Workstream E of the DNS hardening push. Two independent pfSense-side
changes to eliminate single-point DNS failures and the unauthenticated
RFC 2136 update vector.
Part 1 — Multi-IP DHCP option 6
- Before: clients on 10.0.10/24 got only 10.0.10.1; clients on 10.0.20/24
got only 10.0.20.1. Internal resolver outage == cluster-wide DNS dark.
- After:
- 10.0.10/24 -> [10.0.10.1, 94.140.14.14]
- 10.0.20/24 -> [10.0.20.1, 94.140.14.14]
- 192.168.1/24 deliberately untouched (served by TP-Link AP, not pfSense
Kea — pfSense WAN DHCP is disabled); already ships [192.168.1.2,
94.140.14.14] so the end state is consistent across all three subnets.
- Applied via PHP: set $cfg['dhcpd']['lan']['dnsserver'] and
$cfg['dhcpd']['opt1']['dnsserver'] as arrays. pfSense's
services_kea4_configure() implodes the array into "data: a, b" on the
"domain-name-servers" option-data entry (services.inc L1214).
- Verified:
- DevVM (10.0.10.10) resolv.conf shows "nameserver 10.0.10.1" +
"nameserver 94.140.14.14" after networkd renew.
- k8s-node1 (10.0.20.101) same after networkctl reload + systemd-resolved
restart.
- Fallback drill on k8s-node1: `ip route add blackhole 10.0.20.1/32`;
dig @10.0.20.1 google.com -> "no servers could be reached"; dig
@94.140.14.14 google.com -> 216.58.204.110; system resolver
(getent hosts) succeeds via the fallback IP. Blackhole route removed.
Part 2 — TSIG-signed Kea DHCP-DDNS
- Before: /usr/local/etc/kea/kea-dhcp-ddns.conf had `tsig-keys: []` and
Technitium's viktorbarzin.lan zone had update=Deny. Unauthenticated
update vector was latent (DDNS wiring in Kea DHCP4 is actually off
today — "DDNS: disabled" in dhcpd.log) but would activate as soon as
anyone turned on ddnsupdate on LAN/OPT1.
- Generated HMAC-SHA256 secret, base64-encoded 32 random bytes.
- Stored in Vault: secret/viktor/kea_ddns_tsig_secret (version 27).
- Created TSIG key "kea-ddns" on primary/secondary/tertiary Technitium
instances via /api/settings/set (tsigKeys[]).
- Updated kea-dhcp-ddns.conf on pfSense with
tsig-keys[]={name: "kea-ddns", algorithm: "HMAC-SHA256", secret: …}
and key-name: kea-ddns on each forward-ddns / reverse-ddns domain.
Pre-change backup at /usr/local/etc/kea/kea-dhcp-ddns.conf.2026-04-19-pre-tsig.
- Configured viktorbarzin.lan + 10.0.10.in-addr.arpa +
20.0.10.in-addr.arpa + 1.168.192.in-addr.arpa on Technitium primary:
- update = UseSpecifiedNetworkACL
- updateNetworkACL = [10.0.20.1, 10.0.10.1, 192.168.1.2]
- updateSecurityPolicies = [{tsigKeyName: kea-ddns,
domain: "*.<zone>", allowedTypes: [ANY]}]
Technitium requires BOTH a source-IP match AND a valid TSIG signature.
- Verified TSIG end-to-end:
- Signed A-record update from pfSense -> "successfully processed",
dig returns 10.99.99.99 (log: "TSIG KeyName: kea-ddns; TSIG Algo:
hmac-sha256; TSIG Error: NoError; RCODE: NoError").
- Signed PTR update same zone pattern -> dig -x returns tsig-test
FQDN.
- Unsigned update from pfSense IP (in ACL) -> "update failed:
REFUSED" (log: "refused a zone UPDATE request [...] due to Dynamic
Updates Security Policy").
- Test records cleaned up via signed nsupdate.
Safety
- pfSense config backup: /cf/conf/config.xml.2026-04-19-pre-kea-multi-ip
(145898 bytes, pre-change snapshot — keep 30d).
- DDNS config backup: /usr/local/etc/kea/kea-dhcp-ddns.conf.2026-04-19-pre-tsig.
- TSIG secret lives only in Vault + in config.xml/kea-dhcp-ddns.conf on
pfSense; not committed to git.
Docs
- architecture/dns.md: zone dynamic-updates section records the TSIG
policy; Incident History gets a WS E entry.
- architecture/networking.md: DHCP Coverage table now shows the DNS
option 6 values per subnet; pfSense block notes the TSIG-signed DDNS
and config backup path.
- runbooks/pfsense-unbound.md: new "Kea DHCP-DDNS TSIG" section covers
key rotation, emergency bypass, and enforcement-verification.
Closes: code-o6j
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
|
||
|---|---|---|
| .beads | ||
| .claude | ||
| .git-crypt | ||
| .github | ||
| .planning | ||
| .woodpecker | ||
| ci | ||
| cli | ||
| diagram | ||
| docs | ||
| modules | ||
| playbooks | ||
| scripts | ||
| secrets | ||
| stacks | ||
| state/stacks | ||
| .gitattributes | ||
| .gitignore | ||
| .sops.yaml | ||
| AGENTS.md | ||
| config.tfvars | ||
| CONTRIBUTING.md | ||
| LICENSE.txt | ||
| MEMORY.md | ||
| README.md | ||
| terragrunt.hcl | ||
| tiers.tf | ||
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-ownersgroup (grants OIDC group claim for K8s RBAC)Headscale Usersgroup (if they need VPN access)
2. Vault KV Entry
Add a JSON entry to secret/platform → k8s_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"
}
}
usernamekey must match the user's Forgejo username (for Woodpecker admin access)namespaces— K8s namespaces to create and grant admin access todomains— subdomains underviktorbarzin.mefor Cloudflare DNS recordsquota— 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/patchdirectly - 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.
- Install git-crypt.
- Setup gpg keys on the machine
git-crypt unlock
This will unlock the secrets and will lock them on commit