M5b plan: task 13, instance lock in brokerd, memoryd and gatewayd

Each locks <home>/run/<role>.lock in main (gatewayd after its secret,
so nothing is made before the secret is read). brokerd's old
second-instance test in serve.rs expected the audit lock's message,
so serve.rs has a new version; task 01 now copies serve.rs-task01.

Checks: given tests fail at ref 12 as the task says (2 each in
brokerd, memoryd, gatewayd; serve.rs passes); the task's quoted edits
applied to ref 12 reproduce ref 13's tree exactly; replay gate ok with
1118 tests (1113 - 1 + 6), /tmp unchanged; 14 mutations, all caught;
the six instance test files stressed 25 runs under 16 busy loops and
20 under 32, no failure.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
This commit is contained in:
2026-09-26 17:21:14 -07:00
co-authored by Claude Opus 5.5
parent 291d82f21b
commit 5f48ba65b0
7 changed files with 1354 additions and 21 deletions
@@ -53,7 +53,8 @@ This is the complete list. Each one is covered by an edit below or by a given fi
- **new versions** of: `crates/bxcore/tests/wire.rs`, `crates/bxcore/tests/strict.rs`; - **new versions** of: `crates/bxcore/tests/wire.rs`, `crates/bxcore/tests/strict.rs`;
`crates/brokerd/tests/admin.rs`, `broker.rs`, `broker_pending.rs`, `courier.rs`, `ledger.rs`, `crates/brokerd/tests/admin.rs`, `broker.rs`, `broker_pending.rs`, `courier.rs`, `ledger.rs`,
`serve.rs`; `crates/loopd/tests/broker_port.rs`, `tools.rs`, `turn_broker.rs`. Your `serve.rs`; `crates/loopd/tests/broker_port.rs`, `tools.rs`, `turn_broker.rs`. Your
`broker.rs` is the given `broker.rs-task01`: the given `broker.rs` is task 09's. `broker.rs` is the given `broker.rs-task01`: the given `broker.rs` is task 09's. Your
`serve.rs` is the given `serve.rs-task01`: the given `serve.rs` is task 13's.
- Modify: `crates/bxcore/src/wire.rs`, `crates/brokerd/src/args.rs`, - Modify: `crates/bxcore/src/wire.rs`, `crates/brokerd/src/args.rs`,
`crates/brokerd/src/policy/mod.rs`, `crates/brokerd/src/ledger/mod.rs`, `crates/brokerd/src/policy/mod.rs`, `crates/brokerd/src/ledger/mod.rs`,
`crates/brokerd/src/broker.rs`, `crates/loopd/src/tools.rs`, `crates/loopd/src/turn.rs`, `crates/brokerd/src/broker.rs`, `crates/loopd/src/tools.rs`, `crates/loopd/src/turn.rs`,
@@ -498,8 +499,8 @@ The event keeps only the reason: the owner's texts do not change.
crates/brokerd/tests/ crates/brokerd/tests/
cp docs/plans/M5b/files/crates/brokerd/tests/ledger.rs \ cp docs/plans/M5b/files/crates/brokerd/tests/ledger.rs \
crates/brokerd/tests/ crates/brokerd/tests/
cp docs/plans/M5b/files/crates/brokerd/tests/serve.rs \ cp docs/plans/M5b/files/crates/brokerd/tests/serve.rs-task01 \
crates/brokerd/tests/ crates/brokerd/tests/serve.rs
cp docs/plans/M5b/files/crates/loopd/tests/broker_port.rs \ cp docs/plans/M5b/files/crates/loopd/tests/broker_port.rs \
crates/loopd/tests/ crates/loopd/tests/
cp docs/plans/M5b/files/crates/loopd/tests/tools.rs \ cp docs/plans/M5b/files/crates/loopd/tests/tools.rs \
+280
View File
@@ -0,0 +1,280 @@
# M5b task 13: `brokerd`, `memoryd` and `gatewayd` take the instance lock too
**Branch:** `m5b` (run `git switch m5b`; `git status --short` must be empty, otherwise stop)
**Commit subject:** `brokerd, memoryd, gatewayd: a lock file keeps each to one instance`
## Goal
Task 12 wrote `bxcore::instance`, the lock that keeps a daemon to one instance (M5b spec,
section 9a), and made `loopd` and `inferproxy` take it. This task makes the other three daemons
take it the same way: before they touch their sockets, each locks `<home>/run/<role>.lock` and
holds the lock for the life of the process. A second copy against the same home exits 1 with one
line and touches nothing else:
```text
brokerd: another brokerd is running (it holds /var/lib/boxmaker/run/brokerd.lock); see docs/runbook.md#already-running
memoryd: another memoryd is running (it holds /var/lib/boxmaker/run/memoryd.lock); see docs/runbook.md#already-running
gatewayd: another gatewayd is running (it holds /var/lib/boxmaker/run/gatewayd.lock); see docs/runbook.md#already-running
```
Any other error on the lock file stops the daemon too, with the line
`<role>: cannot take the lock <lock file>: <error>; see docs/runbook.md#already-running`. Both
lines come from `LockError::line`; the runbook entry `already-running` is there since task 12, and
covers all five daemons.
## Files
- Copy, from `docs/plans/M5b/files/` (the same path under it):
- new tests: `crates/brokerd/tests/instance.rs`, `crates/memoryd/tests/instance.rs`,
`crates/gatewayd/tests/instance.rs`
- a **new version** of `crates/brokerd/tests/serve.rs` (it replaces the file in the tree). Do
not copy `serve.rs-task01`: it is the older version.
- Modify: `crates/brokerd/src/main.rs` (B1, B2), `crates/memoryd/src/main.rs` (D1, D2),
`crates/gatewayd/src/main.rs` (G1 to G3), `docs/implementer-log.md`.
- Do not touch: `crates/bxcore` (`instance` is done), any other source file, any `Cargo.toml`,
any other test, `docs/runbook.md`.
## Facts you need
- **What `bxcore::instance` gives** (task 12; do not change it):
| Name | What it is |
|---|---|
| `instance::lock` | `pub fn lock(path: &Path) -> Result<InstanceLock, LockError>`: creates the file (0600) and a missing directory (0700), and tries the lock once |
| `InstanceLock` | the held lock; the lock is released when it is dropped or the process ends |
| `LockError` | `Held` (another instance holds it) or `Io(std::io::Error)` |
| `LockError::line` | `e.line("brokerd", &lock_path) -> String`: the whole line to print, pointer included |
- **Keep the lock alive.** Each daemon binds the `InstanceLock` to a name, `_instance`, in `main`
(or `serve` for `gatewayd`), the function that serves until the process ends. `let _ = …`, or a
`match` arm `Ok(_) => {}`, would drop it, and the lock with it, at once. The edits show the form.
