Deis v1.13.0 is the final feature release for Deis. It is a Long Term Support (LTS) release, which means we will continue to patch bugs and accept pull requests, however any new features should be applied to Deis Workflow, the successor to Deis.
Deis v1.13.0 bumps CoreOS to 899.13.0, updates the system's containers to Alpine 3.3, removes the scheduler technology previews, bumps the Heroku buildpacks to the latest stable versions, adds a healthcheck url /healthz to the controller, and allows logspout to re-discover the logger when it jumps to another control plane node.
In part one of this miniseries looking at Docker, we looked at what makes Docker special, the difference between Virtual Machines and containers, and the primary components that make up Docker.
In this post, we'll work directly with some containers. Specifically, we'll show you hot to launch a container, how to build an image with a Dockerfile, how to work with registries, and the basics of data volumes.
Before launching a container you might pull it from the registry:
Launching a container is as simple as running:
The command here is the command you want to run inside the container.
If the image doesn't exist, Docker attempts to fetch it from the public image registry. This happens automatically, but you should expect a time delay.
It's important to note that containers are designed to stop after the command executed within them has exited. For example, if you run /bin/echo hello world as your command, the container starts, prints "hello world" and then stops.
We are excited to announce that we have recently cut a beta release for the next major release of Deis! As many of you know, for 2.0 we’ve decided to re-platform the PaaS from CoreOS’s Fleet onto Kubernetes. This gives us a stable cluster manager, a better scheduler, a smaller overall footprint (potentially a single machine!), and a great Kubernetes community to work with. This lets us focus our efforts on making it as easy as possible to deploy and scale your applications.
To borrow from the late, great David Bowie, beta brings along with it some Ch-ch-ch-ch-changes!
In my last miniseries, we gave an overview of CoreOS. In this miniseries, I want to take a look at Docker. In this post we’ll look at why it’s special and how it’s built. We’ll start at the beginning, so don’t worry if you’re totally new to this.
Containers themselves are just an abstraction over Linux cgroups, which are a lower level kernel construct for jailing and limiting the resources of a process and its children.
Docker was using LinuX Containers (LXC) in the beginning, but then switched to runC, formerly known as libcontainer. runC runs in the same operating system as its host. This allows it to share a lot of the host operating system resources, such as RAM, CPU, networking, and so on.