Cleaning up old git branches

We make heavy use of puppet environments in our workflow. Using r10k, git branches are magically mapped to environments. This allows a process where anyone one the team can individually work on a new feature or change, and then we can collaborate and review/revise/test in a controlled manner. We can rebase to the production branch, and use the diff output as part of our change-management documentation. Once the change is merged, however, sometimes the original branch is not deleted....

March 11, 2021 · 2 min · Jason Lavoie

Terraform validate list object

Since version 0.13, terraform has support for custom validation rules for input variables. The example in the documentation shows how to test a single value: variable "image_id" { type = string description = "The id of the machine image (AMI) to use for the server." validation {# regex(...) fails if it cannot find a match condition = can(regex("^ami-", var.image_id)) error_message = "The image_id value must be a valid AMI id, starting with \"ami-\"....

March 8, 2021 · 1 min · Jason Lavoie
Terraform lock file error

Terraform providers lock

As of version 0.14, terraform now produces a .terraform.lock.hcl file to record which versions of dependencies – currently, just providers – were chosen when terraform init was run. They recommend adding this file to your version control system so that all future runs will use and verify those same dependencies. These can be manually upgraded by running terraform init -upgrade. I commonly will develop locally and generate the lock file on my Mac....

March 3, 2021 · 2 min · Jason Lavoie

Ensuring PXE at every boot

By default VMware virtual machines only PXE boot on first install. Once an operating system has been installed on the hard drive, it will boot that and never try to network boot again. This is due to the default BIOS boot order. By changing the boot order, they can be configured to try a network boot first and after a short timeout boot from disk. In the vSphere client, find the VM in question, and chose Edit Settings....

February 24, 2021 · 2 min · Jason Lavoie
example TextFSM template with syntax highlighting

Writing a vim syntax plugin

Motivation I was creating a TextFSM template, and was disappointed with the lack of syntax highlighting support for this filetype in my favorite text editor. Typically, this is just a plugin away, but an exhaustive search turned up nothing. So, like all good geeks, I rolled up my sleeves and made one myself. Process Over the years, I have written little snippets in my .vim/syntax/ directory, or added some missing syntax to someone else’s syntax plugin, but had never written one from scratch....

February 23, 2021 · 6 min · Jason Lavoie
PXEboot bootscreen

Start Puppet in Debian Preseed

I have a nice netboot setup where we can PXEboot hosts to an automated installer. The last step ensures the puppet agent is running and pointed at the correct puppetmaster. The .preseed files are generated from an erb template that ends in the following: [...] <% if @distcodename == "jessie" -%> d-i preseed/late_command string \ echo -e 'DAEMON_OPTS="--server <%= @puppetmaster %>"' > /target/etc/default/puppet ; \ rm -f /target/var/lib/puppet/state/agent_disabled.lock <% else -%> d-i preseed/late_command string \ in-target sed -i '/\[main\]/a server = <%= @puppetmaster %>' /etc/puppet/puppet....

February 19, 2021 · 1 min · Jason Lavoie
GitHub Drift Success

Terraform Drift Detection with GitHub Actions

The Problem A common issue with infrastructure as code, is that it is often possible for someone to go in after deployment and manually change things. I still want to preserve the ability for the infrastructure folks to go in and make emergency changes, but I also want to discourage this practice as much as possible. To this end, I’ve been using a pattern where any “out of band” changes are alerted to the rest of the team....

September 15, 2020 · 3 min · Jason Lavoie