GitOps is a groundbreaking approach that leverages the power of version control system to streamline and automate the deployment process. By centralizing configuration management and adopting a declarative approach, GitOps enables teams to maintain control, increase collaboration, and achieve a high level of scalability.
In this article, we delve into the world of GitOps and explore its potential for improving continuous deployment practices.
What Is GitOps?
GitOps is a system operation process that uses the version control system Git as a single source of truth for managing infrastructure and application deployments. It is an evolution of infrastructure as code and leverages DevOps best practices to establish a unified approach throughout the software development lifecycle.
With GitOps, all information related to the application being deployed, including documentation, code for container deployments (such as Docker Swarm or Kubernetes), infrastructure configuration, and application code, is stored in Git. This practice ensures that everything, from planning and building to testing, exists within the Git repository. Even test cases can be stored in Git, enabling a comprehensive version-controlled environment.
Primarily used in microservices architectures, particularly when utilizing container orchestration tools like Kubernetes, GitOps empowers developers to take control of the entire architecture and eliminates the need for manual intervention from operations teams. It emphasizes the concept that if it's your code, it's your responsibility to ensure its behavior on the infrastructure. Thus, developers are also responsible for deploying the infrastructure.
The shift in responsibility by GitOps has led to the emergence of tools like Terraform for infrastructure as code and cloud-native tools like AWS CloudFormation, which enable infrastructure deployment through code. By treating Git as the single source of truth for infrastructure management, GitOps ensures that changes to the infrastructure are validated and automatically deployed using Git pull requests. This approach encapsulates the core concept of GitOps.
GitOps aligns with the principles of DevOps, enabling organizations to execute DevOps correctly and achieve proper infrastructure deployments. It establishes best practices that unify all stages of the DevOps pipeline, promoting collaboration, traceability, and version control. While Git is the central tool used in GitOps, it can be implemented on various version control cloud platforms such as GitHub, Bitbucket, or any other suitable platform.
Overall, GitOps streamlines system operations, enhances collaboration, and ensures the reliable and efficient deployment of infrastructure and applications.
How GitOps Works
So let's take a look at how GitHub works and gain a better understanding of its functionality. As a developer, operations expert, or DevOps engineer, you may use Git repositories to manage your code. Whether it's Terraform files, ML files, or Ansible files, you can store them in a master Git repository where multiple individuals collaborate.
However, it's important to note that you shouldn't directly deploy changes or modify the Git files. Instead, you should create a pull request to propose code modifications. This process ensures proper review and integration before any changes are deployed. In other words, you need a CI (Continuous Integration) pipeline to facilitate the integration of your modifications within your DevOps cycle.
This CI pipeline encompasses various stages, such as continuous integration, testing, and continuous deployment. By following this cycle, you can ensure that your changes are thoroughly tested, minimizing the likelihood of introducing unnecessary or incorrect modifications to your infrastructure. GitHub provides the infrastructure necessary to support this entire process, even for operational code or configuration files.
As part of this process, you can define an integration CI pipeline to check for changes, along with automated test cases. These test cases are essential for verifying that your modifications won't adversely impact your infrastructure. Once the tests are completed, the changes undergo review and approval. The approval can come from security personnel or designated approvers specified by you.
Once the pull request is approved, the changes are ready for deployment. GitHub offers continuous deployment (CD) pipelines to automate the deployment process. This means you won't need to execute deployments manually. Additionally, you can define specific stages, such as staging, to conduct further tests before deploying to production. With continuous deployment, your configuration changes flow seamlessly into the production environment.
In modern-day deployments, containers have become an integral part of software development. When following a microservices architecture, applications are broken down into smaller components, each containerized within a Docker container. These components work independently, ensuring that issues within one component do not affect others. For example, a problem with the one services module should not impact the functionality of the customer service, or payment modules.
To manage the deployment of numerous containers effectively, specialized software tools are employed. These container orchestration tools enable container management, replication, and health monitoring. This modern architecture approach involves developing and deploying applications using these tools.
When implementing GitOps, the usage of Git extends beyond version control for application code. GitOps encourages managing cluster configurations for Kubernetes and infrastructure configurations for your application through Git as well. Infrastructure-as-code tools and cloud-native tools enable the management of the entire infrastructure using code. By codifying your architecture, you can recreate the infrastructure quickly in case of failures or changes, saving significant time compared to manual reconfiguration.
