The technology landscape is evolving rapidly. When we started writing this book, the Istio release was 1.0.3, this book's current Istio release is 1.3.5. It is a similar case with Linkerd and Consul. The time to market is of the essence and these three open-source projects show a true CICD (short for Continuous Improvement and Continuous Delivery) approach using agile DevOps tools.

In order to run commands and scripts from this book, stick to the version used herein. However, we will update our GitHub repository for this book at https://github.com/servicemeshbook with newer versions that will be released in the future. You can switch to the newer branch in each repository for updated scripts and commands.

We were conscientious and implemented hands-on testing during development for all three service meshes and it is likely that some issues may remain. We suggest that you open issues that you encounter while going through the book. Use these links to open an issue for any errata and bugs:

• Istio: https://github.com/servicemeshbook/istio/issues
• Linkerd: https://github.com/servicemeshbook/linkerd/issues
• Consul: https://github.com/servicemeshbook/consul/issues

Your feedback is important to us and you may open an issue for suggestions and any further proposed improvements in relation to the above-mentioned service meshes.