Techology

We’re working to upgrade our infrastructure to Puppet 4 and are making use of the catalog preview tool to help identify code that needs to be updated. The preview tool in and of itself is handy, but the output it produces can be a bit daunting. During the “Getting to the Latest Puppet” talk at puppetconf they pointed out a tool that professional services uses to create a nice html version of the output. Naturally I got excited to use this, but discovered it doesn’t properly work with open source Puppet due to some hardcoded Puppet Enterprise paths. Fortunately it was only 3 lines to update! My fork is here if its useful to others. ...

I’ve poked a lot of fun at chatops but I have found some value in portions of the practice. Let me state upfront that I do not believe paying attention to the chat room all day and having your attention interrupted non-stop is a productive or healthy practice. I have found some big benefits to “chatops” however. Visibility Work that is done in the chatroom, or filtered into the chatroom, is visible to the whole team. This helps the team be aware of what others are doing and stay up to date. I’ve picked up on quite a few things from this that I wouldn’t have learned other wise. This is also why we choose to route a fair amount of notifications into chat. For example we have Jira connected to HipChat and it makes it really easy to stay on top of issues. We also push commit notifications, build notifications, etc in the chatroom. The downside to this is that the rooms get noisy and make it harder to follow actual conversations between humans. One strategy we use to combat that is creating multiple rooms and focusing them around a subject. ...

This is immensely useful, and has been a huge time saver. [gallery size=full columns=1] —Practical 365 “PowerShell is an efficient way to perform management tasks for Office 365, and also allows a great deal of automation through the use of PowerShell scripts to perform routine and repetitive tasks.” http://feeds.feedblitz.com//203571740/0/practical365Saving-Credentials-for-Office-PowerShell-Scripts-and-Scheduled-Tasks/

You have a directory with data, and now you’ve mounted a volume over it. How do you get to the data in the underlying directory without interrupting the mounted volume? Bind mount to the rescue! Bind mount the directory to another path and you can manipulate the files in underlying directory without disturbing the volume mounted atop of it.

While troubleshooting site to site links running OpenVPN recently I ran into an issue with MTU sizing on the ec2 end. When we originally setup the links we followed the performance tuning advice found here. The relevant portion is that we set tun-mtu 6000 Why did we do this? Here’s OpenVPN’s explanation By increasing the MTU size of the tun adapter and by disabling OpenVPN's internal fragmentation routines the throughput can be increased quite dramatically. The reason behind this is that by feeding larger packets to the OpenSSL encryption and decryption routines the performance will go up. The second advantage of not internally fragmenting packets is that this is left to the operating system and to the kernel network device drivers. For a LAN-based setup this can work, but when handling various types of remote users (road warriors, cable modem users, etc) this is not always a possibility. During later testing we discovered that we could easily push 40mb/s over the OpenVPN tunnel into the ec2 instance, but only 1mb/s or less going the opposite direction. Obviously not ideal. ...