dns-management

仓库: aj-geddes/useful-ai-prompts
安装量: 128
排名: #6742

安装

npx skills add https://github.com/aj-geddes/useful-ai-prompts --skill dns-management

DNS Management Overview

Implement DNS management strategies for traffic routing, failover, geo-routing, and high availability using Route53, Azure DNS, or CloudFlare.

When to Use Domain management and routing Failover and disaster recovery Geographic load balancing Multi-region deployments DNS-based traffic management CDN integration Health check routing Zero-downtime migrations Implementation Examples 1. AWS Route53 Configuration

route53-setup.yaml

apiVersion: v1 kind: ConfigMap metadata: name: route53-config namespace: operations data: setup-dns.sh: | #!/bin/bash set -euo pipefail

DOMAIN="myapp.com"
HOSTED_ZONE_ID="Z1234567890ABC"
PRIMARY_ENDPOINT="myapp-primary.example.com"
SECONDARY_ENDPOINT="myapp-secondary.example.com"

echo "Setting up Route53 DNS for $DOMAIN"

# Create health check for primary
PRIMARY_HEALTH=$(aws route53 create-health-check \
  --health-check-config '{
    "Type": "HTTPS",
    "ResourcePath": "/health",
    "FullyQualifiedDomainName": "'${PRIMARY_ENDPOINT}'",
    "Port": 443,
    "RequestInterval": 30,
    "FailureThreshold": 3
  }' --query 'HealthCheck.Id' --output text)

echo "Created health check: $PRIMARY_HEALTH"

# Create failover record for primary
aws route53 change-resource-record-sets \
  --hosted-zone-id "$HOSTED_ZONE_ID" \
  --change-batch '{
    "Changes": [{
      "Action": "UPSERT",
      "ResourceRecordSet": {
        "Name": "'$DOMAIN'",
        "Type": "A",
        "TTL": 60,
        "SetIdentifier": "Primary",
        "Failover": "PRIMARY",
        "AliasTarget": {
          "HostedZoneId": "Z35SXDOTRQ7X7K",
          "DNSName": "'${PRIMARY_ENDPOINT}'",
          "EvaluateTargetHealth": true
        },
        "HealthCheckId": "'${PRIMARY_HEALTH}'"
      }
    }]
  }'

# Create failover record for secondary
aws route53 change-resource-record-sets \
  --hosted-zone-id "$HOSTED_ZONE_ID" \
  --change-batch '{
    "Changes": [{
      "Action": "UPSERT",
      "ResourceRecordSet": {
        "Name": "'$DOMAIN'",
        "Type": "A",
        "TTL": 60,
        "SetIdentifier": "Secondary",
        "Failover": "SECONDARY",
        "AliasTarget": {
          "HostedZoneId": "Z35SXDOTRQ7X7K",
          "DNSName": "'${SECONDARY_ENDPOINT}'",
          "EvaluateTargetHealth": false
        }
      }
    }]
  }'

echo "DNS failover configured"

Terraform Route53 configuration

resource "aws_route53_zone" "myapp" { name = "myapp.com"

tags = { Name = "myapp-zone" } }

Health check for primary region

resource "aws_route53_health_check" "primary" { ip_address = aws_lb.primary.ip_address port = 443 type = "HTTPS" resource_path = "/health"

failure_threshold = 3 request_interval = 30

tags = { Name = "primary-health-check" } }

Primary failover record

resource "aws_route53_record" "primary" { zone_id = aws_route53_zone.myapp.zone_id name = "myapp.com" type = "A" ttl = 60 set_identifier = "Primary"

failover_routing_policy { type = "PRIMARY" }

alias { name = aws_lb.primary.dns_name zone_id = aws_lb.primary.zone_id evaluate_target_health = true }

health_check_id = aws_route53_health_check.primary.id }

Secondary failover record

resource "aws_route53_record" "secondary" { zone_id = aws_route53_zone.myapp.zone_id name = "myapp.com" type = "A" ttl = 60 set_identifier = "Secondary"

failover_routing_policy { type = "SECONDARY" }

alias { name = aws_lb.secondary.dns_name zone_id = aws_lb.secondary.zone_id evaluate_target_health = false } }

Weighted routing for canary deployments

resource "aws_route53_record" "canary" { zone_id = aws_route53_zone.myapp.zone_id name = "api.myapp.com" type = "A" ttl = 60 set_identifier = "Canary"

weighted_routing_policy { weight = 10 }

alias { name = aws_lb.canary.dns_name zone_id = aws_lb.canary.zone_id evaluate_target_health = true } }

Geolocation routing

resource "aws_route53_record" "geo_us" { zone_id = aws_route53_zone.myapp.zone_id name = "myapp.com" type = "A" ttl = 60 set_identifier = "US"

geolocation_routing_policy { country = "US" }

alias { name = aws_lb.us_east.dns_name zone_id = aws_lb.us_east.zone_id evaluate_target_health = true } }

resource "aws_route53_record" "geo_eu" { zone_id = aws_route53_zone.myapp.zone_id name = "myapp.com" type = "A" ttl = 60 set_identifier = "EU"

geolocation_routing_policy { continent = "EU" }

alias { name = aws_lb.eu_west.dns_name zone_id = aws_lb.eu_west.zone_id evaluate_target_health = true } }

