dns-management

dns-management is a skill for Claude Code from sawrus/agent-guides. It costs 28 tokens per session (1,280 once invoked), scanned A, original, MIT.

Kubernetes DNS configuration and diagnosis, covering the system that translates service names into network addresses. It includes CoreDNS, external-dns, split-horizon DNS, and bare-metal cluster designs.

In plain words
What is it for?
Use it to tune CoreDNS, automate DNS records with external-dns, forward internal domains, configure separate internal and external answers, and debug name resolution.
Why use it?
It helps explain why services cannot resolve names and keeps internal and external DNS records pointed to the right places.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter.

Good fit Use it to tune CoreDNS, automate DNS records with external-dns, forward internal domains, configure separate internal and external answers, and debug name resolution.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/sawrus/agent-guides/dns-management
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add sawrus/agent-guides --skill dns-management
Clone the repo
git clone --depth 1 https://github.com/sawrus/agent-guides

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for dns-management

README.md
[![agentmods](https://agentmods.dev/badge/skills/sawrus/agent-guides/dns-management/github.svg)](https://agentmods.dev/skills/sawrus/agent-guides/dns-management)
Your own site
<a href="https://agentmods.dev/skills/sawrus/agent-guides/dns-management"><img src="https://agentmods.dev/badge/skills/sawrus/agent-guides/dns-management/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for dns-management

Your own site · 80×15
<a href="https://agentmods.dev/skills/sawrus/agent-guides/dns-management"><img src="https://agentmods.dev/badge/skills/sawrus/agent-guides/dns-management.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 28 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,280 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00028 $0.01280
Opus 5 $0.00014 $0.00640
Sonnet 5 $0.00006 $0.00256
Haiku 4.5 $0.00003 $0.00128

Measured 8d ago against content hash 411ecf0d6315, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

dns-management scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 8d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

areas/devops/networking/skills/dns-management/SKILL.md · 170 lines

How it starts

The opening of the file, as written. The whole thing — 170 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Skill: DNS Management

Expertise: CoreDNS configuration, external-dns operator, split-horizon DNS, DNS debugging, bare-metal DNS topology.

When to load

When services can't resolve DNS, setting up external-dns automation, configuring split-horizon, or designing DNS for a new cluster.

CoreDNS: Cluster DNS Configuration

# ConfigMap: coredns (kube-system)
apiVersion: v1
kind: ConfigMap
metadata:
  name: coredns
  namespace: kube-system
data:
  Corefile: |
    .:53 {
      errors
      health { lameduck 5s }
      ready
      
      # Kubernetes in-cluster DNS
      kubernetes cluster.local in-addr.arpa ip6.arpa {
        pods insecure
        fallthrough in-addr.arpa ip6.arpa
        ttl 30
      }
      
      # Forward internal domain to internal DNS server
      internal.example.com {
        forward . 192.168.10.53
      }
      
      # Forward everything else to upstream resolvers
      forward . 1.1.1.1 8.8.8.8 {
        max_concurrent 1000
        prefer_udp
      }
      
      cache 300           # 5-minute DNS cache
      loop                # detect forwarding loops
      reload              # hot-reload ConfigMap changes
      loadbalance         # round-robin DNS responses
      
      # Log DNS errors (not all queries — too noisy)
      log . {
        class error
      }
    }

external-dns (Automated DNS Record Management)

# external-dns reads Ingress/Service annotations and creates DNS records
# Install:
helm upgrade --install external-dns external-dns/external-dns \
  -n kube-system \
  -f external-dns-values.yaml

# external-dns-values.yaml
provider: cloudflare          # cloudflare, route53, hetzner, etc.
env:
  - name: CF_API_TOKEN
    valueFrom:
      secretKeyRef:
        name: cloudflare-token
        key: token

sources:
  - ingress
  - service
domainFilters:
  - example.com
policy: upsert-only           # never delete records (safer); use 'sync' to delete orphans
txtOwnerId: prod-cluster      # unique per cluster — prevents multi-cluster conflicts
interval: 1m

Read the full file on GitHub · 170 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 8d ago First seen · 170 lines · 28 tokens per session scan A 411ecf0d6315

Subscribe to this mod's changes

dns-management is a skill published in the GitHub repository sawrus/agent-guides (17 stars, last pushed 8d ago), licensed MIT. It adds 28 tokens to every session and 1,280 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.