21 open source DevOps tools (and what they do)

🔨 Build and packaging tools

First let’s take a look at some tools for building and packaging software. These tools help you build or share code.

A build tool helps you package an application into a format which is ready to deploy onto a server, or into the cloud. More and more people are using containers as a packaging format, and Docker helps with that.

Also included in this category are tools which help you to share libraries and packages.

Git

Git is a tool for managing, sharing and tracking changes in source code files.

Initial release	2005
License	GPL v2.0
Download link	Download (for Mac/Windows/Linux), or install on Linux via your package manager
Source code	https://github.com/git/git

Of all of these DevOps tools, Git is probably the most well-known and widely-used, so it makes sense for us to start our list here!

Git is a tool for storing and tracking changes in code. It started life as a tool to help Linux developers manage the Linux source code¹. But it since grew to much more than that. It’s the de facto way to store code. Over 93% of developers use Git².

On Linux, install the git package, and you can start working with Git right away at the command line. Or, on Windows, you can install Git for Windows. There are also lots of graphical Git tools, the most popular is

RECOMMENDED: A Git branching strategy for microservices

What can you do with Git?

• You can store code (in something called a repository). You can “rewind” your code to a previous version, and show the differences between versions – and do this all entirely on your local computer.

• You can create repositories to manage your many different software projects independently of each other.

• When you’re ready to share code with others, you can share your Git repository, including all of its history, on a Linux server.

• It’s even easier to share your code with others if you use an online Git repository hosting service, like GitHub, GitLab or Bitbucket.

Docker

Docker is a toolkit for building and running software in containers.

Initial release	2013
Backed by	Docker, Inc.
License	Apache 2.0
Download link	Docker Desktop (for Windows/Mac desktops), Docker Engine (for Linux)
Source code	https://github.com/moby/moby

You can use Docker to run applications in containers, build your own Docker container images, or find and download images that have been published by other people.

On your desktop, the best way to get started is to install Docker Desktop. Or on a server, you can install Docker Engine.

We’ve got a guide to containers if you want to understand more about containers and what they do!

What types of things can you do with Docker?

• As a desktop user… you can use one of Docker’s tools (like Docker Desktop) to run applications that have been packaged into container form. There are thousands of container images available in Docker Hub.

• As a developer, you can use Docker to build a container image for your own application, and share the image with others.

• As a server administrator, you can use Docker to run applications in containers, whether that’s apps from your developers, or third-party apps like MySQL.

Packer

Packer lets you create virtual machine images from code.

Initial release	June 2013
Backed by	Hashicorp, Inc.
Written in	Go
License	Mozilla Public Licence 2.0
Download link	https://www.packer.io/downloads
Source code	https://github.com/hashicorp/packer

Packer helps you to follow the DevOps practice of “infrastructure-as-code” when you’re working with virtual machines. Traditionally, it hasn’t been so easy to create virtual machine images, because it involved some manual work, or pointing-and-clicking. That’s not easily repeatable.

With Packer, you can create virtual machine images repeatably by writing scripts.

Packer is also extensible through plugins. You can use a variety of provisioners to configure your virtual machines, like PowerShell or Ansible. And you can use a variety of builders to package your virtual machine into one of many formats, like Amazon EC2 or VirtualBox.

What types of things can you do with Packer?

• You can create a custom virtual machine image, containing an operating system, and all of the software that you want, installed and configured with code.

• Once you’ve created your image with Packer, you can upload it to your cloud provider, and use it to create new virtual machines. Packer supports many of the image formats used by the cloud providers, like AWS’s AMI format.

• You might use Packer to create so-called golden images, which are virtual machine images that are customised for your company’s environment. They might have a certain configuration, or some security patches installed. Publishing and using golden images is often used to enforce standards within an organisation.

For a good technical introduction to Packer, check out Sarasa Gunawardhana’s blog on faun.pub.

Sonatype Nexus

Nexus is an artifact repository (or ‘artefact’ if you’re a Brit!).

