infra/AGENTS.md

Infrastructure Repository — AI Agent Instructions

Critical Rules (MUST FOLLOW)

• ALL changes through Terraform/Terragrunt — NEVER kubectl apply/edit/patch/delete for persistent changes. Read-only kubectl is fine.
• NEVER put secrets in plaintext — use secrets.sops.json (SOPS-encrypted) or terraform.tfvars (git-crypt, legacy)
• NEVER restart NFS on the Proxmox host — causes cluster-wide mount failures across all pods
• NEVER commit secrets — triple-check before every commit
• [ci skip] in commit messages when changes were already applied locally
• Ask before git push — always confirm with the user first

Execution

• Apply a service: scripts/tg apply --non-interactive (auto-decrypts SOPS secrets)
• Legacy apply: cd stacks/<service> && terragrunt apply --non-interactive (uses terraform.tfvars)
• kubectl: kubectl --kubeconfig $(pwd)/config
• Health check: bash scripts/cluster_healthcheck.sh --quiet
• Plan all: cd stacks && terragrunt run --all --non-interactive -- plan

Adopting Existing Resources — Use import {} Blocks, Not the CLI

When bringing a live cluster/Vault/Cloudflare resource under Terraform management, use an HCL import {} block (Terraform 1.5+). Do NOT use terraform import on the CLI for anything landing in this repo — the CLI path leaves no audit trail and makes multi-operator adoption fragile.

Canonical workflow:

1. Write the resource block that matches the live object.
2. In the same stack, add an import {} stanza naming the target and the provider-specific ID:

   import {
     to = helm_release.kured
     id = "kured/kured"  # Helm ID format: <namespace>/<release-name>
   }
   
   resource "helm_release" "kured" {
     name       = "kured"
     namespace  = "kured"
     repository = "https://kubereboot.github.io/charts/"
     chart      = "kured"
     version    = "5.7.0"
     # ... values matching the live release
   }
   

3. scripts/tg plan — every change it proposes is real divergence between HCL and live state. Iterate on values until the plan is 0 changes.
4. scripts/tg apply — the import runs alongside whatever zero-change apply you have. If your plan is 0 changes, this commits only the state-ownership transfer.
5. After the apply lands cleanly, delete the import {} block in a follow-up commit. The resource is now fully TF-owned and the stanza would be a no-op that clutters diffs.

Why import {} and not terraform import:

• Reviewable in PRs before any state mutation. The CLI path is an out-of-band action nobody sees.
• Plan-safe: the import plan step shows the exact object being adopted. Mistyped IDs or the wrong resource address are caught before apply, not after.
• Survives state backend changes (Tier 0 SOPS vs Tier 1 PG) transparently — both work identically from the operator's perspective because both use scripts/tg.
• Re-runnable: if the apply fails partway through, the import {} block is idempotent. The CLI path's state mutation is not.

Finding the provider-specific ID: each provider has its own convention.

Resource	ID format	Example
helm_release	<namespace>/<release-name>	kured/kured
kubernetes_manifest	{"apiVersion":"...","kind":"...","metadata":{"namespace":"...","name":"..."}}	(pass as HCL object literal)
kubernetes_<kind>_v1	<namespace>/<name> for namespaced, <name> for cluster-scoped	kube-system/coredns
authentik_provider_proxy	provider UUID	0eecac07-97c7-443c-...
cloudflare_record	<zone-id>/<record-id>	abc123/def456

Secrets Management (SOPS)

• config.tfvars — plaintext config (hostnames, IPs, DNS records, public keys)
• secrets.sops.json — SOPS-encrypted secrets (passwords, tokens, SSH keys, API keys)
• .sops.yaml — defines who can decrypt (age public keys: Viktor + CI)
• scripts/tg — wrapper that auto-decrypts SOPS before running terragrunt
• Edit secrets: sops secrets.sops.json (opens $EDITOR, re-encrypts on save)
• Add a secret: sops set secrets.sops.json '["new_key"]' '"value"'
• Operators push PRs → Viktor reviews → CI decrypts and applies. No encryption keys needed for operators.

Sealed Secrets (User-Managed Secrets)

For secrets that users manage themselves (no SOPS/git-crypt access needed):

1. Create: kubectl create secret generic <name> --from-literal=key=value -n <ns> --dry-run=client -o yaml | kubeseal --controller-name sealed-secrets --controller-namespace sealed-secrets -o yaml > sealed-<name>.yaml
2. Commit: Place sealed-*.yaml files in the stack directory (stacks/<service>/)
3. Terraform picks them up automatically via fileset + for_each:

   resource "kubernetes_manifest" "sealed_secrets" {
     for_each = fileset(path.module, "sealed-*.yaml")
     manifest = yamldecode(file("${path.module}/${each.value}"))
   }
   

4. Deploy: Push → CI runs terragrunt apply → controller decrypts into real K8s Secrets

• Only the in-cluster controller has the private key. kubeseal uses the public key — safe to distribute.
• Naming convention: files MUST match sealed-*.yaml glob pattern.
• The kubernetes_manifest block is safe to add even with zero sealed-*.yaml files (empty for_each).