- **Where each daemon takes it**, and why there:
- `brokerd` (`main` in `crates/brokerd/src/main.rs`): right after the config loads, before
`serve::start`, which opens the audit log and binds both sockets. The home is
`cfg.paths.home`.
- `memoryd` (`main` in `crates/memoryd/src/main.rs`): right after the config loads, before
`serve::start`, which creates `memory/` and the index and binds three sockets. The home is
`config.paths.home`.
- `gatewayd` (`serve` in `crates/gatewayd/src/main.rs`): after the secret is loaded, before the
state directory is made and before `run`, which binds `gateway.sock` and then connects to
Mattermost. Not earlier: the test `a_missing_secret_stops_at_start` in
`crates/gatewayd/tests/main.rs` checks that nothing under the home is made before the secret
is read, and the lock creates `<home>/run`. The home is `config.paths.home`.
- **`brokerd`'s audit lock stays.** `brokerd` has held a lock on `<home>/audit/.lock` since M3a,
and a second `brokerd` used to stop there, with `brokerd is already running` and the pointer
`brokerd-already-running`. It stays: it guards the log itself, and its own test
(`a_second_writer_is_refused` in `crates/brokerd/tests/audit.rs`) still passes. But the instance
lock now comes first, so a second `brokerd` stops with the new line instead. That is why
`serve.rs` has a new version: its test `a_second_brokerd_on_the_same_home_refuses_to_start`
expected the old message, and it is gone; `instance.rs` checks the second `brokerd` now. Nothing
else in `serve.rs` changes.
- **The given tests start each daemon as a process**, as `brokerd`'s `serve.rs` does. The
`gatewayd` one runs it against the fake Mattermost of `tests/support/fake_mm.rs`, with its token
in the environment (`GW_TEST_TOKEN`), and checks that it answers on `gateway.sock` by asking it
to post an approval, as `brokerd` would. Every wait has a deadline and every process is killed by
a guard. Before this task, the `memoryd` and `gatewayd` tests that expect a second instance to be
refused wait out their deadline (the second copy starts and serves), so each of those files takes
about 10 s to fail. That is this, not a hang.
- The calls the edits make: `instance::lock` and `LockError::line` from the table above;
`Path::join` for the lock file's path; `eprintln!` and `ExitCode::from(1)` as the lines around
them already do.
## The edits, exactly
Nothing else in these files changes. Each quoted "before" block occurs exactly once in its file.
### `crates/brokerd/src/main.rs`
**B1.** The line
```rust
use brokerd::serve::{self, ServeError};
```
becomes
```rust
use brokerd::serve::{self, ServeError};
use bxcore::instance;
```
**B2.** In `main`, the line
```rust
// Keep the socket paths for the serving notice, before `cfg` is moved into `start`.
```
becomes
```rust
// One brokerd per home (M5b spec, section 9a). The lock comes before anything is made, the
// audit log's own lock included, so a second copy never takes the sockets of the one that
// runs. Held until the process ends.
let lock_path = cfg.paths.home.join("run/brokerd.lock");
let _instance = match instance::lock(&lock_path) {
Ok(held) => held,
Err(e) => {
eprintln!("{}", e.line("brokerd", &lock_path));
return ExitCode::from(1);
}
};
// Keep the socket paths for the serving notice, before `cfg` is moved into `start`.
```
### `crates/memoryd/src/main.rs`
**D1.** The line
```rust
use memoryd::config::Config;
```
becomes
```rust
use bxcore::instance;
use memoryd::config::Config;
```
**D2.** In `main`, the line
```rust
let log: serve::Log = Arc::new(|line: &str| eprintln!("{line}"));
```
becomes
```rust
// One memoryd per home (M5b spec, section 9a). The lock comes before anything under the home
// is made or bound, so a second copy never takes the sockets of the one that runs. Held until
// the process ends.
let lock_path = config.paths.home.join("run/memoryd.lock");
let _instance = match instance::lock(&lock_path) {
Ok(held) => held,
Err(e) => {
eprintln!("{}", e.line("memoryd", &lock_path));
return ExitCode::from(1);
}
};
let log: serve::Log = Arc::new(|line: &str| eprintln!("{line}"));
```
### `crates/gatewayd/src/main.rs`
**G1.** The line
```rust
use bxcore::secrets;
```
becomes
```rust
use bxcore::{instance, secrets};
```
**G2.** In the comment at the top of `serve`, the line
```rust
// Then `if let Some(warning) = &loaded.warning { eprintln!("{warning}"); }`.
```
becomes
```rust
// Then `if let Some(warning) = &loaded.warning { eprintln!("{warning}"); }`.
// 3b. The instance lock, `<home>/run/gatewayd.lock` (M5b spec, section 9a): after the secret,
// which is read before anything is made, and before the directory and the socket.
```
**G3.** In `serve`, the lines
```rust
if let Some(warning) = &loaded.warning {
eprintln!("{warning}");
}
```
become
```rust
if let Some(warning) = &loaded.warning {
eprintln!("{warning}");
}
let lock_path = config.paths.home.join("run/gatewayd.lock");
let _instance = match instance::lock(&lock_path) {
Ok(held) => held,
Err(e) => {
eprintln!("{}", e.line("gatewayd", &lock_path));
return ExitCode::from(1);
}
};
```
## Steps
- [ ] **1. Copy the given tests.** From the repository root, four commands:
```sh
cp docs/plans/M5b/files/crates/brokerd/tests/instance.rs crates/brokerd/tests/
cp docs/plans/M5b/files/crates/brokerd/tests/serve.rs crates/brokerd/tests/
cp docs/plans/M5b/files/crates/memoryd/tests/instance.rs crates/memoryd/tests/
cp docs/plans/M5b/files/crates/gatewayd/tests/instance.rs crates/gatewayd/tests/
```
- [ ] **2. See them fail.** Three commands, each with a shell timeout of 600000 ms. Each file
compiles; `serve.rs` passes.
- `cargo test -p brokerd --no-fail-fast --test instance --test serve` (`--no-fail-fast`, or
cargo stops at the first failing file): `serve` 8 passed. `instance`: 2 failed.
