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Viktor Barzin 1de2ee307f kyverno: strip resources.limits.cpu cluster-wide via ClusterPolicy
Context
-------
The cluster policy is "no CPU limits anywhere" — CFS throttling causes
more harm than good for bursty single-threaded workloads (Node.js,
Python). LimitRanges are already correct (defaultRequest.cpu only, no
default.cpu), but 22 pods still carried CPU limits injected by upstream
Helm chart defaults — CrowdSec (lapi + agents), descheduler,
kubernetes-dashboard (×4), nvidia gpu-operator.

Previous attempts were ad-hoc: patch each values.yaml, occasionally
missing things on chart upgrade. This replaces that with a declarative
Kyverno mutation at admission time.

This change
-----------
Adds a new ClusterPolicy `strip-cpu-limits` with two foreach rules:

  strip-container-cpu-limit      → containers[]
  strip-initcontainer-cpu-limit  → initContainers[]

Each rule uses `patchesJson6902` with an `op: remove` on
`resources/limits/cpu`. JSON6902 `remove` fails on missing paths, so
per-element preconditions gate the mutation — pods without CPU limits
pass through untouched. A top-level rule precondition short-circuits
using JMESPath filter (`[?resources.limits.cpu != null] | length(@) > 0`)
so the mutation is a no-op for the overwhelming majority of pods.

Admission-time only. No `mutateExistingOnPolicyUpdate`, no `background`.
Existing pods keep their CPU limits until they're restarted naturally
(Helm upgrade, node drain, rollout). We rely on churn, not forced
restarts, to avoid unnecessary thrash.

Memory limits are preserved — they prevent OOM, still useful.

Flow
----

    admission request → match Pod + CREATE
                     → top-level precondition: any container has limits.cpu?
                           no  → skip (fast path)
                           yes → foreach container:
                                   element.limits.cpu present?
                                       no  → skip element
                                       yes → remove /spec/containers/N/resources/limits/cpu
                     → same again for initContainers
                     → mutated pod proceeds to API server

Verification
------------
  kubectl run test-strip-cpu --overrides='{limits:{cpu:500m,memory:64Mi}}'
    → admitted pod.resources = {limits:{memory:64Mi}, requests:{cpu:50m,memory:32Mi}}
    → CPU limit stripped, memory preserved, requests untouched

  kubectl rollout restart deploy/kubernetes-dashboard-metrics-scraper
    → new pod.resources = {limits:{memory:400Mi}, requests:{cpu:100m,memory:200Mi}}
    → cluster-wide count of pods with CPU limits: 22 → 21

Rollout
-------
Remaining 21 pods will drop their CPU limits on natural churn. No manual
restarts in this change — user may want to time a mass restart with a
maintenance window.