Also known as	Nexus, Nexus3, Nexus Repository OSS
Initial release	2008
Backed by	Sonatype, Inc.
License	Eclipse Public Licence 1.0
Download link	https://www.sonatype.com/products/nexus-repository
Source code	https://github.com/sonatype/nexus-public

Jfrog Artifactory

Artifactory is an artifact repository.

It’s very similar to Nexus: it’s a bucket for storing software packages that are consumed or produced by your applications.

Also known as	Artifactory, Artifactory OSS, Jfrog
Initial release	Some time before 2010
Backed by	Jfrog, Ltd.
License	GNU Affero General Public License
Download link	https://jfrog.com/community/download-artifactory-oss/
Source code	https://releases.jfrog.io/artifactory/bintray-artifactory/org/artifactory/oss/jfrog-artifactory-oss/

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🎺 Application orchestration

These tools are designed to help you run applications, keep them up and running, and scale them up when you need to handle more load.

Kubernetes

Kubernetes is an orchestration tool for managing your applications running in containers.

Also known as	Kubernetes, K8s
Initial release	June 2014
Supported by	Google, Cloud Native Computing Foundation, plus many commercial vendors like Red Hat, IBM
Written in	Go
License	Apache License 2.0
Download link	https://kubernetes.io/releases/download/
Source code	https://github.com/kubernetes/kubernetes

As well as plain old “vanilla” Kubernetes, there are other distributions available. OKD is a distribution of Kubernetes which comes with extra features and DevOps tooling.

Nomad

Nomad is a tool for managing your applications, whether they run in containers or not.

Nomad can start and run instances of your applications on a cluster of servers.

Initial release	September 2015
Backed by	Hashicorp, Inc.
License	Mozilla Public Licence 2.0
Written in	Go, JavaScript
License	Apache License 2.0
Download link	https://www.nomadproject.io/
Source code	https://github.com/hashicorp/nomad

Docker Swarm

Docker Swarm is a tool for managing Docker containers running on a cluster of servers.

Initial release	2014
Backed by	Docker, Inc.
License	Apache 2.0
Written in	Go
Download link	https://docs.docker.com/get-docker/
Source code	https://github.com/moby/swarmkit

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🏗 Infrastructure automation

These tools are designed to automate the work involved in setting up infrastructure – this means things like servers, firewalls, network components, and so on.

Terraform

Terraform is a tool for creating and managing cloud resources with code.

Initial release	2014
Backed by	Hashicorp, Inc.
License	Mozilla Public Licence 2.0
Written in	Go
Download link	https://www.terraform.io/downloads
Source code	https://github.com/hashicorp/terraform

Ansible

Ansible is a tool for automatic configuration of infrastructure - e.g. installing packages, configuring web servers, creating user accounts, and so on.

Initial release	2012
Backed by	Red Hat
License	GPL 3.0
Written in	Python
Installation instructions	https://docs.ansible.com/ansible/latest/installation_guide/intro_installation.html
Source code	https://github.com/ansible/ansible

RECOMMENDED: How to run an Ansible playbook

Pulumi

Pulumi is a tool for creating and managing infrastructure in the cloud.

To create infrastructure with Pulumi, you use the Pulumi API for your preferred programming language – available for Python, Go, JavaScript and C# – and Pulumi creates your services in the cloud for you.

Initial release	2019
Backed by	Independent start-up
License	Apache 2.0 License
Written in	Go (+ others)
Installation instructions	https://www.pulumi.com/docs/get-started/install/
Source code	https://github.com/pulumi/pulumi

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⛳ CI/CD

GitLab

GitLab is a tool for managing application source code and automating the build and release of your application.

GitLab’s built-in CI/CD feature lets you create workflows to build, test and deploy your applications.

Initial release	October 2011
Backed by	Independent start-up
License	MIT
Written in	Ruby, JavaScript
Installation instructions	https://about.gitlab.com/install/
Source code	https://gitlab.com/gitlab-org/gitlab

Jenkins

Jenkins is an automation server for running software build and testing jobs, and much more.