`a_second_brokerd_on_the_same_home_is_refused_and_the_first_keeps_serving` fails on `the
lock's line, and nothing else` (the second stopped at the audit lock, with `brokerd is already
running`); `after_the_first_is_killed_a_new_brokerd_removes_the_stale_sockets_and_serves`
fails on `the lock file, mode 0600`, `left: None`, `right: Some(384)`.
- `cargo test -p memoryd --test instance`: 2 failed (about 10 s).
`a_second_memoryd_on_the_same_home_is_refused_and_the_first_keeps_serving` fails on `the
second memoryd: …` with `left: None`, `right: Some(1)` (it started and served);
`after_the_first_is_killed_a_new_memoryd_removes_the_stale_sockets_and_serves` on `the lock
file, mode 0600`, `left: None`.
- `cargo test -p gatewayd --test instance`: 2 failed (about 10 s), the same two shapes:
`the second gatewayd: …` with `left: None`, and `the lock file, mode 0600` with `left: None`.
- [ ] **3. `brokerd`.** Make edits B1 and B2. `cargo check -p brokerd`: no error.
`cargo test -p brokerd --test instance --test serve`: `instance` 2 passed, `serve` 8 passed.
- [ ] **4. `memoryd`.** Make edits D1 and D2. `cargo check -p memoryd`: no error.
`cargo test -p memoryd --test instance`: 2 passed.
- [ ] **5. `gatewayd`.** Make edits G1 to G3. `cargo check -p gatewayd`: no error.
`cargo test -p gatewayd --test instance --test main`: `instance` 2 passed, `main` 5 passed.
- [ ] **6. Check.** `grep -rn 'instance::lock(' crates/*/src` prints exactly five lines, one in
the `main.rs` of each of `brokerd`, `gatewayd`, `inferproxy`, `loopd` and `memoryd`.
`grep -rn 'runbook.md#already-running' crates/*/src` still prints exactly one line, in
`crates/bxcore/src/instance.rs`. `git diff --stat -- crates/bxcore '*Cargo.toml'` prints nothing.
- [ ] **7. Run the gate.** `cargo fmt --all`, then `make gate`, with a shell timeout of 600000 ms.
Expected last line: `gate: ok`, with 1118 tests: 1113 before this task, minus 1 in the new
`crates/brokerd/tests/serve.rs` (its old second-instance test), plus 2 in each of the three new
`instance.rs` files.
- [ ] **8. Log and commit.** `git status --short` lists `crates/brokerd/src/main.rs`,
`crates/memoryd/src/main.rs`, `crates/gatewayd/src/main.rs`, `crates/brokerd/tests/serve.rs`
and your log as modified, and the three `instance.rs` test files as new. Stage with
`git add crates/brokerd crates/memoryd crates/gatewayd docs/implementer-log.md Cargo.lock`,
then commit as `AGENTS.md` says. `Cargo.lock` does not change in this task; the `git add` is
harmless.
## Done when
- `make gate` prints `gate: ok` with 1118 tests.
- `git diff HEAD~1 --stat` lists only the three `main.rs` files, `crates/brokerd/tests/serve.rs`,
the three new `instance.rs` test files and `docs/implementer-log.md`.
## Stop and report if
- A "before" block of B1, B2, D1, D2 or G1 to G3 is not in its file exactly as shown, or is there
more than once.
- Step 2 shows a different result: other failing tests, other messages, or other counts.
- `cargo check` reports an error after an edit made as shown. Quote it and stop.
- After step 3, 4 or 5 a test fails although the edits are as shown. Do not change a test or
`bxcore`: stop, and give the failing tests' names and their messages.
- The fix seems to need a change anywhere else: `bxcore`, another file of a daemon, the test
support files, a `Cargo.toml`, the runbook. It does not; stop and say why you think so.
- A test outside these files fails in the gate: check once whether it fails without your change,
then stop and report both results.
- The gate passes with a count other than 1118.
@@ -0,0 +1,218 @@
//! One `brokerd` per home (M5b spec, section 9a): a second `brokerd serve` against the same home is
//! refused with the lock's line, and the first keeps serving; once the first is killed, a new one
//! removes the stale sockets and serves. Every wait has a deadline, and every process is killed
//! and every path removed by a guard (tip T44). Do not edit.
#[path = "support/tmp.rs"]
mod tmp;
use std::os::unix::fs::PermissionsExt;
use std::os::unix::net::UnixStream;
use std::path::{Path, PathBuf};
use std::process::{Child, Command, Stdio};
use std::time::{Duration, Instant};
use bxcore::{Empty, Envelope, Message, PROTOCOL_VERSION, read_frame, write_frame};
use tmp::TempDir;
const POINTER: &str = "see docs/runbook.md#already-running";
struct Home {
dir: TempDir,
config: PathBuf,
}
impl Home {
fn new(tag: &str) -> Home {
let dir = TempDir::new(tag);
std::fs::create_dir_all(dir.path().join("grants")).unwrap();
let text = format!(
"[paths]\nhome = \"{home}\"\ngrants = \"{home}/grants\"\n",
home = dir.path().display()
);
let config = dir.write("brokerd.toml", &text);
Home { dir, config }
}
fn path(&self, relative: &str) -> PathBuf {
self.dir.path().join(relative)
}
fn command(&self) -> Command {
let mut command = Command::new(env!("CARGO_BIN_EXE_brokerd"));
command
.args(["serve", "--config"])
.arg(&self.config)
.stdin(Stdio::null())
.stdout(Stdio::null());
command
}
/// `brokerd serve` with its stderr in `<home>/<name>.err`, for the messages of a failing test.
fn start(&self, name: &str) -> Daemon {
let err = std::fs::File::create(self.path(&format!("{name}.err"))).unwrap();
Daemon(self.command().stderr(Stdio::from(err)).spawn().unwrap())
}
fn stderr_of(&self, name: &str) -> String {
std::fs::read_to_string(self.path(&format!("{name}.err"))).unwrap_or_default()
}
/// Runs `brokerd serve` to its end, at most 10 s (then it is killed), and gives its exit code
/// (`None` if it had to be killed) and its stderr.
