feat(database): add listDatabases function to list configured databases

[andersonleal]

Summary

Adds database::listDatabases — the worker's 12th function — so callers can discover which databases are configured without access to the raw config. Returns config details only (no health checks, no live pool stats):

{
  "databases": [
    {
      "name": "primary",
      "driver": "sqlite",
      "url": "sqlite::memory:",
      "pool": { "max": 10, "idle_timeout_ms": 30000, "acquire_timeout_ms": 5000 },
      "tls": { "mode": "require", "ca_cert_present": false, "trust_native": true }
    }
  ],
  "count": 1
}

Design notes

• AppState gains a live config snapshot (Arc<RwLock<WorkerConfig>>). Built pools discard their config at build time, so the handler needs this to report details. apply_config now swaps pools and snapshot inside one critical section — a concurrent listDatabases can never observe new pools paired with stale config (and a failed rebuild leaves both untouched, preserving the existing keep-previous-pools contract).
• No credential leaks: connection URLs pass through the existing config::redact_url (password stripped, username → ***); ca_cert is reported as a presence boolean only, never the filesystem path.
• Reuses existing utilities: redact_url, transaction::driver_system, and TlsMode's existing kebab-case serialization — no new dependencies.
• Entries sorted by name for deterministic output; envelope { items, count } mirrors shell::list.

Test plan

• 7 new unit tests: config defaults, postgres/mysql password redaction, sqlite URL passthrough, deterministic sort + count, TLS overrides without cert-path leak, response envelope shape
• 2 new integration tests: list_databases_reports_configured_primary and apply_config_updates_list_snapshot (hot-reload regression guard)
• Full suite green: 193 lib + 5 integration + 3 value-coercion tests
• cargo llvm-cov: 100% line/region/function coverage on the new handler; apply_config fully covered
• cargo fmt --all clean
• Live smoke test against a running engine: iii trigger database::listDatabases '{}'

Summary by CodeRabbit

• New Features

  • Added database::listDatabases API endpoint to list all configured databases with metadata including driver type, connection pool configuration, and TLS settings.

• Documentation

  • Updated function reference documentation to include the new listDatabases operation.

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Project	Deployment	Actions	Updated (UTC)
workers	Ready	Preview, Comment	Jun 4, 2026 5:43pm

[github-actions]

skill-check — worker

0 verified, 14 skipped (no docs/).

Layer	Result
structure	✓
vale	✓
ai	✓
render	✓

Four for four. Nicely done.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 44db96ef-d702-4986-8a84-cc5b70ef72ad

📥 Commits

Reviewing files that changed from the base of the PR and between 84871c4 and 0902360.

⛔ Files ignored due to path filters (1)

• database/Cargo.lock is excluded by !**/*.lock

📒 Files selected for processing (16)

• database/README.md
• database/skills/SKILL.md
• database/src/configuration.rs
• database/src/handlers/begin_transaction.rs
• database/src/handlers/commit_transaction.rs
• database/src/handlers/execute.rs
• database/src/handlers/list_databases.rs
• database/src/handlers/mod.rs
• database/src/handlers/prepare.rs
• database/src/handlers/query.rs
• database/src/handlers/rollback_transaction.rs
• database/src/handlers/run_statement.rs
• database/src/handlers/transaction.rs
• database/src/handlers/transaction_execute.rs
• database/src/main.rs
• database/tests/integration.rs

---

📝 Walkthrough

Walkthrough

This PR adds a new database::listDatabases RPC handler that exposes configured database metadata to callers. The handler reads from a new AppState.config field that stores a snapshot of the current database configuration, which is atomically updated alongside connection pools during configuration reloads.

Changes

Database List Handler

Layer / File(s)	Summary
AppState configuration field and atomic state management database/src/handlers/mod.rs, database/src/configuration.rs	AppState gains a new config: Arc<RwLock<WorkerConfig>> field to store the current database configuration snapshot. apply_config is updated to atomically acquire both the pools and config write locks in order, then assign the newly built pools and new config snapshot within that coordinated critical section.
List databases handler implementation database/src/handlers/list_databases.rs	Introduces ListDatabasesReq, DatabaseInfo, PoolInfo, TlsInfo, and ListDatabasesResp types. The handle function reads configured databases, maps driver names, redacts connection credentials via redact_url, converts TLS metadata (exposing CA presence as a boolean rather than a filesystem path), sorts databases by name for deterministic output, and returns count alongside the list. Includes unit tests validating credential redaction, TLS field masking, and response envelope shape.
Handler registration and wiring database/src/main.rs, database/src/handlers/mod.rs	Imports list_databases handler module, initializes AppState.config from fetched configuration during startup, registers database::listDatabases as an iii function wired to list_databases::handle, and updates the startup function count from 11 to 12.
Test suite updates database/src/handlers/*.rs, database/tests/integration.rs	All handler unit test helpers are updated to initialize the new AppState.config field with default WorkerConfig wrapped in Arc<RwLock<_>>. Integration tests verify that list_databases::handle reports the initial configured database and reflects updates after apply_config.
Documentation database/README.md, database/skills/SKILL.md	README and SKILL.md are updated to document database::listDatabases as a configuration-only listing function that returns database names, drivers, redacted URLs, pool settings, and TLS metadata without performing health checks or reporting live pool statistics.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Possibly related PRs

• iii-hq/workers#194: Introduced the database configuration hot-reload refactor (configuration module and shared state wiring for pools/config) that this PR builds upon by adding the persistent config snapshot field and atomic dual-lock swapping behavior.

Poem

🐰 A database's secrets now laid bare,
Configuration snapshot we gladly share,
List them all with credentials redacted tight,
Atomic swaps keep the state just right,
No more mysteries in the config night! 🔐

🚥 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 describes the main change: a new listDatabases function for listing configured databases, which is the primary feature added across multiple files.
Docstring Coverage	✅ Passed	Docstring coverage is 81.48% which is sufficient. The required threshold is 80.00%.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch feat/database-list-databases

---

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