It is crucial to maintain both the application code and infrastructure code within Git. By doing so, Git becomes the central repository for all aspects of your application. Any questions or concerns regarding the architecture or code can be addressed by referring to Git. This emphasis on Git as the single source of truth is a common theme in GitOps tutorials and guides.
GitOps Use Cases
As a developer, you may already be familiar with GitOps and its core concept of infrastructure as code. Infrastructure as code allows you to define your infrastructure in files rather than relying on manual configurations through GUI tools. Tools like Terraform, Ansible, and orchestrators like Kubernetes embrace this concept by enabling you to define infrastructure components and resources in YAML files.
In a non-GitOps workflow, engineers would typically write infrastructure files and commit them to a Git repository. After committing the code, they would manually apply the changes to the infrastructure. However, in a GitOps approach, this final step is automated using a GitOps operator such as Argo CD or Flux. Once code is committed to the repository, the infrastructure is automatically synchronized to match the defined state in Git. This continuous synchronization process is known as reconciliation. GitOps operators constantly monitor the environment's current state and ensure it aligns with the desired state defined in Git.
Although the automatic synchronization may seem like a small change, it is a game-changer for organizations. They are racing to implement GitOps because it eliminates human errors and inconsistencies. To understand its significance better, let's revisit the traditional approach where an engineer manually applies the changes. Imagine if the engineer creates the infrastructure files, commits them to Git, but then gets distracted, goes for a coffee, scrolls through Reddit, or even worse, leaves for the day without applying the changes. Alternatively, what if they prepare the changes, apply them, but fail to commit and push the new changes? In both cases, the production environment becomes out of sync with what's in Git, leading to troubleshooting nightmares. Such scenarios have occurred even in top companies, and GitOps aims to mitigate these issues.
Benefits of GitOps
In this section, we’ll summarize the most important benefits you’ll expect after implementing GitOps.
The first major benefit is environment transparency. With GitOps operators constantly monitoring your repository and automatically applying changes, Git becomes the source of truth. There's no more guesswork about the configuration running on production servers.
The next major benefit is fewer errors and easy, fast recovery when problems occur. With changes being automatically applied, there is less room for human error during the application process. In case an error does slip through, since everything is in Git, you can easily perform a Git revert to go back to a previous version of the configuration. This is known as a GitOps rollback and is extremely powerful. You can have confidence that even if your changes don't work, it's straightforward to revert to a known working state.
The third benefit is enhanced security. In the example where an engineer manually applies changes, individual engineers no longer need direct permissions to make infrastructure changes. Instead, they are granted access to modify what's in Git. Permissions to make changes in production are assigned to your CI solution or GitOps operator. This approach is much more secure than giving direct access to humans.
Finally, the last major benefit of a GitOps workflow is speed and agility. With the application process automated, deployments can happen faster and more frequently. You can achieve a rapid and agile development cycle.
Now that you have a good understanding of GitOps, let's delve into deployment strategies, which is essential for a comprehensive understanding of the GitOps solutions available in the current market.
GitOps Deployment Models
GitOps offers two different deployment approaches: the push-based and pull-based models. In the push-based model, where engineers manually apply changes, we can simply automate the final step of applying new code to make it GitOps. This automation can be achieved using various CI/CD services such as Jenkins, GitHub Actions, or GitLab. Once the code is checked into Git and the CI tests have passed, the new infrastructure is pushed automatically.
On the other hand, the pull-based model involves installing an operator or agent within the environment. This agent continually checks the environment's current state, and if it deviates from the desired state, it pulls the necessary changes to align with the defined state in Git.
Both the push and pull-based models have their advantages and disadvantages. The push model is easy to set up and understand, offering flexibility in deploying to various targets through pipeline integration. However, there are security concerns, as firewall ports may need to be opened, and CI servers must be granted permissions to make changes in production environments.
In contrast, the pull-based model is fast, efficient, and more secure. It eliminates the need to open firewalls or grant external admin access. However, the pull-based model is currently primarily available for Kubernetes environments.
It's important to consider these pros and cons when choosing between the push and pull-based models for GitOps implementation.
Summary of GitOps
GitOps revolutionizes infrastructure management by leveraging version control and automation. It provides improved visibility, traceability, and collaboration, enabling organizations to achieve consistent and reliable deployments. Adopting GitOps practices streamlines processes and enhances system stability and efficiency.
How Solwey Consulting Can Help
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