Chapter 1. Building applications overview
Using OpenShift Container Platform, you can create, edit, delete, and manage applications using the web console or command line interface (CLI).
1.1. Working on a project
Using projects, you can organize and manage applications in isolation. You can manage the entire project lifecycle, including creating, viewing, and deleting a project in OpenShift Container Platform.
After you create the project, you can grant or revoke access to a project and manage cluster roles for the users using the Developer perspective. You can also edit the project configuration resource while creating a project template that is used for automatic provisioning of new projects.
Using the CLI, you can create a project as a different user by impersonating a request to the OpenShift Container Platform API. When you make a request to create a new project, the OpenShift Container Platform uses an endpoint to provision the project according to a customizable template. As a cluster administrator, you can choose to prevent an authenticated user group from self-provisioning new projects.
1.2. Working on an application
1.2.1. Creating an application
To create applications, you must have created a project or have access to a project with the appropriate roles and permissions. You can create an application by using either the Developer perspective in the web console, installed Operators, or the OpenShift CLI (oc). You can source the applications to be added to the project from Git, JAR files, devfiles, or the developer catalog.
You can also use components that include source or binary code, images, and templates to create an application by using the OpenShift CLI (oc). With the OpenShift Container Platform web console, you can create an application from an Operator installed by a cluster administrator.
1.2.2. Maintaining an application
After you create the application, you can use the web console to monitor your project or application metrics. You can also edit or delete the application using the web console.
When the application is running, not all applications resources are used. As a cluster administrator, you can choose to idle these scalable resources to reduce resource consumption.
1.2.3. Connecting an application to services
An application uses backing services to build and connect workloads, which vary according to the service provider. Using the Service Binding Operator, as a developer, you can bind workloads together with Operator-managed backing services, without any manual procedures to configure the binding connection. You can apply service binding also on IBM Power Systems, IBM Z, and LinuxONE environments.
1.2.4. Deploying an application
You can deploy your application using Deployment or DeploymentConfig objects and manage them from the web console. You can create deployment strategies that help reduce downtime during a change or an upgrade to the application.
You can also use Helm, a software package manager that simplifies deployment of applications and services to OpenShift Container Platform clusters.
1.3. Using the Red Hat Marketplace
The Red Hat Marketplace is an open cloud marketplace where you can discover and access certified software for container-based environments that run on public clouds and on-premises.
