# WDC Runtime Phase 18 Implementation Report **Phase:** 18 — Live Production Service Integration Harness **Date:** 2026-08-18 **Branch:** `feature/phase18` **Base:** Phase 17 (`c42215058ec3c214f84668d5c38aa691c8516951`) ## 1. Scope Phase 18 turns the Phase 17 PostgreSQL/Redis/S3-compatible adapter contracts into an executable integration harness for real services while preserving all existing WDC semantic boundaries. It adds: - `integration/compose.yaml` for PostgreSQL 18, Redis 8, and MinIO; - `IntegrationEnvironment` and `ComposeFaultController`; - PostgreSQL pool lifecycle, health checks, checksum migrations; - Redis lifecycle/health/reopen wrapper; - S3-compatible bucket health, multipart upload, bounded per-part retry, abort, and SHA-256 verification; - optional live-integration pytest suite; - wheel-embedded compose/migration resources; - `wdc integration ...` CLI and `wdc demo live-integration`. ## 2. Permanent boundaries Phase 18 does not change: ```text Evidence TCD Commit Learning Governor Worker protocol Worker lease/fencing Controller epoch semantics ``` Infrastructure failure remains distinct from world/scientific failure. ## 3. PostgreSQL harness `PostgresService` supports: - optional Psycopg 3 / psycopg_pool loading; - min/max pool sizing; - startup `wait()`; - pooled `SELECT 1` health checks; - acquisition/reconnect/idle/lifetime configuration; - close/reopen lifecycle; - checksum-tracked migration application. The packaged migration creates Phase 17 control-state/controller-lease tables. A changed migration with the same ID is rejected by checksum. Reference basis: PostgreSQL 18 documentation and Psycopg 3 pool documentation (`wait`, health check callback, reconnect timeout). ## 4. Redis harness `RedisService` supports: - optional redis-py loading; - connection URL; - connect/command timeouts; - `health_check_interval`; - retry-on-timeout configuration; - PING health; - close/reopen; - direct construction of the Phase 17 Redis-compatible distributed request backend. Reference basis: current redis-py production/connect documentation covering connection pools, health checks, timeouts, and retries. ## 5. S3-compatible harness `S3IntegrationBackend` supports: - optional boto3 loading; - bucket health/creation; - single PUT below threshold; - multipart upload above threshold; - bounded retry of only the failed part; - abort on terminal multipart failure; - `wdc-sha256` metadata; - download-time full SHA-256 verification. WDC content identity remains SHA-256. ETag is provider metadata only. Reference basis: Amazon S3 multipart upload and checksum documentation. ## 6. Live tests The test suite includes four live integration tests: ```text PostgreSQL pool / migration / reopen persistence Redis health / idempotency / rate limit S3 small + multipart roundtrip Compose PostgreSQL/Redis restart recovery ``` All require `WDC_LIVE_INTEGRATION=1`; destructive compose failure injection also requires `WDC_LIVE_COMPOSE=1`. ### Status in this build environment The build environment had: ```text Docker: unavailable Docker Compose: unavailable PostgreSQL service/client: unavailable Redis service/client: unavailable MinIO service/client: unavailable boto3: available in build environment only ``` Therefore the default full suite reports the four live tests as **explicit skips**. This report does not claim live PostgreSQL/Redis/S3 execution. ## 7. Local verification completed before final archive gate ```text full source suite: 227 passed, 4 skipped compileall: PASS source live-integration demo: PASS wheel contains compose resource: PASS wheel contains PostgreSQL migration resource: PASS clean-venv install: PASS installed integration capabilities: PASS installed compose render: PASS installed integration smoke: PASS installed live-integration demo: PASS ``` The installed clean-venv demo correctly reported: ```text live_status = SKIPPED live_services_tested = [] epistemic_state_mutated = false ``` ## 8. What remains for a real service execution environment Phase 18 deliberately does not claim completion of: - live PostgreSQL pool/failover testing; - live Redis reconnect testing; - live MinIO/S3 multipart testing; - Docker Compose stop/start/restart fault injection; - production credentials/TLS for the reference compose services; - production service HA. The harness is designed so these tests can be enabled without changing source code once Docker or externally managed service endpoints are available. ## 9. Tracked-source archive gate A Git-tracked-only candidate Source ZIP was created from the committed Phase 18 tree and extracted into a fresh directory. Fresh extraction verification: ```text 227 passed, 4 skipped compileall: PASS live-integration demo: PASS live_status: SKIPPED epistemic_state_mutated: false ``` A delivery candidate ZIP, Git bundle, wheel, and report were also produced before the final metadata commit, so completion metadata is based on existing artifacts rather than anticipated artifacts. ## 10. Delivery interpretation For Phase 18, the four skipped tests are an intentional part of the result. They mean the harness has live-test wiring but the build host had no live PostgreSQL/Redis/S3/Compose environment. They must not be read as successful live-service tests. ## 11. Final delivery verification Final source commit: ```text branch = feature/phase18 HEAD = 635a03a7e269eb8f717ac449abaffdc1ddbc6fc0 ``` Final source-tree verification: ```text 227 passed, 4 skipped compileall: PASS git diff --check: PASS working tree: clean ``` Final Source ZIP fresh extraction: ```text 227 passed, 4 skipped compileall: PASS live-integration demo: PASS live_status: SKIPPED epistemic_state_mutated: false ``` Final wheel clean-venv verification: ```text install: PASS wdc integration capabilities: PASS wdc integration compose --action render: PASS wdc integration smoke: PASS wdc demo live-integration: PASS ``` The four skipped tests are the live PostgreSQL, Redis, S3, and destructive compose failover tests. They remain skipped because the build host had no Docker/PostgreSQL/Redis/MinIO services. They are not counted as successful live-service verification.