Core Principles of GitOps
GitOps is built upon a set of core principles that ensure a robust, reliable, and auditable system for managing infrastructure and applications. These principles guide how systems are described, how changes are managed, and how operations are performed.
1. Declarative Configuration
The entire desired state of your system must be described declaratively. This means configuration files define the intended state of the infrastructure (e.g., Kubernetes manifests, Terraform configurations), rather than a series of imperative scripts or commands. This declarative nature allows for easier understanding and management of the system's state. This principle is also vital in Infrastructure as Code (IaC) practices.
2. Version Control as the Single Source of Truth
The Git repository is the single source of truth for the declarative configuration. All changes to the desired state of the system must be committed to Git. This provides a complete audit trail of all changes, allows for easy rollbacks, and facilitates collaboration among team members. If the Git repo says X, then the system should be X.
3. Automated Reconciliation
Approved changes committed to the Git repository are automatically applied to the live system. Software agents (operators or controllers) running in the cluster continuously work to ensure that the actual state of the system converges to the desired state declared in Git. This automation removes the need for manual interventions (e.g., `kubectl apply -f`) for deployments or updates.
4. Continuous Monitoring and Control (Software Agents)
Software agents continuously monitor the live state of the system and compare it against the desired state in Git. Any divergence or drift is detected. These agents are also responsible for applying the changes and can, in some configurations, automatically correct any unapproved changes made directly to the live system, ensuring it always reflects the state in Git.
Adhering to these principles allows organizations to achieve many of the benefits associated with GitOps, such as improved reliability, faster deployments, and enhanced security. Understanding these pillars is key before moving on to explore the practical tools and technologies that enable GitOps.