linearvoid/docs/DEVELOPMENT.md

DEVELOPMENT.md — Linear Void Remaining Tasks

Test Fixtures (COMPLETE)

• Create test media fixtures in backend/playout/testdata/:

  • valid_720p30.mp4 — small (1-2s) H.264/AAC compliant file
  • invalid_h265.mp4 — wrong codec
  • invalid_24fps.mp4 — wrong framerate
  • Generate via ffmpeg commands documented in test file headers
  • Windows dev path: C:\Users\zwits\AppData\Local\Microsoft\WinGet\Packages\Gyan.FFmpeg_Microsoft.Winget.Source_8wekyb3d8bbwe\ffmpeg-9.0-full_build\bin\ffmpeg.exe

• Create test playlist fixtures in backend/playout/testdata/:

  • valid_playlist.txt, empty_playlist.txt, comments_only.txt, mixed_valid_invalid.txt

• Document ffmpeg fixture-generation commands in playlist_test.go header

User Frontend Tests (PARTIALLY COMPLETE)

• Video player behavior (play, pause, seek, buffering, error handling) - HLS player startup, native/fallback, URL resolution, error recovery with retries/backoff/reconnecting overlay
• Chat functionality (send/receive messages, presence, rate limiting, moderation) - send, receive, presence join/leave, DM flow, reconnect covered
• State management and data flow
• Responsive design and layout across different screen sizes - chat-collapsed toggle, CSS grid, now-playing aria
• Accessibility testing (keyboard navigation, screen reader support) - video controls, aria-labels, aria-expanded, input labels, reconnecting overlay aria-live/role
• Integration with backend APIs (mocking API responses for testing)
• Test coverage for all critical frontend components and interactions
• Add code coverage reporting and enforce minimum coverage threshold in CI/CD pipeline
• Document test cases and expected outcomes

Admin Frontend Tests (PARTIALLY COMPLETE)

• Playlist management UI (add/remove videos, reorder, normalize) - save/error handling, sortable rendering
• User moderation tools (mute/ban/report users, view moderation logs)
• Metrics and monitoring dashboards (Prometheus/Grafana integration) - overview + analytics rendering
• State management and data flow
• Responsive design and layout across different screen sizes - tab content visibility, essential tabs
• Accessibility testing (keyboard navigation, screen reader support) - nav aria-label, active tab aria-current, nav button focusability
• Integration with backend APIs (mocking API responses for testing)
• Test coverage for all critical admin UI components and interactions
• Add code coverage reporting and enforce minimum coverage threshold in CI/CD pipeline
• Document test cases and expected outcomes

Cloudflare R2 Integration Test (PARTIALLY COMPLETE)

• Upload test HLS segments and manifests to R2 bucket (SyncToR2 with mock, verified bucket/key/body)
• Verify correct cache headers are applied (immutable segments via segmentCacheControl, short-lived manifests via manifestCacheControl)
• Test retrieval of segments and manifests from R2 via Cloudflare edge
• Validate cache hit/miss behavior and performance metrics
• Ensure integration test can run in CI/CD pipeline with proper mocking/stubbing of R2 API (putObject mock, no network calls)
• Document test cases and expected outcomes (TestSyncToR2 + TestSyncToR2_ManifestCacheHeaders + TestSyncToR2_NoCacheHeadersForUnknownExt)
• Document required stubs or mocks (putObject variable injection pattern)

Cloudflare Configuration (manual — Cloudflare dashboard)

Evidence tracker: docs/operations/cloudflare-uptimerobot-checklist.md Cloudflare Pages deploy workflow created (.gitea/workflows/pages-deploy.yml); setup docs written (docs/operations/cloudflare-pages-setup.md, docs/operations/gitea-cloudflare.pages.md).

