#!/usr/bin/env bash
# build-golden.sh — build the Felhom golden base LXC archive (slice 7).
#
# Produces a minimal Debian + Docker, unprivileged, nesting=1,keyctl=1, overlayfs LXC, baked
# identity-clean, and archives it for a token-restore by the bring-up reconcile job
# (internal/reconcile/bringup.go). Run as root@pam on a Proxmox host (the keyctl=1 feature flag
# is root-only — phase3 #1; this is the ONE root step, off the per-customer path).
#
# Grounded by documentation/tests/slice7-bringup-spike-findings.md (commit 3342993):
#   - F3: removing the SSH host keys does NOT auto-regenerate them on Debian (pct restore runs no
#     keygen hook), so a baked, Condition-gated first-boot unit regenerates them — keeping the
#     agent's front half host-side-only. The gate (ConditionPathExists=!…) makes it fire on a
#     provision (golden, keys absent) and no-op on a DR restore (customer backup, keys present),
#     symmetric with machine-id.
#   - machine-id: truncated; systemd regenerates it on first boot for free (no unit needed).
#
# Slice 8A — the golden now also BAKES the in-guest controller (decision: image baked at golden
# build on the trusted host, so NO registry credential ever enters a customer guest at deploy) and
# a controller-bootstrap unit that, on boot, deploys the baked image from the agent-populated
# config mount (/etc/felhom-bootstrap/bootstrap.json) — no docker login/pull at deploy. Refreshing
# the golden bumps the controller baseline; controller self-update covers in-between drift.
#
# Usage: build-golden.sh [VMID] [TEMPLATE_VOLID] [ROOTFS_STORAGE] [ARCHIVE_STORAGE] [BRIDGE] [CONTROLLER_IMAGE]
# Build-time registry login for the controller pull (used ONCE inside the build guest, then logged
# out — never baked): set REGISTRY_USER + REGISTRY_TOKEN in the environment.
set -euo pipefail

VMID="${1:-9100}"
TEMPLATE="${2:-local:vztmpl/debian-13-standard_13.1-2_amd64.tar.zst}"
ROOTFS_STORAGE="${3:-local-lvm}"
ARCHIVE_STORAGE="${4:-local}"
BRIDGE="${5:-vmbr0}"
CONTROLLER_IMAGE="${6:-gitea.dooplex.hu/admin/felhom-controller:v0.35.0}"
REGISTRY_HOST="${CONTROLLER_IMAGE%%/*}"

echo "[golden] creating build LXC $VMID (nesting=1,keyctl=1, unprivileged) …"
pct create "$VMID" "$TEMPLATE" \
  --hostname felhom-golden --unprivileged 1 \
  --features nesting=1,keyctl=1 \
  --rootfs "${ROOTFS_STORAGE}:8" --cores 2 --memory 2048 \
  --net0 "name=eth0,bridge=${BRIDGE},ip=dhcp" --onboot 0

echo "[golden] starting + installing Docker (official repo, trixie channel) …"
pct start "$VMID"
# wait for DHCP/DNS
for i in $(seq 1 30); do
  if pct exec "$VMID" -- getent hosts download.docker.com >/dev/null 2>&1; then break; fi
  sleep 1
done
pct exec "$VMID" -- bash -c '
  set -e
  export DEBIAN_FRONTEND=noninteractive
  apt-get update -qq
  apt-get install -y -qq ca-certificates curl >/dev/null
  install -m0755 -d /etc/apt/keyrings
  curl -fsSL https://download.docker.com/linux/debian/gpg -o /etc/apt/keyrings/docker.asc
  echo "deb [signed-by=/etc/apt/keyrings/docker.asc] https://download.docker.com/linux/debian trixie stable" \
    > /etc/apt/sources.list.d/docker.list
  apt-get update -qq
  apt-get install -y -qq docker-ce docker-ce-cli containerd.io >/dev/null
'
echo "[golden] verifying Docker works in the build guest …"
pct exec "$VMID" -- bash -c 'systemctl start docker; sleep 2; docker run --rm hello-world >/dev/null && echo "  docker OK ($(docker info 2>/dev/null | sed -n "s/.*Storage Driver: //p"))"'

echo "[golden] baking the in-guest controller image $CONTROLLER_IMAGE (no registry cred at deploy) …"
# docker login is used ONCE here on the trusted build host, then logged out before archiving so
# the credential is NEVER baked into the golden. The IMAGE is what gets baked (in Docker storage).
if [ -n "${REGISTRY_USER:-}" ] && [ -n "${REGISTRY_TOKEN:-}" ]; then
  pct exec "$VMID" -- bash -c "systemctl start docker; sleep 1; echo '$REGISTRY_TOKEN' | docker login '$REGISTRY_HOST' -u '$REGISTRY_USER' --password-stdin >/dev/null"
fi
pct exec "$VMID" -- bash -c "docker pull '$CONTROLLER_IMAGE'"
pct exec "$VMID" -- bash -c "docker logout '$REGISTRY_HOST' >/dev/null 2>&1 || true; rm -f /root/.docker/config.json"
# Record the baked image ref for the bootstrap unit (so the unit needs no login/pull).
pct exec "$VMID" -- bash -c "printf '%s\n' '$CONTROLLER_IMAGE' > /etc/felhom-controller-image"

