Phase 12: Readiness Checklist¶

Document Type: Readiness Checklist
Phase: 12 - Serverless Functions
Status: In Progress

Documentation Checklist¶

• FUNCTIONS_VISION.md - Goals and philosophy
• FUNCTIONS_ARCHITECTURE.md - WASM runtime and components
• FUNCTIONS_FUNCTION_MODEL.md - Function structure and metadata
• FUNCTIONS_EXECUTION_MODEL.md - Trigger types and execution flow
• FUNCTIONS_INVARIANTS.md - Security and isolation invariants
• FUNCTIONS_FAILURE_MODEL.md - Error handling and recovery
• FUNCTIONS_TESTING_STRATEGY.md - Test coverage plan
• FUNCTIONS_READINESS.md - Freeze criteria (this document)

Status: ✅ All 8 documents complete

Implementation Checklist¶

Core Modules¶

• src/functions/mod.rs - Module entry point
• src/functions/errors.rs - Function error types
• src/functions/function.rs - Function model and config
• src/functions/trigger.rs - Trigger types (HTTP, DB, Schedule)
• src/functions/registry.rs - Function registry with indexing
• src/functions/runtime.rs - WASM runtime integration (wasmer/wasmtime)
• src/functions/invoker.rs - Function execution with limits
• src/functions/scheduler.rs - Cron job scheduler
• src/functions/host_functions.rs - Host function implementations

Priority: runtime.rs requires WASM integration (external dependency)

API Endpoints¶

• POST /functions/v1/deploy - Deploy new function
• GET /functions/v1/{name} - Get function metadata
• PATCH /functions/v1/{name} - Update function config
• DELETE /functions/v1/{name} - Undeploy function
• POST /functions/v1/invoke/{name} - Invoke HTTP trigger
• GET /functions/v1/{name}/logs - Get invocation logs

WASM Runtime¶

• Integrate wasmer or wasmtime
• Module compilation and caching
• Instance creation with host functions
• Timeout enforcement (Tokio)
• Memory limit enforcement (store limiter)
• Stack limit enforcement

Host Functions¶

• db_query - Query database with RLS
• log - Write logs
• env - Get environment variables
• http_fetch - External HTTP requests (future)

Triggers¶

• HTTP trigger - Synchronous invocation
• Database trigger - Fire on INSERT/UPDATE/DELETE
• Schedule trigger - Cron-based execution
• Webhook trigger - External POST with signature (future)

Metadata Storage¶

• functions collection schema
• function_invocations collection schema
• Executor integration for metadata queries

Test Checklist¶

Unit Tests¶

• Registry operations (> 10 tests)
• Runtime module loading (> 8 tests)
• Invoker execution (> 15 tests)
• Scheduler cron parsing (> 10 tests)
• Host functions (> 10 tests)
• Error handling (> 10 tests)

Target: > 60 unit tests, > 90% coverage

Integration Tests¶

• HTTP function E2E
• Database trigger E2E
• Schedule trigger E2E
• RLS enforcement with functions
• Concurrent invocations

Target: > 10 integration tests

Stress Tests¶

• 1000 concurrent invocations
• Memory leak detection
• Timeout enforcement under load

Security Tests¶

• RLS bypass attempts blocked
• Secrets redacted in logs
• Sandbox escape attempts blocked

Invariant Validation¶

Each invariant must have tests proving it holds:

Performance Benchmarks¶

Integration Points¶

AeroDB Core¶

• Executor integration for db_query host function
• WAL integration for database triggers
• RLS context from auth module

REST API (Phase 9)¶

• Function endpoints registered
• Multipart upload for WASM binaries
• Error mapping to HTTP status codes

Authentication (Phase 8)¶

• RLS context passed to all invocations
• Service role bypass tested
• JWT validation for HTTP triggers

Real-Time (Phase 10)¶

• Function writes propagate to event log
• Events visible to subscribers

External Dependencies¶

WASM Runtime¶

Option 1: wasmer (Recommended)

[dependencies]
wasmer = "4.0"
wasmer-wasi = "4.0"

Option 2: wasmtime

[dependencies]
wasmtime = "15.0"

Decision: Choose wasmer for better resource limit API

Cron Parser¶

[dependencies]
cron = "0.12"

Deployment Checklist¶

Configuration¶

• functions.timeout_default = 10s
• functions.memory_default = 128MB
• functions.wasm_max_size = 10MB
• functions.concurrent_limit = 1000

Migration¶

• Create functions schema
• Create function_invocations schema
• Index on function name
• Index on trigger type

Monitoring¶

• Metrics: invocations, duration, errors
• Metrics: cold start latency
• Logs: function invocation with context
• Alerts: error rate > 5%, timeout rate > 10%

Freeze Criteria¶

Phase 12 can be frozen when:

1. ✅ All 8 documentation files complete
2. ⬜ All 9 core modules implemented
3. ⬜ WASM runtime integrated (wasmer)
4. ⬜ All 6 API endpoints working
5. ⬜ All 4 host functions implemented
6. ⬜ All 3 trigger types working (HTTP, DB, Schedule)
7. ⬜ Metadata stored in AeroDB via executor
8. ⬜ All 8 invariants have test coverage
9. ⬜ > 60 unit tests passing
10. ⬜ > 10 integration tests passing
11. ⬜ Performance benchmarks meet targets
12. ⬜ Timeout and memory limits enforced
13. ⬜ RLS enforcement verified

Current Status: 🔴 NOT READY (docs complete, implementation needed)

Known Limitations (Deferred)¶

• WASI support for filesystem/network access
• Multi-language SDKs (JavaScript, Python compile to WASM)
• Function-to-function calls
• Warm instance pooling (cold start optimization)
• Retry policies for failed invocations
• Dead letter queue for errors
• Distributed tracing
• Custom npm/pip packages in functions
• Webhook signature verification
• Rate limiting per function

These are explicitly deferred to keep Phase 12 focused on core WASM execution.

Risk Assessment¶

Sign-Off Required¶

• Lead Engineer: Core implementation review
• Security: Sandbox and RLS review
• QA: Test coverage and edge cases
• Docs: All 8 documents complete (✅ DONE)
• Performance: Benchmarks meet targets
• DevOps: WASM runtime dependencies ready