PODMAN: ‘overlay’ is not supported over xfs

I *love* Podman. While Podman purports to be a way to test and troubleshoot Pods - "the smallest deployable units of computing that can be created and managed in Kubernetes" - where its real value lies for me and my coworkers is as a non-root, daemonless, drop-in replacement for Docker. We can run containers on … Continue reading PODMAN: ‘overlay’ is not supported over xfs

ERROR: could not find an available, non-overlapping IPv4 address pool

Creating network "" with the default driver ERROR: could not find an available, non-overlapping IPv4 address pool among the defaults to assign to the network This appears to be related to the number of IP addresses reserved for Docker networks. On my laptop, it looks like 31 is the magic number (a /27 subnet, perhaps?). … Continue reading ERROR: could not find an available, non-overlapping IPv4 address pool

Buildah: A new way to build container images

Project Atomic's new tool, Buildah, facilitates new ways to build container images A previous post covered a few different strategies for building container images. The first, building container images in place, is what everyone is familiar with from a traditional Docker build. The second strategy, injecting code into a pre-built image, allows developers to add … Continue reading Buildah: A new way to build container images

[UPDATE] Disk partition scheme for RHEL Atomic Hosts

Back in February of this year, I wrote a short piece about the partition scheme I was considering for our RHEL Atomic Host systems at work.  Six months on, I've got some real-world experience with the scheme - and it's time to re-think some things. Most of the assumptions remain valid from the last outing in this … Continue reading [UPDATE] Disk partition scheme for RHEL Atomic Hosts

Disk partition scheme for RHEL Atomic Hosts

I've been working on what will likely be the production disk partition system for our RHEL Atomic Host systems at work.  There's a bit of a balancing act to this setup, with three things to take into consideration. First, since these are Atomic hosts, most of the system is made up of a versioned filesystem tree … Continue reading Disk partition scheme for RHEL Atomic Hosts

Quick Tip – Docker ENV variables

It took me a little while to notice what was happening here, so I'm writing it down in case someone else needs it. Consider this example Dockerfile: FROM centos:centos7 MAINTAINER Chris Collins ENV VAR1="foo" ENV VAR2="bar" It's common practice to collapse the ENV lines into a single line, to save a layer: FROM centos:centos7 MAINTAINER Chris … Continue reading Quick Tip – Docker ENV variables