foundation/runners/index.ts

// runners/index.ts — Step-0-after-foundation: the fenced Actions runner fleet.
//
// ISOLATED STACK, decoupled from `bootstrap` on purpose (see Pulumi.yaml). A
// @pulumi/libvirt provider dials the runner HOST (e.g. crunchy01) on every
// up/refresh/preview; keeping that here — never imported by bootstrap — means
// foundation ops never require, and are never blocked by, the runner host being
// reachable. One-way dependency only: this stack mints a runner token FROM the
// forge, so it runs after the foundation stands.
//
// It codifies what SESSION_2026-07-01_003 built by hand (see runners/README.md):
//   1. an Ubuntu VM on the host's LAN bridge, with docker + qemu-guest-agent;
//   2. a kube-router-proof FORWARD accept (the host is a k3s node whose FORWARD
//      policy is DROP — bridged VM traffic needs an idempotent, re-asserted rule);
//   3. a Forgejo Actions runner registered with a distinct label ("fenced") so
//      ecosystem/untrusted jobs (runs-on: fenced) run OFF the forge VM (R5).
//
// PREREQUISITE (host, one-time, kept OUT of this stack so the libvirt provider
// always has something to connect to): qemu-kvm + libvirt-daemon-system +
// libvirt-clients + virtinst + cloud-image-utils installed on the host, libvirtd
// enabled, and a LAN bridge (br0). See runners/README.md §Host prep.
import * as pulumi from "@pulumi/pulumi";
import * as libvirt from "@pulumi/libvirt";
import * as command from "@pulumi/command";
import * as fs from "fs";
import * as yaml from "js-yaml";

const cfg = new pulumi.Config();

// --- runner host (libvirt over qemu+ssh) ---
const host = {
  address: cfg.get("host.address") ?? "192.168.1.2", // crunchy01
  user: cfg.get("host.user") ?? "root",
  bridge: cfg.get("host.bridge") ?? "br0", // LAN bridge the VM joins
  pool: cfg.get("host.pool") ?? "default", // libvirt storage pool (nvme)
};
// SSH key reaching the host AND the created VM (root). Path via ENV, never config.
const sshKeyPath =
  process.env.RUNNER_SSH_KEY_PATH ??
  `${process.env.HOME}/.ssh/foundation-test_ed25519`;
const sshPrivateKey = pulumi.secret(fs.readFileSync(sshKeyPath, "utf8"));
const sshPublicKey = fs.readFileSync(`${sshKeyPath}.pub`, "utf8").trim();
const hostConn: command.types.input.remote.ConnectionArgs = {
  host: host.address,
  port: cfg.getNumber("host.sshPort") ?? 22,
  user: host.user,
  privateKey: sshPrivateKey,
};

// --- the forge (mint a runner registration token; reached over SSH via docker) ---
const forge = {
  address: cfg.get("forge.address") ?? "204.168.234.72",
  sshPort: cfg.getNumber("forge.sshPort") ?? 222,
  user: cfg.get("forge.user") ?? "root",
  instanceUrl: cfg.get("forge.instanceUrl") ?? "https://forge.olsitec.net",
  container: cfg.get("forge.container") ?? "foundation-forgejo",
};
const forgeConn: command.types.input.remote.ConnectionArgs = {
  host: forge.address,
  port: forge.sshPort,
  user: forge.user,
  privateKey: sshPrivateKey,
};

// --- the VM + runner shape ---
const vm = {
  name: cfg.get("vm.name") ?? "foundation-runner-01",
  vcpu: cfg.getNumber("vm.vcpu") ?? 4,
  memoryMiB: cfg.getNumber("vm.memoryMiB") ?? 8192,
  diskGiB: cfg.getNumber("vm.diskGiB") ?? 40,
  // LAN address for the VM. Empty → DHCP (the runner polls the forge outbound, so a
  // fixed address is optional). Default matches the hand-built VM.
  ipCidr: cfg.get("vm.ipCidr") ?? "192.168.1.15/24",
  gateway: cfg.get("vm.gateway") ?? "192.168.1.251",
  nameservers: (cfg.getObject<string[]>("vm.nameservers")) ?? [
    "192.168.1.251",
    "1.1.1.1",
  ],
  ubuntuImageUrl:
    cfg.get("vm.ubuntuImageUrl") ??
    "https://cloud-images.ubuntu.com/noble/current/noble-server-cloudimg-amd64.img",
};
// The runner label(s). `fenced` routes runs-on: fenced here; the schema maps it to a
// default job image on the VM's docker.
const runnerLabels =
  cfg.get("runner.labels") ?? "fenced:docker://node:20-bookworm";