echo "[golden] baking the controller-bootstrap unit (deploys the BAKED controller from the config mount) …"
pct push "$VMID" /dev/stdin /usr/local/sbin/felhom-controller-bootstrap.sh --perms 700 <<'BOOTSH'
#!/bin/bash
# felhom controller-bootstrap (slice 8A): the host agent's back-half populated the read-only
# config mount /etc/felhom-bootstrap; this golden-baked oneshot deploys the BAKED controller image
# with that config. NO docker login / NO docker pull — the image is already in this golden's Docker
# storage (and self-update handles version drift). Host-side only; the agent never enters the guest.
set -euo pipefail
CFG=/etc/felhom-bootstrap/bootstrap.json
[ -r "$CFG" ] || { echo "[ctrl-bootstrap] no $CFG — not provisioned, nothing to do"; exit 0; }
IMAGE=$(cat /etc/felhom-controller-image 2>/dev/null || true)
[ -n "$IMAGE" ] || { echo "[ctrl-bootstrap] FATAL: /etc/felhom-controller-image missing"; exit 1; }
echo "[ctrl-bootstrap] deploying $IMAGE from $CFG"
docker rm -f felhom-controller >/dev/null 2>&1 || true
docker run -d --name felhom-controller --restart unless-stopped \
  -e FELHOM_BOOTSTRAP_PATH=/etc/felhom-bootstrap/bootstrap.json \
  -v /etc/felhom-bootstrap:/etc/felhom-bootstrap:ro \
  -v felhom-controller-data:/opt/docker/felhom-controller \
  -v /var/run/docker.sock:/var/run/docker.sock \
  "$IMAGE"
echo "[ctrl-bootstrap] controller started"
BOOTSH
pct exec "$VMID" -- bash -c 'cat > /etc/systemd/system/felhom-controller-bootstrap.service <<UNIT
[Unit]
Description=Felhom controller bootstrap (deploy the baked controller from the agent-populated config mount)
After=docker.service network-online.target
Wants=docker.service network-online.target
ConditionPathExists=/etc/felhom-bootstrap/bootstrap.json

[Service]
Type=oneshot
RemainAfterExit=yes
ExecStart=/usr/local/sbin/felhom-controller-bootstrap.sh

[Install]
WantedBy=multi-user.target
UNIT
systemctl enable felhom-controller-bootstrap.service'

echo "[golden] baking the first-boot SSH host-key regeneration unit (F3) …"
pct exec "$VMID" -- bash -c 'cat > /etc/systemd/system/felhom-regen-hostkeys.service <<UNIT
[Unit]
Description=Regenerate SSH host keys on first boot if absent
ConditionPathExists=!/etc/ssh/ssh_host_ed25519_key
DefaultDependencies=no
After=local-fs.target
Before=ssh.service sshd.service

[Service]
Type=oneshot
RemainAfterExit=yes
ExecStart=/usr/bin/ssh-keygen -A

[Install]
WantedBy=multi-user.target
UNIT
systemctl enable felhom-regen-hostkeys.service'

echo "[golden] identity-clean + minimize …"
pct exec "$VMID" -- bash -c '
  systemctl stop docker containerd 2>/dev/null || true
  apt-get clean; rm -rf /var/lib/apt/lists/*
  rm -f /etc/ssh/ssh_host_*            # regenerated on first boot by the baked unit (F3)
  truncate -s 0 /etc/machine-id        # systemd regenerates on first boot (free)
  rm -f /var/lib/dbus/machine-id; ln -sf /etc/machine-id /var/lib/dbus/machine-id
  rm -rf /var/log/*; : > /root/.bash_history
  rm -f /etc/hostname                  # set per-guest at provision (host-side token config)
'

echo "[golden] stop + archive …"
pct stop "$VMID"
vzdump "$VMID" --storage "$ARCHIVE_STORAGE" --mode stop --compress zstd

VOLID=$(pvesm list "$ARCHIVE_STORAGE" --content backup 2>/dev/null | awk -v v="$VMID" '$1 ~ ("vzdump-lxc-" v "-") {print $1}' | sort | tail -1)
echo "[golden] DONE. golden archive volid: ${VOLID:-<check ${ARCHIVE_STORAGE} dump dir>}"
echo "[golden] (the build guest $VMID is stopped; destroy it with: pct destroy $VMID --purge)"