Architecture

Terragrunt-based homelab managing a Kubernetes cluster (5 nodes, v1.34.2) on Proxmox VMs.

• 100+ stacks, each in stacks/<service>/ with its own Terraform state
• Core platform: stacks/platform/ is now an empty shell — all modules have been extracted to independent stacks under stacks/
• Public domain: viktorbarzin.me (Cloudflare) | Internal: viktorbarzin.lan (Technitium DNS)
• Onboarding portal: https://k8s-portal.viktorbarzin.me — self-service kubectl setup + docs
• CI/CD: Woodpecker CI — PRs run plan, merges to master auto-apply all stacks

Key Paths

• stacks/<service>/main.tf — service definition
• stacks/platform/modules/<service>/ — core infra modules
• modules/kubernetes/ingress_factory/ — standardized ingress with auth, rate limiting, anti-AI, and auto Cloudflare DNS (dns_type = "proxied" or "non-proxied")
• modules/kubernetes/nfs_volume/ — NFS volume module (CSI-backed, soft mount)
• config.tfvars — non-secret configuration (plaintext)
• secrets.sops.json — all secrets (SOPS-encrypted JSON)
• terraform.tfvars — legacy secrets file (git-crypt, kept for reference)
• scripts/cluster_healthcheck.sh — 25-check cluster health script

Storage

• NFS (nfs-proxmox StorageClass): For app data. Use the nfs_volume module, never inline nfs {} blocks.
• proxmox-lvm-encrypted (proxmox-lvm-encrypted StorageClass): Default for all sensitive data — databases, auth, email, passwords, git repos, health data. LUKS2 encryption via Proxmox CSI. Passphrase in Vault, backup key on PVE host.
• proxmox-lvm (proxmox-lvm StorageClass): For non-sensitive stateful apps (configs, caches, tools). Proxmox CSI driver.
• NFS server: Proxmox host at 192.168.1.127. HDD NFS at /srv/nfs (2TB ext4 LV pve/nfs-data), SSD NFS at /srv/nfs-ssd (100GB ext4 LV ssd/nfs-ssd-data). Exports use async mode (safe with UPS + databases on block storage). TrueNAS (10.0.10.15) decommissioned.
• SQLite on NFS is unreliable (fsync issues) — always use proxmox-lvm or local disk for databases.
• NFS mount options: Always soft,timeo=30,retrans=3 to prevent uninterruptible sleep (D state).
• NFS export directory must exist on the Proxmox host before Terraform can create the PV.
• Backup (3-2-1): Copy 1 = live PVCs on sdc. Copy 2 = sda /mnt/backup (PVC file backups, auto SQLite backups, pfSense, PVE config). Copy 3 = Synology offsite (two-tier: sda→pve-backup/, NFS→nfs/+nfs-ssd/ via inotify change tracking).
• daily-backup (Daily 05:00): Auto-discovered BACKUP_DIRS (glob), auto SQLite backup (magic number + ?mode=ro), pfSense, PVE config. No NFS mirror step (NFS syncs directly to Synology via inotify).
• offsite-sync-backup (Daily 06:00): Step 1: sda→Synology pve-backup/. Step 2: NFS→Synology nfs/+nfs-ssd/ via rsync --files-from (inotify change log). Monthly full --delete.
• nfs-change-tracker.service: inotifywait on /srv/nfs + /srv/nfs-ssd, logs to /mnt/backup/.nfs-changes.log. Incremental syncs complete in seconds.
• Synology layout (/volume1/Backup/Viki/): pve-backup/ (from sda), nfs/ (from /srv/nfs), nfs-ssd/ (from /srv/nfs-ssd). truenas/ renamed to nfs/, pve-backup/nfs-mirror/ removed.

Shared Variables (never hardcode)

var.nfs_server (192.168.1.127), var.redis_host, var.postgresql_host, var.mysql_host, var.ollama_host, var.mail_host

Kyverno Drift Suppression (# KYVERNO_LIFECYCLE_V1)

Kyverno's admission webhook mutates every pod with a dns_config { option { name = "ndots"; value = "2" } } block (fixes NxDomain search-domain floods — see k8s-ndots-search-domain-nxdomain-flood skill). Terraform does not manage that field, so without suppression every pod-owning resource shows perpetual spec[0].template[0].spec[0].dns_config drift.

