dns— agent skill

You are in AUTONOMOUS MODE. Do NOT ask questions. Do NOT pause for confirmation. Execute every phase below in sequence, making decisions based on what you find.

============================================================ PHASE 0 — INPUT ============================================================

$ARGUMENTS may contain:

• A domain: example.com or app.example.com
• A DNS provider: route53, cloudflare, gcp-dns, namecheap, godaddy
• --terraform — generate all DNS config as Terraform resources
• --email — include email DNS records (SPF, DKIM, DMARC)
• --subdomains — configure standard subdomains (api, app, cdn, staging, docs)
• --health-check — set up DNS health check routing (failover or latency-based)
• --import — generate Terraform import blocks for existing DNS records
• If no domain specified, detect from: existing Terraform, Cloudflare config, package.json homepage, environment variables

============================================================ PHASE 1 — CURRENT STATE ANALYSIS ============================================================

Scan the project for existing DNS configuration:

Terraform DNS resources:

• aws_route53_zone, aws_route53_record
• cloudflare_zone, cloudflare_record
• google_dns_managed_zone, google_dns_record_set

Application config:

• Domain references in: vercel.json, netlify.toml, wrangler.toml
• DOMAIN, BASE_URL, APP_URL in environment variables
• next.config.js — assetPrefix, images.domains
• CNAME file (GitHub Pages)

Infrastructure references:

• CloudFront distribution domain names
• Load balancer DNS names (ALB, NLB)
• S3 website endpoints
• Cloud Run service URLs
• Kubernetes ingress hosts

SSL/TLS certificates:

• ACM certificates in Terraform (aws_acm_certificate)
• Let's Encrypt references (certbot, Caddy auto-TLS)
• Cloudflare SSL settings
• Self-signed certificates (flag for replacement)

Compile a list of:

• Current domain and all subdomains in use
• Where each domain/subdomain points (target/origin)
• Current SSL/TLS status per domain

============================================================ PHASE 2 — DNS RECORD GENERATION ============================================================

Generate DNS records for all required domains. Organize by record type:

Root domain (example.com):

A     example.com    ->  {load balancer IP or CDN}
AAAA  example.com    ->  {IPv6 address if available}

• For AWS: use ALIAS record to CloudFront or ALB
• For Cloudflare: use proxied A/CNAME record (orange cloud)
• For bare domain with CNAME target: use ALIAS/ANAME (provider-specific)

Standard subdomains (if --subdomains):

Terraform format (if --terraform):

Generate Route53, Cloudflare, or GCP Cloud DNS resources based on detected provider. Include:

• Zone resource with proper tagging (Project, Environment, ManagedBy)
• A/ALIAS record for root domain pointing to CDN or load balancer
• CNAME records for each subdomain
• Variable references for all environment-specific values (no hardcoded IPs)

Cloudflare specifics:

• Set proxied = true for A/CNAME records behind Cloudflare proxy
• Set ttl = 1 (auto) for proxied records

GCP Cloud DNS specifics:

• Enable DNSSEC with state = "on"
• Append trailing dot to dns_name

============================================================ PHASE 3 — SSL/TLS CERTIFICATE SETUP ============================================================

Configure SSL certificates for all domains:

AWS ACM:

• Wildcard certificate covering *.{domain} and root domain
• DNS validation with Route53 records (auto-validated via Terraform)
• CloudFront certificates MUST be in us-east-1 — use a separate provider alias
• create_before_destroy = true lifecycle for zero-downtime renewal

Cloudflare:

• SSL mode: Full (strict) — origin must have valid certificate
• Enable Universal SSL (automatic, covers root + www)
• For origin certificates: generate Cloudflare Origin CA cert (15-year validity)

Let's Encrypt (self-hosted):

• Generate Certbot command for certificate acquisition
• Set up auto-renewal cron: 0 0 1 * * certbot renew --quiet
• Or use Caddy/Traefik for automatic TLS

============================================================ PHASE 4 — EMAIL DNS (if --email) ============================================================

Configure email authentication records to prevent spoofing:

SPF (Sender Policy Framework):

TXT  example.com  "v=spf1 include:_spf.google.com include:amazonses.com ~all"

• Adjust include: based on detected email provider (Google Workspace, Microsoft 365, AWS SES, SendGrid, Postmark)
• Always end with ~all (soft fail) or -all (hard fail)

DKIM (DomainKeys Identified Mail):

• Provider-specific DKIM CNAME records
• Multiple DKIM records for multiple senders (transactional + marketing)

DMARC (Domain-based Message Authentication):

TXT  _dmarc.example.com  "v=DMARC1; p=quarantine; rua=mailto:[email protected]; ruf=mailto:[email protected]; pct=100"

• Start with p=none to monitor, then move to p=quarantine, then p=reject
• rua for aggregate reports, ruf for forensic reports

MX records (mail routing):

