containerdays-2024-dns

Resources used for the ContainerDays 2024 Talk «Building and Operating a Highly Reliable Cloud Native DNS Service With Open Source Technologies»

Authors

Please feel free to approach us with feedback and questions!

Hoang Anh Mai hoanganh.mai@swisscom.com Fabian Schulz fabian.schulz1@swisscom.com Joel Studler joel.studler@swisscom.com

Contact us on slack:

• https://cloud-native.slack.com
• https://kubernetes.slack.com

Getting started

For docker engine / virtualization we use colima but any other tool for docker such as docker desktop should also work.

Prerequisites

• colima:
  • brew install colima
  • colima start dns1 -c 4 -m 4 --network-address
  • colima ssh -p dns1 # ssh onto colima node
    • edit /etc/sysctl.conf and add: # We need to increase the file handler limit of the linux distro
      • fs.inotify.max_user_watches = 1048576
      • fs.inotify.max_user_instances = 512
  • colima restart dns1
• docker cli: brew install docker
• kind: brew install kind

Demo Environment setup

Call the prepare-demo scripts without parameters to create your environment. The prepare-demo scripts 2 & 3 come in two flavours:

• prepare-demoX-fresh.sh which first deletes the kind clusters and sets them up from scratch
• prepare-demoX-continued.sh which keeps the setup from the previous demo

Manual Environment setup

Use the create-kind-clusters.sh and setup-kind.sh scripts to create your environment. Below are the instructions for a 2-cluster setup, the scripts also support more than two if your machine does.

To create 2 kind clusters execute: ./create-kind-clusters.sh 2

The clusters will be named dns-0, dns-1.

The setup script accepts the cluster id and an optional clusternameprefix parameter, so call it for each cluster like that:

• ./setup-kind.sh 0
• ./setup-kind.sh 1

Environment teardown

To teardown the kind clusters simply execute: ./destroy-kind.sh 2