hyperhive/hive-c0re/src/lifecycle/mod.rs

1021 lines
41 KiB
Rust

//! `nixos-container` lifecycle + per-agent config flake generation.
mod git;
mod host_config;
mod setup;
#[cfg(test)]
mod tests;
pub use git::{
git, git_command, git_fetch_to_tag, git_read_tree_reset, git_rev_parse, git_tag,
git_tag_annotated, git_update_ref,
};
pub use host_config::{
CONTAINER_MANAGER_AGENTS_MOUNT, CONTAINER_MANAGER_APPLIED_MOUNT, write_dropins,
};
pub use setup::{
ensure_agent_state_subvolume, ensure_claude_dir, ensure_state_dir, initial_flake_nix,
setup_applied, setup_proposed,
};
use std::path::Path;
use anyhow::{Context, Result, bail};
use tokio::process::Command;
use crate::coordinator::{AgentPaths, HiveEnv};
/// Sub-agent container prefix. `nixos-container` caps the total container name
/// at 11 chars (it gets encoded into network interface names), so the agent
/// name itself can be at most `MAX_AGENT_NAME` chars.
pub const AGENT_PREFIX: &str = "h-";
pub const MAX_AGENT_NAME: usize = 9;
/// Logical name of the manager agent (broker recipient, state-dir key,
/// meta flake attribute). All persistent state lives under `ruth/`.
pub const MANAGER_NAME: &str = "ruth";
/// Container name of the manager. Uses the same `h-` prefix as sub-agents
/// so `nixos-container list` output is uniform and the list filter is
/// a single `starts_with(AGENT_PREFIX)` check. Logical name → container
/// name: `ruth` → `h-ruth`.
pub const MANAGER_CONTAINER: &str = "h-ruth";
/// Mount point of the per-agent runtime directory inside the container.
pub const CONTAINER_RUNTIME_MOUNT: &str = "/run/hive";
/// Where the per-agent Claude credentials dir mounts inside the
/// container. The harness service runs as a non-root unix user
/// whose home is `/home/<agent>/`, so the mount path varies per
/// agent — `container_claude_mount(name)` returns
/// `/home/<name>/.claude` for every agent including the manager.
/// `claude` inside the container reads
/// `$HOME/.claude` and the service environment sets `HOME` to the
/// same path, so the OAuth session survives container restarts.
#[must_use]
pub fn container_claude_mount(name: &str) -> String {
format!("/home/{name}/.claude")
}
/// Mount point of the shared directory accessible to all agents.
/// All agents can read/write here; agents should only put things they're
/// willing to lose (other agents may delete them).
pub const CONTAINER_SHARED_MOUNT: &str = "/shared";
/// Sub-agent web UI port range. Deterministic from the agent's name (FNV-1a
/// hash mod range size), so the dashboard can compute the same port without
/// asking hive-c0re.
const WEB_PORT_BASE: u16 = 8100;
const WEB_PORT_RANGE: u16 = 900;
/// FNV-1a hash of a string — shared by `agent_web_port` and
/// `agent_network_ip` so the derivation rule is identical.
fn fnv1a(s: &str) -> u32 {
let mut hash: u32 = 2_166_136_261;
for b in s.bytes() {
hash ^= u32::from(b);
hash = hash.wrapping_mul(16_777_619);
}
hash
}
/// Per-agent web UI port — `WEB_PORT_BASE + FNV-1a(name) %
/// WEB_PORT_RANGE` for every agent including the manager. The port
/// allocation rule reads the same for every name; collisions are
/// possible (birthday paradox at ~30 agents) and the operator
/// resolves them by renaming an agent (different hash → different
/// port). Stable across hosts, restarts, and dashboard renders —
/// no state-file dance.
#[must_use]
pub fn agent_web_port(name: &str) -> u16 {
// Modulo of a u32 by a u16's value is guaranteed < u16::MAX, so try_from never fails.
WEB_PORT_BASE + u16::try_from(fnv1a(name) % u32::from(WEB_PORT_RANGE)).unwrap_or(0)
}
/// Deterministic IPv4 address for an agent inside an isolated subnet.
///
/// Parses `subnet_cidr` as `<network_ip>/<prefix_len>` (e.g.
/// `"10.42.0.0/24"`), then computes:
///
/// ```text
/// host_count = 2^(32 - prefix_len)
/// usable = host_count - 3 // skip .0 (network), .1 (gateway), .255 (broadcast)
/// offset = FNV-1a(name) % usable + 2 // .2 is the first agent slot
/// agent_ip = network_base_u32 + offset
/// ```
///
/// Returns `None` when `subnet_cidr` can't be parsed (invalid format,
/// prefix out of range, etc.) so callers can fall back gracefully.
/// Collisions are possible (birthday paradox) and the operator resolves
/// them by renaming an agent, same as for port collisions.
#[must_use]
pub fn agent_network_ip(name: &str, subnet_cidr: &str) -> Option<String> {
let (ip_str, prefix_str) = subnet_cidr.split_once('/')?;
let prefix_len: u32 = prefix_str.parse().ok()?;
if prefix_len > 30 {
// /31 and /32 have no room for agents; /30 has 1 usable slot.