fn run_to_end(&self) -> (Option<i32>, String) {
let mut child = Daemon(self.command().stderr(Stdio::piped()).spawn().unwrap());
let deadline = Instant::now() + Duration::from_secs(10);
let mut code = None;
while Instant::now() < deadline {
if let Ok(Some(status)) = child.0.try_wait() {
code = status.code();
break;
}
std::thread::sleep(Duration::from_millis(20));
}
let _ = child.0.kill();
let _ = child.0.wait();
let mut stderr = String::new();
if let Some(mut pipe) = child.0.stderr.take() {
let _ = std::io::Read::read_to_string(&mut pipe, &mut stderr);
}
(code, stderr)
}
fn tools(&self) -> PathBuf {
self.path("run/loop-broker/broker.sock")
}
fn admin(&self) -> PathBuf {
self.path("run/owner-broker/admin.sock")
}
}
/// A running `brokerd serve`, killed and waited for when dropped. Declared after the `Home`, so it
/// drops first.
struct Daemon(Child);
impl Drop for Daemon {
fn drop(&mut self) {
let _ = self.0.kill();
let _ = self.0.wait();
}
}
impl Daemon {
fn running(&mut self) -> bool {
matches!(self.0.try_wait(), Ok(None))
}
}
/// True when `brokerd` answers on its owner's socket: `approvals` gets the list of approvals. Any
/// other answer, or none within 5 s, is false.
fn answers(admin: &Path) -> bool {
let Ok(mut stream) = UnixStream::connect(admin) else {
return false;
};
let limit = Some(Duration::from_secs(5));
if stream.set_read_timeout(limit).is_err() || stream.set_write_timeout(limit).is_err() {
return false;
}
let ask = Envelope {
v: PROTOCOL_VERSION,
id: 1,
r#final: true,
msg: Message::Approvals(Empty {}),
};
if write_frame(&mut stream, &ask).is_err() {
return false;
}
matches!(
read_frame(&mut stream),
Ok(Envelope {
msg: Message::ApprovalList(_),
..
})
)
}
/// Waits up to 10 s for `brokerd` to answer on `admin` and to listen on `tools`.
fn wait_until_it_answers(home: &Home) -> bool {
let deadline = Instant::now() + Duration::from_secs(10);
while Instant::now() < deadline {
if answers(&home.admin()) && UnixStream::connect(home.tools()).is_ok() {
return true;
}
std::thread::sleep(Duration::from_millis(20));
}
false
}
fn inode(path: &Path) -> u64 {
use std::os::unix::fs::MetadataExt;
std::fs::symlink_metadata(path)
.map(|m| m.ino())
.unwrap_or(0)
}
#[test]
fn a_second_brokerd_on_the_same_home_is_refused_and_the_first_keeps_serving() {
let home = Home::new("inst-twice");
let mut first = home.start("first");
assert!(
wait_until_it_answers(&home),
"the first brokerd never answered; stderr: {}",
home.stderr_of("first")
);
let before = (inode(&home.tools()), inode(&home.admin()));
let (code, stderr) = home.run_to_end();
let line = format!(
"brokerd: another brokerd is running (it holds {}); {POINTER}",
home.path("run/brokerd.lock").display()
);
assert_eq!(code, Some(1), "the second brokerd: {stderr}");
assert_eq!(
stderr,
format!("{line}\n"),
"the lock's line, and nothing else"
);
assert!(first.running(), "the first brokerd is still running");
assert_eq!(
(inode(&home.tools()), inode(&home.admin())),
before,
"the first's sockets are still there"
);
assert!(
answers(&home.admin()),
"the first brokerd still answers; its stderr: {}",
home.stderr_of("first")
);
}
#[test]
fn after_the_first_is_killed_a_new_brokerd_removes_the_stale_sockets_and_serves() {
let home = Home::new("inst-restart");
let mut first = home.start("first");
assert!(
wait_until_it_answers(&home),
"the first brokerd never answered; stderr: {}",
home.stderr_of("first")
);
let _ = first.0.kill();
let _ = first.0.wait();
assert!(
home.tools().exists() && home.admin().exists(),
"a killed brokerd leaves its sockets"
);
assert!(!answers(&home.admin()), "nobody serves the stale socket");
let _next = home.start("next");
assert!(
wait_until_it_answers(&home),
"the new brokerd never answered; stderr: {}",
home.stderr_of("next")
);
let lock = home.path("run/brokerd.lock");
let mode = std::fs::metadata(&lock).map(|m| m.permissions().mode() & 0o777);
assert_eq!(mode.ok(), Some(0o600), "the lock file, mode 0600");
}
@@ -216,24 +216,6 @@ fn a_stale_socket_is_replaced() {
); );
} }
#[test]
fn a_second_brokerd_on_the_same_home_refuses_to_start() {
let home = Home::new("serve-twice", 900_000);
let _running = home.serve();
let second = home.run(&[]);
assert_eq!(second.status.code(), Some(1));
let text = stderr(&second);
assert!(text.contains("brokerd is already running"), "{text}");
assert!(
text.trim_end()
.ends_with("see docs/runbook.md#brokerd-already-running"),
"{text}"
);
// The first still has its sockets.
let frames = exchange(&home.admin(), 1, Message::Approvals(Empty {}));
assert!(matches!(frames[0].msg, Message::ApprovalList(_)));
}
#[test] #[test]
fn it_answers_each_socket_and_refuses_the_other_kinds() { fn it_answers_each_socket_and_refuses_the_other_kinds() {
let home = Home::new("serve-kinds", 900_000); let home = Home::new("serve-kinds", 900_000);
@@ -0,0 +1,411 @@
//! `brokerd serve` as a process: its startup, both sockets, and the expiry thread. Do not edit.
#[path = "support/tmp.rs"]
mod tmp;
use std::os::unix::fs::PermissionsExt;
use std::os::unix::net::{UnixListener, UnixStream};
use std::path::{Path, PathBuf};
use std::process::{Child, Command, Output, Stdio};
use std::time::{Duration, Instant};
use brokerd::audit::RECOVERED_NOTICE;
use brokerd::runner::REFUSING;
use bxcore::{
AuditEvent, CallId, DenyReason, Empty, Envelope, ErrorCode, Message, PROTOCOL_VERSION,
ResultStatus, SessionId, ToolRequest, ToolResponse,
};
use tmp::TempDir;
struct Home {
dir: TempDir,
config: PathBuf,
}
impl Home {
fn new(tag: &str, ttl_ms: u64) -> Home {
let dir = TempDir::new(tag);
std::fs::create_dir_all(dir.path().join("grants")).unwrap();
let text = format!(
"[paths]\nhome = \"{home}\"\ngrants = \"{home}/grants\"\n[approvals]\nttl_ms = {ttl_ms}\n",
home = dir.path().display()
);
let config = dir.write("brokerd.toml", &text);
Home { dir, config }
}
fn path(&self, relative: &str) -> PathBuf {
self.dir.path().join(relative)
}
fn tools(&self) -> PathBuf {
self.path("run/loop-broker/broker.sock")
}
fn admin(&self) -> PathBuf {
self.path("run/owner-broker/admin.sock")
}
fn grant(&self, id: &str, mode: &str) {
let text = format!(
"tool = \"read_file\"\nmode = \"{mode}\"\nmax_taint = \"secret\"\n\
result_class = \"private\"\nuntrusted = false\n[constraints]\npaths = [\"/n\"]\n"
);
std::fs::write(self.path(&format!("grants/{id}.toml")), text).unwrap();
}
fn command(&self, extra: &[&str]) -> Command {
let mut command = Command::new(env!("CARGO_BIN_EXE_brokerd"));
command
.args(["serve", "--config"])
.arg(&self.config)
.args(extra);
command
}
/// Starts `brokerd serve` and waits until both sockets answer.
