Argo CD Application resource drift

What is Argo CD Application resource drift

Understanding Argo CD

Argo CD is a declarative, GitOps continuous delivery tool for Kubernetes. It automates the deployment of the desired application states defined in Git repositories to Kubernetes clusters. By continuously monitoring the state of applications, Argo CD ensures that the live state of applications matches the desired state specified in Git.

Identifying Application Resource Drift

One common issue encountered by users of Argo CD is Application Resource Drift. This occurs when resources in the Kubernetes cluster deviate from the desired state defined in the Git repository. Symptoms of this issue include discrepancies between the live state of resources and the state defined in Git, often visible in the Argo CD dashboard.

Symptoms of Resource Drift

Argo CD dashboard shows applications in a OutOfSync state. Unexpected changes in application behavior or configuration. Manual changes in the Kubernetes cluster not reflected in Git.

Understanding the Issue

Resource drift is a common challenge in environments where manual changes are made directly to the Kubernetes cluster. These changes can lead to inconsistencies between the live state and the desired state specified in Git. Argo CD detects these discrepancies and flags the application as OutOfSync.

Root Causes of Drift

Manual edits to resources in the Kubernetes cluster. Automated processes or scripts altering resources without updating Git. Configuration changes not committed to the Git repository.

Steps to Resolve Application Resource Drift

Resolving resource drift involves reconciling the live state with the desired state. Here are the steps to address this issue:

Step 1: Perform a Manual Sync

To reconcile the differences, perform a manual sync from the Argo CD dashboard:

Navigate to the Argo CD dashboard. Select the application that is OutOfSync. Click on the Sync button to initiate a manual sync.

This action will apply the desired state from Git to the Kubernetes cluster, resolving the drift.

Step 2: Investigate Persistent Drift

If the drift persists, further investigation is needed:

Check for any automated processes that might be altering resources. Review recent changes in the Git repository for any discrepancies. Ensure all configuration changes are committed to Git.

Preventing Future Drift

To prevent future occurrences of resource drift, consider the following best practices:

Adopt a strict GitOps workflow where all changes are made through Git. Implement access controls to prevent unauthorized changes to the cluster. Regularly audit and review changes in both the cluster and Git repository.

For more information on managing application states with Argo CD, visit the official Argo CD documentation.