• Google Workspace: aspmx.l.google.com priority 10 + alternates
• Microsoft 365: {tenant}.mail.protection.outlook.com
• Self-hosted: mail.example.com

Additional email records:

• autodiscover CNAME for Outlook auto-configuration
• _imaps._tcp SRV for IMAP service discovery

============================================================ PHASE 5 — HEALTH CHECK ROUTING (if --health-check) ============================================================

Set up DNS-level health checks for failover or latency-based routing:

AWS Route53 health checks:

• HTTPS health check on /health endpoint, 30s interval, 3 failure threshold
• Failover routing policy with PRIMARY and SECONDARY targets
• Low TTL (60s) on failover records for fast switchover

Cloudflare load balancing:

• Configure origin pools (primary + fallback)
• Health check monitors (HTTP/HTTPS)
• Steering policy: failover, round-robin, or latency-based

Latency-based routing (multi-region):

• Separate Route53 records per region with latency_routing_policy
• Each record pointed to the regional origin

============================================================ PHASE 6 — VALIDATION ============================================================

After generating configuration, verify:

1. No conflicting records — check for duplicate A/CNAME on same name
2. CNAME restrictions — CNAME cannot coexist with other record types on same name
3. TTL values — production records should use reasonable TTLs (300-3600s)
4. Missing records — warn if www redirect, SSL validation records, or MX records are absent
5. DNSSEC — recommend enabling if provider supports it

============================================================ SELF-HEALING VALIDATION (max 2 iterations) ============================================================

After completing deployment/infrastructure changes, validate:

1. Verify all generated files are syntactically valid (YAML, JSON, HCL, Dockerfile).
2. Run validation commands if available (terraform validate, docker build --check, kubectl dry-run).
3. Verify no secrets, credentials, or sensitive values are hardcoded.
4. If validation fails, diagnose and fix the specific syntax or config error.
5. Repeat up to 2 iterations.

IF STILL FAILING after 2 iterations:

• Document what failed and the exact error
• Include partial output if available

============================================================ OUTPUT ============================================================

## DNS Configuration Complete

### Domain: {domain}
### Provider: {provider}

### Records Generated
| Type | Name | Value | TTL | Notes |
|------|------|-------|-----|-------|
| A | {domain} | {target} | 300 | Root domain |
| CNAME | www | {domain} | 300 | www redirect |
| CNAME | api | {alb/origin} | 300 | API endpoint |
| TXT | {domain} | v=spf1... | 3600 | SPF |
| TXT | _dmarc | v=DMARC1... | 3600 | DMARC |

### SSL/TLS
- Certificate: {ACM/Cloudflare/Let's Encrypt}
- Coverage: {domain}, *.{domain}
- Auto-renewal: {yes/no}

### Files Created
{list of files}

### Nameservers (if new zone)
{ns1, ns2, ns3, ns4 — update at registrar}

============================================================ NEXT STEPS ============================================================

1. If new zone: update nameservers at your domain registrar
2. Wait for DNS propagation (up to 48 hours, usually minutes)
3. Verify records: dig +short example.com A and dig +short example.com MX
4. Verify SSL: curl -vI https://example.com 2>&1 | grep 'SSL certificate'
5. Test email authentication: send test email and check headers for SPF/DKIM/DMARC pass
6. Set up monitoring for DNS resolution and certificate expiration
7. If using DMARC with p=none, monitor reports for 2 weeks then tighten to p=quarantine

============================================================ SELF-EVOLUTION TELEMETRY ============================================================

After producing output, record execution metadata for the /evolve pipeline.

Check if a project memory directory exists:

• Look for the project path in ~/.claude/projects/
• If found, append to skill-telemetry.md in that memory directory

Entry format:

### /dns — {{YYYY-MM-DD}}
- Outcome: {{SUCCESS | PARTIAL | FAILED}}
- Self-healed: {{yes — what was healed | no}}
- Iterations used: {{N}} / {{N max}}
- Bottleneck: {{phase that struggled or "none"}}
- Suggestion: {{one-line improvement idea for /evolve, or "none"}}

Only log if the memory directory exists. Skip silently if not found. Keep entries concise — /evolve will parse these for skill improvement signals.

============================================================ DO NOT ============================================================

• Do NOT set TTL below 60 seconds without good reason (DDoS amplification risk)
• Do NOT use CNAME at zone apex — use ALIAS, ANAME, or A record instead
• Do NOT create MX records pointing to IP addresses — use hostnames
• Do NOT use p=reject DMARC policy without first monitoring with p=none
• Do NOT create DNS records for services that do not exist yet
• Do NOT delete existing DNS records — only add or modify
• Do NOT hardcode IP addresses that may change — use CNAME to stable DNS names
• Do NOT skip SSL/TLS setup — all domains must serve over HTTPS
• Do NOT create wildcard DNS records unless specifically needed (security risk)
• Do NOT overwrite existing Terraform DNS resources without reading them first