1. Introduction

GitOps is a software management approach focused on infrastructure and software deployment with a Git version control ecosystem. It uses declarative configuration management and automatic synchronization, eliminating the necessity of manual operations and maintenance.

In this tutorial, we’ll discuss its origins, principles, workflow, and pros and cons in detail.

2. GitOps Origins: Infrastructure as Code

GitOps emerged as a natural extension of Infrastructure as Code (IaC).

  • 2011: Rise of IaC (e.g., Terraform, Puppet)
  • 2016: Kubernetes popularizes declarative infrastructure
  • 2018: GitOps term coined by Weaveworks
  • 2020+: Adoption of tools like FluxCD and ArgoCD

While IaC focuses on defining infrastructure using code, GitOps builds on this idea by using Git as the central control mechanism. It allows teams to manage both infrastructure and application deployment declaratively, leveraging version control for traceability and automation.

The main reasons why we may prefer GitOps over IaC are: automation, the ability to monitor changes, and continuous synchronization. In GitOps, each change is automatically monitored and implemented, which reduces the risk of configuration drift and human errors that may occur when using Infrastructure-as-a-Code manually.

Moreover, GitOps strengthens cooperation and management by making Git a single source of truth. It allows faster system recovery after failures and improves security by executing access controls and audit paths as part of with Git workflow.

3. Core Principles

GitOps is based on four key principles:

  1. Declarativeness
  2. Single Source of Truth
  3. Automatic Synchronization
  4. Self-Healing

They are widely adopted and defined in the GitOps community.

3.1. Declarativeness

Using GitOps, teams can declaratively define the whole infrastructure and the application’s configuration. In other words, instead of manual maintenance, teams can define the target state of software deployment using tools like Terraform scripts or Kubernetes manifests.

As a result, the GitOps operator, along with supporting tools, can automatically set up the entire infrastructure from scratch, ensuring consistency and eliminating the need for manual intervention.

Below is an example of a declarative Kubernetes deployment that would be stored and managed via Git in a GitOps workflow:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: frontend-app
spec:
  replicas: 2
  selector:
    matchLabels:
      app: frontend
  template:
    metadata:
      labels:
        app: frontend
    spec:
      containers:
      - name: frontend
        image: my-registry/frontend:1.2.3
        ports:
        - containerPort: 8080

3.2. Single Source of Truth

The Git repository stores the full history of system changes and states at any particular moment. A Git pull request introduces every change related to configuration or infrastructure.

Therefore, every modification is versioned, auditable, and easy to retrieve when needed. This enhances quality control and team collaboration.

3.3. Automatic Synchronization

A Git operator is a service that monitors the Git repository and ensures that the infrastructure state always meets the requirements and declarations stored as code. Examples are FluxCD and ArgoCD.

After detection, the operator automatically updates the infrastructure to achieve the new targeted state. Consequently, deployment doesn’t require manual interventions. The process is executed and controlled based on the changes in the repository state.

3.4. Self-Healing

When the infrastructure’s state doesn’t fit the declaration specified in the Git repository, the GitOps mechanisms automatically restore the proper configuration.

This self-healing mechanism increases the system’s fault tolerance and resilience. Further, it eliminates configuration drifts and ensures that the infrastructure is always working as expected.

4. The GitOps Workflow

GitOps changes the way development teams manage and deploy applications. Instead of manual environment configuration, the team members introduce changes via the Git repository. The Git operator automatically synchronizes them with the target environment.

4.1. Configuration Updates

The GitOps workflow starts with changing the software code and its configuration. A developer working on a new functionality modifies not only the code but also the configuration files. As a result, every change to the application includes corresponding updates to the configuration files.

This ensures that the infrastructure evolves in lockstep with the software, reducing deployment mismatches and improving consistency across environments.

4.2. Commit and Code Reviews

When the code is ready, the developer commits it to the Git repository. The team collaboration relies on pull requests and code reviews. Thus, the team verifies the quality of the committed code and accepts it or requests improvements.

After all necessary fixes are made, the PR is merged into the main branch. Consequently, only verified changes go into production and the environment through CI/CD processes.

4.3. Automatic Deployment

After the code is accepted and merged, the GitOps operator detects any configuration changes and synchronizes the environment. GitOps complements the traditional CI/CD pipeline: the CI pipeline is still responsible for building and testing the code, but the GitOps operator handles the deployment part (CD).

Hence, deployments are repeatable, resilient, and streamlined to eliminate unnecessary manual actions.

4.4. Monitoring and Rollbacks

If a problem occurs, GitOps allows developers to quickly undo changes by restoring an earlier version of the configuration. To restore the system to a stable state, team members need only perform a simple revert command.

git revert <bad-commit-id>
git push origin main

Automatic monitoring also detects unauthorized changes and brings the system back into compliance with the state stored in Git.

4.5. Workflow Summary

Below, we can see a visual representation of the GitOps workflow:

GitOps Workflow

The workflow starts from the change in the Git repository, goes through the pull requests and code review, and ends with automatic implementation and further monitoring of the infrastructure.

5. Pros and Cons of GitOps

GitOps introduces powerful automation and governance into modern DevOps workflows. It improves consistency, security, and team collaboration through its Git-centric model, but it also brings new challenges that teams must be prepared to address.

The table below provides a side-by-side comparison of the main benefits and drawbacks of GitOps.

Characteristic

Pros

Cons

Deployment standardization

Ensures a uniform process across teams and environments

Requires adaptation to Git-based workflows

Team collaboration

Encourages structured reviews and approvals

May introduce overhead in change management

Operational resilience

Automatically prevents unauthorized changes

Strong dependency on Git availability

Learning curve

Promotes best practices in infrastructure management

Requires expertise in declarative infrastructure

Security

Reduces manual access to production environments

Access management in Git must be carefully controlled

Despite its trade-offs, GitOps offers strong operational advantages, especially in cloud-native environments where consistency and automation are critical. By combining infrastructure as code with Git-based workflows, teams can deliver software with greater speed, safety, and reliability.

6. Conclusion

In this article, we explored GitOps, its origins, principles, workflow, advantages, and limitations.

GitOps is a deployment and infrastructure management approach that treats Git as the single source of truth. It relies on automation and a declarative model to ensure consistency, simplify deployment processes, and improve team collaboration.

GitOps enhances security and reduces manual intervention. However, it requires a well-structured repository and can be challenging in highly dynamic environments.


原始标题:What Is GitOps?