Closes: code-eaf
Closes: code-4bz

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-04-18 11:34:39 +00:00
.beads bd init: initialize beads issue tracking 2026-04-06 15:38:46 +03:00
.claude [docs] Update anti-AI and rybbit docs after rewrite-body removal 2026-04-17 21:43:13 +00:00
.git-crypt Add 1 git-crypt collaborator [ci skip] 2025-10-24 18:00:00 +00:00
.github chore: sort outage report service list alphabetically 2026-04-15 18:01:54 +00:00
.planning [ci skip] add auto-generated tiers.tf, planning docs, and helm chart cache 2026-03-06 23:55:57 +00:00
.woodpecker [claude-agent-service] Migrate all pipelines from DevVM SSH to K8s HTTP 2026-04-18 10:12:02 +00:00
ci feat: CI/CD performance overhaul 2026-04-15 11:22:26 +00:00
cli add IPv6 connectivity via Hurricane Electric 6in4 tunnel 2026-03-23 02:22:00 +02:00
diagram [ci skip] Sunset Drone CI: remove all artifacts, DNS, configs, and references 2026-02-23 19:38:55 +00:00
docs [docs] Update auto-upgrade docs — new HTTP auth path + n8n expression gotcha 2026-04-18 10:42:11 +00:00
modules Add broker-sync Terraform stack (#7) 2026-04-17 21:17:45 +01:00
playbooks [ci skip] Reduce node config drift: GPU label, OIDC idempotency, node-exporter, rebuild docs 2026-02-22 22:59:38 +00:00
scripts [claude-agent-service] Migrate all pipelines from DevVM SSH to K8s HTTP 2026-04-18 10:12:02 +00:00
secrets [cleanup] Remove ollama from dashy + docs + nfs_directories 2026-04-18 11:17:59 +00:00
stacks kyverno: strip resources.limits.cpu cluster-wide via ClusterPolicy 2026-04-18 11:34:39 +00:00
state/stacks state(dbaas): update encrypted state 2026-04-17 22:33:13 +00:00
.gitattributes Add broker-sync Terraform stack (#7) 2026-04-17 21:17:45 +01:00
.gitignore chore: add pre-commit size guard and harden .gitignore 2026-04-15 14:13:18 +00:00
.sops.yaml state: per-stack Transit keys for namespace-owner access control 2026-03-17 23:08:18 +00:00
AGENTS.md [claude-agent-service] Migrate all pipelines from DevVM SSH to K8s HTTP 2026-04-18 10:12:02 +00:00
config.tfvars [config] Remove ollama_host root variable 2026-04-18 11:14:53 +00:00
CONTRIBUTING.md multi-user access: fix template memory default, add storage quota, add CONTRIBUTING.md [ci skip] 2026-03-19 23:49:15 +00:00
LICENSE.txt Drone CI Update TLS Certificates Commit 2025-10-12 00:13:18 +00:00
MEMORY.md Update MEMORY.md timestamp 2026-03-07 16:43:15 +00:00
README.md add architecture documentation for all infrastructure subsystems [ci skip] 2026-03-24 00:55:25 +02:00
setup-monitoring.sh fix(monitoring): Add setup script for automated health check environment 2026-03-13 13:57:11 +00:00
terragrunt.hcl [infra] Migrate Terraform state from local SOPS to PostgreSQL backend 2026-04-16 19:33:12 +00:00
tiers.tf [ci skip] Phase 1: PostgreSQL migrated to CNPG on local disk 2026-02-28 19:08:06 +00:00

This repo contains my infra-as-code sources.

My infrastructure is built using Terraform, Kubernetes and CI/CD is done using Woodpecker CI.

Read more by visiting my website: https://viktorbarzin.me

Documentation

Full architecture documentation is available in docs/ — covering networking, storage, security, monitoring, secrets, CI/CD, databases, and more.

Adding a New User (Admin)

Adding a new namespace-owner to the cluster requires three steps — no code changes needed.

1. Authentik Group Assignment

In the Authentik admin UI, add the user to:

  • kubernetes-namespace-owners group (grants OIDC group claim for K8s RBAC)
  • Headscale Users group (if they need VPN access)

2. Vault KV Entry

Add a JSON entry to secret/platformk8s_users key in Vault:

"username": {
  "role": "namespace-owner",
  "email": "user@example.com",
  "namespaces": ["username"],
  "domains": ["myapp"],
  "quota": {
    "cpu_requests": "2",
    "memory_requests": "4Gi",
    "memory_limits": "8Gi",
    "pods": "20"
  }
}
  • username key must match the user's Forgejo username (for Woodpecker admin access)
  • namespaces — K8s namespaces to create and grant admin access to
  • domains — subdomains under viktorbarzin.me for Cloudflare DNS records
  • quota — resource limits per namespace (defaults shown above)

3. Apply Stacks

vault login -method=oidc

cd stacks/vault && terragrunt apply --non-interactive
# Creates: namespace, Vault policy, identity entity, K8s deployer role

cd ../platform && terragrunt apply --non-interactive
# Creates: RBAC bindings, ResourceQuota, TLS secret, DNS records

cd ../woodpecker && terragrunt apply --non-interactive
# Adds user to Woodpecker admin list

What Gets Auto-Generated

Resource Stack
Kubernetes namespace vault
Vault policy (namespace-owner-{user}) vault
Vault identity entity + OIDC alias vault
K8s deployer Role + Vault K8s role vault
RBAC RoleBinding (namespace admin) platform
RBAC ClusterRoleBinding (cluster read-only) platform
ResourceQuota platform
TLS secret in namespace platform
Cloudflare DNS records platform
Woodpecker admin access woodpecker

New User Onboarding

If you've been added as a namespace-owner, follow these steps to get started.