fn serve(&self) -> Running {
let child = self
.command(&[])
.stdout(Stdio::null())
.stderr(Stdio::piped())
.spawn()
.unwrap();
let running = Running(Some(child));
let until = Instant::now() + Duration::from_secs(10);
while UnixStream::connect(self.tools()).is_err()
|| UnixStream::connect(self.admin()).is_err()
{
assert!(Instant::now() < until, "brokerd never listened");
std::thread::sleep(Duration::from_millis(20));
}
running
}
/// Runs `brokerd serve` expecting it to exit by itself.
fn run(&self, extra: &[&str]) -> Output {
self.command(extra).output().unwrap()
}
fn events(&self) -> Vec<AuditEvent> {
let dir = self.path("audit");
let mut names: Vec<String> = std::fs::read_dir(&dir)
.unwrap()
.map(|e| e.unwrap().file_name().into_string().unwrap())
.filter(|n| n.ends_with(".jsonl"))
.collect();
names.sort();
names
.iter()
.flat_map(|n| {
let text = std::fs::read_to_string(dir.join(n)).unwrap();
text.lines()
.map(|l| {
serde_json::from_str::<bxcore::AuditRecord>(l)
.unwrap()
.event
})
.collect::<Vec<_>>()
})
.collect()
}
}
/// Kills the daemon when dropped; `stop` returns what it printed.
struct Running(Option<Child>);
impl Running {
fn stop(mut self) -> String {
let mut child = self.0.take().unwrap();
child.kill().unwrap();
let output = child.wait_with_output().unwrap();
String::from_utf8_lossy(&output.stderr).to_string()
}
}
impl Drop for Running {
fn drop(&mut self) {
if let Some(child) = &mut self.0 {
let _ = child.kill();
let _ = child.wait();
}
}
}
fn mode(path: &Path) -> u32 {
std::fs::metadata(path).unwrap().permissions().mode() & 0o777
}
fn exchange(socket: &Path, id: u64, msg: Message) -> Vec<Envelope> {
let mut stream = UnixStream::connect(socket).unwrap();
stream
.set_read_timeout(Some(Duration::from_secs(10)))
.unwrap();
let env = Envelope {
v: PROTOCOL_VERSION,
id,
r#final: true,
msg,
};
bxcore::write_frame(&mut stream, &env).unwrap();
let mut frames = Vec::new();
loop {
let env = bxcore::read_frame(&mut stream).unwrap();
let last = env.r#final;
frames.push(env);
if last {
return frames;
}
}
}
fn read_notes(call: u64) -> Message {
Message::ToolRequest(ToolRequest {
session: SessionId::new("s1").unwrap(),
call: CallId(call),
tool: "read_file".to_string(),
arguments: r#"{"path":"/n/a"}"#.to_string(),
})
}
fn last_response(frames: &[Envelope]) -> &ToolResponse {
match &frames.last().unwrap().msg {
Message::ToolResponse(r) => r,
other => panic!("{other:?}"),
}
}
fn stderr(output: &Output) -> String {
String::from_utf8_lossy(&output.stderr).to_string()
}
#[test]
fn it_makes_its_directories_0700_and_its_sockets_0600() {
let home = Home::new("serve-modes", 900_000);
// One directory found too open, one made.
std::fs::create_dir_all(home.path("run/owner-broker")).unwrap();
std::fs::set_permissions(
home.path("run/owner-broker"),
std::fs::Permissions::from_mode(0o755),
)
.unwrap();
let running = home.serve();
assert_eq!(mode(&home.path("run/loop-broker")), 0o700);
assert_eq!(mode(&home.path("run/owner-broker")), 0o700);
assert_eq!(mode(&home.tools()), 0o600);
assert_eq!(mode(&home.admin()), 0o600);
assert_eq!(mode(&home.path("audit")), 0o700);
let printed = running.stop();
assert!(printed.contains("serving"), "{printed}");
}
#[test]
fn a_stale_socket_is_replaced() {
let home = Home::new("serve-stale", 900_000);
std::fs::create_dir_all(home.path("run/loop-broker")).unwrap();
drop(UnixListener::bind(home.tools()).unwrap());
assert!(home.tools().exists(), "the stale socket file is there");
let _running = home.serve();
let frames = exchange(&home.tools(), 3, read_notes(3));
assert_eq!(
last_response(&frames),
&ToolResponse::Denied {
reason: DenyReason::NoGrant,
detail: None,
}
);
}
#[test]
fn a_second_brokerd_on_the_same_home_refuses_to_start() {
let home = Home::new("serve-twice", 900_000);
let _running = home.serve();
let second = home.run(&[]);
assert_eq!(second.status.code(), Some(1));
let text = stderr(&second);
assert!(text.contains("brokerd is already running"), "{text}");
assert!(
text.trim_end()
.ends_with("see docs/runbook.md#brokerd-already-running"),
"{text}"
);
// The first still has its sockets.
let frames = exchange(&home.admin(), 1, Message::Approvals(Empty {}));
assert!(matches!(frames[0].msg, Message::ApprovalList(_)));
}
#[test]
fn it_answers_each_socket_and_refuses_the_other_kinds() {
let home = Home::new("serve-kinds", 900_000);
home.grant("notes", "auto");
let running = home.serve();
let frames = exchange(&home.tools(), 7, read_notes(7));
assert_eq!(frames[0].id, 7);
// The production runtime runs nothing.
assert_eq!(
last_response(&frames),
&ToolResponse::Failed {
message: REFUSING.to_string()
}
);
let wrong = exchange(&home.tools(), 8, Message::Approvals(Empty {}));
assert!(matches!(&wrong[0].msg, Message::Error(e) if e.code == ErrorCode::Forbidden));
let wrong = exchange(&home.admin(), 9, read_notes(9));
assert!(matches!(&wrong[0].msg, Message::Error(e) if e.code == ErrorCode::Forbidden));
let printed = running.stop();
assert!(
printed.contains("approvals on broker.sock\nsee docs/runbook.md#socket-forbidden"),
"{printed}"
);
assert!(
printed.contains("tool_request on admin.sock\nsee docs/runbook.md#socket-forbidden"),
"{printed}"
);
assert!(matches!(
home.events().as_slice(),
[
AuditEvent::Decision { .. },
AuditEvent::Result {
status: ResultStatus::Failed,
..
