Docker

A Practical Introduction to Docker Container Terminology
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Red Hat Software Collections 2.0 Docker images, Beta release

Joe Orton

I'm very happy to announce that Docker images based on collections from Red Hat Software Collections (RHSCL) 2.0 are in beta testing. The images are available from the Red Hat Container Registry, and we've got the set of collections for language, databases and web servers covered - a complete list is below. If you've not tried out the Docker package from RHEL7 Extras, you need to enable the Extras channel, install the docker page, and start the docker service; an...

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Can't We Just Run Boot2Docker in Production?

Scott McCarty (fatherlinux)

Background I’ve been working with the CTO of a online video game company to develop a container architecture for his business. The goal is to simplify the deployment of new applications as well as make it easier to go back and change code on older applications. The desired state is environmental parity across the infrastructure -- this will simplify the assignment of work on different applications to different developers. From developer laptops to production servers, the code will just work...

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Containers in the enterprise - Are you ready for this?

Matt (Stuempfle) Lyteson

So here's are deal: We've created what we're calling "PaaS-Containers" in our IT production environment. It consists of core technologies like RHEL Atomic Host, Kubernetes, and Docker along with supporting CI/CD components like Jenkins together as part of an offering that supports the end-to-end automated deployments of applications from a code-commit event through automated testing and roll-out through multiple environments (dev, QA, stage, prod). Oh, did I mention that it's also integrated with our enterprise logging and monitoring as well...

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Imagine this - the life of an image

Matt (Stuempfle) Lyteson

Imagine this: deploy an application from code-commit to qa, validate through automated testing, and then push the same image into production with no manual intervention, no outage, no configuration changes, and with full audibility through change records. A month-and-a-half ago, we formed a tiger team and gave them less than 90 days to do it. How? Build an end-to-end CI/CD environment leveraging RHEL Atomic 7.1 as the core platform and integrating with key technologies like git, Jenkins, packer.io, in a...

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Remote debugging with GDB

Gary Benson

This past few weeks I've been working on making remote debugging in GDB easier to use. What's remote debugging? It's where you run GDB on one machine and the program being debugged on another. To do this you need something to allow GDB to control the program being debugged, and that something is called the remote stub. GDB ships with a remote stub called gdbserver, but other remote stubs exist. You can write them into your own program too, which...

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Microservice principles and Immutability - demonstrated with Apache Spark and Cassandra

jay vyas

Containerizing things is particularly popular these days. Today we'll talk about the idioms we can use for containerization, and specifically play with apache spark and cassandra in our use case for creating easily deployed, immutable microservices. Note: This post is done using centos7 as a base for the containers, but these same recipes will apply with RHEL and Fedora base images. There are a few different ways to build a container. For example, for beginners, you can build a container...

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Creating custom Atomic trees, images, and installers - Part 2

Brent Baude

This blog is a continuation of " Creating custom Atomic trees, images, and installers - Part 1." In part one, we learned how to compose our own atomic trees and consume them in a guest. In part two, we will learn how to create our own disk images and installer media. Creating custom disk images As mentioned in the previous blog, the subcommand imagefactory can be used to create disk images. As of this writing, the imagefactory subcommand can output...

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JBoss on Docker At a Glance

Markus Eisele (@myfear)

If one thing survived all the New Year parties, it is Docker. It was hot at the end of 2014 and it looks like it is getting even hotter in 2015. And Red Hat is one of the key drivers behind the adoption of this amazing container technology. This is a short summary blog post about a bunch of resources to get you started with Java EE, WildFly and Microservices on Docker mostly collecting resources and information from the JBoss...

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Our 5 most popular developer posts in 2014

Mike Guerette

Here are five most read articles on developerblog.redhat.com in 2014 - be sure to read them: A Practical Introduction to Docker Containers, by Scott McCarty - 25,000 views Comprehensive Overview of Storage Scalability in Docker, by Jeremy Eder - 19,000 Why Python 4.0 won’t be like Python 3.0, by Nick Coghlan - 14,000 Red Hat Enterprise Linux 7 now Generally Available, 13,000 GCC Undefined Behavior Sanitizer – ubsan, by Marek Polacek, 10,000

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Running PHP FPM in Docker

Remi Collet

Use cases In Red Hat Enterprise Linux we support a variety of different versions of PHP. Sometimes users find they need to run a legacy application, requiring an older version of PHP, on a newer version of RHEL. Developers may want to develop an application on their Fedora Workstation and deploy it on a RHEL server or ensure it will be compatible with all available PHP versions in enterprise distributions. This example can be easily adapted for all PHP versions...

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Dockerfiles now available for Red Hat Software Collections

Joe Orton

We recently announced that we've made available a set of Dockerfiles for Red Hat Software Collections. We are making these available since we think they may be useful to customers looking to build more complex application containers on top of RHEL and RHSCL. We don't intend the Dockerfiles to produce useful standalone images which you'll immediately put in production - the Docker images which these create are very simple containers which give you RHEL plus the basic set of packages...

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Repost: Deploying a PostgreSQL Pod in OpenShift V3 – w/ Docker

Mike Guerette

An interesting article as OpenShift v3 introduces Docker containers. At Crunchy Data Solutions (Crunchy)we were excited to hear the recent announcement from the OpenShift team regarding the new public Origin repo integrating the work Red Hat has been doing for over twelve months in OpenShift Origin and related projects like Docker, Kubernetes, GearD and Project Atomic. Crunchy has been working with the OpenShift team for some time and witnessed the value proposition of combining PostgreSQL, a leading open source object...

