docs/services/secrets-manager.md

Secrets Manager — Infisical on CT 109

Status: deployed 2026-05-22; migrated CT 112 → CT 109 on 2026-05-26. Running at http://192.168.1.8:8200 (http://secrets.nuclide.lan:8200). LAN-only, no Zoraxy route — secrets must not be internet-exposed.

Stack: infisical/infisical:latest-postgres + Postgres 16 + Redis 7, all on CT 109 (ops, 192.168.1.8). Compose at /opt/stacks/infisical/ on CT 109. CT 112 ("secrets") is decommissioned; LXC pending removal.

Problem statement

Secrets are currently scattered across:

Location	Count	Risk
/opt/stacks/ai/.env on CT 104	~55 keys	Not versioned; duplicated across stacks
Per-stack .env files CT 104	~30 keys	Several duplicated (WALG keys, IMMICH_API_KEY, etc.)
CT 101, 111, 113 .env files	~30 keys	No central rotation story
Coder main.tf (hardcoded env vars)	6	Committed to Gitea; visible in template history
HA secrets.yaml on HAOS VM 100	unknown	Not backed up centrally

Goal: single LAN-only secret store that agents, Docker services, and Coder workspaces pull from programmatically. ~85 unique secrets identified in sweep (2026-05-22).

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Candidate solutions

1. Infisical (recommended)

Open-source HashiCorp Vault alternative. Docker-compose deployable. Native integrations for:

• Docker secrets injection (Infisical agent sidecar)
• Kubernetes/Coder workspace env injection
• REST API + OIDC machine identities
• OIDC SSO (can federate with Pocket-ID)
• Web UI

Deployment: separate LXC (recommended — see rationale below). Postgres backend → candidate for CT 113 consolidation once second NVMe lands.

Port: 8080 internally; no external exposure needed (LAN-only MCP sidecar pattern).

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2. HashiCorp Vault (OSS)

Industry standard. Steeper ops overhead (unsealing, audit logs, lease renewal). Overkill for a homelab unless you need HSM-grade guarantees.

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3. Doppler (SaaS)

Managed; free tier; native CLI and Docker integration. Outbound dependency; secrets leave the homelab. Not suitable given the DLR/LUMEN data handling doctrine.

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4. Stay with Vaultwarden + manual OIDC

Already deployed. Works for human access. No programmatic injection without writing custom code. Dead end for agent/pipeline automation.

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Recommendation: Infisical on a dedicated LXC

Why a separate LXC?

1. Blast radius isolation — if the CT 104 Docker stack is compromised, the secret store is not on the same attack surface.
2. Minimal footprint — Infisical + Postgres is the only workload; nothing else can mess with the process space.
3. Simpler audit — outbound connections from CT 104 are numerous; a dedicated secrets LXC should have near-zero egress.
4. HA restart independence — CT 104 restarts (image gen, GPU passthrough experiments) don't affect secret availability.

Suggested: CT 112 (next available), 2 vCPU / 2 GB RAM, 8 GB disk on local-zfs.

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Architecture

flowchart TD
  subgraph CT112["CT 112 — secrets"]
    infisical["Infisical Server\n:8080"]
    pg_sec["Postgres\n(infisical DB)"]
    infisical --- pg_sec
  end

  subgraph CT104["CT 104 — Docker host"]
    agent["Infisical Agent\n(sidecar per stack)"]
    env_file[".env (templated)\nrendered at startup"]
    agent -->|pull on start| infisical
    agent --> env_file
  end

  subgraph CT111["CT 111 — Coder"]
    coder["Coder server"]
    ws["Workspace containers\n(env injected at provision)"]
    coder -->|agent token| infisical
    coder --> ws
  end

  subgraph CT110["CT 110 — Pocket-ID"]
    oidc["OIDC IdP"]
  end

  oidc -->|machine identity| infisical
  oidc -->|user SSO| infisical

---

Setup plan

Phase 1 — Deploy Infisical on CT 112

# On Proxmox host
pvesh create /nodes/nuc/lxc \
  --ostemplate local:vztmpl/debian-12-standard_12.7-1_amd64.tar.zst \
  --vmid 112 --hostname secrets --memory 2048 --cores 2 \
  --rootfs local-zfs:8 --net0 name=eth0,bridge=vmbr0,ip=dhcp

# Inside CT 112
apt-get install -y docker.io docker-compose-plugin
# Deploy from https://github.com/Infisical/infisical (official compose)

Infisical requires a Redis instance alongside Postgres. The official docker-compose.yml bundles both.

Phase 2 — Migrate CT 104 secrets

1. Create an Infisical project homelab/ct104
2. Import existing .env keys via Infisical CLI: infisical import --env prod --path /homelab/ct104 < .env
3. Add Infisical agent to each compose stack as a sidecar that renders .env from templates at container start

Phase 3 — Coder workspace injection

Infisical has a native Coder integration (via machine identity token). Replace hardcoded env vars in main.tf with:

data "external" "secrets" {
  program = ["infisical", "export", "--env", "prod", "--path", "/coder/workspaces", "--format", "dotenv-export"]
}

Or use the Infisical agent installed in the workspace image.

Phase 4 — OIDC SSO via Pocket-ID

Infisical supports OIDC SSO under Settings → Authentication → OIDC. Register a new client in Pocket-ID with callback https://secrets.nuclide.systems/api/v1/sso/oidc/callback (or LAN-only URL).

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Prioritisation

Item	Effort	Value
Create CT 112, deploy Infisical	1h	High — removes .env sprawl
Migrate CT 104 .env	30min	High
Coder template injection	1h	Medium — workspaces currently work
HA secrets.yaml → Infisical	30min (HA add-on)	Medium
OIDC SSO via Pocket-ID	30min	Low (convenience)

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Short-term mitigation (before CT 112 is built)

1. Remove secrets from Coder main.tf that appear in Gitea history — use Coder template variables or env injection instead.
2. Keep /opt/stacks/ai/.env mode 0600; ensure it is in .gitignore for any repo that mounts that directory.
3. Use Vaultwarden as the authoritative human copy; rotate any key that has appeared in Claude Code context (see audit-claude-code-meta.md).

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Related

• postgres-consolidation — CT 113 will consolidate Postgres instances including Infisical's DB
• feedback_zoraxy_confirm — Zoraxy route for secrets.nuclide.systems will need operator approval when CT 112 is ready
• security/audit-claude-code-meta.md — lists secrets that transited Claude API this session