Image Replication and Distribution Security

Image Replication and Distribution Security

Registry replication enables global image distribution and disaster recovery. However, replication introduces security challenges including authentication federation, encrypted transfers, and consistency verification. Replication policies must balance availability requirements with security constraints. Geographic restrictions may limit replication destinations for compliance.

Pull-through caching registries reduce bandwidth while maintaining security. Cache registries authenticate to upstream registries on behalf of clients. This architecture centralizes credential management and enables network isolation. However, cache poisoning attacks require careful validation of cached content. Cache expiration policies balance performance with security currency.

#!/bin/bash
# Example: Secure registry replication setup

# Configure replication endpoints
cat > /etc/registry/replication-config.yaml <<EOF
version: 1.0
registries:
  - name: primary-registry
    url: https://registry-primary.company.com
    auth:
      type: bearer
      token_url: https://auth.company.com/token
      service: registry-primary
      client_id: replication-client
      client_secret_file: /secrets/client-secret
    tls:
      ca_cert: /certs/company-ca.crt
      client_cert: /certs/replication-client.crt
      client_key: /certs/replication-client.key
      verify: true

  - name: dr-registry  
    url: https://registry-dr.company.com
    auth:
      type: basic
      username_file: /secrets/dr-username
      password_file: /secrets/dr-password
    tls:
      ca_cert: /certs/company-ca.crt
      verify: true

replication_rules:
  - name: production-images
    source: primary-registry
    destination: dr-registry
    filters:
      - type: name
        pattern: "prod/*"
      - type: tag
        pattern: "v*"
    trigger:
      type: event
      events: ["push", "delete"]
    bandwidth_limit: 100  # MB/s
    retry_policy:
      max_attempts: 3
      backoff: exponential

  - name: security-scanned
    source: primary-registry  
    destination: dr-registry
    filters:
      - type: label
        key: "security.scan.status"
        value: "passed"
    trigger:
      type: scheduled
      cron: "0 2 * * *"  # Daily at 2 AM
    
security:
  signature_verification:
    enabled: true
    trust_roots:
      - /certs/signing-ca.crt
  
  integrity_check:
    algorithm: sha256
    verify_manifests: true
    verify_layers: true
  
  audit:
    enabled: true
    log_level: info
    log_file: /logs/replication-audit.log
EOF

# Start secure replication service
docker run -d \
  --name registry-replicator \
  --restart always \
  -v /etc/registry:/etc/registry:ro \
  -v /secrets:/secrets:ro \
  -v /certs:/certs:ro \
  -v /logs:/logs \
  --security-opt no-new-privileges:true \
  --read-only \
  --tmpfs /tmp \
  registry-replicator:latest

Content delivery networks (CDN) accelerate image distribution but require security consideration. CDN authentication prevents unauthorized access to cached images. Signed URLs provide time-limited access to specific images. Geographic restrictions enforce data residency requirements. SSL/TLS to origin servers prevents CDN cache poisoning. Organizations must balance performance benefits against security implications.