Best of 2021 – 11 Open Source DevOps Tools We Love For 2021

As we head into 2021, we at wanted to highlight the most popular articles of the year. Here is the eighth installment in our Best of 2021 series.

DevOps isn’t just a cultural shift – it requires great tools to pay off. Below, we have compiled a list of some of the most popular DevOps tools available today. But, spending a lot of money on fancy SaaS solutions can quickly eat up your cloud budget. All of these DevOps tools are open source, and enable everything from container builds and orchestration to microservice networking, configuration management, CI/CD automation, full monitoring and more. Here are some of our favorite open source DevOps tools for 2021.

With the proliferation of microservices and container-based software, it’s no surprise that Kubernetes tops the list of open source DevOps tools this year. Kubernetes, whose adoption rate increased by 48% in 2020, is used to orchestrate containers. Instead of manually releasing microservices, Kubernetes can automate the deployment, maintenance, and scaling of container clusters in production. Kubernetes, sometimes written as K8s, is hosted by the Cloud-Native Computing Foundation (CNCF).

Docker, the software, is a free and open source platform used to build, ship, and run an application as a lightweight container. Containers package the binaries, libraries, configuration files, and dependencies required to run the program. Over the past decade, containers have played a major role in rapid development, and Docker containers have led the revolution. At its core is the Docker Engine. The Docker Hub is also an excellent resource for finding and sharing prepackaged jobs as containers. Also, to bridge vulnerabilities in a container, it may be useful to use open source container auditing tools such as Docker Bench or Achore.

Microservices are a useful development technique, but they bring new development and engineering interests. Specifically, how do we apply network policies such as security, encryption, monitorability, and telemetry elements consistently across all of our services? Well, service network is one answer. The service network places a proxy side next to each container and summarizes these networking capabilities into a level of control. Istio is an open source service network that has seen widespread adoption. Istio is built on Envoy, which opens it up to options for plugins and extensibility. We should also mention Linkerd and Kuma as viable open source service network alternatives.

GitHub is arguably the most popular source control and software collaboration platform on the planet. The GitHub platform itself, which is based on Git, has seen some significant updates in the past few years. Most notable is the possibility of GitHub Actions. GitHub actions enable software packages hosted on GitHub to accept input and run other processes. This could help automate some of the great DevOps workflows within GitHub, such as code reviews, branch management, or CI/CD operations – the combinations of possibilities here are endless. GitHub actions are, essentially, YAML files hosted in GitHub repositories that take advantage of GitHub webhooks. Although this is more of an advantage than an open source tool, we feel it is important to include it here. Actions are free for public repositories with a maximum of 100 actions.

A big part of DevOps’ philosophy is to find ways to more efficiently automate and deploy new iterations. Part of this goal is to create a simplified Continuous Integration (CI/CD) pipeline. Jenkins is an open source automation server that contains hundreds of plug-ins to automate building, deploying, and testing software projects. Although GitHub Actions could theoretically replace a CI server in the future, CI tools like Jenkins, CircleCI, TravisCI, and GitLab Community Edition are still preferred by many DevOps teams.

Measurements and alerting systems are essential for site reliability engineers to visualize applications and respond to problems. Prometheus, a CNCF graduate project, is a well-loved open source monitoring solution. Prometheus server collects time series metrics by scraping HTTP endpoints and creating a system to interact with this data, offering deep query, visualization, storage, and other capabilities. Check out this great Prometheus list for Prometheus introductions and additional resources.

Ansible is all about automation. Ansible, an open source project sponsored by Red Hat, can be used to automate things like cloud provisioning, networking, deployment, configuration management, and other tasks. Ansible has a simple yet effective architecture that is relatively easy to compile – all you need is a text editor and a command line. You describe your infrastructure in a text document and organize the states you want into a directory. For a working example, see How OpenIO Uses Ansible. Cédric Delgehier, Ops at OpenIO, wrote: “Ansible is our standard tool for not only deploying OpenIO core, but WebUI, OIO-FS and all options to come.”

Chef is another Infrastructure as Token (IaC) solution to automate your configuration management. Chef Ruby is used to automate server configurations and works well with all Cloud Service Providers (CSPs). This can be very useful when building and provisioning large amounts of hardware. Like the other automation tools on this list, the user describes their components and states in a declarative format. These are known in the Chef as ‘Recipes’, which can be grouped together into ‘Cookbooks’. You can’t compromise the chef for not being involved in the topic!

Terraform is another IaC tool that can be used to start building and release more automation with configuration files. “Terraform is a tool for building, changing, and releasing infrastructure safely and efficiently,” GitHub describes. Terraform follows an “execution plan” that the user creates using high-level syntax. One of the unique aspects of Terraform is its focus on versioning – this allows you to version your service schema just as you would your software.

As I’ve covered before, JAMStack combines JavaScript, APIs, and markdown to create web-based applications. While the “headless development” methodology is more of a single open source tool, JAMStack projects are often built using open source components. For example, JAMStack often makes use of open source headless CMSs such as Ghost, Strapi, and/or Netlify CMS.

ELK Stack is a consortium of three open source projects maintained by Elastic: Elasticsearch, Logstash, and Kibana. With these three components, developers can take and log data from any source and create useful visualizations. This centralized logging is enabled with a NoSQL database for storage with Elasticsearch, processing and data collection with Logstash, and visualization with Kibana. Increased visibility is vital for data analysis and helps identify errors to reduce mean recovery time (MTTR).

Rounding out the DevOps Toolkit for 2021

Programming isn’t just about shipping quality code, it’s about effective execution. This drive to improve operations across the board really puts Ops into everything. By using the great open source DevOps tools, it means that more and more architects can adopt the DevOps approach in their deployment models.

DevOps as a practice, as well as its core technology, is constantly evolving. In 2021, a lot of effort is being made to counteract the effects of introducing the microservice development method. As a result, we observed the maturation of the container regulators and the service network. Planning infrastructure as code and creating repeatable automated configurations is another essential to implementing automated build and release pipelines. Not to mention that many no-code and low-code platforms open up the capabilities of DevOps to non-programmers, albeit from a proprietary perspective.

It’s also worth noting that some popular open source DevOps tools have been acquired – like Docker and Chef – blurring the lines between their business and their open source roots. When it comes to open source tools, it is good practice to adopt vendor-neutral tools with strong community support representing diverse stakeholders. This will help prove your project in the future. Even though open source is “free,” users must ensure that the benefits outweigh the time spent on service as well as the OPEX of self-hosting.

DevOps tools are useful for automating software deployment. Here, we have tried to list some of the most exciting tools to help automate this process. Of course, many new tools are appearing in the DevOps space, and we have barely scratched the surface. Do you have a favorite DevOps tool not mentioned above? Let us know in the comments below!

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