UC-000: Use Cases Overview

This section provides a comprehensive overview of the different ways to integrate with your BIND DNS server setup. Each use case addresses specific needs and deployment scenarios.

Integration Context Diagram

graph TB
    subgraph "BIND DNS Server Environment"
        DNS[BIND DNS Server<br/>Docker Compose]
        TSIG[TSIG Keys<br/>env-manager.sh]
        ENV[Environment Files<br/>.env, .env.prod, .env.dev]
        DNS --> TSIG
        TSIG --> ENV
    end

    subgraph "Kubernetes Ecosystem"
        K8S[Kubernetes Cluster]
        ING[Ingress Controllers]
        SVC[Services]
        EXT[External-DNS]

        K8S --> ING
        K8S --> SVC
        ING --> EXT
        SVC --> EXT
    end

    subgraph "DNS Management Tools"
        DNSCTL[DNSControl<br/>JavaScript DSL]
        OCTODNS[octoDNS<br/>Python YAML]

        subgraph "Configuration Files"
            DNSCONFIG[dnsconfig.js]
            OCTOYAML[config.yaml<br/>zone.yaml]
        end

        DNSCTL --> DNSCONFIG
        OCTODNS --> OCTOYAML
    end

    subgraph "CI/CD & Automation"
        GHA[GitHub Actions]
        GITLAB[GitLab CI]
        JENKINS[Jenkins]

        GHA --> DNSCTL
        GHA --> OCTODNS
        GITLAB --> DNSCTL
        GITLAB --> OCTODNS
        JENKINS --> DNSCTL
        JENKINS --> OCTODNS
    end

    %% Connections to DNS Server
    EXT -.->|TSIG Auth<br/>Dynamic Updates| DNS
    DNSCTL -.->|TSIG Auth<br/>Zone Updates| DNS
    OCTODNS -.->|TSIG Auth<br/>Record Sync| DNS

    %% Security layer
    TSIG -.->|Secure Keys| EXT
    TSIG -.->|Secure Keys| DNSCTL
    TSIG -.->|Secure Keys| OCTODNS

    classDef dnsServer fill:#263238,stroke:#37474f,stroke-width:2px,color:#ffffff
    classDef k8s fill:#1a237e,stroke:#283593,stroke-width:2px,color:#ffffff
    classDef tools fill:#bf360c,stroke:#d84315,stroke-width:2px,color:#ffffff
    classDef cicd fill:#1b5e20,stroke:#2e7d32,stroke-width:2px,color:#ffffff
    classDef security fill:#b71c1c,stroke:#c62828,stroke-width:2px,color:#ffffff

    class DNS,TSIG,ENV dnsServer
    class K8S,ING,SVC,EXT k8s
    class DNSCTL,OCTODNS,DNSCONFIG,OCTOYAML tools
    class GHA,GITLAB,JENKINS cicd

Use Case Comparison

Feature	External-DNS	DNSControl	octoDNS
Primary Use Case	Kubernetes DNS automation	Declarative DNS management	Multi-provider DNS sync
Configuration Language	Kubernetes annotations	JavaScript DSL	YAML
Automation Level	Fully automatic	Semi-automatic	Semi-automatic
Multi-Provider Support	Yes (limited)	Yes (extensive)	Yes (extensive)
Kubernetes Integration	Native	Manual	Manual
Validation	Basic	Advanced	Advanced
Rollback Support	Limited	Yes	Yes
Learning Curve	Low	Medium	Medium
Best For	K8s-native workflows	Infrastructure as Code	Multi-cloud DNS

Integration Scenarios

1. External-DNS Integration

When to use: Kubernetes-native environments where DNS records should automatically reflect service and ingress changes.

sequenceDiagram
    participant K8s as Kubernetes
    participant ExtDNS as External-DNS
    participant BIND as BIND Server

    K8s->>ExtDNS: Service/Ingress created
    ExtDNS->>ExtDNS: Generate DNS records
    ExtDNS->>BIND: TSIG authenticated update
    BIND->>BIND: Update zone records
    Note over K8s,BIND: Automatic DNS management

