Docker for Mac Tips for Troubleshooting Container Problems

I’ve used Docker for Mac since the Beta release opened to wider audiences. With the rapid prototyping I’m doing on Hadoop environments, I’m finding it great for providing quick environments to test out theories. Problem: How do you access the Docker for Mac VM? The problem with a black box is not being able to easily get inside […]

A followup on the strange stunnel behavior in docker

This is a quick followup to the strange stunnel behavior I was seeing that I wrote about previously. After discussing the issue with a colleague, we came up with two different solutions to this problem with stunnel writing to /dev/console inside a docker container. Indirect route with docker exec In his method, we invoke the container and […]

Strange stunnel debug logging behavior in docker

I’ve been playing with xenserver lately to quickly model small Hadoop clusters. One of the frustrating things about xenserver is the lack of good graphical user interfaces that provide for a minimal amount of automation. This means I’m frequently dropping to the command line on the xenserver master and running the xe tools by hand […]

Creating RPMS with fpm and docker

Now and again, you need to create RPMS of third-party tools, such as Python libraries or Ruby gems.  The most effective (and best!) way to do this is with fpm. Historically, I have built RPMS using a few dedicated virtual machines for CentOS5 and CentOS6-specific builds. These virtual machines have gotten crufty with all the various libraries installed. Wouldn’t it be nice to have […]

5-whys at Hubspot: an Introspective response

Ran across Post mortems at Hubspot: What I learned from 250 Whys today.  This is a good review of Hubspot’s experience with 5-whys to facilitate post-mortems. The part that most caught my eye was the idea that “slow down” probably should not be the initial response to development velocity and mistakes if you don’t also consider the cost […]

What’s in my datacenter tool kit?

Every Operations person or datacenter (DC) junkie that I know has a datacenter tool kit of some sort, containing their favorite bits of gear for doing work inside the cold, lonely world of the datacenter. Now, one would like to think that each company stocks the right tools for their folks to work, but tools […]

Rebooting Linux temporarily loses (some) limits.conf settings

Like any wildly managed environment, you probably have to create custom-defined settings in your /etc/security/limits.conf because of application specific requirements. Maybe you have to allow for more open files. Maybe you have to reduce the memory allowed to a process. Or maybe you just like being ultra-hardcore in defining exactly what a user can do. […]

Augeas made my grub.conf too quiet!

A reader contacted me after working through the examples in my last previous post on Augeas. He was having a difficult time figuring out how to add a valueless key back into the kernel command line. This was the opposite of what I was doing with quiet and rhgb Many thanks. I have been pounding […]

Using augeas and puppet to modify grub.conf

In my environment, we rely heavily upon Puppet to do large-scale automation and updating of our various systems. One of the tasks that we do on an infrequent basis is to modify grub.conf across many (or even all) systems to apply the same types of changes. In Puppet, there are several ways you can do […]

Followup on Cloudera HUE’s Kerberos kt_renewer

Just a short followup about the HUE kt_renewer issue I discovered. It turns out that the issue was me and not HUE. The fix turned out to be pretty simple once I saw the clue in a related issue. It seems like Cloudera Manager had the same issue. The problem ended up being a missing […]