Our Most Popular Blog Posts of 2016

2016, what a year. Ansible upgrades galore, Tower 3 was released, a tipping point for DevOps, and much more.

All these themes were reflected in our blog this year. From doing more with automation, working across platforms (think Windows automation), orchestrating containers at scale, to exploring all the great new features in Tower 3, we covered a lot.

Just in case you missed them, here are our 10 most viewed blog posts of the year (plus a sneaky few honorable mentions).

1. 6 Ways Ansible Makes Docker-Compose Better

Containers are an integral part of DevOps workflows. With containers you can be sure that if you build an application once, you can run it in the same way across every environment along the application lifecycle. That’s great, until one developer announces the need for a second, third, or fourth container. More of them, all doing different things, and all connecting together – somehow. But how? Docker has a tool that can help – docker-compose. But it’s limited to environments with a Docker-centric view of the world and doesn’t solve non-Docker orchestration problems. That’s where Ansible comes in. Read more

2. Testing Ansible Roles with Docker

Ansible plus Docker was a big deal in 2016, Continue reading

Opening Web Internet Location Files on Ubuntu

As part of my effort to make myself and my workflows more “cross-platform friendly,” I’ve been revisiting certain aspects of how I do things. One of the things I’m reviewing is how I capture—and later review—posts or articles on the web. On OS X, I would run an AppleScript that generated a .webloc file (aka an Internet location file). This is an XML file that OS X understands. However, Linux doesn’t natively understand these files, so today I came up with a solution to reading .webloc files with Ubuntu and Firefox.

The solution to the file involves the use of xmllint, a tool that you can install on Ubuntu as part of the “libxml2-utils” package. Using xmllint, you can easily extract a single XML element from an XML file—and .webloc files are just XML files. For the sake of illustration, here’s the contents of a .webloc file generated on OS X:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>URL</key>
    <string>http://blog.fntlnz.wtf/post/systemd-nspawn/</string>
</dict>
</plist>

Using xmllint, you can extract the URL value, and then pass Continue reading

Understanding Docker Networking Drivers and their use cases

Applications requirements and networking environments are diverse and sometimes opposing forces. In between applications and the network sits Docker networking, affectionately called the Container Network Model or CNM. It’s CNM that brokers connectivity for your Docker containers and also what abstracts away the diversity and complexity so common in networking. The result is portability and it comes from CNM’s powerful network drivers. These are pluggable interfaces for the Docker Engine, Swarm, and UCP that provide special capabilities like multi-host networking, network layer encryption, and service discovery.

Naturally, the next question is which network driver should I use? Each driver offers tradeoffs and has different advantages depending on the use case. There are built-in network drivers that come included with Docker Engine and there are also plug-in network drivers offered by networking vendors and the community. The most commonly used built-in network drivers are bridge, overlay and macvlan. Together they cover a very broad list of networking use cases and environments. For a more in depth comparison and discussion of even more network drivers, check out the Docker Network Reference Architecture.

Bridge Network Driver

The bridge networking driver is the first driver on our list. It’s simple to understand, Continue reading

Docker & Prometheus Joint Holiday Meetup Recap

Last Wednesday we had our 52nd meetup at Docker HQ, but this time we joined forces with the Prometheus user group to host a mega-meetup! There was a great turnout and members were excited to see the talks on using Docker with Prometheus, OpenTracing and the new Docker playground; play-with-docker.

First up was Stephen Day, a Senior Software Engineer at Docker, who presented a talk entitled, ‘The History of Metrics According to Me’. Stephen believes that metrics and monitoring should be built into every piece of software we create, from the ground up. By solving the hard parts of application metrics in Docker, he thinks it becomes more likely that metrics are a part of your services from the start. See the video of his intriguing talk and slides below.