2. DNSControl Integration

When to use: Infrastructure as Code approach with version-controlled DNS configurations and team collaboration.

sequenceDiagram
    participant Dev as Developer
    participant Git as Git Repository
    participant CI as CI/CD Pipeline
    participant BIND as BIND Server

    Dev->>Git: Push dnsconfig.js changes
    Git->>CI: Trigger pipeline
    CI->>CI: dnscontrol check
    CI->>CI: dnscontrol preview
    CI->>BIND: dnscontrol push (TSIG auth)
    BIND->>BIND: Apply DNS changes
    Note over Dev,BIND: Controlled DNS deployment

3. octoDNS Integration

When to use: Multi-provider environments requiring DNS synchronization and advanced validation capabilities.

sequenceDiagram
    participant Admin as DNS Admin
    participant octoDNS as octoDNS
    participant BIND as BIND Server
    participant Cloud as Cloud Provider

    Admin->>octoDNS: octodns-sync --plan
    octoDNS->>BIND: Query current state
    octoDNS->>Cloud: Query current state
    octoDNS->>Admin: Show diff/plan
    Admin->>octoDNS: octodns-sync
    octoDNS->>BIND: Apply changes (TSIG auth)
    octoDNS->>Cloud: Apply changes (API auth)
    Note over Admin,Cloud: Multi-provider sync

Security Architecture

All integrations leverage the same security foundation:

graph LR
    subgraph "Security Layer"
        ENVMGR[env-manager.sh]
        TSIGKEY[TSIG Keys]
        ENVFILE[Environment Files]

        ENVMGR --> TSIGKEY
        TSIGKEY --> ENVFILE
    end

    subgraph "DNS Clients"
        EXT[External-DNS]
        DNSCTL[DNSControl]
        OCTODNS[octoDNS]
    end

    subgraph "BIND Server"
        BIND[BIND DNS]
        ZONES[DNS Zones]

        BIND --> ZONES
    end

    TSIGKEY -.->|Secure Auth| EXT
    TSIGKEY -.->|Secure Auth| DNSCTL
    TSIGKEY -.->|Secure Auth| OCTODNS

    EXT -.->|Authenticated Updates| BIND
    DNSCTL -.->|Authenticated Updates| BIND
    OCTODNS -.->|Authenticated Updates| BIND

    classDef security fill:#b71c1c,stroke:#c62828,stroke-width:2px,color:#ffffff
    classDef client fill:#bf360c,stroke:#d84315,stroke-width:2px,color:#ffffff
    classDef server fill:#263238,stroke:#37474f,stroke-width:2px,color:#ffffff

    class ENVMGR,TSIGKEY,ENVFILE security
    class EXT,DNSCTL,OCTODNS client
    class BIND,ZONES server

Choosing the Right Integration

For Kubernetes Environments

• Start with External-DNS if you want automatic DNS management
• Add DNSControl or octoDNS for manual DNS records and infrastructure

For Traditional Infrastructure

• Use DNSControl for JavaScript-familiar teams and simple setups
• Use octoDNS for complex multi-provider environments

For Hybrid Environments

• Combine External-DNS + DNSControl/octoDNS for comprehensive DNS management
• Use External-DNS for dynamic K8s resources
• Use DNSControl/octoDNS for static infrastructure records

Getting Started

1. Set up your BIND DNS server using the provided Docker Compose setup
2. Generate TSIG keys using env-manager.sh generate-keys
3. Choose your integration approach based on your requirements
4. Follow the specific integration guide for detailed setup instructions

Next Steps

• UC-001: External-DNS Integration - Kubernetes-native DNS automation
• UC-002: DNSControl Integration - JavaScript-based DNS management
• UC-003: octoDNS Integration - Python-based multi-provider DNS sync

Each integration guide provides detailed setup instructions, configuration examples, and best practices for secure DNS management.