}
]
));
}
#[test]
fn an_approval_nobody_answers_expires() {
let home = Home::new("serve-expire", 100);
home.grant("notes", "ask");
let _running = home.serve();
let started = Instant::now();
let frames = exchange(&home.tools(), 2, read_notes(2));
assert_eq!(frames.len(), 2, "{frames:?}");
assert!(matches!(
&frames[0].msg,
Message::ToolResponse(ToolResponse::PendingApproval { approval: 0, .. })
));
assert_eq!(
last_response(&frames),
&ToolResponse::Denied {
reason: DenyReason::ApprovalExpired,
detail: None,
}
);
// The expiry thread looks every second.
assert!(
started.elapsed() < Duration::from_secs(5),
"{:?}",
started.elapsed()
);
}
fn copy_case(home: &Home, case: &str, only: &[&str]) {
let from = format!(
"{}/../bxcore/tests/fixtures/audit/{case}",
env!("CARGO_MANIFEST_DIR")
);
std::fs::create_dir_all(home.path("audit")).unwrap();
for name in only {
std::fs::copy(
format!("{from}/{name}"),
home.path(&format!("audit/{name}")),
)
.unwrap();
}
}
fn snapshot(dir: &Path) -> Vec<(String, Vec<u8>)> {
let mut all: Vec<(String, Vec<u8>)> = std::fs::read_dir(dir)
.unwrap()
.map(|e| e.unwrap())
.filter(|e| e.file_name().to_string_lossy().ends_with(".jsonl"))
.map(|e| {
(
e.file_name().into_string().unwrap(),
std::fs::read(e.path()).unwrap(),
)
})
.collect();
all.sort();
all
}
#[test]
fn a_broken_chain_stops_it_before_any_socket_and_nothing_is_written() {
let home = Home::new("serve-broken", 900_000);
copy_case(&home, "changed-byte", &["2026-09-17.jsonl"]);
let before = snapshot(&home.path("audit"));
let output = home.run(&[]);
assert_eq!(output.status.code(), Some(1));
let text = stderr(&output);
assert!(text.contains("2026-09-17.jsonl:4: "), "{text}");
assert!(
text.trim_end()
.ends_with("see docs/runbook.md#audit-chain-broken"),
"{text}"
);
assert_eq!(snapshot(&home.path("audit")), before);
assert!(!home.tools().exists() && !home.admin().exists());
}
#[test]
fn a_torn_tail_is_recovered_and_it_serves() {
let home = Home::new("serve-torn", 900_000);
copy_case(
&home,
"torn-tail",
&["2026-09-17.jsonl", "2026-09-18.jsonl"],
);
let running = home.serve();
let printed = running.stop();
assert!(printed.contains(RECOVERED_NOTICE), "{printed}");
assert!(RECOVERED_NOTICE.ends_with("see docs/runbook.md#audit-recovered"));
}
#[test]
fn accept_break_with_nothing_to_accept_exits_2() {
let home = Home::new("serve-nothing", 900_000);
let output = home.run(&["--accept-break"]);
assert_eq!(output.status.code(), Some(2));
assert!(
stderr(&output).contains("nothing to accept"),
"{}",
stderr(&output)
);
}
#[test]
fn bad_arguments_and_bad_configs_do_not_start() {
let brokerd = env!("CARGO_BIN_EXE_brokerd");
for args in [
&[][..],
&["serve"][..],
&["serve", "--config"][..],
&["serve", "--config", "a", "--config", "b"][..],
&["serve", "--config", "a", "--loud"][..],
&["run", "--config", "a"][..],
] {
let output = Command::new(brokerd).args(args).output().unwrap();
assert_eq!(output.status.code(), Some(2), "{args:?}");
assert!(
stderr(&output).starts_with("usage: brokerd serve"),
"{args:?}"
);
}
let home = Home::new("serve-config", 900_000);
std::fs::write(&home.config, "[paths]\nhoem = \"/x\"\n").unwrap();
let output = home.run(&[]);
assert_eq!(output.status.code(), Some(1));
assert!(
stderr(&output).contains("brokerd.toml"),
"{}",
stderr(&output)
);
std::fs::remove_file(&home.config).unwrap();
assert_eq!(home.run(&[]).status.code(), Some(1));
assert!(
!home.path("audit").exists(),
"nothing made before the config is read"
);
}
@@ -0,0 +1,218 @@
//! One `gatewayd` per home (M5b spec, section 9a): a second `gatewayd serve` against the same home
//! is refused with the lock's line, and the first keeps serving `gateway.sock`; once the first is
//! killed, a new one removes the stale socket and serves. Each runs against the fake Mattermost.
//! Every wait has a deadline, and every process is killed and every path removed by a guard (tip
//! T44). Do not edit.
