Argo CD: A Declarative GitOps CD for Kubernetes

In the fast-paced world of software development, continuous integration and continuous delivery (CI/CD) practices have become indispensable. They enable teams to iterate rapidly, deploy code frequently, and maintain high-quality software. However, managing deployments across multiple environments while ensuring consistency and reliability can be challenging. This is where Argo CD comes into play.

In this blog, we’ll explore the features, benefits, and best practices of Argo CD, shedding light on how it can streamline your continuous delivery workflows.

In this blog we will learn:

1. What is Argo CD?
2. Key Features of Argo CD
3. Benefits of Using Argo CD
4. Best Practices for Argo CD Adoption
5. Install Argo CD
6. Conclusion
7. FAQs

What is Argo CD?

Argo CD is an open-source continuous delivery tool designed to automate the deployment of applications to Kubernetes clusters. With its declarative approach and GitOps principles, Argo CD simplifies the process of managing complex deployment pipelines, making it a go-to choice for DevOps teams worldwide.

Argo CD operates on the principles of GitOps, a methodology for managing infrastructure and applications through version-controlled repositories. In essence, it uses Git repositories as the source of truth for defining the desired state of your Kubernetes resources. When changes are made to the Git repository, Argo CD automatically synchronizes the cluster with the desired state, ensuring consistency and traceability.

Key Features of Argo CD

1. Declarative Configuration: It allows you to define the desired state of your applications and environments using YAML manifests. This declarative approach makes it easy to manage complex deployments and promotes consistency across environments.
2. Automated Sync: By continuously monitoring the Git repository for changes, Argo CD automatically detects updates to your application configuration and triggers synchronization with the cluster. This automation eliminates the need for manual intervention, reducing the risk of human error and ensuring rapid deployments.
3. Rollback Capabilities: In case of failed deployments or undesired changes, Argo CD provides seamless rollback capabilities. You can easily revert to a previous version of your application configuration with a single command, mitigating the impact of errors and ensuring service reliability.
4. Multi-Tenancy Support: It supports multi-tenancy, allowing teams to manage multiple environments and applications within a single Argo CD instance. With RBAC (Role-Based Access Control) policies, you can enforce granular access controls and ensure secure collaboration across teams.
5. Integration with CI/CD Pipelines: It integrates seamlessly with popular CI/CD tools such as Jenkins, GitLab CI, and GitHub Actions. You can trigger deployments automatically upon successful CI builds, enabling end-to-end automation of your software delivery pipeline.

Benefits of Using Argo CD

1. Enhanced Productivity: By automating the deployment process and providing a centralized dashboard for monitoring applications, Argo CD enables teams to focus on writing code rather than managing deployments manually. This leads to increased productivity and faster time-to-market for software releases.
2. Improved Reliability: With Argo CD’s declarative approach and automated synchronization, you can ensure consistency and reliability across all environments. This minimizes the risk of configuration drift and reduces the likelihood of production incidents, enhancing overall system reliability.
3. Scalability and Flexibility: Whether you’re managing a single-cluster deployment or a complex multi-cluster setup, Argo CD scales effortlessly to meet your needs. Its flexible architecture supports various deployment strategies, including canary releases and blue-green deployments, empowering teams to adopt best practices that suit their requirements.

Best Practices for Argo CD Adoption

1. GitOps Workflow: Embrace the GitOps workflow by storing your application configuration in version-controlled Git repositories. Follow best practices such as branching strategies, code reviews, and automated testing to ensure the reliability of your deployment pipelines.
2. Infrastructure as Code (IaC): Treat your infrastructure as code by defining Kubernetes resources using YAML manifests. This approach allows you to manage infrastructure changes alongside application code, promoting consistency and traceability across your stack.
3. Continuous Monitoring and Feedback: Implement monitoring and observability tools to track the health and performance of your applications deployed with Argo CD. Leverage metrics, logs, and alerts to proactively identify issues and iterate on improvements iteratively.
4. Security and Compliance: Pay attention to security best practices when configuring Argo CD instances, including RBAC policies, network segmentation, and encryption at rest and in transit. Regularly audit access controls and review configuration changes to ensure compliance with regulatory requirements.

👉 To learn more about GitOps, Click here

Install Argo CD

To install Argo CD, we will need:

• Installed kubectl command-line tool.
• Have a kubeconfig file (default location is ~/.kube/config).
• CoreDNS.

To have all these three configured, we will better use a Kubernetes Cluster where all the requirments will be configured.

