Development

Using Make for SysAdmin Tasks

Aug 8, 2019

When most people hear about make they think of compiling source code. While that is often what it’s used for, there are other good uses as well. Here’s an example of using it with Terraform/Ansible to build your infrastructure. Make has some advantages over just using a shell script. One is the native concept of dependencies. You can easily define which targets are dependencies of other targets. Make also has some idempotence baked in (as long as everything isn’t a phony target).

Ansible Modules with Go

Jun 6, 2019

Since Ansible 2.2 you can use binary applications as modules for Ansible. This means you can write modules in languages other than Python. The downside is that the modules aren’t integrated as well as if they were written in Python with Ansiballz. The binary modules only takes the filename as an argument which is a temporary file containing the JSON data of the modules parameters. I took the boilerplate code that Ansible had here and created a small module to generate a random password.

Ansible and Jenkins Remote Triggers

Jun 6, 2019

Ansible Tower has an awesome feature that I’ve talked about before called provisioning callbacks. It’s hard to beat their simplicity, one click of a button and you have an API endpoint and a key to use. However you can replicate this in Jenkins with just about the same amount of work. Coming from using both Tower and Jenkins, I currently prefer to use Jenkins. I find it a little more flexible.

Transient Playbooks for Ansible

Jun 6, 2019

So I had a unique scenario where we built a solution for users using Ansible but wanted to make it simple so that it didn’t require the end users to understand how to build an inventory or playbooks. So the solution we came up with was to build Ansible playbooks and inventories with Ansible itself. The users just need a single YAML file and then run a make command and Ansible builds itself the inventory, playbooks, and group_vars at run time.

Goniq

May 5, 2019

In my journey to better my development skills I’ve been trying to write some small Go applications. I needed a sorter like uniq but on a Windows machine for a project I was doing. So I decided to write one. Unlike uniq the input does not need sorted beforehand. The program takes either stdin or can read from a file which is passed as the first argument. inputs stdin file 1

Nomad

Jul 7, 2018

Nomad is a job scheduler created by Hashicorp. Since it’s written in Go, it’s a single, cross platform, statically linked binary. It has drivers for Docker, Qemu, Rkt, Java, App execution, and a beta for LXC. I’ll just go over the exec driver in this post. To start you need to download Nomad from here. I stuck it in /usr/local/bin. I used Vagrant to bring up a server and two clients.

XFS Deduplication with Reflinks

Mar 3, 2018

Reflinks for XFS are available in Fedora 27, so you no longer need to pull and compile xfsprogs from git. To leverage reflinks in XFS, you need to create a file system with the reflink=1 flag. [[email protected] mnt]# mkfs.xfs -m reflink=1 filesystem In my example I just created a file and mounted it on a loop device. [[email protected] mnt]# mkfs.xfs -m reflink=1 test.img Then I’ll mount it [[email protected] mnt]# mount -o loop test.

Directory Server using Go

Feb 2, 2018

I’ve been spending time learning Go and here’s a small utility I wrote that’s similar to Python’s SimpleHTTPServer. This utility just creates a small HTTP server serving the directory you define: package main import ( "log" "net/http" "os" ) func main() { if len(os.Args) < 2 { log.Fatal("You must enter a path") } path := os.Args[1] http.Handle("/", http.FileServer(http.Dir(path))) http.ListenAndServe(":8000", nil) } Then just do: go build main.go ./serve /etc

Create VMs on KVM with Ansible

Oct 10, 2017

So the Ansible virt module doesn’t have a clone option and the creation of guests is a little limited. Because of this we have to use the shell or command modules and try to make them idempotent. This is a simple example and the dictionary can be expanded to a lot more customization. There is a way to use libvirt as a dynamic inventory and set group and host vars on guests, but I’ll cover that in a different post.

Automated Ansible Testing with Molecule

Sep 9, 2017

Infrastructure testing provides some challenges just because of the mere fact you are building machines and not just compiling code. To test Ansible, I used to run Ansible with --syntax-check and --list-tasks. For roles I would run local tests with Vagrant using the tests/ directory in the role. The tests had Ansible test itself with the uri module or other checks. This is ok for simple checks but can be cumbersome and time consuming as it doesn’t catch everything.

Goniq

John Hooks

Using Make for SysAdmin Tasks

Ansible Modules with Go

Ansible and Jenkins Remote Triggers

Transient Playbooks for Ansible

Goniq

Nomad

XFS Deduplication with Reflinks

Directory Server using Go

Create VMs on KVM with Ansible

Automated Ansible Testing with Molecule