  1. DNS Failover Script

!/bin/bash

dns-failover.sh - Manage DNS failover

set -euo pipefail

DOMAIN="${1:-myapp.com}" HOSTED_ZONE_ID="${2:-Z1234567890ABC}" NEW_PRIMARY="${3:-}"

if [ -z "$NEW_PRIMARY" ]; then echo "Usage: $0 " exit 1 fi

echo "Initiating DNS failover for $DOMAIN"

Get current primary

CURRENT_PRIMARY=$(aws route53 list-resource-record-sets \ --hosted-zone-id "$HOSTED_ZONE_ID" \ --query "ResourceRecordSets[?Name=='$DOMAIN.' && SetIdentifier=='Primary'].AliasTarget.DNSName" \ --output text)

echo "Current primary: $CURRENT_PRIMARY" echo "New primary: $NEW_PRIMARY"

Verify new endpoint is healthy

echo "Verifying new endpoint health..." if ! curl -sf --max-time 5 "https://${NEW_PRIMARY}/health" > /dev/null; then echo "ERROR: New endpoint is not healthy" exit 1 fi

Update primary record

aws route53 change-resource-record-sets \ --hosted-zone-id "$HOSTED_ZONE_ID" \ --change-batch '{ "Changes": [{ "Action": "UPSERT", "ResourceRecordSet": { "Name": "'$DOMAIN'", "Type": "A", "TTL": 60, "SetIdentifier": "Primary", "Failover": "PRIMARY", "AliasTarget": { "HostedZoneId": "Z35SXDOTRQ7X7K", "DNSName": "'$NEW_PRIMARY'", "EvaluateTargetHealth": true } } }] }'

echo "DNS failover completed: $NEW_PRIMARY is now primary"

  1. CloudFlare DNS Configuration

!/bin/bash

cloudflare-dns.sh - CloudFlare DNS management

set -euo pipefail

CF_EMAIL="${CF_EMAIL}" CF_API_KEY="${CF_API_KEY}" DOMAIN="${1:-myapp.com}" ZONE_ID="${2:-}"

Get zone ID

if [ -z "$ZONE_ID" ]; then ZONE_ID=$(curl -s -X GET "https://api.cloudflare.com/client/v4/zones?name=$DOMAIN" \ -H "X-Auth-Email: $CF_EMAIL" \ -H "X-Auth-Key: $CF_API_KEY" \ -H "Content-Type: application/json" \ | jq -r '.result[0].id') fi

echo "Zone ID: $ZONE_ID"

Create DNS record

create_record() { local type="$1" local name="$2" local content="$3" local ttl="${4:-3600}"

curl -s -X POST "https://api.cloudflare.com/client/v4/zones/$ZONE_ID/dns_records" \
    -H "X-Auth-Email: $CF_EMAIL" \
    -H "X-Auth-Key: $CF_API_KEY" \
    -H "Content-Type: application/json" \
    --data '{
        "type":"'$type'",
        "name":"'$name'",
        "content":"'$content'",
        "ttl":'$ttl',
        "proxied":true
    }' | jq '.'

}

List records

list_records() { curl -s -X GET "https://api.cloudflare.com/client/v4/zones/$ZONE_ID/dns_records" \ -H "X-Auth-Email: $CF_EMAIL" \ -H "X-Auth-Key: $CF_API_KEY" \ -H "Content-Type: application/json" | jq '.result[] | {id, type, name, content}' }

list_records

  1. DNS Monitoring and Validation

dns-monitoring.yaml

apiVersion: batch/v1 kind: CronJob metadata: name: dns-health-check namespace: operations spec: schedule: "/5 * * * " # Every 5 minutes jobTemplate: spec: template: spec: containers: - name: health-check image: curlimages/curl:latest command: - sh - -c - | DOMAIN="myapp.com" PRIMARY_IP=$(nslookup $DOMAIN | grep "Address:" | tail -1 | awk '{print $2}')

              echo "Checking DNS resolution for $DOMAIN"
              echo "Resolved to: $PRIMARY_IP"

              # Verify connectivity
              if curl -sf --max-time 10 "https://$PRIMARY_IP/health" > /dev/null 2>&1; then
                echo "PASS: Primary endpoint is healthy"
                exit 0
              else
                echo "FAIL: Primary endpoint is unreachable"
                exit 1
              fi
      restartPolicy: OnFailure

Best Practices ✅ DO Use health checks with failover Set appropriate TTL values Implement geolocation routing Use weighted routing for canary Monitor DNS resolution Document DNS changes Test failover procedures Use DNS DNSSEC ❌ DON'T Use TTL of 0 Point to single endpoint Forget health checks Mix DNS and application failover Change DNS during incidents Ignore DNS propagation time Use generic names Skip DNS monitoring DNS Routing Policies Simple: Single resource Weighted: Distribute by percentage Latency-based: Route to lowest latency Failover: Active/passive failover Geolocation: Route by geography Multi-value: Multiple resources with health checks Resources AWS Route53 Documentation CloudFlare DNS API Azure DNS Documentation DNS Best Practices

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