Deploying app workloads from images in a public registry

Deploy your app with Code Engine. You can create an app from the console or with the CLI.

Deploying an app from the console

Deploy an application with an image from a public registry that does not require credentials with the Code Engine console.

This example references the public icr.io/codeengine/helloworld image in IBM Cloud® Container Registry. Alternatively, you can also reference an image in a public Docker Hub or an image in a private registry.

Open the Code Engine console.
Select Let's go.
Select Application.
Enter a name for the application. Use a name for your application that is unique within the project.
Select a project from the list of available projects. You can also create a new one. You must have a selected project to deploy an app.
Specify a container image for your app, for example, icr.io/codeengine/helloworld. If you have your own source code that you want to turn into a container image for the app, see Planning your build. For more information about the code that is used for this example, see helloworld.
Modify any default values for endpoint or runtime settings. For more information about these options, see Options for endpoint visibility of apps and Options for deploying an app.
Click Create.
After the application status changes to Ready, you can test the application. Click Test application and then click Send request in the Test application pane. To open the application in a web page, click Application URL.

Now that you have deployed your application, you can view information about application revisions and any running instances, and configuration details.

Deploying an app with the CLI

To create and deploy your app with the CLI, use the app create command. This command requires a name and an image and also allows other optional arguments. For a complete listing of options, see the ibmcloud ce app create command.

Before you begin

Set up your Code Engine CLI environment.
Create and work with a project.

The following application create command creates and deploys an app that is named myapp and uses the container image icr.io/codeengine/hello.

ibmcloud ce application create --name myapp --image icr.io/codeengine/hello

Example output

Creating application 'myapp'...
OK
[...]
Run 'ibmcloud ce application get -n myapp' to check the application status.
OK

https://myapp.4idmmq6xpss.us-south.codeengine.appdomain.cloud

The following table summarizes the options that are used with the app create command in this example. For more information about the command and its options, see the ibmcloud ce app create command.

Table 1. Command description
Option	Description
`--name`	The name of the application. Use a name that is unique within the project. This value is required. The name must begin with a lowercase letter. The name must end with a lowercase alphanumeric character. The name must be 55 characters or fewer and can contain letters, numbers, and hyphens (-).
`--image`	The name of the image that is used for this application. This value is required. The format is `REGISTRY/NAMESPACE/REPOSITORY:TAG` where `REGISTRY` and `TAG` are optional. If `TAG` is not specified, the default is `latest`. For images in Docker Hub, you can specify the image with `NAMESPACE/REPOSITORY`, as the default for `Registry` is `docker.io`. For other registries, use `REGISTRY/NAMESPACE/REPOSITORY` or `REGISTRY/NAMESPACE/REPOSITORY:TAG`.

Next steps

After your app deploys, access your app through a URL.
You can create a custom domain mapping and assign it to your app. For more information about deploying apps across multiple regions with a custom domain name, see Configuring a highly available application.
Now that your app is deployed, consider making your apps event-driven. By using event subscriptions, you can trigger your apps by periodic schedules or set your app to react to events such as file uploads or Kafka messages.

After your app is deployed, you can update your deployed app and its referenced code by using any of the following ways, independent of how you created or previously updated your app:

If you have a container image, per the Open Container Initiative (OCI) standard, then you need to provide only a reference to the image, which points to the location of your container registry when you deploy your app. You can deploy your app with an image in a public registry or private registry.

If you created your app by using the app create command and you specified the --build-source option to build the container image from local or repository source, and you want to change your app to point to a different container image, you must first remove the association of the build from your app. For example, run ibmcloud ce application update -n APP_NAME --build-clear. After you remove the association of the build from your app, you can update the app to reference a different image.
If you are starting with source code that resides in a Git repository, you can choose to let Code Engine take care of building the image from your source and deploying the app with a single operation. In this scenario, Code Engine uploads your image to IBM Cloud® Container Registry. To learn more, see Deploying your app from repository source code. If you want more control over the build of your image, then you can choose to build the image with Code Engine before you deploy your app.
If you are starting with source code that resides on a local workstation, you can choose to let Code Engine take care of building the image from your source and deploying the app with a single CLI command. In this scenario, Code Engine uploads your image to IBM Cloud® Container Registry. To learn more, see Deploying your app from local source code with the CLI. If you want more control over the build of your image, then you can choose to build the image with Code Engine before you deploy your app.

For example, you might choose to let Code Engine handle the build of your local source while you evolve the development of your source for the app. Then, after the image is matured, you can update the deployed app to reference the specific image that you want. You can repeat this process as needed.

When you deploy your updated app, the latest version of your referenced container image is downloaded and deployed, unless a tag is specified for the image. If a tag is specified for the image, then the tagged image is used for the deployment.

Looking for more code examples? Check out the Samples for IBM Cloud Code Engine GitHub repo.