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Introducing a *Super* Privileged Container Concept

Daniel Walsh

Letting the containers out of containment I have written a lot about *Containing the Containers*, e.g. * Are Docker containers really secure?* and * Bringing new security features to Docker*. However, what if you want to ship a container that needs to have access to the host system or other containers? Well, let's talk about removing all the security! Safely? Packaging Model I envision a world where lots of software gets shipped in image format. In other words, the application...

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Opensource.com - Bringing new security features to Docker

Daniel Walsh

In the first of this series on Docker security, I wrote "containers do not contain." In this second article, I'll cover why and what we're doing about it. Docker, Red Hat, and the open source community are working together to make Docker more secure. When I look at security containers, I am looking to protect the host from the processes within the container, and I'm also looking to protect containers from each other. With Docker we are using the layered...

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Opensource.com - Are Docker containers really secure?

Daniel Walsh

This article from opensource.com is based on a talk I gave at DockerCon this year. It will discuss Docker container security, where we are currently, and where we are headed. Containers do not contain I hear and read about a lot of people assuming that Docker containers actually sandbox applications—meaning they can run random applications on their system as root with Docker. They believe Docker containers will actually protect their host system. I have heard people say Docker containers are...

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Repost: OpenShift V3 Deep Dive - The Next Generation of PaaS w/ Docker

Mike Guerette

By Ben Parees There have been a lot of announcements lately around Red Hat’s OpenShift v3 plans, specifically around Docker and Kubernetes. OpenShift v3 is being built around the central idea of user applications running in Docker containers with scheduling/management support provided by the Kubernetes project, and augmented deployment, orchestration, and routing functionality built on top. This means if you can run your application in a container, you can run it in OpenShift v3. Let’s dig in and see just...

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Comprehensive Overview of Storage Scalability in Docker

Jeremy Eder

Backstory First, a brief backstory on the storage situation for Docker since it was open-sourced in early 2013. At that time, Docker relied on a filesystem called AUFS (advanced multi layered unification filesystem). This Union filesystem provided the necessary features to support several of Docker's main selling points: container creation speed copy-on-write image->container Docker still supports the AUFS backend, but Ubuntu has disabled it and moved the AUFS kernel module to linux-image-extra. The fact that AUFS never made it into...

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OpenCloud2014 slides: Linda Wang - Use Cases for Docker in Enterprise Linux Environment

Linda Wang

Abstract: Linux Container as a feature has been available for hobbyist usage for a while now; however, not only 'til recently where Docker, as a container deployment technolog, help built an open source community and gain wide adoption, has provided an easy way to deploy Linux Containers on the enterprise Linux. This talk will introduce and cover the various use cases and deployment models that are available and suited for enterprise devops work environment. By Linda Wang, Red Hat Sr...

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Performance Analysis of Docker on Red Hat Enterprise Linux 7

Jeremy Eder +1

Containers introduce some intriguing usability, packaging and deployment patterns. These new patterns offer the potential to effect massive improvements to the enterprise application development and operations specialties. Containers also offer the promise of bare metal performance while offering some amount of isolation as well. But can they deliver on that promise ? Since earlier this year, the Performance Engineering Group at Red Hat has run huge amounts of microbenchmarks, benchmarks and application workloads in Docker containers. The output of that...

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Getting Started with Kubernetes / Docker on Fedora

Scott Collier

******* EDIT This entry is out of date, I have moved the instructions to the Google Kubernetes github repo. END EDIT ******* These are my notes on how to get started evaluating a Fedora / Docker / kubernetes environment. I'm going to start with two hosts. Both will run Fedora rawhide. The goal is to stand up both hosts with kubernetes / Docker and use kubernetes to orchestrate the deployment of a couple of simple applications. Derek Carr has already...

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How Red Hat's Inception DevOps team utilized Docker for the Release Engine

Ryan Cook

As we have discussed in the past, Team Inception has been working on a release engine to automate RPM code deployments within Red Hat IT. On July 8 we passed a significant milestone by successfully using Release Engine in our QA environment. This was an incredible achievement which included a number of feature requests, defect fixes, and collaboration between multiple teams to produce an open source application that will a ddress growing needs internally in Red Hat IT . We...

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A practical introduction to Docker containers

Scott McCarty (fatherlinux) +1

Background Why Docker has quite an amount of buzz around it today because it makes so many things easy that were difficult with virtual machines. Docker containers makes it easy for Developers, Systems Administrators, Architects, Consultants and others to quickly test a piece of software in a container; much quicker than a virtual machine, and using less resources. The average command in Docker takes under a second to complete. [root@keith]# time docker run fedora cat /etc/redhat-release Fedora release 20 (Heisenbug)...

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Moving an RHSCL app to Docker on Atomic

Langdon White

As many of you have probably heard, Red Hat announced a new " Docker server" at Summit. The new server is called "Atomic" and details can be found at the project home page. As you all know, I tend to be interested in using Software Collections to ensure the portability of applications. So, putting my foot^W money where my mouth is, I decided to download Atomic, run it as a VM, create a Docker image with a Software Collection, and...

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Running systemd within a Docker Container

Daniel Walsh

UPDATE: Read the new article " How to run systemd in a container" for the latest information. I have been working on Docker for the last few months, mainly getting SELinux added to help CONTAIN Containers. libvirt-sandbox – virt-sandbox-service For the last couple of years I was working on a different container technology using libvirt-lxc, in addition to my regular SELinux job. I built the virt-sandbox-service tool which would carve up your host system into a bunch of service containers...