‘The History of Metrics According to Me’ @stevvooe talking #metrics and #monitoring at the #Docker SF #meetup! @prometheusIO @CloudNativeFdn pic.twitter.com/6hk0yAtats

— Docker (@docker) December 15, 2016

Next up was Ben Sigelman, an expert in distributed tracing, whose talk ‘OpenTracing Isn’t Just Tracing: Measure Twice, Instrument Once’ was both informative and humorous. He Continue reading

The Linux Migration: Initial Progress Report

About 4 years ago, I discussed some changes in the Apple ecosystem that might lead me to move away from OS X. To be honest, I’ve made only token efforts since that time to actually migrate away, even though the forces that I described in that post are still in full effect. In fact, some might say that the “iOS-ification” of OS X (now rebranded as “macOS”) is even stronger now. As a result, I’ve stepped up my work on a Linux migration, and I’m happy to report that I’ve made some progress.

Here’s a quick update on where things stand so far.

Linux Distribution

I’ve looked at a fair number of Linux distributions. I tried Elementary OS, which some have raved about but which I found too simplistic. I also went back and looked again at Ubuntu derivatives like Linux Mint. Given that Ubuntu is itself derived from Debian, I also took a look at Debian “Jessie”. Finally, I tested Fedora 25. For a number of reasons—which I’ll describe in more detail in a moment—I’ve settled on Ubuntu 16.04.

So, why Ubuntu 16.04 “Xenial Xerus”? Keep in mind that the reasons I list below are my Continue reading

Announcing Federal Security and Compliance Controls for Docker Datacenter

Continue reading

Hiding the User List on the Ubuntu Login Screen

In this post, I’m going to share how to hide the user list on the login screen for Ubuntu 16.04. The information here isn’t necessarily new or ground-breaking; however, in searching for the solution myself I found a lot of conflicting information as to how this may or may not be accomplished. I’m publishing this post in the hopes of providing a bit more clarity around this topic.

I’ve verified that this procedure works on the desktop distribution of Ubuntu 16.04. Note also that this is probably not the only way of making this work; it’s likely there are other ways of accomplishing the same thing.

To make configuration changes to the login screen, you’ll want to add configuration files to /etc/lightdm/lightdm.conf.d. I used a single file to hide the user list and disable guest logins; presumably, you could use separate files for each configuration directive.

To disable the user list and disallow guest logins, add this content to a file in the etc/lightdm/lightdm.conf.d directory (I used the filename 00-hide-user-list.conf):

[SeatDefaults]
greeter-hide-users=true
greeter-show-manual-login=true
allow-guest=false

Once this file is in place, you’ll need to either restart your Ubuntu system, or restart the LightDM Continue reading

An Early Look at Ansible Container v0.3.0

The Ansible Container project is targeting mid-January for its next release, and so we thought now would be a good time to check in and look at the features actively under development and anticipated to ship.

With only a glance at the roadmap page, the casual visitor may think it seems a bit smallish, having only three items. However, the items represent features that are important to the project, and require a level of effort that’s anything but small, as we’ll see.

Building container images

The first item up is an image build cache. Building container images is of course a core function of the tool, and having a caching mechanism can improve the speed at which images are built.

If you’re not familiar with container images and how they’re built, think of an image as a tall building with dozens of floors, where each floor is layered on top of the previous floor, starting with the building’s foundation, and adding one floor or layer at a time until you reach the top. In the same way, a container image is a file system built in layers.

The build process starts with a base image, say Fedora 25, Continue reading

More details about containerd, Docker’s core container runtime component

Today we announced that Docker is extracting a key component of its container platform, a part of the engine plumbing–containerd a core container runtime–and commits to donating it to an open foundation. containerd is designed to be less coupled, and easier to integrate with other tools sets. And it is being written and designed to address the requirements of the major cloud providers and container orchestration systems.

Because we know a lot of Docker fans want to know how the internals work, we thought we would share the current state of containerd and what we plan for version 1.0. Before that, it’s a good idea to look at what Docker has become over the last three and a half years.

The Docker platform isn’t a container runtime. It is in fact a set of integrated tools that allow you to build ship and run distributed applications. That means Docker handles networking, infrastructure, build, orchestration, authorization, security, and a variety of other services that cover the complete distributed application lifecycle.