#[path = "support/brokerd_client.rs"]
mod brokerd_client;
#[path = "support/fake_mm.rs"]
mod fake_mm;
#[path = "support/tmp.rs"]
mod tmp;
use std::os::unix::fs::PermissionsExt;
use std::path::{Path, PathBuf};
use std::process::{Child, Command, Stdio};
use std::time::{Duration, Instant};
use brokerd_client::{ask, pending};
use fake_mm::{FakeMm, KYLE};
use tmp::TempDir;
const POINTER: &str = "see docs/runbook.md#already-running";
const TOKEN: &str = "tok-instance-test";
const WAIT: Duration = Duration::from_secs(10);
struct Home {
dir: TempDir,
config: PathBuf,
}
impl Home {
fn new(tag: &str, mm: &FakeMm) -> Home {
let dir = TempDir::new(tag);
let text = format!(
"[mattermost]\nurl = \"{}\"\n[secrets.mattermost_token]\nenv = \"GW_TEST_TOKEN\"\n\
[allow]\nusers = [\"{KYLE}\"]\n[paths]\nhome = \"{}\"\n",
mm.url(),
dir.path().display()
);
let config = dir.write("gatewayd.toml", &text);
Home { dir, config }
}
fn path(&self, relative: &str) -> PathBuf {
self.dir.path().join(relative)
}
fn socket(&self) -> PathBuf {
self.path("run/gateway/gateway.sock")
}
fn command(&self) -> Command {
let mut command = Command::new(env!("CARGO_BIN_EXE_gatewayd"));
command
.args(["serve", "--config"])
.arg(&self.config)
.env_remove("CREDENTIALS_DIRECTORY")
.env("GW_TEST_TOKEN", TOKEN)
.stdin(Stdio::null())
.stdout(Stdio::null());
command
}
/// `gatewayd serve` with its stderr in `<home>/<name>.err`, for the messages of a failing test.
fn start(&self, name: &str) -> Daemon {
let err = std::fs::File::create(self.path(&format!("{name}.err"))).unwrap();
Daemon(self.command().stderr(Stdio::from(err)).spawn().unwrap())
}
fn stderr_of(&self, name: &str) -> String {
std::fs::read_to_string(self.path(&format!("{name}.err"))).unwrap_or_default()
}
/// Runs `gatewayd serve` to its end, at most 10 s (then it is killed), and gives its exit code
/// (`None` if it had to be killed) and its stderr.
fn run_to_end(&self) -> (Option<i32>, String) {
let mut child = Daemon(self.command().stderr(Stdio::piped()).spawn().unwrap());
let deadline = Instant::now() + WAIT;
let mut code = None;
while Instant::now() < deadline {
if let Ok(Some(status)) = child.0.try_wait() {
code = status.code();
break;
}
std::thread::sleep(Duration::from_millis(20));
}
let _ = child.0.kill();
let _ = child.0.wait();
let mut stderr = String::new();
if let Some(mut pipe) = child.0.stderr.take() {
let _ = std::io::Read::read_to_string(&mut pipe, &mut stderr);
}
(code, stderr)
}
}
/// A running `gatewayd serve`, killed and waited for when dropped. Declared after the `Home` and
/// the `FakeMm`, so it drops first.
struct Daemon(Child);
impl Drop for Daemon {
fn drop(&mut self) {
let _ = self.0.kill();
let _ = self.0.wait();
}
}
impl Daemon {
fn running(&mut self) -> bool {
matches!(self.0.try_wait(), Ok(None))
}
}
/// True when `gatewayd` answers on `gateway.sock` as it does for `brokerd`: approval `approval`,
/// of a `bxctl chat` session, is posted to the first approver and the posts come back. The
/// connection is then closed, which ends the approval.
fn answers(socket: &Path, approval: u64) -> bool {
match ask(socket, pending(approval, "chat-1789700000-1", "{}")) {
Ok(asking) => {
let answered = !asking.posts.is_empty();
asking.close();
answered
}
Err(_) => false,
}
}
/// Waits up to 10 s for `gatewayd` to answer on `socket`.
fn wait_until_it_answers(socket: &Path, approval: u64) -> bool {
let deadline = Instant::now() + WAIT;
while Instant::now() < deadline {
if answers(socket, approval) {
return true;
}
std::thread::sleep(Duration::from_millis(50));
}
false
}
fn inode(path: &Path) -> u64 {
use std::os::unix::fs::MetadataExt;
std::fs::symlink_metadata(path)
.map(|m| m.ino())
.unwrap_or(0)
}
#[test]
fn a_second_gatewayd_on_the_same_home_is_refused_and_the_first_keeps_serving() {
let mm = FakeMm::start();
let home = Home::new("inst-twice", &mm);
let mut first = home.start("first");
let _ws = mm.next_ws(WAIT);
assert!(
wait_until_it_answers(&home.socket(), 1),
"the first gatewayd never answered; stderr: {}",
home.stderr_of("first")
);
let before = inode(&home.socket());
let (code, stderr) = home.run_to_end();
let line = format!(
"gatewayd: another gatewayd is running (it holds {}); {POINTER}",
home.path("run/gatewayd.lock").display()
);
assert_eq!(code, Some(1), "the second gatewayd: {stderr}");
assert_eq!(
stderr,
format!("{line}\n"),
"the lock's line, and nothing else"
);
assert!(first.running(), "the first gatewayd is still running");
assert_eq!(
inode(&home.socket()),
before,
"the first's socket is still there"
);
assert!(
answers(&home.socket(), 2),
"the first gatewayd still answers; its stderr: {}",
home.stderr_of("first")
);
}
#[test]
fn after_the_first_is_killed_a_new_gatewayd_removes_the_stale_socket_and_serves() {
let mm = FakeMm::start();
let home = Home::new("inst-restart", &mm);
let mut first = home.start("first");
let _ws = mm.next_ws(WAIT);
assert!(
wait_until_it_answers(&home.socket(), 1),
"the first gatewayd never answered; stderr: {}",
home.stderr_of("first")
);
let _ = first.0.kill();
let _ = first.0.wait();
assert!(
home.socket().exists(),
"a killed gatewayd leaves its socket"
);
assert!(
!answers(&home.socket(), 2),
"nobody serves the stale socket"
);
let _next = home.start("next");
let _ws = mm.next_ws(WAIT);
assert!(
wait_until_it_answers(&home.socket(), 3),
"the new gatewayd never answered; stderr: {}",
home.stderr_of("next")
);
let lock = home.path("run/gatewayd.lock");
let mode = std::fs::metadata(&lock).map(|m| m.permissions().mode() & 0o777);
assert_eq!(mode.ok(), Some(0o600), "the lock file, mode 0600");
}
@@ -0,0 +1,223 @@
//! One `memoryd` per home (M5b spec, section 9a): a second `memoryd serve` against the same home is
//! refused with the lock's line, and the first keeps serving; once the first is killed, a new one
//! removes the stale sockets and serves. Every wait has a deadline, and every process is killed
//! and every path removed by a guard (tip T44). Do not edit.
