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In our last blog post, Peter talked about how to Simulate A Docker Hub Outage, where he gave some context on what a pull-through cache (aka registry mirror) is and why Shipyard needs to mirror parts of Docker Hub.
Peter described the implementation as straightforward. While he’s not exactly wrong, I wanted to share some gotchas and tell you some caveats that I wish I knew before implementing this.
Containers are not a fad. They’re never overkill for any project and they simplify many aspects of development, even when running locally. With a wide selection of relevant tools and resources, there has never been a better time than now to implement containers in your organization and get ahead of the curve.
Containers are portable, self-sufficient, standardized units that store all code, assets, and dependencies of a program. They can be shared and run on virtually any hardware. Containerization has been around for years, although it has recently been gaining more traction with the advent of Docker. Many organizations are recognizing the value of managing their code in a simplified, shareable, and maintainable way. What does this mean for you and your organization?
Kubernetes (k8s) is an increasingly popular container orchestration platform. With that popularity has grown an ecosystem of tools and frameworks. One such tool is Kustomize.
K8s desired states are declaratively described in resource description files such as deployment, services, configmaps, secrets, etc. As we vary the environments from dev to QA to prod these configurations to change. The database may change from an embedded H2 in dev to a MariaDB in QA to Oracle in prod, the amount of allocated memory for a container may change, secrets of user rid and password for the database may also change. Managing all these varying YAML files of deployment, services, etc. per environment can be quite a chore. Configuration management tools maintain consistency across these environments.
Moving on, you may not know this, but you can have a functional single-node Kubernetes cluster running locally with your Docker Desktop by following the below steps. But wait, What is Docker Desktop?
As per the official documentation, Docker Desktop is an application for macOS and Windows machines for the building and sharing of containerized applications and microservices.
Starting with Kubernetes 1.20, released on December 8th, developers have received a warning that Kubernetes is deprecating Docker. This means that Kubernetes officially ceases to support the Docker tech stack, as you can already see in the release notes on GitHub.
The news wasn’t a big surprise. The Kubernetes development team had been planning and preparing this step for three years, so it was only a matter of time. Since Kubernetes was originally developed to orchestrate Docker containers, many Kubernetes users probably didn’t like this.
Kubernetes 1.20 was released last week. This version contains a number of amazing enhancements including graceful node shutdown, more visibility into resource requests, and snapshotting volumes.
But the change generating the most buzz is the deprecation of Docker as a container runtime.
Kubernetes is a platform for orchestrating containers and services, launched by Google in 2014. The key feature is that it naturally handles containers for you, monitors their availability and uses currently available computing capacity.
Containers are favored by developers around the world, mainly by addressing the shortcomings of classic virtualization.
Kubernetes and Docker Swarm are leading container orchestration tools today. So before using them in your prod, you should know what exactly they are and how they work. To understand the very same, read this blog which talks about the performance and usability face-off between Kubernetes vs. Docker Swarm.
You may also enjoy: Kubernetes vs. Docker
The differences between Kubernetes versus Docker Swarm are briefly summarized in the below table. A detailed explanation is provided later in the blog.