# Update container configuration
<a name="studio-updated-byoi-how-to-container-configuration"></a>

You can bring custom Docker images into your machine learning workflows. A key aspect of customizing these images is configuring the container configurations, or [https://docs.aws.amazon.com/sagemaker/latest/APIReference/API_ContainerConfig.html](https://docs.aws.amazon.com/sagemaker/latest/APIReference/API_ContainerConfig.html). The following page provides an example on how to configure your `ContainerConfig`. 

An entrypoint is the command or script that runs when the container starts. Custom entrypoints enable you to set up your environment, initialize services, or perform any necessary setup before your application launches. 

This example provides instructions on how to configure a custom entrypoint, for your JupyterLab application, using the AWS CLI. This example assumes that you have already created a custom image and domain. For instructions, see [Attach your custom image to your domain](studio-updated-byoi-how-to-attach-to-domain.md).

1. First set your variables for the AWS CLI commands that follow.

   ```
   APP_IMAGE_CONFIG_NAME=app-image-config-name
   ENTRYPOINT_FILE=entrypoint-file-name
   ENV_KEY=environment-key
   ENV_VALUE=environment-value
   REGION=aws-region
   DOMAIN_ID=domain-id
   IMAGE_NAME=custom-image-name
   IMAGE_VERSION=custom-image-version
   ```
   + `app-image-config-name` is the name of your application image configuration.
   + `entrypoint-file-name` is the name of your container's entrypoint script. For example, `entrypoint.sh`.
   + `environment-key` is the name of your environment variable.
   + `environment-value` is the value assigned to your environment variable.
   + `aws-region` is the AWS Region of your Amazon SageMaker AI domain. You can find this at the top right of any AWS console page. 
   + `domain-id` is your domain ID. To view your domains, see [View domains](domain-view.md).
   + `custom-image-name` is the name of your custom image. To view your custom image details, see [View custom image details (console)](studio-updated-byoi-view-images.md#studio-updated-byoi-view-images-console).

     If you followed the instructions in [Attach your custom image to your domain](studio-updated-byoi-how-to-attach-to-domain.md), you may want to use the same image name you used in that process.
   + `custom-image-version` is the version number of your custom image. This should be an integer, representing the version of your image. To view your custom image details, see [View custom image details (console)](studio-updated-byoi-view-images.md#studio-updated-byoi-view-images-console).

1. Use the [https://docs.aws.amazon.com/sagemaker/latest/APIReference/API_CreateAppImageConfig.html](https://docs.aws.amazon.com/sagemaker/latest/APIReference/API_CreateAppImageConfig.html) API to create an image configuration.

   ```
   aws sagemaker create-app-image-config \
       --region ${REGION} \
       --app-image-config-name "${APP_IMAGE_CONFIG_NAME}" \
       --jupyter-lab-app-image-config "ContainerConfig = {
           ContainerEntrypoint = "${ENTRYPOINT_FILE}", 
           ContainerEnvironmentVariables = {
               "${ENV_KEY}"="${ENV_VALUE}"
           }
       }"
   ```

1. Use the [https://docs.aws.amazon.com/sagemaker/latest/APIReference/API_UpdateDomain.html](https://docs.aws.amazon.com/sagemaker/latest/APIReference/API_UpdateDomain.html) API to update the default settings for your domain. This will attach the custom image as well as the application image configuration. 

   ```
   aws sagemaker update-domain \
       --region ${REGION} \
       --domain-id "${DOMAIN_ID}" \
       --default-user-settings "{
           \"JupyterLabAppSettings\": {
               \"CustomImages\": [
                   {
                       \"ImageName\": \"${IMAGE_NAME}\",
                       \"ImageVersionNumber\": ${IMAGE_VERSION},
                       \"AppImageConfigName\": \"${APP_IMAGE_CONFIG_NAME}\"
                   }
               ]
           }
       }"
   ```