What are the most effective DNS architecture practices for containers?

2 Implementing a DNS cache

A DNS cache is a mechanism that stores the results of DNS queries locally, so that subsequent requests for the same domain name can be resolved faster and with less network traffic. A DNS cache can be implemented at different levels, such as on the host, on the container, or on a dedicated server. A DNS cache can improve the performance and reliability of your containerized applications, especially if they rely on external DNS services.

3 Choosing a suitable DNS resolver

A DNS resolver is the component that performs the DNS queries on behalf of your applications. Depending on your container orchestration platform, you may have different options for choosing a DNS resolver. For example, Docker uses an embedded DNS server that runs on each host and forwards queries to the host's DNS settings. Kubernetes uses a cluster-wide DNS service called kube-dns that integrates with the service discovery tool. You should choose a DNS resolver that meets your requirements for scalability, security, and customization.

4 Applying DNS security best practices

DNS security is an essential part of DNS architecture, as it helps protect your containerized applications from malicious attacks such as DNS spoofing, hijacking, or denial-of-service. To safeguard your containers, you should employ best practices like using TLS or HTTPS for encrypted communication between your applications and the DNS resolver, DNSSEC to verify the authenticity and integrity of the DNS responses, DNS filtering to block unwanted or harmful domain names, and DNS monitoring and logging to detect and troubleshoot any anomalies or issues.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?