The core container runtime, which is containerd, is a small but vital part of the platform. We started breaking out containerd from the rest of the engine in Docker 1.11, Continue reading

containerd – a core container runtime project for the industry

Today Docker is spinning out its core container runtime functionality into a standalone component, incorporating it into a separate project called containerd, and will be donating it to a neutral foundation early next year. This is the latest chapter in a multi-year effort to break up the Docker platform into a more modular architecture of loosely coupled components.

Over the past 3 years, as Docker adoption skyrocketed, it grew into a complete platform to build, ship and run distributed applications, covering many functional areas from infrastructure to orchestration, the core container runtime being just a piece of it. For millions of developers and IT pros, a complete platform is exactly what they need. But many platform builders and operators are looking for “boring infrastructure”: a basic component that provides the robust primitives for running containers on their system, bundled in a stable interface, and nothing else. A component that they can customize, extend and swap out as needed, without unnecessary abstraction getting in their way. containerd is built to provide exactly that.

What Docker does best is provide developers and operators with great tools which make them more productive. Those tools come from integrating many different components into a Continue reading

Installing Ansible 2.2 on Ubuntu 16.04

A few weeks ago I wrote a post about installing Ansible 2.2 on Fedora 25; today, I’d like to tackle what’s involved in installing Ansible 2.2 on Ubuntu 16.04. This post, like its Fedora counterpart, stems from my ongoing evaluation of Linux distributions and desktop environments. While the information here is very similar to the information in the Fedora post, I’m putting it in its own post in the hopes of making the information easier for readers to find.

It’s not really a secret that I like to run Ansible in a Python virtualenv, but I don’t believe that it will make any difference to the procedure described in this post. The errors that result when trying to install Ansible 2.2 without the necessary prerequisite packages should be the same either way (in a virtualenv or not). However, I’m happy to be corrected if someone knows otherwise.

To create a Python virtualenv, you’ll first need virtualenv installed. I prefer to install virtualenv globally for all users using this command:

sudo -H pip install virtualenv

Alternately, you could install it via a package, with apt install virtualenv. As far as I can tell, either approach Continue reading

‘Tis the Season to Decorate Your Playbook

The holidays are upon us. And while we can't automate your gift wrapping, we can make your Playbook more festive.

Introducing Ansible holiday-themed cowsay!

Copy and paste this code:

---
curl "https://gist.githubusercontent.com/jlaska/14bc829af01526add07efcaa83582aaf/raw/5f4918be06ffa69ea848354c5563c6a2d7b59807/happy_holidays.sh" | bash

Decorations are popping up everywhere so why not in your Playbook?

Share your designs with #AnsibleCowsay @ansible

Tweet #AnsibleCowsay

Ascii sources: chris.com and ascii-code.com

Convert ASP.NET Web Servers to Docker with Image2Docker

A major update to Image2Docker was released last week, which adds ASP.NET support to the tool. Now you can take a virtualized web server in Hyper-V and extract a Docker image for each website in the VM – including ASP.NET WebForms, MVC and WebApi apps. 

Image2Docker is a PowerShell module which extracts applications from a Windows Virtual Machine image into a Dockerfile. You can use it as a first pass to take workloads from existing servers and move them to Docker containers on Windows.

The tool was first released in September 2016, and we’ve had some great work on it from PowerShell gurus like Docker Captain Trevor Sullivan and Microsoft MVP Ryan Yates. The latest version has enhanced functionality for inspecting IIS – you can now extract ASP.NET websites straight into Dockerfiles.

In Brief

If you have a Virtual Machine disk image (VHD, VHDX or WIM), you can extract all the IIS websites from it by installing Image2Docker and running ConvertTo-Dockerfile like this:

Install-Module Image2Docker
Import-Module Image2Docker
ConvertTo-Dockerfile -ImagePath C:\win-2016-iis.vhd -Artifact IIS -OutputPath c:\i2d2\iis

That will produce a Dockerfile which you can build into a Windows container image, using docker build.