• Cloudflare Pages: create project in dashboard, link custom domain, or deploy via Gitea Actions Direct Upload
• Tiered Cache: enable Smart Tiered Cache, validate Cf-Cache-Status: HIT from upper tier
• WAF: enable OWASP Managed Ruleset, set to Simulate → review 48h → Block, enable Bot Fight Mode
• Rate limiting: /api/admin/login + /api/admin/* → 10 req/10s per IP, Challenge action
• HTTPS/WSS: Always Use HTTPS, HSTS max-age=31536000 includeSubDomains preload, min TLS 1.2
• HTTPS/WSS: enforce at edge (Cloudflare) and origin (nginx), redirect HTTP → HTTPS

External Services

Evidence tracker: docs/operations/cloudflare-uptimerobot-checklist.md

• UptimeRobot: add HTTP monitor for https://linearvoid.tv/health (5min interval)
• UptimeRobot: add keyword monitor for https://linearvoid.tv/hls/playlist.m3u8 (keyword: #EXTM3U, 5min)
• Alert on 2 consecutive failures, notify via email + Discord/Slack webhook

Production Deployment (Hetzner — not provisioned)

• Provision Hetzner CX22 (2 vCPU, 4 GB, 40 GB) in Ashburn VA, Ubuntu 24.04
• Install Docker Engine + Compose plugin, open firewall: 80/443 (public), 2375 (runner IP only)
• Configure Docker daemon for remote TLS access (-H tcp://0.0.0.0:2376 with certs)
• Create /srv/linearvoid/data/{playlist,media,hls,chat,slate} directories
• Add CI_PROD_* secrets to Gitea: DOCKER_HOST, R2 keys, admin password, DB password, Grafana password
• Trigger CD workflow with DOCKER_HOST pointing to Hetzner IP
• Verify all 11 containers start healthy, check /health, /hls/playlist.m3u8, WebSocket
• Update Cloudflare A record linearvoid.tv → Hetzner IP, SSL Full (strict), test HTTPS + WSS
• Smoke test: viewer SPA loads, HLS plays, chat connects, admin login → upload → playlist → playout
• Set up Prometheus alerting notifications + UptimeRobot on production URL
• Run scripts/backup-db.sh + scripts/verify-backups.sh on production host
• Document production IP, SSH access, rollback procedure, scaling thresholds

Scaling & Performance (planning only)

• Tune manifest TTL: measure Cf-Cache-Status distribution, adjust to 0.5× segment duration
• Measure TTFB: WebPageTest from 3+ US regions, target <4s warm cache, document baseline
• Load-test WebSocket: artillery or Go script, ramp 10→100→500→1000 connections, measure p95 latency + errors (scaffolding complete; benchmark execution pending)
• Benchmark admin API: wrk/k6 against /api/admin/*, target p95 <1s, identify slow queries (scaffolding complete; benchmark execution pending)
• Load-test scaffolding: ws-chat.yml, admin-api.js, run-loadtests.ps1, summarizers, README
• Cache-hit ratio exporter (scripts/cache-hit-ratio.js + .ps1)
• Saturation alerts: chat p95 latency, Redis memory usage, cache-hit ratio
• Track cache hit ratio: Cloudflare GraphQL → Grafana panel, alert <90%
• Capacity triggers: Prometheus rules for cache-miss >10%/15min, CPU >80%/10min (chat p95, Redis memory, cache-hit already done)
• Phase 2 plan: document boundaries (playout CPU, chat latency, DB state, monitoring), estimate per-service resources
• Phase 3 plan: research second Hetzner location, design warm standby + DNS failover + DB/Redis replication

Streaming Pipeline (2026-08-10 audit → 2026-08-10 implemented)

Gaps between STREAMING.md contract and playlist.go/main.ts implementation:

• Continuous R2 sync during playout (HIGH): fsnotify watcher uploads segments in real-time (~7s delay)
• Globally unique segment naming (HIGH): r-{ISOTIME}/seg-{seq}.m4s via run ID + monotonic sequence
• Atomic manifest publication (MEDIUM): Upload to .tmp, then CopyObject to final key
• Manifest Cache-Control alignment (LOW): public, max-age=1, s-maxage=2, must-revalidate
• CORS headers on HLS responses (MEDIUM): Needs Cloudflare R2 CORS config (infrastructure, not code)
• Player error recovery (MEDIUM): hls.on(ERROR) handler with 5x retries, exponential backoff (2s→32s), reconnecting overlay
• Health endpoint detail (LOW): Added run_id, active_item, playlist_revision, last_segment_seq, last_r2_pub, consecutive_failures, unhealthy detection
• Source media contract + validation — implemented
• fMP4 HLS packaging (6s, 24 window) — implemented
• Slate fallback + recovery — implemented
• R2 cache headers (immutable segments, short-lived manifest) — implemented
• Cloudflare Worker immutable .m4s headers — implemented