// /0 (the other extreme) is handled further down: host_count
// overflows checked_shl(32) → 0 → usable = 0 → None.
return None;
}
// Parse dotted-decimal IPv4.
let octets: Vec<u8> = ip_str
.split('.')
.map(|o| o.parse::<u8>().ok())
.collect::<Option<Vec<_>>>()?;
if octets.len() != 4 {
return None;
}
let base_u32 = u32::from_be_bytes([octets[0], octets[1], octets[2], octets[3]]);
// Mask off host bits to get the true network address.
let mask = if prefix_len == 0 {
0u32
} else {
!0u32 << (32 - prefix_len)
};
let network_base = base_u32 & mask;
let host_count: u32 = 1u32.checked_shl(32 - prefix_len).unwrap_or(0);
// `.0` = network, `.1` = bridge gateway, last = broadcast → 3 reserved.
let usable = host_count.saturating_sub(3);
if usable == 0 {
return None;
}
let offset = fnv1a(name) % usable + 2; // +2: skip .0 and .1
let ip_u32 = network_base + offset;
let [a, b, c, d] = ip_u32.to_be_bytes();
Some(format!("{a}.{b}.{c}.{d}"))
}
/// Extract the bridge gateway IP from `HIVE_NETWORK_SUBNET`.
///
/// `HIVE_NETWORK_SUBNET` carries the host-side bridge address verbatim
/// (e.g. `10.42.0.1/24`), **not** the canonical network address — see
/// the note in `set_nspawn_flags` + `docs/network.md`. The IP part is
/// therefore the bridge IP itself: the host end of the bridge, the
/// default-route target for isolated containers, and the address the
/// hive dnsmasq resolver binds. Returns the dotted-decimal IP with the
/// `/<prefix>` stripped, or `None` if the input isn't a valid
/// `<ipv4>/<prefix>` pair.
///
/// Deliberately returns the operator-configured address verbatim rather
/// than deriving `network + 1`: an operator who sets `bridgeIp` to a
/// non-`.1` host address (e.g. `10.42.0.254`) runs the bridge + resolver
/// there, so that — not `.1` — is the real gateway.
#[must_use]
pub fn bridge_gateway_ip(subnet_cidr: &str) -> Option<String> {
let (ip_str, prefix_str) = subnet_cidr.split_once('/')?;
// Validate the prefix is a sane IPv4 CIDR length and the address is
// dotted-decimal IPv4 — same shape `agent_network_ip` accepts — so a
// malformed `HIVE_NETWORK_SUBNET` can't smuggle a bogus HOST_ADDRESS
// into the nspawn conf.
let prefix_len: u32 = prefix_str.parse().ok()?;
if prefix_len > 32 {
return None;
}
let octets: Vec<u8> = ip_str
.split('.')
.map(|o| o.parse::<u8>().ok())
.collect::<Option<Vec<_>>>()?;
if octets.len() != 4 {
return None;
}
Some(ip_str.to_owned())
}
#[must_use]
pub fn container_name(name: &str) -> String {
format!("{AGENT_PREFIX}{name}")
}
/// Read the agent user's `(uid, gid)` from the container's nixos-managed
/// `/etc/passwd`. Returns `None` when the container hasn't been built
/// yet, the passwd file is unparseable, or the agent user is missing
/// (e.g. legacy container that still runs as root).
///
/// Used by `forge` + `matrix` after writing per-agent state files so
/// the bind-mounted host file ends up readable by the agent user
/// without waiting for the next container activation to run the chown
/// fixup.
///
/// Notes:
/// - Reads the *container-local* passwd at
/// `/var/lib/nixos-containers/<container>/etc/passwd`, not the host's.
/// The container's user-namespace shares uids with the host (no
/// `PrivateUsers`), so the uid is directly usable in host-side
/// `chown(2)`.
/// - Best-effort: caller treats `None` as "skip the chown".
#[must_use]
pub fn agent_uid_gid(agent_name: &str) -> Option<(u32, u32)> {
let container = container_name(agent_name);
let passwd_path = format!("/var/lib/nixos-containers/{container}/etc/passwd");
let content = std::fs::read_to_string(&passwd_path).ok()?;
for line in content.lines() {
let mut parts = line.split(':');
let user = parts.next()?;
if user != agent_name {
continue;
}
let _ = parts.next()?; // x (password placeholder)
let uid: u32 = parts.next()?.parse().ok()?;
let gid: u32 = parts.next()?.parse().ok()?;
return Some((uid, gid));
}
None
}
/// Best-effort `chown(path, agent_uid, agent_gid)`. Resolves the agent's
/// uid/gid via [`agent_uid_gid`] and shells out to `std::os::unix::fs::chown`.
