You can deploy applications in the application center of the Container Service for Kubernetes (ACK) console. This topic describes the features, concepts, and core components of the application center.

Background

If you use a template to deploy an application to a Kubernetes cluster, multiple resources are created for the application. In the community solution, you cannot manage application resources in a unified manner. For example, if you deploy WordPress to a cluster, multiple resources are created for the application, such as deployments, services, ingresses, service accounts, and roles. However, you cannot view the overall topology of the application or centrally manage or roll back application versions in scenarios such as continuous deployment.

Architecture

Architecture of the application center

The application center enables centralized management of applications. This allows you to view the overall topologies of applications in your cluster. You can view the deployment status and changes of all Kubernetes resources used by each application. You can also use templates or Helm charts on GitHub to deploy different versions of an application to a cluster. You can roll back the application to each version or deploy the application versions to a cluster.

Concepts

Concept Description
Application A set of Kubernetes resources specified in a deployment template.
Target Status The desired status of an application. The status is specified in a deployment template or a Helm chart on GitHub.
Current Status The current status of an application, such as the status of the pods assigned to the application.
Deploy Status Indicates whether the current status of an application matches its desired status specified in a deployment template or a Helm chart on GitHub.
Deploy Enables an application to reach its desired status. For example, you can run the kubectl apply command to deploy an application to a cluster.
Refresh Compares the current status of an application with its desired status specified in the latest deployment template on GitHub.
Health Status Indicates whether an application is running properly.

Core components

All components of the application center are deployed in the appcenter namespace of a cluster. The following table lists four core components.

Component Description
application-controller Maintains the versions of applications. You can view the earlier versions of applications and roll back applications to specified versions.
redis Stores the cached data generated by running applications.
repo-server Pulls application deployment templates from remote repositories, such as GitHub or Helm chart repositories.
server Works as a gRPC server that can access the Internet.