Top 50 Argocd Interview Questions and Answers

11 Jun 2024 - Shyam Mohan

1. What is ArgoCD?

ArgoCD is a declarative, GitOps continuous delivery tool for Kubernetes.

2. How does ArgoCD work?

ArgoCD continuously monitors Git repositories and ensures the desired state of the application matches the state in the repository.

3. What are the main features of ArgoCD?

GitOps-based deployment, support for multiple environments, automated synchronization, health status, rollbacks, and self-healing.

4. What is GitOps?

GitOps is a practice of using Git repositories as the source of truth for declarative infrastructure and applications.

5. How does ArgoCD integrate with Kubernetes?

ArgoCD operates as a Kubernetes controller that continuously compares the desired application state defined in Git with the live state on the cluster.

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6. How do you install ArgoCD?

You can install ArgoCD using the provided manifests from the official ArgoCD repository, typically with kubectl apply -n argocd -f .

7. What are the prerequisites for installing ArgoCD?

A Kubernetes cluster, kubectl installed, and appropriate access rights to install and manage resources on the cluster.

8. How do you access the ArgoCD UI?

You can port-forward the ArgoCD server service to your local machine using kubectl port-forward svc/argocd-server -n argocd 8080:443 and then access it via https://localhost:8080.

9. How do you authenticate to ArgoCD?

The initial password for the admin user is the name of the ArgoCD server pod. This can be changed after the first login.

10. How do you configure ArgoCD to connect to a Git repository?

Through the ArgoCD UI, CLI, or declarative configurations where you define the repository credentials in the ArgoCD settings.

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11. How do you create an application in ArgoCD?

Applications can be created via the ArgoCD UI, CLI (argocd app create), or by defining an Application custom resource.

12. What are the key components of an ArgoCD Application resource?

spec.source for the repository location, spec.destination for the target cluster and namespace, and spec.project for project association.

13. What is ApplicationSet in ArgoCD?

An ApplicationSet is a CRD that allows you to create multiple ArgoCD Applications based on a template and a generator.

14. How do you synchronize an application?

Synchronization can be done manually via the UI, CLI, or automatically if auto-sync is configured in the application spec.

15. What are the different sync policies in ArgoCD?

Manual sync, auto-sync, prune, and self-healing.

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16. What is a sync wave in ArgoCD?

Sync waves allow you to control the order in which Kubernetes manifests are applied during a sync operation.

17. How do you handle sync failures in ArgoCD?

Sync failures can be handled by configuring retry policies or manually troubleshooting and resolving the issues.

18. What are health checks in ArgoCD?

Health checks determine the health status of Kubernetes resources, ensuring they are in the desired state.

19. How do you define custom health checks?

Custom health checks can be defined in the argocd-cm ConfigMap using Lua scripts.

20. How do you perform a rollback in ArgoCD?

Rollbacks can be performed via the UI or CLI by selecting a previous application revision.

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21. How do you configure RBAC in ArgoCD?

RBAC is configured using policies defined in the argocd-rbac-cm ConfigMap.

22. What roles are available in ArgoCD?

Predefined roles include role:admin, role:edit, role:read, and custom roles can be defined as needed.

23. How do you secure ArgoCD?

By configuring HTTPS, using strong authentication methods, limiting access via RBAC, and regularly updating ArgoCD.

24. Can ArgoCD integrate with SSO?

Yes, ArgoCD supports SSO integration with providers like OAuth2, OIDC, SAML, and LDAP.

25. What is the purpose of the argocd-cm ConfigMap?

The argocd-cm ConfigMap stores the main configuration settings for ArgoCD, including repository credentials, sync policies, and more.

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26. How do you manage multiple clusters with ArgoCD?

Multiple clusters are managed by registering them in the argocd-cm ConfigMap and specifying the target cluster in the application spec.

27. What are ArgoCD projects?

Projects are a way to group applications, enforce policies, and manage access control within ArgoCD.

28. How do you define a project in ArgoCD?

Projects are defined using the AppProject custom resource.

29. How do you restrict resource usage per project?

Resource usage can be restricted by defining quotas and allowed namespaces in the AppProject spec.

30. What is ArgoCD’s HA mode?

HA mode ensures high availability by deploying multiple replicas of ArgoCD components and using a highly available backend database.

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31. How do you debug sync issues in ArgoCD?

By reviewing the application’s sync history, logs, and events through the UI or CLI.

32. What are common causes of sync failures?

Incorrect resource definitions, missing dependencies, insufficient permissions, and misconfigured Git repository access.

33. How do you view ArgoCD logs?

Logs can be viewed using kubectl logs for ArgoCD pods or through the ArgoCD UI.

34. How do you handle application drift?

Drift is detected by ArgoCD and can be corrected by synchronizing the application to match the desired state in the Git repository.

35. What is the difference between argocd app sync and argocd app refresh?

argocd app sync triggers a synchronization of the application, while argocd app refresh updates the application state from the Git repository without syncing.

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36. How do you integrate ArgoCD with CI/CD pipelines?

By using webhooks to trigger deployments or by including ArgoCD CLI commands in the pipeline scripts.

37. What is an ArgoCD webhook?

Webhooks are HTTP callbacks that notify ArgoCD of changes in the Git repository, triggering application synchronization.

38. How do you configure webhooks in ArgoCD?

Webhooks are configured in the Git repository settings, pointing to the ArgoCD webhook receiver URL.

39. Can ArgoCD manage Helm charts?

Yes, ArgoCD can deploy and manage applications defined as Helm charts.

40. How do you handle secrets in ArgoCD?

Secrets can be managed using tools like Sealed Secrets, HashiCorp Vault, or Kubernetes secrets.

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41. How do you scale ArgoCD?

By increasing the number of replicas for ArgoCD components and using a distributed backend database.

42. What is the ArgoCD Application Controller?

The Application Controller is responsible for reconciling the desired and live state of applications managed by ArgoCD.

43. How do you optimize ArgoCD performance?

By using caching, optimizing Git repository structure, and tuning resource limits and requests.

44. What are resource limits and requests in ArgoCD?

Resource limits and requests are Kubernetes settings that control the CPU and memory resources allocated to ArgoCD components.

45. How does ArgoCD handle large Git repositories?

By using shallow cloning, caching, and configuring Git depth.

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46. What are some best practices for using ArgoCD?

Use Git as the single source of truth, define clear sync policies, manage secrets securely, and implement robust RBAC.

47. How do you ensure continuous delivery with ArgoCD?

By using automated sync policies, health checks, and integrating ArgoCD with CI/CD pipelines.

48. What are some common pitfalls when using ArgoCD?

Misconfigured sync policies, insufficient RBAC settings, neglecting to monitor ArgoCD components, and not handling secrets properly.

49. How do you backup and restore ArgoCD?

By backing up the ArgoCD database and configurations and restoring them in case of failure.

50. What’s the future roadmap for ArgoCD?

Enhancements in multi-cluster management, improved UI/UX, better performance optimizations, and more integrations with other DevOps tools.