Add opt-in DISABLE_SIGNALS to ignore shutdown signals

[telcharr]

Closes #199

Adds an opt-in DISABLE_SIGNALS env var so hbbs/hbbr can ignore shutdown signals on hosts without a process supervisor. Accepts a comma separated list of hup,term,int,quit or all. A listed signal is caught and swallowed instead of triggering a shutdown. DISABLE_SIGNALS=hup is enough to survive an ssh logout without nohup. setsid or a supervisor is still the better path, but this helps if neither are available.

Summary by CodeRabbit

• New Features

  • Added support for selectively ignoring termination signals via the DISABLE_SIGNALS environment variable on Unix, allowing finer control over graceful shutdown; when all relevant signals are disabled, shutdown won't be triggered by those signals.

• Tests

  • Added tests covering signal-configuration parsing, including empty input, case/whitespace variations, “all”, and unknown tokens.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

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Configuration used: defaults

Review profile: CHILL

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Run ID: 8457c926-6738-44dc-b070-4d8912d033f5

📥 Commits

Reviewing files that changed from the base of the PR and between 2a7a1f1 and d1e17ea.

📒 Files selected for processing (1)

• src/common.rs

🚧 Files skipped from review as they are similar to previous changes (1)

• src/common.rs

---

📝 Walkthrough

Walkthrough

The Unix signal handler now respects a DISABLE_SIGNALS environment variable to selectively ignore specific termination signals. The implementation adds parsing for comma-separated signal names with flexible formatting, registers ignore handlers for disabled signals, and races only the remaining graceful signals during shutdown.

Changes

Selective Signal Disabling

Layer / File(s)	Summary
DisabledSignals state and listen_signal rewrite src/common.rs (lines 157–235)	Introduces DisabledSignals enum and parsing from DISABLE_SIGNALS env var with support for comma-separated tokens, optional sig prefix, case-insensitive matching, and the all keyword. Rewrites listen_signal() to conditionally register ignore handlers for each disabled signal and tokio::select! only over the enabled graceful shutdown signals, with fallback when all are disabled.
Unit tests for parse_disabled_signals src/common.rs (lines 274–299)	Tests parse_disabled_signals() across empty input, single/multiple signal tokens, whitespace and case variations, the all keyword, and unknown token handling.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Poem

I’m a rabbit in code, ears tuned to the breeze,
I tuck away signals with elegant ease,
DISABLE_SIGNALS whispers which ones to ignore,
The server keeps running, still nimble and sure,
🐰✨

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately and concisely summarizes the main change: adding an opt-in DISABLE_SIGNALS feature to selectively ignore shutdown signals.
Linked Issues check	✅ Passed	The changes fully implement the feature requested in issue #199: adding an environment variable to disable specific signal handlers, allowing the server to ignore shutdown signals.
Out of Scope Changes check	✅ Passed	All changes in src/common.rs are directly related to implementing the DISABLE_SIGNALS feature and are within scope of the linked issue.
Docstring Coverage	✅ Passed	Docstring coverage is 83.33% which is sufficient. The required threshold is 80.00%.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

---

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[coderabbitai]

Actionable comments posted: 1

🧹 Nitpick comments (1)

src/common.rs (1)

280-299: ⚡ Quick win

Add coverage for sig-prefixed tokens.

parse_disabled_signals() supports optional sig prefixes, but current tests don’t assert that behavior. Add cases like sigint, sighup, and mixed forms to lock this contract.

Suggested test additions

     #[test]
     fn parse_signals() {
         assert_eq!(parse_disabled_signals(""), DisabledSignals::default());
@@
         assert_eq!(
             parse_disabled_signals("bogus,quit"),
             DisabledSignals { quit: true, ..Default::default() }
         );
+        assert_eq!(
+            parse_disabled_signals("sigint,sighup"),
+            DisabledSignals { int: true, hup: true, ..Default::default() }
+        );
+        assert_eq!(
+            parse_disabled_signals("SIGQUIT,sigterm"),
+            DisabledSignals { quit: true, term: true, ..Default::default() }
+        );
     }

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@src/common.rs` around lines 280 - 299, Update the parse_signals unit test to
cover the optional "sig" prefix support: add assertions that
parse_disabled_signals("sigint") yields DisabledSignals { int: true,
..Default::default() }, parse_disabled_signals("sighup") yields DisabledSignals
{ hup: true, ..Default::default() }, and include a mixed-case/whitespace example
such as parse_disabled_signals(" SIGTERM , sigquit ") or
parse_disabled_signals("sigint,quit") to ensure parse_disabled_signals and the
DisabledSignals behavior handle "sig"-prefixed tokens and mixed forms correctly.

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@src/common.rs`:
- Around line 207-211: The ignore closure currently swallows errors from
signal(kind); update it to log failures when signal(kind) returns Err (e.g.,
with log::error or log::warn) so misconfiguration is visible: replace the if let
Ok(mut s) = signal(kind) branch with a match or an else that logs the returned
error (including the signal name and error), and keep the existing tokio::spawn
loop behavior in the Ok arm unchanged.

---

Nitpick comments:
In `@src/common.rs`:
- Around line 280-299: Update the parse_signals unit test to cover the optional
"sig" prefix support: add assertions that parse_disabled_signals("sigint")
yields DisabledSignals { int: true, ..Default::default() },
parse_disabled_signals("sighup") yields DisabledSignals { hup: true,
..Default::default() }, and include a mixed-case/whitespace example such as
parse_disabled_signals(" SIGTERM , sigquit ") or
parse_disabled_signals("sigint,quit") to ensure parse_disabled_signals and the
DisabledSignals behavior handle "sig"-prefixed tokens and mixed forms correctly.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: 6bea4400-9b80-44f1-8195-7edb1cb99453

📥 Commits

Reviewing files that changed from the base of the PR and between 815c728 and 2a7a1f1.

📒 Files selected for processing (1)

• src/common.rs