// =============================================================================
// libvirt provider — qemu+ssh to the host. Lazy-connects when a libvirt resource
// is created; the host prerequisite (libvirtd) must already be satisfied.
// =============================================================================
const provider = new libvirt.Provider("runner-host", {
  uri: `qemu+ssh://${host.user}@${host.address}/system?sshauth=privkey&keyfile=${sshKeyPath}&known_hosts_verify=ignore`,
});

// --- host prep: the kube-router-proof bridged-FORWARD accept (idempotent timer) ---
// The host is a k3s node; kube-router sets FORWARD policy DROP and re-syncs iptables,
// which drops bridged VM↔LAN traffic and can flush a hand-added rule. A 60s systemd
// timer re-asserts it. This is a control-plane op on the HOST (not a libvirt resource).
const FIREWALL = `set -eu
cat > /etc/systemd/system/libvirt-bridge-forward.service <<'U'
[Unit]
Description=Ensure bridged VM traffic passes iptables FORWARD (libvirt on a kube-router host)
After=network-online.target
[Service]
Type=oneshot
ExecStart=/bin/sh -c 'iptables -C FORWARD -m physdev --physdev-is-bridged -j ACCEPT 2>/dev/null || iptables -I FORWARD 1 -m physdev --physdev-is-bridged -j ACCEPT'
U
cat > /etc/systemd/system/libvirt-bridge-forward.timer <<'U'
[Unit]
Description=Re-assert the bridged-FORWARD accept rule (kube-router flushes iptables on resync)
[Timer]
OnBootSec=30s
OnUnitActiveSec=60s
AccuracySec=5s
[Install]
WantedBy=timers.target
U
systemctl daemon-reload
systemctl enable --now libvirt-bridge-forward.timer >/dev/null
echo "bridged-FORWARD timer active"`;
const firewall = new command.remote.Command("runner-host-firewall", {
  connection: hostConn,
  create: FIREWALL,
  update: FIREWALL,
});

// =============================================================================
// The VM: Ubuntu base volume → backed domain disk → cloud-init → domain.
// Ubuntu (not the Debian genericcloud image) because Debian's cloud-init wrote
// netplan the image never applied (no IPv4); Ubuntu renders + applies it cleanly.
// =============================================================================
const base = new libvirt.Volume(
  `${vm.name}-base`,
  {
    name: `${vm.name}-ubuntu-base.img`,
    source: vm.ubuntuImageUrl,
    pool: host.pool,
    format: "qcow2",
  },
  { provider },
);
const disk = new libvirt.Volume(
  `${vm.name}-disk`,
  {
    name: `${vm.name}.qcow2`,
    pool: host.pool,
    format: "qcow2",
    baseVolumeId: base.id,
    size: vm.diskGiB * 1024 * 1024 * 1024,
  },
  { provider },
);

// cloud-init user-data: docker + qemu-guest-agent + our SSH key + a marker.
const userData =
  "#cloud-config\n" +
  yaml.dump({
    hostname: vm.name,
    manage_etc_hosts: true,
    ssh_pwauth: false,
    users: [
      {
        name: "root",
        lock_passwd: false,
        ssh_authorized_keys: [sshPublicKey],
      },
    ],
    packages: ["ca-certificates", "curl", "jq", "qemu-guest-agent"],
    runcmd: [
      ["sh", "-c", "curl -fsSL https://get.docker.com | sh"],
      "systemctl enable --now docker qemu-guest-agent",
      "touch /root/cloud-init-done",
    ],
  });
// network-config v2: static on enp1s0 if ipCidr set, else DHCP. Ubuntu applies both.
const networkConfig = yaml.dump({
  version: 2,
  ethernets: {
    enp1s0: vm.ipCidr
      ? {
          dhcp4: false,
          addresses: [vm.ipCidr],
          routes: [{ to: "default", via: vm.gateway }],
          nameservers: { addresses: vm.nameservers },
        }
      : { dhcp4: true },
  },
});
const cloudinit = new libvirt.CloudInitDisk(
  `${vm.name}-cloudinit`,
  { name: `${vm.name}-cloudinit.iso`, pool: host.pool, userData, networkConfig },
  { provider },
);

