick@wg0`, re-`PUT` the new pubkey to the hub — 2 minutes, zero peer downtime +> beyond the restart.) + +## 3. Firewall (nftables, v4+v6) + +```sh +cat > /etc/nftables.conf <<'EOF' +#!/usr/sbin/nft -f +flush ruleset +table inet filter { + chain input { + type filter hook input priority 0; policy drop; + ct state established,related accept + iif "lo" accept + tcp dport 22 accept + udp dport 443 accept + tcp dport 8007 iifname "wg0" accept + ip protocol icmp accept + meta l4proto ipv6-icmp accept + } + chain forward { + type filter hook forward priority 0; policy drop; + } +} +EOF +systemctl enable --now nftables +nft list ruleset | head -20 +sysctl net.ipv4.ip_forward +``` +Verify (doc 06 §4.5 — no inter-peer routing by topology): forward chain policy **drop**, +`net.ipv4.ip_forward = 0`. From an outside vantage: `ssh` (22) connects; **8007 publicly +CLOSED** — `curl -sk --max-time 8 https://:8007/` must time out (the spike-P2b +firewall proof, repeated). 443/udp is proven by the first WG handshake in step 7's validation. + +## 4. PBS + +```sh +curl -fsSL https://enterprise.proxmox.com/debian/proxmox-release-trixie.gpg \ + -o /usr/share/keyrings/proxmox-archive-keyring.gpg +echo 'deb [signed-by=/usr/share/keyrings/proxmox-archive-keyring.gpg] http://download.proxmox.com/debian/pbs trixie pbs-no-subscription' \ + > /etc/apt/sources.list.d/pbs.list +apt update && DEBIAN_FRONTEND=noninteractive apt install -y --no-install-recommends \ + proxmox-backup-server proxmox-backup-client # client is a SEPARATE package (namespace ops need it) +rm -f /etc/apt/sources.list.d/pbs-enterprise.sources # the install adds the ENTERPRISE repo → 401s every apt update +apt update +proxmox-backup-manager datastore create felhom-offsite /srv/pbs-felhom +# prove namespace ops (per-customer tenancy, doc 06 D5) with a THROWAWAY token, then remove it +# (root@pam has no password on a cloud image; S4 wires the real per-customer tokens): +umask 077 +proxmox-backup-manager user generate-token root@pam nsproof > /root/.nsproof +proxmox-backup-manager acl update /datastore/felhom-offsite DatastoreAdmin --auth-id 'root@pam!nsproof' +export PBS_PASSWORD="$(tr -d '\n' < /root/.nsproof | sed -n 's/.*"value": "\([^"]*\)".*/\1/p')" +export PBS_FINGERPRINT="$(proxmox-backup-manager cert info | grep -i fingerprint | awk '{print $3}')" +proxmox-backup-client namespace create test-ns --repository 'root@pam!nsproof@localhost:felhom-offsite' +proxmox-backup-client namespace delete test-ns --repository 'root@pam!nsproof@localhost:felhom-offsite' +proxmox-backup-manager user delete-token root@pam nsproof && rm -f /root/.nsproof +``` +Verify: `systemctl is-active proxmox-backup proxmox-backup-proxy` → both `active`; the +datastore parent is `/srv` (world-traversable — a datastore under `/root` fails with +`Permission denied` for the `backup` user). GUI: reachable ONLY via SSH port-forward +(`ssh -L 8007:127.0.0.1:8007 root@`) or through the tunnel — by design, no public 8007. + +## 5. Peersync surface + +```sh +useradd -m -s /bin/sh felhom-peersync # real shell required for the forced command; + # access is bounded by the key options + sudoers, not the shell +apt install -y jq +# install the script (from the repo; strip CRLF if staging via a Windows checkout): +tr -d '\r' < scripts/felhom-peersync.sh > /usr/local/bin/felhom-peersync +chown root:root /usr/local/bin/felhom-peersync && chmod 0755 /usr/local/bin/felhom-peersync +cat > /etc/sudoers.d/felhom-peersync <<'EOF' +felhom-peersync ALL=(root) NOPASSWD: /usr/local/bin/felhom-peersync +EOF +visudo -c +``` +Verify: `visudo -c` → "parsed OK". The authorized_keys entry is written in step 6 (it needs +the hub's pubkey): + +``` +restrict,command="sudo /usr/local/bin/felhom-peersync" ssh-ed25519 AAAA... hub@felhom +``` + +(`restrict` kills pty/forwarding/X11/agent in one word; the forced command overrides whatever +the client asks to run.) + +## 6. Hub credential (build server + the box + k3s) + +On the build server (192.168.0.180): + +```sh +ssh-keygen -t ed25519 -f wg-endpoint-ssh -N "" -C hub@felhom +``` + +- The **pubkey** (`wg-endpoint-ssh.pub`) goes into step 5's authorized_keys line on the box: + `printf 'restrict,command="sudo /usr/local/bin/felhom-peersync" %s\n' "$(cat wg-endpoint-ssh.pub)" > /home/felhom-peersync/.ssh/authorized_keys` + (as root on the box; `.ssh` dir 0700, file 0600, owner `felhom-peersync`). +- Read the endpoint's **host key on the box itself** (never trust `ssh-keyscan` alone): + `cat /etc/ssh/ssh_host_ed25519_key.pub` +- Create the k8s Secret, then **shred the local private key** — from this point it exists ONLY + in the Secret: + +```sh +sudo kubectl -n felhom-system create secret generic wg-endpoint-ssh \ + --from-file=key=wg-endpoint-ssh \ + --from-literal=hostkey='ssh-ed25519 AAAA...the-host-key-line' +shred -u wg-endpoint-ssh wg-endpoint-ssh.pub +``` + +Then apply the manifest + roll the hub (`manifests/hub.yaml` already mounts the Secret as +optional): expect `[INFO] WG peer-sync enabled (endpoint 167.233.158.164:22, ...)` in the hub +log (before the Secret existed it says `disabled (endpoint not configured)`). + +## 7. Register the endpoint in the hub + +```sh +curl -s -X PUT https://hub.felhom.eu/api/v1/admin/wg/endpoint \ + -H "Authorization: Bearer " \ + -d '{"dns_name":"ep0.felhom.eu","wg_port":443,"server_pubkey":"", + "tunnel_subnet":"10.77.0.0/24","pbs_tunnel_ip":"10.77.0.1"}' +``` + +Validation loop (the S1 done-criterion): `POST /api/v1/admin/wg/peers {"pubkey":...}` with a +throwaway pubkey → response `sync:"ok"` → on the box `wg show wg0 peers` lists it → +`DELETE /api/v1/admin/wg/peers {"pubkey":...}` → gone from `wg show`. A live handshake + +`curl -sk https://10.77.0.1:8007/` through a throwaway client tunnel proves 443/udp + the +wg0-only 8007 rule end-to-end. + +## 8. Re-provision from nothing (the DR story) + +The rebuild is **steps 1–7 on a fresh VM**. What is lost vs regenerable: + +- **WG server keypair — regenerable**, but every existing peer's config then points at a dead + server pubkey. Until S2/S3 deliver endpoint coords via desired-state, re-keying is a + **manual client-side update** (dev-acceptable; note per doc 06 §7). Register the new pubkey + via step 7; peers re-converge as they're updated. +- **The hub's peer registry survives** (it lives in the hub DB): a rebuilt endpoint converges + on the first reconciler tick (≤5 min) or the next mutation — no re-registration needed. +- **The PBS datastore is the real loss** — customer ciphertext. PBS-side redundancy is a + deferred economics call (doc 06 §7); until then, endpoint loss = offsite history loss + (customers still hold local backups + a re-seedable offsite). +- The hub's SSH credential + pinned host key must be **rotated on rebuild** (new box = new + host key): repeat step 6 (`kubectl delete secret wg-endpoint-ssh` first), roll the hub.