How It Works

The Image2Docker Continue reading

DockerCon 2017: Registration And CFP Now Open!

DockerCon 2017 tickets are now available! Take advantage of our lowest pricing today – tickets are limited and Early Bird will sell out fast! We have extended DockerCon to a three-day conference with repeat sessions, hands-on labs and summits taking place on Thursday.

Register for DockerCon

The DockerCon 2017 Call for Proposals is open! Before you submit your cool hack or session proposals, take a look at our tips for getting selected below. We have narrowed the scope of sessions we’re looking for this year down to Cool Hacks and Use Cases. The deadline for submissions is January 14, 2017 at 11:59 PST.

Submit a talk

Proposal Dos:

Submitting a Cool Hack:

Be novel

Show us your cool hacks and wow us with the interesting ways you can push the boundaries of the Docker stack. Check out past audience favorites like Serverless Docker, In-the-air update of a drone with Docker and Resin.io and building a UI for container management with Minecraft for inspiration.

Be clear

You do not have to have your hack ready by the submission deadline, rather, plan to clearly explain your hack, what makes it cool and the technologies you will use.

All Continue reading

Docker for Azure Public Beta

Last week Docker for AWS went public beta, and today Docker for Azure reached the same milestone and is ready for public testing. Docker for Azure is a great way for ops to setup and maintain secure and scalable Docker deployments on Azure.

With Docker for Azure, IT ops teams can:

• Deploy a standard Docker platform to ensure teams can seamlessly move apps from developer laptops to Dockerized staging and production environments, without risk of incompatibilities or lock-in.
• Integrate deeply with underlying infrastructure to ensure Docker takes advantage of the host environment’s native capabilities and exposes a familiar interface to administrators.
• Deploy the platform to all the places where you want to run Dockerized apps, simply and efficiently
• Make sure the latest and greatest Docker versions are available for the hardware, OSs, and infrastructure you love, and provide solid upgrade paths from one Docker version to the next.

To try the latest Docker for Azure beta based on the latest Docker Engine betas, click the button below or get more details on the beta site:

Installation takes a few minutes, and will give you a fully functioning swarm, ready to deploy and scale Dockerized apps.

We first unveiled the Docker for Continue reading

Tips for Troubleshooting Apps in Production with Docker Datacenter

If you have been using Docker for some time, after the initial phases of building Dockerfiles and running a container here and there, the real work begins in building, deploying and operating multi-container applications in a production environment.  Are you operationally ready to take your application to production? Docker Datacenter provides an integrated management framework for your Dockerized environment and applications and when coupled with clear strategies in approaching and resolving anomalies, IT ops teams can be assured in successfully operationalizing Docker.

Let’s use a sports metaphor to approach troubleshooting:

• Pre-Game will cover the planning phase for your applications
• Game Time will cover troubleshooting tools available in Docker Datacenter
• Post-Game will discuss complementary tools to aid in ongoing insights

Pre-Game

Whether or not you are sports fan, you can appreciate the importance of the planning out any task. This is no different than what you would do for your applications. Health checks are a great way to provide a deeper level of insight into how your application is performing. Since Docker 1.12 there is a new HEALTHCHECK directive. We can use this directive to signal to the Docker Engine whether or not the application is healthy.

There are a two ways to implement the HEALTHCHECK Continue reading

Learn Docker with More Hands-On Labs

Docker Labs is a rich resource for technical folks from any background to learn Docker. Since the last update on the Docker Blog, three new labs have been published covering Ruby, SQL Server and running a Registry on Windows. The self-paced, hands-on labs are a popular way for people to learn how to use Docker for specific scenarios, and it’s a resource which is growing with the help of the community.

