Book Image

The Docker Workshop

By : Vincent Sesto, Onur Yılmaz, Sathsara Sarathchandra, Aric Renzo, Engy Fouda
5 (3)
Book Image

The Docker Workshop

5 (3)
By: Vincent Sesto, Onur Yılmaz, Sathsara Sarathchandra, Aric Renzo, Engy Fouda

Overview of this book

No doubt Docker Containers are the future of highly-scalable software systems and have cost and runtime efficient supporting infrastructure. But learning it might look complex as it comes with many technicalities. This is where The Docker Workshop will help you. Through this workshop, you’ll quickly learn how to work with containers and Docker with the help of practical activities.? The workshop starts with Docker containers, enabling you to understand how it works. You’ll run third party Docker images and also create your own images using Dockerfiles and multi-stage Dockerfiles. Next, you’ll create environments for Docker images, and expedite your deployment and testing process with Continuous Integration. Moving ahead, you’ll tap into interesting topics and learn how to implement production-ready environments using Docker Swarm. You’ll also apply best practices to secure Docker images and to ensure that production environments are running at maximum capacity. Towards the end, you’ll gather skills to successfully move Docker from development to testing, and then into production. While doing so, you’ll learn how to troubleshoot issues, clear up resource bottlenecks and optimize the performance of services. By the end of this workshop, you’ll be able to utilize Docker containers in real-world use cases.
Table of Contents (17 chapters)
Preface

Troubleshooting Swarm Nodes

For the work we will be doing in this chapter, we will be using only a single-node swarm to host our services. Docker Swarm has been providing production-level environments for years now. However, this doesn't mean there will never be any issues with your environment, especially when you start hosting services in a multi-node swarm. If you need to troubleshoot any of the nodes running on your cluster, there are a number of steps you can take to make sure you are correcting any issues they may have:

  • Reboot: Usually the easiest option is to either reboot or restart the node system to see whether this resolves the issues you may be experiencing.
  • Demote the node: If the node is a manager on your cluster, try demoting the node using the node demote command:
    docker node demote <node_id>

    If this node is the leader, it will allow one of the other manager nodes to become the leader of the swarm and hopefully resolve any issues you may be experiencing...