/// Silently no-ops when the container isn't built yet (`None` from
/// [`agent_uid_gid`]) and logs at debug on chown syscall failure — the
/// activation script in `harness-base.nix` is the steady-state safety
/// net. Used by per-agent state writers in `forge` + `matrix` so the
/// agent can read the file without waiting for the next container
/// rebuild.
pub fn chown_to_agent(name: &str, path: &Path, subsystem: &str) {
let Some((uid, gid)) = agent_uid_gid(name) else {
return;
};
if let Err(e) = std::os::unix::fs::chown(path, Some(uid), Some(gid)) {
tracing::debug!(%name, %subsystem, path = %path.display(), error = %e, "chown to agent failed");
}
}
fn validate(name: &str) -> Result<()> {
if name.is_empty() {
bail!("agent name must not be empty");
}
if name.len() > MAX_AGENT_NAME {
bail!(
"agent name '{name}' is too long ({} chars); max {MAX_AGENT_NAME}",
name.len()
);
}
Ok(())
}
/// First name (≠ `self_name`) currently running whose hashed port
/// matches this agent's. The harness inside the colliding container
/// would otherwise loop on `AddrInUse` forever; we surface the
/// conflict here so spawn / rebuild fails loudly with an actionable
/// message instead.
async fn port_collision(self_name: &str) -> Option<String> {
let port = agent_web_port(self_name);
let raw = list().await.unwrap_or_default();
for c in raw {
let Some(other) = c.strip_prefix(AGENT_PREFIX) else {
continue;
};
if other == self_name {
continue;
}
if agent_web_port(other) == port && is_running(other).await {
return Some(other.to_owned());
}
}
None
}
pub async fn spawn(name: &str, hive: &HiveEnv, paths: &AgentPaths) -> Result<()> {
create_container(name, hive, paths).await?;
// Runtime dir must exist before nixos-container start (nspawn bind-mount
// source). Create it here so callers don't need a separate preamble step.
ensure_agent_runtime_dir(name)?;
write_dropins(name, hive, paths).await?;
priv_run("start", name).await
}
/// First-spawn provisioning + `nixos-container create`, without the
/// drop-in write or the start — the job queue's `Create` node.
/// `spawn` composes this with `write_dropins` + start for direct
/// callers (root-agent bootstrap).
pub async fn create_container(name: &str, hive: &HiveEnv, paths: &AgentPaths) -> Result<()> {
validate(name)?;
if let Some(other) = port_collision(name).await {
bail!(
"port {} is already taken by '{other}' — rename one of them and retry",
agent_web_port(name)
);
}
setup_proposed(&paths.proposed_dir, name).await?;
setup_applied(&paths.applied_dir, Some(&paths.proposed_dir), name).await?;
ensure_agent_state_subvolume(name).await?;
ensure_claude_dir(&paths.claude_dir)?;
ensure_state_dir(&paths.notes_dir)?;
// Meta flake gets the new agent's input + nixosConfiguration
// before `nixos-container create` so the `--flake meta#<name>`
// ref resolves.
let agents = agents_after_spawn(name).await?;
crate::meta::sync_agents(hive, &agents).await?;
priv_run("create", name).await
}
/// Rebuild-path preamble shared by the job queue's `Prebuild` node and
/// `rebuild_no_meta`: fail fast on a port collision, then make sure
/// the applied repo + state dirs exist. Container untouched.
pub async fn prepare_rebuild_dirs(name: &str, paths: &AgentPaths) -> Result<()> {
validate(name)?;
if let Some(other) = port_collision(name).await {
bail!(
"port {} is already taken by '{other}' — rename one of them and retry",
agent_web_port(name)
);
}
setup_applied(&paths.applied_dir, None, name).await?;
ensure_agent_state_subvolume(name).await?;
ensure_claude_dir(&paths.claude_dir)?;
ensure_state_dir(&paths.notes_dir)?;
Ok(())
}
/// Profile-swap for an existing, stopped container: re-apply the
/// drop-ins, then `nixos-container update`. The job queue's `Swap`
/// node. Requires the container stopped (the queue's `StopForUpdate`
/// upstream); does NOT start it — the DAG's tail `Reconcile` owns
/// bringing the agent back to its wanted power state.
pub async fn swap_update(
name: &str,
hive: &HiveEnv,
paths: &AgentPaths,
on_step: &(dyn Fn(&str) + Send + Sync),
on_build_log_id: &(dyn Fn(i64) + Send + Sync),
) -> Result<()> {
write_dropins(name, hive, paths).await?;
on_step("nixos-container update");
priv_run_inner("update", name, Some(on_build_log_id)).await
}
/// Build the `AgentSpec` list for the meta flake from `nixos-container
/// list` + a hypothetical extra name not yet in the list (for spawn
/// where the new agent's container doesn't exist yet). Pass empty
/// `name_to_add` from rebuild paths where the agent is already in the
/// container list.
///
/// Propagates errors from `list()` rather than swallowing them.
