Top 5 Blog Post 2018: Simplifying Kubernetes with Docker Compose and Friends

All this week we’ve been bringing you the top 5 blog posts for 2018 –coming in at #1 is our post on open sourcing our Docker Compose on Kubernetes capability. This new capability enables you to simplify the Kubernetes experience. To learn more, continue reading…     

Today we’re happy to announce we’re open sourcing our support for using Docker Compose on Kubernetes. We’ve had this capability in Docker Enterprise for a little while but as of today you will be able to use this on any Kubernetes cluster you choose.

Why do I need Compose if I already have Kubernetes?

The Kubernetes API is really quite large. There are more than 50 first-class objects in the latest release, from Pods and Deployments to ValidatingWebhookConfiguration and ResourceQuota. This can lead to a verbosity in configuration, which then needs to be managed by you, the developer. Let’s look at a concrete example of that.

The Sock Shop is the canonical example of a microservices application. It consists of multiple services using different technologies and backends, all packaged up as Docker images. It also provides example configurations using different tools, including both Compose and raw Kubernetes configuration. Let’s have a look Continue reading

Docker App and CNAB

Docker App is a new tool we spoke briefly about back at DockerCon US 2018. We’ve been working on `docker-app` to make container applications simpler to share and easier to manage across different teams and between different environments, and we open sourced it so you can already download Docker App from GitHub at https://github.com/docker/app.

In talking to others about problems they’ve experienced sharing and collaborating on the broad area we call “applications” we came to a realisation: it’s a more general problem that others have been working on too. That’s why we’re happy to collaborate with Microsoft on the new Cloud Native Application Bundle (CNAB) specification.

Today’s cloud native applications typically use different technologies, each with their own toolchain. Maybe you’re using ARM templates and Helm charts, or CloudFormation and Compose, or Terraform and Ansible. There is no single solution in the market for defining and packaging these multi-service, multi-format distributed applications.

CNAB is an open source, cloud-agnostic specification for packaging and running distributed applications that aims to solve some of these problems. CNAB unifies the management of multi-service, distributed applications across different toolchains into a single all-in-one packaging format.

The draft specification is available at cnab.io and Continue reading

Simplifying Kubernetes with Docker Compose and Friends

Today we’re happy to announce we’re open sourcing our support for using Docker Compose on Kubernetes. We’ve had this capability in Docker Enterprise for a little while but as of today you will be able to use this on any Kubernetes cluster you choose.

Why do I need Compose if I already have Kubernetes?

The Kubernetes API is really quite large. There are more than 50 first-class objects in the latest release, from Pods and Deployments to ValidatingWebhookConfiguration and ResourceQuota. This can lead to a verbosity in configuration, which then needs to be managed by you, the developer. Let’s look at a concrete example of that.

The Sock Shop is the canonical example of a microservices application. It consists of multiple services using different technologies and backends, all packaged up as Docker images. It also provides example configurations using different tools, including both Compose and raw Kubernetes configuration. Let’s have a look at the relative sizes of those configurations:

$ git clone https://github.com/microservices-demo/microservices-demo.git
$ cd deployment/kubernetes/manifests
$ (Get-ChildItem -Recurse -File | Get-Content | Measure-Object -line).Lines
908
$ cd ../../docker-compose
$ (Get-Content docker-compose.yml | Measure-Object -line).Lines
174

Describing the exact same multi-service application using just Continue reading

Making Compose Easier to Use with Application Packages

Docker Compose is wildly popular with developers for describing an application. In fact, there are more than 300,000 Docker Compose files on GitHub. With a set of services described in a docker-compose.yml file, it’s easy to launch a complex multi-service application (or a simple, single-service app) on Docker by running a single command. This ease of use makes Docker Compose perfect for development teams striving for a quick way of getting started with projects.

Over time Compose has evolved, adding lots of features which help when deploying those same applications to production environments, for example specifying a number of replicas, memory resource constraints or a custom syslog server. But those attributes can become specific to your own environment. There are a number of different strategies for trying to address this situation, but the most common is relying on copy and paste. It’s fairly common to maintain multiple Compose files for the same application running in different environments for example. This leads to two problems:

1. We share Docker images all the time, but don’t have a good way of sharing the multi-service applications that use them
2. It’s hard to collaborate between developers and operators around a Compose file. This waters Continue reading

Introducing an Easier Way To Design Applications in Docker Desktop

In today’s DockerCon keynote we previewed an upcoming Docker Desktop feature that will make it easier than ever to design your own container-based applications. For a certain set of developers, the current iteration of Docker Desktop has everything one might need to containerize an applications, but it does require an understanding of the Dockerfile and Compose file specifications in order to get started and the Docker CLI to build and run your applications.

But we’ve been thinking about ways to bring this capability to ALL developers. We want to make it easier to get started with containerization, and we want to make it even easier to share and collaborate and integrate container-based development in to more developers’ toolsets. This new guided workflow feature is a preview of what we’re working on and we wanted to share more details on the ideas we’ve incorporated and are thinking about for the future.

The first thing you’ll notice is this is a graphical tool. We’re not breaking anything that’s already working today – everything being created behind the scenes is still Dockerfiles and Compose – we’re just giving you a new way to get from Point A to Point B, because not everyone Continue reading

Docker for Desktop is Certified Kubernetes

“You are now Certified Kubernetes.” With this comment, Docker for Windows and Docker for Mac passed the Kubernetes conformance tests. Kubernetes has been available in Docker for Mac and Docker for Windows since January, having first being announced at DockerCon EU last year. But why is this important to the many of you who are using Docker for Windows and Docker for Mac?

Kubernetes is designed to be a platform that others can build upon. As with any similar project, the risk is that different distributions vary enough that applications aren’t really portable. The Kubernetes project has always been aware of that risk – and this led directly to forming the Conformance Working Group. The group owns a test suite that anyone distributing Kubernetes can run, and submit the results for to attain official certification. This test suite checks that Kubernetes behaves like, well, Kubernetes; that the various APIs are exposed correctly and that applications built using the core APIs will run successfully. In fact, our enterprise container platform, Docker Enterprise Edition, achieved certification using the same test suite  You can find more about the test suite at https://github.com/cncf/k8s-conformance.

This is important for Docker for Windows and Docker for Continue reading