Defer annotation update until after watchdog is started

[kwohlfahrt]

Why we need this PR

Currently, the watchdog timeout is read upon creating the watchdog, before starting it. This always returns a value of 0, because the timeout is only available after the watchdog's start.

Changes made

• Add a Started() method to the watchdog interface, that notifies when the watchdog is started
• Add a new runnable that waits for the watchdog to start, and then calls the annotation updater
• Fix a bug where watchdog initialization errors were not surfaced when software fallback is disabled

Which issue(s) this PR fixes

Fixes #332

Test plan

Added new unit test. I'm open to suggestions for a more thorough e2e test, but am not familiar enough with the test setup to come up with a clean idea.

[openshift-ci]

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[openshift-ci]

Hi @kwohlfahrt. Thanks for your PR.

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[coderabbitai]

📝 Walkthrough

Summary by CodeRabbit

• Bug Fixes
  • Improved startup status reporting for the agent’s reboot watchdog.
  • Reboot capability is now updated only after watchdog startup completes.
  • Reboot capability is correctly cleared when no watchdog is available.
  • Watchdog start failures and software-reboot fallback are handled more reliably, with consistent timeout and malfunction behavior.
• Tests
  • Added coverage for watchdog start signalling and start-failure scenarios (including software reboot enabled).

Walkthrough

The watchdog now signals startup completion through Started(). The agent waits for this signal before updating the node annotation with watchdog state and timeout. Tests cover successful startup and software-reboot fallback.

Changes

Watchdog startup and annotation

Layer / File(s)	Summary
Watchdog startup signal internal/watchdog/interface.go, internal/watchdog/synchronized.go, internal/watchdog/watchdog_test.go	The Watchdog interface exposes Started(). The synchronized watchdog closes the channel after hardware startup or software fallback. Tests verify startup signalling, timeout, and malfunction state.
Startup-aware annotation update cmd/main.go	Watchdog-enabled agents wait for startup before updating the node annotation. Agents without a watchdog set non-reboot-capable state with a zero timeout.

Estimated code review effort: 3 (Moderate) | ~20 minutes

Sequence Diagram(s)

sequenceDiagram
  participant Agent
  participant synchronizedWatchdog
  participant NodeAnnotation
  Agent->>synchronizedWatchdog: wait for Started()
  synchronizedWatchdog-->>Agent: startup channel closes
  Agent->>NodeAnnotation: update armed state and timeout

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Suggested reviewers: jmontleon, mshitrit

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Linked Issues check	✅ Passed	The changes address issue #332 by updating the annotation after startup when the configured watchdog timeout is available.
Out of Scope Changes check	✅ Passed	The changes remain focused on watchdog startup signaling, annotation accuracy, startup errors, and related tests.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Title check	✅ Passed	The title clearly states that the annotation update is deferred until after the watchdog starts.
Description check	✅ Passed	The description explains the watchdog timeout bug, the Started() change, the annotation update, error handling, and testing.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[coderabbitai]

Actionable comments posted: 2

🤖 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 `@cmd/main.go`:
- Around line 358-364: Update the runnable setup around wd.Started() to call
UpdateNodeAnnotations with the unavailable state (false and timeout 0) before
registering the runnable with mgr. Preserve the existing context cancellation
behavior, then call UpdateNodeAnnotations again after wd.Started() closes using
wd.Status() == watchdog.Armed and wd.GetTimeout() so the reachable state is
published.

In `@internal/watchdog/watchdog_test.go`:
- Around line 90-94: Move the context.WithCancel(context.Background()) setup out
of the BeforeEach callback into a package-level test helper, then invoke that
helper from BeforeEach while preserving the existing ctx, cancel, and
DeferCleanup behavior. Update the test setup around BeforeEach without changing
the test lifecycle semantics.

🪄 Autofix

Fix all unresolved CodeRabbit comments on this PR:

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

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: 3bab509f-bd01-4260-a4f9-aeb4c5618c05

📥 Commits

Reviewing files that changed from the base of the PR and between 08359bb and f6eacc7.

📒 Files selected for processing (4)

• cmd/main.go
• internal/watchdog/interface.go
• internal/watchdog/synchronized.go
• internal/watchdog/watchdog_test.go