/// Using `.unwrap_or_default()` here would silently produce an empty
/// agent list when `nixos-container list` fails (priv helper down, race),
/// which `sync_agents` would then commit to meta — dropping every agent
/// from `flake.nix`. Callers that can tolerate failures (e.g. migration)
/// handle the `Err` themselves with `.unwrap_or_default()`.
async fn agents_for_meta(name_to_add: Option<&str>) -> Result<Vec<crate::meta::AgentSpec>> {
let containers = list().await?;
let mut out: Vec<crate::meta::AgentSpec> = containers
.into_iter()
.filter_map(|c| {
let name = c.strip_prefix(AGENT_PREFIX)?.to_owned();
Some(crate::meta::AgentSpec {
is_manager: name == MANAGER_NAME,
port: agent_web_port(&name),
name,
})
})
.collect();
if let Some(extra) = name_to_add
&& !out.iter().any(|a| a.name == extra)
{
out.push(crate::meta::AgentSpec {
is_manager: extra == MANAGER_NAME,
port: agent_web_port(extra),
name: extra.to_owned(),
});
}
out.sort_by(|a, b| a.name.cmp(&b.name));
Ok(out)
}
async fn agents_after_spawn(name: &str) -> Result<Vec<crate::meta::AgentSpec>> {
agents_for_meta(Some(name)).await
}
/// Like `agents_for_meta_listing` but with an extra agent added (for a
/// container that doesn't exist yet). Used by the first-spawn path in
/// `actions::run_apply_commit` to register the new agent in meta before
/// `prepare_deploy` tries to update its input lock.
pub async fn agents_for_meta_listing_with(extra: &str) -> Result<Vec<crate::meta::AgentSpec>> {
agents_for_meta(Some(extra)).await
}
/// Public enumeration of currently-existing agents (whatever
/// `nixos-container list` says), sorted, no extras. For callers
/// outside this module that need to reseed meta after lifecycle
/// changes — destroy, startup reconciliation, etc.
pub async fn agents_for_meta_listing() -> Result<Vec<crate::meta::AgentSpec>> {
agents_for_meta(None).await
}
/// True when the named container already exists (appears in
/// `nixos-container list`). Used by the apply-commit path to decide
/// between first-spawn (`nixos-container create`) and normal rebuild
/// (`nixos-container update`).
pub async fn container_exists(name: &str) -> bool {
let container = container_name(name);
list()
.await
.unwrap_or_default()
.iter()
.any(|c| c == &container)
}
pub async fn kill(name: &str) -> Result<()> {
validate(name)?;
priv_run("stop", name).await
}
/// Start a container. Success is defined as the container's unit reaching
/// `active`, **not** the `nixos-container start` exit code — a start-job
/// timeout on a slow boot (e.g. DHCP taking ~10s) exits non-zero while
/// `container@<c>.service` keeps retrying and the container comes up seconds
/// later. So a zero exit returns immediately (already active), and a non-zero
/// exit polls the unit state for [`START_SETTLE_TIMEOUT`] before concluding
/// the start actually failed. Every caller (dashboard restart, reconcile
/// start, the cold-start fallback) gets this truth for free.
pub async fn start(name: &str) -> Result<()> {
validate(name)?;
if priv_run("start", name).await.is_ok() {
return Ok(());
}
let container = container_name(name);
if wait_until_running(name, START_SETTLE_TIMEOUT).await {
tracing::info!(
container = %container,
"start exited non-zero but the container reached active on systemd's retry; treating as success"
);
return Ok(());
}
Err(anyhow::anyhow!(
"container {container} did not reach active within {}s of start",
START_SETTLE_TIMEOUT.as_secs()
))
}
/// Opaque token produced by [`converge_start_preamble`].
/// [`start_with_fallback`] requires this as proof that the pre-start
/// preamble (runtime dir + drop-ins) ran. Dropping the token without
/// calling `start_with_fallback` is a no-op.
#[must_use = "call lifecycle::start_with_fallback(token) to start the container"]
pub struct StartableAgent {
name: String,
}
/// Run the per-agent start preamble: ensure the runtime dir exists and write
/// the nspawn / resource-limits drop-ins. Returns a [`StartableAgent`] token
/// as typed proof that the preamble ran; pass it to [`start_with_fallback`].
/// Callers that omit this step cannot call `start_with_fallback` — the type
/// system makes forgetting the preamble a compile error.
///
/// # Errors
///
/// Returns an error if `ensure_agent_runtime_dir` or `write_dropins` fails.
pub async fn converge_start_preamble(
name: &str,
hive: &HiveEnv,
paths: &AgentPaths,
) -> Result<StartableAgent> {
ensure_agent_runtime_dir(name)?;
write_dropins(name, hive, paths).await?;
Ok(StartableAgent {
name: name.to_owned(),
})
}
/// Start with the cold-start fallback: when a plain start fails (the
/// activation-error shape), retry once via stop + kill + start before
/// giving up. Used by the queue's fast-lane `Start` handler and the
/// inline start-after-rebuild path.
/// See `docs/coordinator.md::Cold-start fallback`.
///
/// Requires a [`StartableAgent`] token from [`converge_start_preamble`]
/// to prove the preamble ran. For internal use within this module (where
/// the preamble is already enforced structurally) call
/// `start_with_fallback_inner` directly.