Jenkins is a bit of a stalwart and has a mixed following. (Some people love it, some people hate it!)

Initial release	February 2011, a fork of the Hudson project from 2005
Backed by	CloudBees
License	MIT
Written in	Java
Download link	https://www.jenkins.io/download/
Source code	https://github.com/jenkinsci/jenkins

Tekton

Tekton is a tool for running pipelines inside Kubernetes.

With Tekton, you can create CI/CD pipelines on Kubernetes, to build, test and deploy your apps.

Initial release	2018
Backed by	Google, Red Hat
License	Apache 2.0
Written in	Go
Download link	https://tekton.dev/
Source code	https://github.com/tektoncd

Argo CD

Argo CD is a continuous delivery tool for Kubernetes, which uses the principle of GitOps.

GitOps is the principle of using Git as the single source of truth for application deployment information, and ensuring that the state of a cluster is the same as the state which is defined in Git.

Initial release	2018
Supported by	Red Hat, used in Red Hat OpenShift GitOps
License	Apache 2.0
Written in	Go
Download link	https://argoproj.github.io/cd/
Source code	https://github.com/argoproj/argo-cd

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🛂 Testing & quality

These tools help to run tests against your software, and ensure its quality.

Sonarqube

Sonarqube is a code-quality checking tool.

Initial release	2007
Backed by	SonarSource S.A
License	LGPL 2.0
Written in	Java
Download link	https://www.sonarqube.org/downloads/
Source code	https://github.com/SonarSource/sonarqube

Selenium

Selenium is a browser automation tool. It’s used to simulate interactions with websites, fetch information, and perform tests.

Initial release	2004
Backed by	Software Freedom Conservancy (non-profit)
License	Apache 2.0
Written in	Java, C#, JavaScript & others
Download link	https://www.selenium.dev/downloads/
Source code	https://github.com/SeleniumHQ/selenium

Cypress

Cypress is a testing tool for anything that runs in a browser.

With Cypress, you can write and run end-to-end tests for your web applications.

Initial release	~2015
Backed by	Independent
License	MIT
Download link	https://on.cypress.io/installing-cypress
Source code	https://github.com/cypress-io/cypress

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📈 Logging & monitoring

Prometheus

Prometheus is a monitoring and alerting toolkit.

Initial release	November 2012
Supported by	Cloud Native Computing Foundation, initially developed at SoundCloud
License	Apache 2.0
Written in	Go
Download link	https://prometheus.io/download/
Source code	https://github.com/prometheus/prometheus

Prometheus consists of a time-series database and some tools to collect metrics from applications or servers.

Grafana

Grafana is a dashboarding tool. It’s often used to show system and application stats, to make it easier to visualise what’s happening in a system.

Initial release	2014
Backed by	Grafana Labs
License	AGPL 3.0
Written in	TypeScript, Go
Download link	https://grafana.com/get/
Source code	https://github.com/grafana/grafana

Grafana lets you create visual dashboards to display data stored in different places. It supports lots of different types of data stores, from metrics tools like Prometheus, to databases like Postgresql.

Grafana runs on a server, and you create and view dashboards using any web browser.

What types of things can you do with Grafana?

• Create a dashboard to monitor your sourdough starter (with a little help from a temperature and humidity sensor!)

Elasticsearch

Elasticsearch is a search engine which is usually used to analyse log files and other huge archives of data.

Initial release	February 2010
Backed by	Elasticsearch B.V.
License	Server Side Public License
Written in	Java
Download link	https://www.elastic.co/downloads/elasticsearch
Source code	https://github.com/elastic/elasticsearch

Elasticsearch is often combined with Logstash and Kibana to gather logs from servers and applications, and produce dashboards. When these three tools are used together, it’s known as “the ELK stack”.

Elasticsearch is based on the Apache Lucene library.