const domain = new libvirt.Domain(
  vm.name,
  {
    name: vm.name,
    memory: vm.memoryMiB,
    vcpu: vm.vcpu,
    cpu: { mode: "host-passthrough" },
    autostart: true,
    qemuAgent: true,
    cloudinit: cloudinit.id,
    disks: [{ volumeId: disk.id }],
    networkInterfaces: [{ bridge: host.bridge }],
    // A real PTY console so `virsh console <vm>` works (learned the hard way).
    consoles: [
      { type: "pty", targetPort: "0", targetType: "serial" },
      { type: "pty", targetPort: "1", targetType: "virtio" },
    ],
  },
  { provider, dependsOn: [firewall] },
);

// =============================================================================
// Register the Forgejo runner: mint a token on the forge, then register + run
// act_runner inside the VM (docker), reachable once cloud-init has installed docker.
// =============================================================================
// 1) token — instance-scoped registration token, minted over SSH via docker exec.
const tokenCmd = new command.remote.Command("runner-token", {
  connection: forgeConn,
  create: `docker exec -u git ${forge.container} forgejo actions generate-runner-token`,
  // Re-mint if the forge container id or the label set changes.
  triggers: [runnerLabels],
});
const runnerToken = pulumi.secret(tokenCmd.stdout.apply((s) => s.trim()));

// 2) register + run — connect to the VM (its static/DHCP IP). The script waits for
// cloud-init (docker) to be ready, registers idempotently, and runs the daemon with
// the host docker gid so uid-1000 act_runner can reach the socket.
const vmIp = vm.ipCidr ? vm.ipCidr.split("/")[0] : host.address; // static → known IP
const REGISTER = pulumi.interpolate`set -eu
IMG=code.forgejo.org/forgejo/runner:6
for _ in $(seq 1 60); do [ -f /root/cloud-init-done ] && docker info >/dev/null 2>&1 && break; sleep 5; done
DGID=$(stat -c %g /var/run/docker.sock)
docker volume inspect crunchy-runner-data >/dev/null 2>&1 || docker volume create crunchy-runner-data >/dev/null
docker pull -q "$IMG" >/dev/null
if docker run --rm -v crunchy-runner-data:/data --entrypoint sh "$IMG" -c '[ -s /data/.runner ]'; then
  echo "already registered"
else
  printf '%s' '${runnerToken}' | docker run --rm -i -v crunchy-runner-data:/data --entrypoint sh "$IMG" -c 'cat > /tmp/t'
  docker run --rm -v crunchy-runner-data:/data --entrypoint /bin/forgejo-runner "$IMG" \
    register --no-interactive --instance ${forge.instanceUrl} --token "$(docker run --rm -v crunchy-runner-data:/data --entrypoint sh "$IMG" -c 'cat /tmp/t')" \
    --name ${vm.name} --labels '${runnerLabels}' >/dev/null
  echo "registered"
fi
docker rm -f forgejo-runner >/dev/null 2>&1 || true
docker run -d --name forgejo-runner --restart unless-stopped --group-add "$DGID" \
  -v crunchy-runner-data:/data -v /var/run/docker.sock:/var/run/docker.sock \
  --entrypoint /bin/forgejo-runner "$IMG" daemon >/dev/null
echo "runner daemon up"`;
const register = new command.remote.Command(
  "runner-register",
  {
    connection: {
      host: vmIp,
      port: 22,
      user: "root",
      privateKey: sshPrivateKey,
    },
    create: REGISTER,
    triggers: [domain.id, runnerToken, runnerLabels],
  },
  { dependsOn: [domain, tokenCmd] },
);

export const runnerHost = host.address;
export const runnerVmIp = vmIp;
export const runnerLabelsOut = runnerLabels;
export const forgeInstance = forge.instanceUrl;
void register;