///
/// # Errors
///
/// Propagates the retry's start error (annotated with the original
/// failure) when the fallback also fails.
pub async fn start_with_fallback(token: StartableAgent) -> Result<()> {
start_with_fallback_inner(&token.name).await
}
/// How long to wait for a container's unit to reach `active` after a
/// `nixos-container start` that returned a non-zero exit. A start-job timeout
/// on a slow boot (e.g. DHCP taking ~10s) returns an error while
/// `container@<c>.service` keeps retrying and the container comes up seconds
/// later — so the exit code is NOT authoritative, the unit state is. 60s
/// comfortably covers an observed slow boot (the reported incident settled
/// ~16s after the "failure") without pinning a queue node on a genuine
/// never-boots failure for too long.
const START_SETTLE_TIMEOUT: std::time::Duration = std::time::Duration::from_mins(1);
/// Poll cadence while waiting for a container to reach `active`.
const START_SETTLE_POLL: std::time::Duration = std::time::Duration::from_secs(2);
/// Poll [`is_running`] until the container's unit is active or `timeout`
/// elapses; returns true as soon as it's active.
async fn wait_until_running(name: &str, timeout: std::time::Duration) -> bool {
let deadline = tokio::time::Instant::now() + timeout;
loop {
if is_running(name).await {
return true;
}
if tokio::time::Instant::now() >= deadline {
return false;
}
tokio::time::sleep(START_SETTLE_POLL).await;
}
}
/// Internal implementation of the cold-start fallback. Used by
/// [`start_with_fallback`] (public, token-gated) and by
/// [`rebuild_no_meta`] where the preamble is already enforced structurally.
///
/// [`start`] already treats unit-active (not the exit code) as success and
/// waits out a slow boot, so this only layers the activation-error recovery on
/// top: if the container is still down after `start`, tear it down and try
/// `start` once more. The teardown prefers a graceful `stop` and only
/// escalates to SIGKILL when that `stop` itself fails.
async fn start_with_fallback_inner(name: &str) -> Result<()> {
validate(name)?;
if start(name).await.is_ok() {
return Ok(());
}
tracing::warn!(
%name,
"start did not bring the container up; hard-resetting (stop, kill only if that fails) and retrying once"
);
// Graceful `stop` first; only escalate to SIGKILL if the stop itself
// fails (e.g. a wedged container whose `machinectl poweroff` never
// completes). A clean stop is enough on its own — SIGKILL is the
// last-resort teardown for when graceful shutdown can't finish.
if let Err(stop_err) = priv_run("stop", name).await {
tracing::warn!(
%name,
error = %stop_err,
"graceful stop failed; escalating to SIGKILL"
);
priv_run("kill", name).await.unwrap_or_else(|e| {
tracing::warn!(
%name,
error = %e,
"kill after failed stop also failed (ignored)"
);
});
}
start(name)
.await
.with_context(|| format!("cold-start fallback also failed for {name}"))
}
/// Stop + start without regenerating any config. For "kick the container"
/// without touching the flake or nspawn flags.
pub async fn restart(name: &str) -> Result<()> {
kill(name).await?;
start(name).await
}
/// True when the container's systemd unit is active. Used by the dashboard
/// to gate stop/restart buttons.
pub async fn is_running(name: &str) -> bool {
let container = container_name(name);
let unit = format!("container@{container}.service");
Command::new("systemctl")
.args(["is-active", "--quiet", &unit])
.status()
.await
.is_ok_and(|s| s.success())
}
/// Fully tear down a sub-agent's container: stop + remove via `nixos-container
/// destroy`, then clean our own systemd drop-in. Leaves it to the caller to
/// wipe `/var/lib/hyperhive/...` state and the per-agent runtime dir.
pub async fn destroy(name: &str) -> Result<()> {
validate(name)?;
let container = container_name(name);
// nixos-container destroy handles stop + removal of /var/lib/nixos-containers/<C>
// and /etc/nixos-containers/<C>.conf. Tolerate "no such container".
if let Err(e) = priv_run("destroy", name).await {
tracing::warn!(error = ?e, "nixos-container destroy returned an error; continuing cleanup");
}
// Remove the systemd resource-limits drop-in via hive-priv.
if let Err(e) = crate::priv_client::remove_service_dropin(&container).await {
tracing::warn!(error = ?e, "remove service drop-in failed (non-fatal)");
}
Ok(())
}
/// Container-level rebuild without touching the meta repo. The one
/// remaining fused stop/update/start pipeline: the approval deploy
/// (`actions::deploy_applied_target`) drives meta through the
/// two-phase prepare/finalize/abort flow itself and needs the inline
/// start to verify the agent comes back up before finalizing. Every
/// other rebuild is a job-queue DAG (`Prebuild → StopForUpdate → Swap
/// → Reconcile`) whose `Prebuild` executor owns the meta sync +
/// relock this path's deleted `rebuild` wrapper used to do.
///
/// `on_step` is called at each phase boundary with a short human-readable
/// label so callers can surface progress (e.g. update the rebuild-queue
/// step shown in the dashboard). Pass `&|_| ()` when progress reporting
/// is not needed.