#[path = "support/tmp.rs"]
mod tmp;
use std::os::unix::fs::PermissionsExt;
use std::os::unix::net::UnixStream;
use std::path::{Path, PathBuf};
use std::process::{Child, Command, Stdio};
use std::time::{Duration, Instant};
use bxcore::{Empty, Envelope, Message, PROTOCOL_VERSION, read_frame, write_frame};
use tmp::TempDir;
const POINTER: &str = "see docs/runbook.md#already-running";
const SOCKETS: [&str; 3] = [
"run/loop-memory/memory.sock",
"run/broker-memory/memory.sock",
"run/owner-memory/admin.sock",
];
struct Home {
dir: TempDir,
config: PathBuf,
}
impl Home {
fn new(tag: &str) -> Home {
let dir = TempDir::new(tag);
let soul = dir.write("etc/soul.md", "You are Boxmaker.\n");
let text = format!(
"[paths]\nhome = \"{}\"\n[memory]\nsoul_starter = \"{}\"\n",
dir.path().display(),
soul.display()
);
let config = dir.write("memoryd.toml", &text);
Home { dir, config }
}
fn path(&self, relative: &str) -> PathBuf {
self.dir.path().join(relative)
}
fn command(&self) -> Command {
let mut command = Command::new(env!("CARGO_BIN_EXE_memoryd"));
command
.args(["serve", "--config"])
.arg(&self.config)
.stdin(Stdio::null())
.stdout(Stdio::null());
command
}
/// `memoryd serve` with its stderr in `<home>/<name>.err`, for the messages of a failing test.
fn start(&self, name: &str) -> Daemon {
let err = std::fs::File::create(self.path(&format!("{name}.err"))).unwrap();
Daemon(self.command().stderr(Stdio::from(err)).spawn().unwrap())
}
fn stderr_of(&self, name: &str) -> String {
std::fs::read_to_string(self.path(&format!("{name}.err"))).unwrap_or_default()
}
/// Runs `memoryd serve` to its end, at most 10 s (then it is killed), and gives its exit code
/// (`None` if it had to be killed) and its stderr.
fn run_to_end(&self) -> (Option<i32>, String) {
let mut child = Daemon(self.command().stderr(Stdio::piped()).spawn().unwrap());
let deadline = Instant::now() + Duration::from_secs(10);
let mut code = None;
while Instant::now() < deadline {
if let Ok(Some(status)) = child.0.try_wait() {
code = status.code();
break;
}
std::thread::sleep(Duration::from_millis(20));
}
let _ = child.0.kill();
let _ = child.0.wait();
let mut stderr = String::new();
if let Some(mut pipe) = child.0.stderr.take() {
let _ = std::io::Read::read_to_string(&mut pipe, &mut stderr);
}
(code, stderr)
}
fn inodes(&self) -> Vec<u64> {
SOCKETS.iter().map(|s| inode(&self.path(s))).collect()
}
}
/// A running `memoryd serve`, killed and waited for when dropped. Declared after the `Home`, so it
/// drops first.
struct Daemon(Child);
impl Drop for Daemon {
fn drop(&mut self) {
let _ = self.0.kill();
let _ = self.0.wait();
}
}
impl Daemon {
fn running(&mut self) -> bool {
matches!(self.0.try_wait(), Ok(None))
}
}
/// True when `memoryd` answers on `socket`, `loopd`'s: `memory_block` gets the block. Any other
/// answer, or none within 5 s, is false.
fn answers(socket: &Path) -> bool {
let Ok(mut stream) = UnixStream::connect(socket) else {
return false;
};
let limit = Some(Duration::from_secs(5));
if stream.set_read_timeout(limit).is_err() || stream.set_write_timeout(limit).is_err() {
return false;
}
let ask = Envelope {
v: PROTOCOL_VERSION,
id: 1,
r#final: true,
msg: Message::MemoryBlock(Empty {}),
};
if write_frame(&mut stream, &ask).is_err() {
return false;
}
matches!(
read_frame(&mut stream),
Ok(Envelope {
msg: Message::MemoryBlockReply(_),
..
})
)
}
/// Waits up to 10 s for `memoryd` to answer on `loopd`'s socket and to listen on the other two.
fn wait_until_it_answers(home: &Home) -> bool {
let deadline = Instant::now() + Duration::from_secs(10);
while Instant::now() < deadline {
if answers(&home.path(SOCKETS[0]))
&& SOCKETS[1..]
.iter()
.all(|s| UnixStream::connect(home.path(s)).is_ok())
{
return true;
}
std::thread::sleep(Duration::from_millis(20));
}
false
}
fn inode(path: &Path) -> u64 {
use std::os::unix::fs::MetadataExt;
std::fs::symlink_metadata(path)
.map(|m| m.ino())
.unwrap_or(0)
}
#[test]
fn a_second_memoryd_on_the_same_home_is_refused_and_the_first_keeps_serving() {
let home = Home::new("inst-twice");
let mut first = home.start("first");
assert!(
wait_until_it_answers(&home),
"the first memoryd never answered; stderr: {}",
home.stderr_of("first")
);
let before = home.inodes();
let (code, stderr) = home.run_to_end();
let line = format!(
"memoryd: another memoryd is running (it holds {}); {POINTER}",
home.path("run/memoryd.lock").display()
);
assert_eq!(code, Some(1), "the second memoryd: {stderr}");
assert_eq!(
stderr,
format!("{line}\n"),
"the lock's line, and nothing else"
);
assert!(first.running(), "the first memoryd is still running");
assert_eq!(home.inodes(), before, "the first's sockets are still there");
assert!(
answers(&home.path(SOCKETS[0])),
"the first memoryd still answers; its stderr: {}",
home.stderr_of("first")
);
}
#[test]
fn after_the_first_is_killed_a_new_memoryd_removes_the_stale_sockets_and_serves() {
let home = Home::new("inst-restart");
let mut first = home.start("first");
assert!(
wait_until_it_answers(&home),
"the first memoryd never answered; stderr: {}",
home.stderr_of("first")
);
let _ = first.0.kill();
let _ = first.0.wait();
assert!(
SOCKETS.iter().all(|s| home.path(s).exists()),
"a killed memoryd leaves its sockets"
);
assert!(
!answers(&home.path(SOCKETS[0])),
"nobody serves the stale socket"
);
let _next = home.start("next");
assert!(
wait_until_it_answers(&home),
"the new memoryd never answered; stderr: {}",
home.stderr_of("next")
);
let lock = home.path("run/memoryd.lock");
let mode = std::fs::metadata(&lock).map(|m| m.permissions().mode() & 0o777);
assert_eq!(mode.ok(), Some(0o600), "the lock file, mode 0600");
}