👉 To Setup A Multi-Node Kubernetes Cluster Step By Step, Click Here

Once the cluster is set up, then please follow the below steps to install Argo CD.

1. Verify the status of the k8s cluster:

$ kubectl get nodes

2. Create an “argocd” namespace in your cluster, which will serve as the environment for Argo CD and its related services.

$ kubectl create namespace argocd

3. Now, execute the installation script for Argo CD as provided by the developers of the project.

$ kubectl apply -n argocd -f https://raw.githubusercontent.com/argoproj/argo-cd/stable/manifests/install.yaml

4. Once the installation is finished without any errors, you can utilize the “watch” command to monitor the status of your Kubernetes pods.

$ watch kubectl get pods -n argocd

5. View the services associated with argocd.

$ kubectl get svc -n argocd

Above, we can see a service named argocd-server using which we can access the dashboard.

But it is of ClusterIP type by default, to access that we will have to convert it to either Loadbalancer or NodePort. In this lab, we will convert it to NodePort.

6. Convert the ClusterIP type to NodePort using the patch command.

$ kubectl patch svc argocd-server -n argocd --type='json' -p '[{"op":"replace","path":"/spec/type","value":"NodePort"}]'

7. Verify whether the service is converted or not.

$ kubectl get svc -n argocd argocd-server

As above we can see it has been converted to NodePort and we now have a Port number exposed on 80/TCP.

8. Now we can access the dashboard using this port number along with the public IP of any of the cluster nodes on browser.(as shown below)

<Public IP of Node>:<NodePort>

Note: Then you It will ask you for login. We will log in to the dashboard once we retrieve the password in the coming sections.

9. Download the CLI from Github.

$ curl -sSL -o argocd-linux-amd64 https://github.com/argoproj/argo-cd/releases/latest/download/argocd-linux-amd64
$ ls

10. Install the CLI

$ install -m 555 argocd-linux-amd64 /usr/local/bin/argocd

11. Check the version

$ argocd version

Note: Ignore the above error for now, it will disappear once we login to the ArgoCd server in next steps.

12. For login to the ArgoCd server, we will require the username and password. The initial password for the admin account is auto-generated and stored as clear text in the field password in a secret named argocd-initial-admin-secret in your Argo CD installation namespace. You can simply retrieve the password using the argocd CLI.

$ argocd admin initial-password -n argocd

13. Using this password and the default username “admin”, login to the server.

To log in, we will require the public IP address of any of the Cluster nodes/VMs along with the nodeport that we got in step 7, as instructed below.

$ argocd login <Public IP of Node>:<NodePort>

Note: For the warning- “server certificate had error: x509: cannot validate certificate for <public ip> because it doesn’t contain any IP SANs. Proceed insecurely (y/n)?”, Type:y

14. Now we will update the password.

$ argocd account update-password

Note: Choose a password of your choice and remember/Note it, we will need this while accessing the dashboard from the browser.

15. Now login using the password:

To do so go to the tab on your browser where you have opened the ArgoCD Dashboard and Login using the credentials.

• Username: admin
• Password: Your own password that you have created

Now we have successfully logged in.

Conclusion

Argo CD offers a powerful solution for automating Kubernetes deployments and embracing GitOps principles in your CI/CD workflows. By leveraging its declarative approach, automated synchronization, and rollback capabilities, teams can streamline their continuous delivery pipelines and achieve greater efficiency, reliability, and scalability in software delivery.

As organizations continue to adopt cloud-native technologies and embrace DevOps practices, Argo CD stands out as a valuable tool for orchestrating complex deployments with ease. Whether you’re a small startup or a large enterprise, incorporating Argo CD into your toolchain can accelerate your journey toward achieving continuous delivery excellence in the Kubernetes ecosystem.

FAQs

Related/References

• Visit our YouTube channel “K21Academy”
• Certified Kubernetes Administrator (CKA) Certification Exam
• (CKA) Certification: Step By Step Activity Guides/Hands-On Lab Exercise & Learning Path
• Certified Kubernetes Application Developer (CKAD) Certification Exam
• (CKAD) Certification: Step By Step Activity Guides/Hands-On Lab Exercise & Learning Path
• Create AKS Cluster: A Complete Step-by-Step Guide
• Container (Docker) vs Virtual Machines (VM): What Is The Difference?
• How To Setup A Three Node Kubernetes Cluster For CKA: Step By Step

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