///
/// `on_build_log_id` is called with the build-log row id immediately after
/// the `nixos-container update` log row opens, before the actual update
/// command starts. Callers can use this to link the queue entry to the log
/// for live streaming. Pass `&|_| ()` when not needed.
///
/// `defer_start` skips the start-after-update for a previously-running
/// container and returns `true` instead, so a queue-side caller can hand
/// the (potentially slow) container boot to the fast lane rather than
/// holding the serialized build lane through it. With `defer_start =
/// false` the start (with cold-start fallback) runs inline as before and
/// the return value is always `false`. The spawn path always starts
/// inline — a freshly-created container boots as part of provisioning.
pub async fn rebuild_no_meta(
name: &str,
hive: &HiveEnv,
paths: &AgentPaths,
defer_start: bool,
on_step: &(dyn Fn(&str) + Send + Sync),
on_build_log_id: &(dyn Fn(i64) + Send + Sync),
) -> Result<bool> {
prepare_rebuild_dirs(name, paths).await?;
let flake_ref = format!("{}#{name}", crate::meta::meta_dir().display());
if container_exists(name).await {
// Rebuild strategy: stop-before-update + pre-build.
// See `docs/coordinator.md::Container lifecycle`.
let was_running = is_running(name).await;
write_dropins(name, hive, paths).await?;
if was_running {
on_step("nix build");
prebuild_toplevel(name, &flake_ref, &|_| ()).await?;
on_step("nixos-container stop");
priv_run("stop", name).await?;
}
on_step("nixos-container update");
let update_result = priv_run_inner("update", name, Some(on_build_log_id)).await;
if let Err(ref update_err) = update_result {
// The update failed (e.g. nix build error). If the agent was
// running before we stopped it, try to bring it back up on the
// previous successful configuration so it doesn't stay dead.
// The start failure is logged but not promoted to an error —
// we always propagate the original update error (below).
if was_running {
tracing::warn!(
%name,
error = %update_err,
"nixos-container update failed; attempting restart on old config"
);
on_step("nixos-container start (recovery)");
if let Err(e) = priv_run("start", name).await {
tracing::warn!(%name, error = %e, "recovery start after failed update also failed");
}
}
}
update_result?;
if was_running {
if defer_start {
// The caller re-queues the start on the fast lane so the
// build lane is freed for the next entry instead of
// waiting out the container boot here.
return Ok(true);
}
on_step("nixos-container start");
// write_dropins was called above; use the inner fn directly
// since the preamble is enforced structurally in this path.
start_with_fallback_inner(name).await?;
}
Ok(false)
} else {
// Spawn path: create is atomic, no prebuild needed.
// See `docs/coordinator.md::Spawn path`.
on_step("nixos-container create");
priv_run("create", name).await?;
// Runtime dir must exist before nixos-container start.
ensure_agent_runtime_dir(name)?;
write_dropins(name, hive, paths).await?;
on_step("nixos-container start");
priv_run("start", name).await?;
Ok(false)
}
}
/// Pre-build `system.build.toplevel` against `meta#<name>` so the
/// subsequent `nixos-container update` finds the result cached and
/// skips straight to the profile-swap. Store-warming only — container
/// is untouched. See `docs/coordinator.md::Rebuild path` for why
/// the prebuild happens before stop, and `docs/coordinator.md::Prebuild
/// attr path` for why the explicit nixosConfigurations attr is required.
///
/// `on_build_log_id` fires with the `build_logs` row id as soon as the
/// row opens, so queue-side callers can link their node to the live
/// stream. Pass `&|_| ()` when not needed.
pub async fn prebuild_toplevel(
name: &str,
flake_ref: &str,
on_build_log_id: &(dyn Fn(i64) + Send + Sync),
) -> Result<()> {
use tokio::io::{AsyncBufReadExt, BufReader};
// Split `<root>#<name>` so we can re-emit with the explicit
// `nixosConfigurations.<name>` segment. The flake_ref shape is
// constructed by `rebuild_no_meta` and always contains exactly one
// `#`; `split_once` returning None here would be a programmer
// error we'd want to surface loudly rather than paper over.
let (flake_root, fragment) = flake_ref
.split_once('#')
.with_context(|| format!("flake_ref {flake_ref:?} missing '#<name>' fragment"))?;
// Sanity-check the fragment matches the agent name we were
// passed — guards against future calls that pass a divergent
// pair (no current callsite does, but the pair is redundant
// and worth checking once).
if fragment != name {
anyhow::bail!("prebuild_toplevel: flake_ref fragment '{fragment}' ≠ agent name '{name}'");
}
let attr = format!("{flake_root}#nixosConfigurations.{name}.config.system.build.toplevel");
let args = vec![
"--extra-experimental-features",
"nix-command flakes",
"build",
"--no-link",
"--print-out-paths",
&attr,
];
let cmdline = format!("nix {}", args.join(" "));
tracing::info!(%name, %cmdline, "prebuild: warming system toplevel");
// Open a build_logs row for this attempt (best-effort — None when
// the global handle hasn't been installed, e.g. early startup
// or standalone tests). Lines pumped from stdout/stderr append
// into the row; `finish` lands the terminal status before we bail.