1. Join the VPN

# Install Tailscale: https://tailscale.com/download
tailscale login --login-server https://headscale.viktorbarzin.me
# Send the registration URL to Viktor, wait for approval
ping 10.0.20.100  # verify connectivity

2. Install Tools

Run the setup script to install kubectl, kubelogin, Vault CLI, Terraform, and Terragrunt:

# macOS
bash <(curl -fsSL https://k8s-portal.viktorbarzin.me/setup/script?os=mac)

# Linux
bash <(curl -fsSL https://k8s-portal.viktorbarzin.me/setup/script?os=linux)

3. Authenticate

# Log into Vault (opens browser for SSO)
vault login -method=oidc

# Test kubectl (opens browser for OIDC login)
kubectl get pods -n YOUR_NAMESPACE

4. Deploy Your First App

# Clone the infra repo
git clone https://github.com/ViktorBarzin/infra.git && cd infra

# Copy the stack template
cp -r stacks/_template stacks/myapp
mv stacks/myapp/main.tf.example stacks/myapp/main.tf

# Edit main.tf — replace all <placeholders>

# Store secrets in Vault
vault kv put secret/YOUR_USERNAME/myapp DB_PASSWORD=secret123

# Submit a PR
git checkout -b feat/myapp
git add stacks/myapp/
git commit -m "add myapp stack"
git push -u origin feat/myapp

After review and merge, an admin runs cd stacks/myapp && terragrunt apply.

5. Set Up CI/CD (Optional)

Create .woodpecker.yml in your app's Forgejo repo:

steps:
  - name: build
    image: woodpeckerci/plugin-docker-buildx
    settings:
      repo: YOUR_DOCKERHUB_USER/myapp
      tag: ["${CI_PIPELINE_NUMBER}", "latest"]
      username:
        from_secret: dockerhub-username
      password:
        from_secret: dockerhub-token
      platforms: linux/amd64

  - name: deploy
    image: hashicorp/vault:1.18.1
    commands:
      - export VAULT_ADDR=http://vault-active.vault.svc.cluster.local:8200
      - export VAULT_TOKEN=$(vault write -field=token auth/kubernetes/login
          role=ci jwt=$(cat /var/run/secrets/kubernetes.io/serviceaccount/token))
      - KUBE_TOKEN=$(vault write -field=service_account_token
          kubernetes/creds/YOUR_NAMESPACE-deployer
          kubernetes_namespace=YOUR_NAMESPACE)
      - kubectl --server=https://kubernetes.default.svc
          --token=$KUBE_TOKEN
          --certificate-authority=/var/run/secrets/kubernetes.io/serviceaccount/ca.crt
          -n YOUR_NAMESPACE set image deployment/myapp
          myapp=YOUR_DOCKERHUB_USER/myapp:${CI_PIPELINE_NUMBER}

Useful Commands

# Check your pods
kubectl get pods -n YOUR_NAMESPACE

# View quota usage
kubectl describe resourcequota -n YOUR_NAMESPACE

# Store/read secrets
vault kv put secret/YOUR_USERNAME/myapp KEY=value
vault kv get secret/YOUR_USERNAME/myapp

# Get a short-lived K8s deploy token
vault write kubernetes/creds/YOUR_NAMESPACE-deployer \
  kubernetes_namespace=YOUR_NAMESPACE

Important Rules

  • All changes go through Terraform — never kubectl apply/edit/patch directly
  • Never put secrets in code — use Vault: vault kv put secret/YOUR_USERNAME/...
  • Always use a PR — never push directly to master
  • Docker images: build for linux/amd64, use versioned tags (not :latest)

git-crypt setup

To decrypt the secrets, you need to setup git-crypt.

  1. Install git-crypt.
  2. Setup gpg keys on the machine
  3. git-crypt unlock

This will unlock the secrets and will lock them on commit