Docker Archives - Red Hat Developer

Transitioning from Docker to Podman

By Cedric Clyburn November 19, 2020November 26, 2020

Podman is an excellent alternative to Docker containers when you need increased security, unique identifier (UID) separation using namespaces, and integration with systemd. In this article, I use real-world examples to show you how to install Podman, use its basic commands, and transition from the Docker command-line interface (CLI) to Podman. You’ll also see how to run an existing image with Podman and how to set up port forwarding.

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Introducing the Red Hat build of the OpenJDK Universal Base Images—now in Red Hat Enterprise Linux 8.2

By Ezequiel Aguilar and Jonathan Dowland June 25, 2020June 25, 2020

With the recent release of Red Hat Enterprise Linux 8.2, we also added the first Red Hat build of OpenJDK Universal Base Images. These General Availability (GA) images for OpenJDK 8 and OpenJDK 11 set a new baseline for anyone who wants to develop Java applications that run inside containers in a secure, stable, and tested manner.

In this article, we introduce the new OpenJDK Universal Base Images and explain their benefits for Java developers. Before we do that, let’s quickly review what we know about UBIs in general.

About Universal Base Images

Red Hat Universal Base Images (UBIs) are:

OCI-compliant container base operating system images with complementary runtime languages and packages that are freely redistributable. Like previous base images, they are built from portions of Red Hat Enterprise Linux (RHEL). UBI images can be obtained from the Red Hat container catalog and be built and deployed anywhere.

In other words, UBIs help application developers reach the secure, stable, and portable world of containers. These images are accessible using well-known tools like Podman/Buildah and Docker. Red Hat Universal Base Images also allow users to build and distribute their own applications on top of enterprise-quality bits that are supportable on Red Hat OpenShift and Red Hat Enterprise Linux.

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Use Node.js 14 on Red Hat OpenShift

By Lucas Holmquist May 21, 2020June 26, 2020

On April 21st, Node.js released its latest major version with Node.js 14. Because this is an even-numbered release, it will become a Long Term Support (LTS) release in October 2020. This release brings a host of improvements and features, such as improved diagnostics, a V8 upgrade, an experimental Async Local Storage API, hardened the streams APIs, and more.

While Red Hat will release a Universal Base Image (UBI) for Node.js 14 in the coming months for Red Hat OpenShift and Red Hat Enterprise Linux, this article helps you get started today. If you’re interested in more about Node.js 14’s improvements and new features, check out the article listed at the end.

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Open Liberty 20.0.0.5 brings updates to EJB persistent timers coordination and failover across members

By Tom Jennings May 13, 2020June 26, 2020

In Open Liberty 20.0.0.5, you can now configure failover for Enterprise JavaBeans (EJB) persistent timers, load Java Authentication and Authorization Service (JAAS) classes directly from the resource adapter, format your logs to JSON or dev, and specify which JSON fields to leave out of your logs. In this article, we will discuss each of these features and how to implement them.

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Red Hat Universal Base Images for Docker users

By Fernando Lozano March 24, 2020September 15, 2020

Red Hat Universal Base Images (UBIs) allow developers using Docker on Windows and Mac platforms to tap into the benefits of the large Red Hat ecosystem. This article demonstrates how to use Red Hat Universal Base Images with Docker from a non-Red Hat system, such as a Windows or Mac workstation.

Red Hat Enterprise Linux and Docker

When Red Hat Enterprise Linux (RHEL) 8 was released almost a year ago, and it came with lots of new features related to containers. The biggest ones were the new container tools (Podman, Buildah, and skopeo) and the new Red Hat Universal Base Images. There was also confusion because RHEL 8 dropped support for the Docker toolset. Some developers thought that they could not work with Docker anymore, and had to either migrate to a Red Hat-ecosystem Linux system such as CentOS or stay away from Red Hat customers.

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Introduction to Eclipse JKube: Java tooling for Kubernetes and Red Hat OpenShift

By Rohan Kumar January 28, 2020October 28, 2020

We as Java developers are often busy working on our applications by optimizing application memory, speed, etc. In recent years, encapsulating our applications into lightweight, independent units called containers has become quite a trend, and almost every enterprise is trying to shift its infrastructure onto container technologies like Docker and Kubernetes.

Kubernetes is an open source system for automating deployment, scaling, and management of containerized applications, but it has a steep learning curve, and an application developer with no background in DevOps can find this system a bit overwhelming. In this article, I will talk about tools that can help when deploying your Maven applications to Kubernetes/Red Hat OpenShift.

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Using Kubernetes ConfigMaps to define your Quarkus application’s properties

By Sébastien Blanc January 23, 2020June 29, 2020

So, you wrote your Quarkus application, and now you want to deploy it to a Kubernetes cluster. Good news: Deploying a Quarkus application to a Kubernetes cluster is easy. Before you do this, though, you need to straighten out your application’s properties. After all, your app probably has to connect with a database, call other services, and so on. These settings are already defined in your application.properties file, but the values match the ones for your local environment and won’t work once deployed onto your cluster.

So, how do you easily solve this problem? Let’s walk through an example.

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Best practices for running Buildah in a container

By Daniel Walsh August 14, 2019October 17, 2019

One of the cool things about separating the container runtimes into different tools is that you can start to combine them to help secure one other.

Lots of people would like to build OCI/container images within a system like Kubernetes. Imagine you have a CI/CD system that is constantly building container images, a tool like Red Hat OpenShift/Kubernetes would be useful for distributing the load of builds. Until recently, most people were leaking the Docker socket into the container and then allowing the containers to do docker build. As I pointed out years ago, this is one of the most dangerous things you can do. Giving people root access on the system or sudo without requiring a password is more secure than allowing access to the Docker socket.

Because of this, many people have been attempting to run Buildah within a container. We have been watching and answering questions on this for a while. We have built an example of what we think is the best way to run Buildah inside of a container and have made these container images public at quay.io/buildah.

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Working with Red Hat Enterprise Linux Universal Base Images (UBI)

By Fernando Lozano May 31, 2019September 23, 2019

If you’re like me—a developer who works with customers who rely on the tried-and-true Red Hat Enterprise Linux (RHEL), works with containerized applications, and also prefers to work with Fedora Linux as their desktop operating system—you’re excited by the announcement of the Universal Base Images (UBI). This article shows how UBI actually works, by building the container image for a simple PHP application.

With UBI, you can build and redistribute container images based on Red Hat Enterprise Linux without requiring a Red Hat subscription. Users of UBI-based container images do not need Red Hat subscriptions. No more extra work creating CentOS-based container images for your community projects or for your customers that prefer self-support.

I tested all these steps on my personal Fedora 29 system, and they should work on any Linux distribution. I am also a big fan of the new container tools such as Podman, which should be available to your favorite Linux distribution. If you are working on a Windows or MacOS system, you can replace the Podman commands with Docker.

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2 tips to make your C++ projects compile 3 times faster

By Konrad Kleine May 15, 2019September 3, 2019

In this article, I will demonstrate how to speed up your compilation times by distributing compilation load using a distcc server container. Specifically, I’ll show how to set up and use containers running a distcc server to distribute the compilation load over a heterogeneous cluster of nodes (development laptop, old desktop PC, and a Mac). To improve the speed of recompilation, I will use ccache.

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Blog Articles

About Universal Base Images

Red Hat Enterprise Linux and Docker