let logs = crate::build_logs::global();
let log_id = logs.as_ref().and_then(|h| {
h.start(name, "prebuild", &cmdline)
.map_err(|e| {
tracing::warn!(error = ?e, "build_logs: start failed (prebuild log dropped)");
})
.ok()
});
if let Some(id) = log_id {
on_build_log_id(id);
}
let mut child = Command::new("nix")
.args(&args)
.stdout(std::process::Stdio::piped())
.stderr(std::process::Stdio::piped())
.spawn()
.with_context(|| format!("spawn {cmdline}"))?;
let stdout = child.stdout.take().expect("piped stdout");
let stderr = child.stderr.take().expect("piped stderr");
let stdout_cmdline = cmdline.clone();
let stdout_logs = logs.clone();
let pump_stdout = tokio::spawn(async move {
let mut lines = BufReader::new(stdout).lines();
while let Ok(Some(line)) = lines.next_line().await {
tracing::info!(target: "nix-prebuild", cmdline = %stdout_cmdline, "{line}");
if let (Some(h), Some(id)) = (&stdout_logs, log_id) {
h.append_stdout(id, &line);
}
}
});
let stderr_cmdline = cmdline.clone();
let stderr_logs = logs.clone();
let pump_stderr = tokio::spawn(async move {
let mut lines = BufReader::new(stderr).lines();
while let Ok(Some(line)) = lines.next_line().await {
tracing::warn!(target: "nix-prebuild", cmdline = %stderr_cmdline, "{line}");
if let (Some(h), Some(id)) = (&stderr_logs, log_id) {
h.append_stderr(id, &line);
}
}
});
let status = child
.wait()
.await
.with_context(|| format!("wait {cmdline}"))?;
let _ = pump_stdout.await;
let _ = pump_stderr.await;
let ok = status.success();
if let (Some(h), Some(id)) = (&logs, log_id) {
h.finish(
id,
if ok {
crate::build_logs::BuildStatus::Ok
} else {
crate::build_logs::BuildStatus::Fail
},
);
}
if !ok {
match log_id {
Some(id) => bail!("prebuild {cmdline} failed ({status}); see build log #{id}"),
None => bail!("prebuild {cmdline} failed ({status})"),
}
}
Ok(())
}
pub async fn list() -> Result<Vec<String>> {
let stdout = crate::priv_client::list_containers().await?;
Ok(stdout
.lines()
.map(str::trim)
.filter(|line| line.starts_with(AGENT_PREFIX))
.map(str::to_owned)
.collect())
}
/// Sync `/etc/tmpfiles.d/hyperhive-agents.conf` with the currently-known
/// agent set (from `nixos-container list`). Strips the `h-` prefix to get
/// logical names. Best-effort: errors are logged but never propagated — a
/// failed tmpfiles write shouldn't block a spawn or destroy.
///
/// Called at hive-c0re startup and after each spawn / destroy so the file
/// always reflects the live agent set. `systemd-tmpfiles-setup.service`
/// reads the file at boot (before any container units start), pre-creating
/// bind-mount source dirs so container@h-* units don't race hive-c0re.
pub async fn sync_tmpfiles() {
let agents = match list().await {
Ok(containers) => containers
.into_iter()
.filter_map(|c| c.strip_prefix(AGENT_PREFIX).map(str::to_owned))
.collect::<Vec<_>>(),
Err(e) => {
tracing::warn!(error = ?e, "sync_tmpfiles: list failed; skipping");
return;
}
};
if let Err(e) = crate::priv_client::sync_agent_tmpfiles(&agents).await {
tracing::warn!(error = ?e, "sync_tmpfiles: priv call failed");
} else {
tracing::debug!(count = agents.len(), "sync_tmpfiles: ok");
}
}
/// Ensure the per-agent runtime directory `/run/hyperhive/agents/<name>`
/// exists. The directory is also written by `SyncAgentTmpfiles` (run at
/// boot + spawn/destroy), but explicit creation in start/spawn paths guards
/// against races where hive-c0re starts a container before tmpfiles.d has
/// applied the new entry.
///
/// Pure filesystem op — no `Coordinator` dependency — so callers that only
/// need the dir do not have to hold an `Arc<Coordinator>`.
