What is Argo CD ?
ArgoCD is a Kubernetes-native continuous deployment(CD) tool. Unlike external CD tools that only enable push-based deployments, Argo CD can pull updated code from git repo and deploy it directly to kubernetes resources.
It enables developers to manage both infrastructure configuration and application updates in one system.
Argo CD has some really cool features and capabilities, such as:
Automatic synchronization of application state to the current version of declarative configuration.
WebUser interface and command-line interface (CLI).
Manual or automatic deployment of applications to kubernestes cluster.
Role-based access control enabling multi-cluster management.
Ability to visualize deployment issues, detect, and fix configuration drift.
Single sign On (SSO) with providers such as GitHub, Microsoft, OAuth2, GitLab, OIDC and LDAP.
Support for webhooks triggering actions in GitLab, GitHub and BitBucket.
Why Argo CD ?
Application definitions, configurations, and environment should be declarative and version-controlled.
Application deployment and lifecycle management should be automated and easy to undersatnd.
How does Argo CD work?
When using Argo CD, you can specify application configuration using several types of K8s manifests, including plain YAML or JSON manifest. Helm charts, Kustomize and Ksonnet applications. It is also possible to use any custom configuration management tools as a plugin.
Argo CD operates by continuously monitoring a Git repository for any changes in the codebase. When updates are detected, it pulls the updated code and deploys it directly to the Kubernetes resources. This process ensures that the application's state is always in sync with the current version of the declarative configuration stored in the Git repository.
Argo CD manages both infrastructure configuration and application updates, providing a unified system for developers. One of its key features is automatic synchronization, which ensures that any changes in the Git repository are reflected in the Kubernetes cluster without manual intervention. This helps maintain consistency and reduces the risk of configuration drift.
Additionally, Argo CD offers both a web user interface(UI) and a command-line interface (CLI), making it accessible and easy to use for developers with different preferences. The role-based access control (RBAC) feature allows for secure multi-cluster management, ensuring that only authorized users can make changes.
Argo CD also includes deployment visualization tools, which help developers identify and resolve deployment issues quickly. This feature is particularly useful for detecting and fixing configuration drift, where the actual state of the application differs from the desired state defined in the Git repository.
Moreover, Argo CD supports Single Sign-On (SSO) with various providers such as GitHub, Microsoft, OAuth2, GitLab, OIDC, and LDAP, streamlining the authentication process. It also supports webhooks, which can trigger actions in response to events in GitLab, GitHub, and BitBucket, further enhancing its automation capabilities.
Overall, Argo CD simplifies the process of application deployment and lifecycle management, making it automated, declarative, and easy to understand..
Basic Components of Argo CD
Argo CD is made up of several key components that work together to make continuous deployment a breeze:
API Server: This is the heart of Argo CD, handling all the API requests and managing the state of your applications.
Repository Server: This component fetches the application definitions from your Git repositories.
Controller: The controller keeps an eye on your Kubernetes cluster, ensuring that the actual state matches the desired state defined in your Git repository.
User Interface (UI): The UI provides a friendly, web-based interface where you can manage and monitor your deployments.
Command-Line Interface (CLI): For those who prefer the command line, the CLI offers a powerful way to interact with Argo CD.
These components work together to provide a seamless and efficient deployment experience.