New Labs

• Ruby FAQ. You can Dockerize Ruby and Ruby on Rails apps, but there are considerations around versioning, dependency management and the server runtimes. The Ruby FAQ walks through some of the challenges in moving Ruby apps to Docker and proposes solutions. This lab is just beginning, we would love to have your contributions.
• SQL Server Lab. Microsoft maintain a SQL Server Express image on Docker Hub that runs in a Windows container. That image lets you attach an existing database to the container, but this lab walks you through a full development and deployment process, building a Docker image that packages your own database schema into an image.
• Registry Windows Lab. Docker Registry is an open-source registry server for storing Docker images, which you can run Continue reading

Using OVN with KVM and Libvirt

In this post, I’m going to discuss how to use OVN (Open Virtual Network; part of the Open vSwitch project) with KVM and Libvirt to provide virtual networking for KVM-based virtual machines. This post will build on some concepts around OVS and Libvirt that I’ve discussed previously; be sure to review the OVS posts and Libvirt posts on this site for more details and prerequisite knowledge.

I’ll structure this discussion around 2 key steps:

1. Setting up OVN
2. Integrating KVM/Libvirt into OVN

Note that I’m not going to discuss setting up KVM/Libvirt, as that’s something I’ve covered previously and is well-documented.

Ready? Let’s jump in!

Setting up OVN

The biggest “challenge” here is package availability—many Linux distributions don’t have packages available for OVS 2.6.0, which is the first release with non-experimental support of OVN. If you’re an Ubuntu user, then you can use the Ubuntu Cloud Archive for the OpenStack “Newton” release, which includes OVS/OVN 2.6.0 packages. For other distributions, you’ll probably need to compile from source. In that case, the OVS installation documentation is quite accurate and usable.

For the purposes of this post, I’ll assume you’re using Ubuntu 16.04 and will pull packages Continue reading

Technology Short Take #74

Welcome to Technology Short Take #74! The end of 2016 is nearly upon us, and it looks as if there will be only one more Technology Short Take before the end of the year. So, let’s get on with the content—time is short!

Networking

• If you haven’t heard of Apstra, David Varnum has a great introduction to Apstra available on his site.
• Will Robinson talks about how to structure your Ansible playbooks in the context of using Ansible to control your network gear.
• This is an interesting project to watch, I think—it’s porting OVN (Open Virtual Network) from a “traditional” OvS back-end to an IOVisor-based back-end (IOVisor implements the data plane in eBPF).
• If you’re interested in playing around with OVN, I’ve built a Vagrant-based environment running OVS/OVN 2.6.0 on Ubuntu 16.04. Have a look here.

Servers/Hardware

Nothing this time, but I’ll stay alert for content to include in the future.

Security

• Jake Bennett discusses strengthening your AWS security posture by protecting application credentials and rotating EC2 and IAM keys.
• Gert van Dijk has a great article on upgrading your SSH keys to take advantage of new key types and enhanced security.
• In case you’re interested, here’s Continue reading

Get all the Docker talks from Tech Field Day 12

As 2016 comes to a close, we are excited to have participated in a few of the Tech Field Day and inaugural Cloud Field Day events to share the Docker technology with the IT leaders and evangelists that Stephen Foskett and Tom Hollingsworth have cultivated into this fantastic group.  The final event was Tech Field Day 12 hosting in Silicon Valley.

In case you missed the live stream, check out videos of the sessions here.

Session 1: Introduction to Docker and Docker Datacenter

Session 2: Securing the Software Supply Chain with Docker

Session 3: Docker for Windows Server and Windows Containers

Session 4: Docker for AWS and Azure

Session 5: Docker Networking Fabric

These are great overviews of the Docker technology applied to enterprise app pipelines, operations, and  diverse operating systems and cloud environments. And most importantly, this was a great opportunity to meet some new people and get them excited about what we are excited about.

+1!!! #TFD12 #Docker https://t.co/Zdsuw1emlo

— Alex Galbraith (@alexgalbraith) November 17, 2016

Visit the Tech Field Day site to watch more videos from previous events, read articles written by delegates or view the conversation online.

New #Docker videos from #TFD12 @TechFieldDay w/ @SFoskett @GestaltIT Continue reading