Rule: every kubernetes_deployment, kubernetes_stateful_set, kubernetes_daemon_set, and kubernetes_cron_job_v1 MUST include the following lifecycle block, tagged with the # KYVERNO_LIFECYCLE_V1 marker so every site is greppable:

# kubernetes_deployment / kubernetes_stateful_set / kubernetes_daemon_set
lifecycle {
  ignore_changes = [spec[0].template[0].spec[0].dns_config] # KYVERNO_LIFECYCLE_V1
}

# kubernetes_cron_job_v1 (extra job_template nesting)
lifecycle {
  ignore_changes = [spec[0].job_template[0].spec[0].template[0].spec[0].dns_config] # KYVERNO_LIFECYCLE_V1
}

Why not a shared module? Terraform's ignore_changes meta-argument only accepts static attribute paths. It rejects module outputs, locals, variables, and any expression. A DRY module is therefore impossible — the canonical pattern IS the snippet + marker. When kubernetes_manifest resources get Kyverno generate.kyverno.io/* annotations mutated, a sibling convention # KYVERNO_MANIFEST_V1 will be introduced (Phase B).

Audit: rg "KYVERNO_LIFECYCLE_V1" stacks/ | wc -l — should grow (never shrink). Add the marker to every new pod-owning resource. The _template/main.tf.example stub shows the canonical form.

Tier System

0-core | 1-cluster | 2-gpu | 3-edge | 4-aux — Kyverno auto-generates LimitRange + ResourceQuota per namespace based on tier label.

• Containers without explicit resources {} get default limits (256Mi for edge/aux — causes OOMKill for heavy apps)
• Always set explicit resources on containers that need more than defaults
• Opt-out: labels resource-governance/custom-quota=true / resource-governance/custom-limitrange=true

Infrastructure

• Proxmox: 192.168.1.127 (Dell R730, 22c/44t, 142GB RAM)
• Nodes: k8s-master (10.0.20.100), node1 (GPU, Tesla T4), node2-4
• GPU: node_selector = { "gpu": "true" } + toleration nvidia.com/gpu
• Pull-through cache: 10.0.20.10 — docker.io (:5000), ghcr.io (:5010) only. Caches stale manifests for :latest tags — use versioned tags or pre-pull with ctr --hosts-dir '' to bypass.
• pfSense: 10.0.20.1 (gateway, firewall, DNS forwarding)
• MySQL InnoDB Cluster: 1 instance on proxmox-lvm (scaled from 3 — only Uptime Kuma + phpIPAM remain), PriorityClass mysql-critical + PDB, anti-affinity excludes k8s-node1 (GPU node)
• SMTP: var.mail_host port 587 STARTTLS (not internal svc address — cert mismatch)

Contributor Onboarding

1. Get Authentik account + Headscale VPN access (ask Viktor)
2. Clone repo — AGENTS.md is auto-loaded by Codex
3. Create branch → edit → push → open PR
4. Viktor reviews → CI applies → Slack notification
5. Portal: https://k8s-portal.viktorbarzin.me/onboarding for full guide

Common Operations

• Deploy new service: Use stacks/<existing-service>/ as template. Create stack, add DNS in tfvars, apply platform then service.
• Fix crashed pods: Run healthcheck first. Safe to delete evicted/failed pods and CrashLoopBackOff pods with >10 restarts.
• OOMKilled: Check kubectl describe limitrange tier-defaults -n <ns>. Increase resources.limits.memory in the stack's main.tf.
• Add a secret: sops set secrets.sops.json '["key"]' '"value"' then commit.
• NFS exports: Create dir on Proxmox host (ssh root@192.168.1.127 "mkdir -p /srv/nfs/<service>"), add to /etc/exports, run exportfs -ra.

Automated Service Upgrades

• Pipeline: DIUN (detect) → n8n webhook (filter + rate limit) → HTTP POST → claude-agent-service (K8s) → claude -p (upgrade agent)
• Agent: .claude/agents/service-upgrade.md — analyzes changelogs, backs up DBs, bumps versions, verifies health, rolls back on failure
• Config: .claude/reference/upgrade-config.json — GitHub repo mappings, DB-backed services, skip patterns
• Rate limit: Max 5 upgrades per 6h DIUN scan cycle (configured in n8n workflow)
• Skipped: databases, :latest, custom images (viktorbarzin/*), infrastructure images
• Risk: SAFE (2min verify) vs CAUTION (10min, DB backup, step through versions) based on changelog analysis
• Docs: docs/architecture/automated-upgrades.md

Detailed Reference

See .claude/reference/patterns.md for: NFS volume code examples, iSCSI details, Kyverno governance tables, anti-AI scraping layers, Terragrunt architecture, node rebuild procedure, archived troubleshooting runbooks index.