///
/// # Errors
/// Returns an error if `create_dir_all` fails.
pub fn ensure_agent_runtime_dir(name: &str) -> Result<()> {
let dir = std::path::PathBuf::from(format!("/run/hyperhive/agents/{name}"));
std::fs::create_dir_all(&dir)
.with_context(|| format!("create agent runtime dir {}", dir.display()))
}
/// Build the per-line callback for `create_container_streaming` /
/// `update_container_streaming`. Both ops share identical dispatch logic
/// (stdout → info + `append_stdout`, stderr → warn + `append_stderr`); this
/// helper avoids duplicating that match body across the two call sites.
fn make_log_callback(
logs: Option<std::sync::Arc<crate::build_logs::BuildLogs>>,
log_id: Option<i64>,
cmdline: String,
) -> impl FnMut(hive_sh4re::priv_proto::PrivStream, &str) {
use hive_sh4re::priv_proto::PrivStream;
move |stream, line| match stream {
PrivStream::Stdout => {
tracing::info!(target: "nixos-container", cmdline = %cmdline, "{line}");
if let (Some(h), Some(id)) = (&logs, log_id) {
h.append_stdout(id, line);
}
}
PrivStream::Stderr => {
tracing::warn!(target: "nixos-container", cmdline = %cmdline, "{line}");
if let (Some(h), Some(id)) = (&logs, log_id) {
h.append_stderr(id, line);
}
}
}
}
/// Execute a container operation via hive-priv and integrate with
/// `build_logs.sqlite`. hive-priv runs as root and forwards output lines
/// to hive-c0re in real time via the streaming priv protocol. Each line
/// is appended to the build-log row as it arrives, so the dashboard
/// shows live progress during long `nixos-container create` / `update` runs.
async fn priv_run(kind: &str, name: &str) -> Result<()> {
priv_run_inner(kind, name, None).await
}
/// Like `priv_run` but calls `on_log_id(log_id)` immediately after the
/// build-log row is opened — before the actual container op starts.
/// This lets callers surface the row id for live streaming (e.g. the
/// rebuild-queue worker sets `build_log_id` on the queue entry so the
/// dashboard can link to `/api/build-logs/id/{id}/stream`).
///
/// The callback fires only when a build-log row is successfully opened
/// (i.e. the global `BuildLogs` handle is installed AND `h.start()`
/// succeeds). No-op when `on_log_id` is `None` — that's the path for
/// all callers that don't need the id.
async fn priv_run_inner(
kind: &str,
name: &str,
on_log_id: Option<&(dyn Fn(i64) + Send + Sync)>,
) -> Result<()> {
let container = container_name(name);
let cmdline = format!("nixos-container {kind} {container}");
let logs = crate::build_logs::global();
let log_id = logs.as_ref().and_then(|h| {
h.start(name, kind, &cmdline)
.map_err(|e| {
tracing::warn!(error = ?e, "build_logs: start failed (priv_run log dropped)");
})
.ok()
});
// Notify the caller as soon as the log row exists so it can surface
// the id for live streaming before the container op even starts.
if let (Some(id), Some(cb)) = (log_id, on_log_id) {
cb(id);
}
// For long-running ops use the streaming protocol so build_logs
// receives lines in real time rather than as a batch at completion.
let result: Result<()> = match kind {
"create" => {
crate::priv_client::create_container_streaming(
name,
make_log_callback(logs.clone(), log_id, cmdline.clone()),
)
.await
}
"update" => {
crate::priv_client::update_container_streaming(
name,
make_log_callback(logs.clone(), log_id, cmdline.clone()),
)
.await
}
"start" => crate::priv_client::start_container(name).await,
"stop" => crate::priv_client::stop_container(name).await,
"kill" => crate::priv_client::kill_container(name).await,
"destroy" => crate::priv_client::destroy_container(name).await,
other => Err(anyhow::anyhow!("unknown container op: {other}")),
};
let succeeded = result.is_ok();
if let (Some(h), Some(id)) = (&logs, log_id) {
h.finish(
id,
if succeeded {
crate::build_logs::BuildStatus::Ok
} else {
crate::build_logs::BuildStatus::Fail
},
);
}
match result {
Ok(()) => Ok(()),
Err(e) => {
let journal = if kind == "update" {
container_journal_tail(&container).await
} else {
String::new()
};
match log_id {
Some(id) => bail!("{e:#}; see build log #{id}{journal}"),
None => bail!("{e:#}{journal}"),
}
}
}
}
/// On a failed `nixos-container update`, the stderr nixos-container
/// itself prints is often terse ("failed to reload container") — the
/// real reason (which unit failed `switch-to-configuration` during
/// the reload phase) lands in the *container's* own journal, not on
/// the host. Fetch the tail of it so a failed rebuild self-documents
/// the failing unit in the error string, no second round-trip.
///
/// Scoped to `update`: that's the reload-phase case, and the
/// container is still up (running the old generation) so
/// `journalctl -M` works. Best-effort — returns "" for other verbs
/// or when the journal can't be read (machine gone, journalctl
/// missing); it never produces an error of its own.
async fn container_journal_tail(container: &str) -> String {
// `-M` enters the container namespace and needs root, so the read
// is delegated to hive-priv (hive-c0re itself runs unprivileged).
let res = crate::priv_client::read_container_journal(
container,
hive_sh4re::priv_proto::JournalQuery {
lines: 40,
..Default::default()
},
)
.await;
match res {
Ok((stdout, _)) if !stdout.is_empty() => format!(
"\n--- last 40 journal lines from container '{container}' ---\n{}",
stdout.trim_end()
),
_ => String::new(),
}
}