5.8 KiB
ZeroLagHub — Session Handover (Apr 7, 2026)
Platform Overview
ZeroLagHub is a game server hosting platform targeting modded/indie Minecraft.
Custom stack: Node.js API, Next.js portal, Go agent, Velocity proxy, LXC containers on Proxmox.
Source of truth: git.zerolaghub.com/jester/zlh-grind (mirrored to GitHub jester1181/)
Key docs in this repo:
OPEN_THREADS.md— all active and future workINFRASTRUCTURE.md— server specs, VM inventory, IPsPROJECT_CONTEXT.md— stack, architecture (note: has old VM IDs, INFRASTRUCTURE.md is authoritative)SCRATCH/— session notes, debug docs, specs
Infrastructure
Single host: GTHost Detroit — Supermicro 2029TP-HTR, Xeon Gold 6152 22c/44t, 192GB DDR4, 2x1.92TB SSD, $99/mo, Proxmox VE 9.x
Denver host decommissioned Apr 2, 2026 — OS wiped, disks striped.
Key VMs (all 9000s range):
- 9001 zlh-router — OPNsense, 10.60.0.254, WAN 66.163.115.221
- 9002 zpack-router — OPNsense, 10.70.0.1, WAN 66.163.115.115
- 9010 zpack-dns — Technitium DNS, 10.60.0.14
- 9011 zlh-proxy — Caddy, 10.60.0.16
- 9012 zpack-proxy — Traefik v3, 10.70.0.11
- 9014 zlh-artifacts — Caddy file server, 10.60.0.17
- 9015 zpack-velocity — Velocity 3.5, 10.70.0.10
- 9017 zlh-back — PBS, 10.60.0.24 / 172.60.0.30
- 9020 zpack-api — Node.js API, MariaDB, Redis, 10.60.0.18
- 9021 zpack-portal — Next.js, 10.60.0.19
Full IP table in INFRASTRUCTURE.md.
Architecture
Control plane: API ↔ Agent ↔ services via direct IP env vars (not DNS)
- internal.zlh DNS exists but must NOT be used in service-to-service hot paths
- See
SCRATCH/service-discovery.mdfor spec
Data plane: user/browser → Traefik (zpack-proxy) → domain-based routing
Game containers: LXC, IDs 5000+ Dev containers: LXC, IDs 6000+ Base template: ID 820 (zlh-base)
Agent runs inside every container on :18888. Only caller is the API. API is central authority for routing, console, orchestration. Velocity (ZpackVelocityBridge plugin) handles Minecraft player routing via HTTP bridge on :8081.
Current System State
System is stable and deterministic following stabilization work.
Resolved this week:
- ✅ Duplicate server creation — was frontend issue, not API
- ✅ DB/Redis state drift from Denver→Detroit migration — Redis flushed, DB verified clean
- ✅ Console routing — browser → API → agent
- ✅ IP-based control plane — internal.zlh removed from hot paths
- ✅ Velocity rehydration — uses DB + Redis, not Proxmox live state
- ✅ Denver fully decommissioned
Active Issues (Next Session Priority)
1. Fabric Readiness Gating (Agent fix needed)
Root cause: Velocity registration happens before Fabric server is fully ready to accept proxy traffic. Results in "proxy starting" errors until Velocity is restarted.
Fix: Gate Velocity registration behind TCP probe success (port 25565). The agent already runs a TCP probe — Velocity registration just needs to happen after probe returns success, not at process start.
Does NOT require: Changes to Velocity, FabricProxy-Lite version, or Fabric API version.
See SCRATCH/session-stabilization-fabric-findings.md
2. Fabric/Vanilla Stack (what's working)
- Fabric server starts correctly with Fabric API + FabricProxy-Lite pre-seeded in mods/
- Correct versions for 1.21.7:
fabric-api-0.129.0+1.21.7.jar+fabricproxy-lite-2.9.0.jar - Agent normalizes "vanilla" game type → fabric profile, pulls Fabric loader as server.jar
- Forwarding secret must be written to
config/FabricProxy-Lite.tomlat provisioning time - See
SCRATCH/minecraft-velocity-forwarding.mdfor full per-game-type requirements
3. Velocity Config (current state)
player-info-forwarding-mode = "modern"
forwarding-secret-file = "forwarding.secret"
Lobby fallback removed. ZpackVelocityBridge handles all routing dynamically.
Pre-Launch Checklist (from OPEN_THREADS)
Blockers:
- Billing / Stripe — cannot take money without this
- Game server world backup/restore — trust-critical
- User onboarding flow — guided first-server creation after register
- Fabric readiness gating — agent-level fix
- Password reset flow — verify wired up
- Usage limits / quota enforcement
- Email notifications
- Upload testing
- Billing endpoints
- Stress testing — k6 + Minecraft bot + code-server memory baseline
- OPNsense audit
- Service discovery migration — remaining internal.zlh refs in hot paths
- Provisioning validation — single controlled test post-cleanup
Key Decisions Made
- Forwarding mode:
modern—nonebreaks player identity/UUID stability - Vanilla servers: Use Fabric loader + FabricProxy-Lite, not vanilla JAR
- Service discovery: IP env vars, not DNS, for control plane
- Redis: Never restore from backup — always start clean
- Database: Source of truth for all state
- Hosting: GTHost Detroit long-term (most cost-effective)
- Velocity plugin: ZpackVelocityBridge — in-memory only, re-registration needed after restart
Repo Registry
All at git.zerolaghub.com/jester/<repo>:
zlh-grind— execution workspace, continuity, this filezlh-docs— API/agent/portal reference docszpac-api— API sourcezpac-portal— portal sourcezlh-agent— agent source (Go)
Session Guidance for Claude
- Read
OPEN_THREADS.mdat session start for current state - Read
INFRASTRUCTURE.mdfor IPs and VM inventory SCRATCH/has detailed docs for specific topics- Agent is authority on filesystem — API must not duplicate filesystem logic
- Portal never calls agents directly — all traffic through API
- Game publish flow must never be modified by dev routing changes
- Do not mark unimplemented work as complete