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Deploy models with REST

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Learn how to use the Azure Machine Learning REST API to deploy models.

The REST API uses standard HTTP verbs to create, retrieve, update, and delete resources. The REST API works with any language or tool that can make HTTP requests. REST's straightforward structure makes it a good choice in scripting environments and for MLOps automation.

In this article, you learn how to use the new REST APIs to:

  • Create machine learning assets
  • Create a basic training job
  • Create a hyperparameter tuning sweep job

Prerequisites

Set endpoint name

Note

Endpoint names need to be unique at the Azure region level. For example, there can be only one endpoint with the name my-endpoint in westus2.

export ENDPOINT_NAME=endpt-rest-`echo $RANDOM`

Azure Machine Learning online endpoints

Online endpoints allow you to deploy your model without having to create and manage the underlying infrastructure as well as Kubernetes clusters. In this article, you'll create an online endpoint and deployment, and validate it by invoking it. But first you'll have to register the assets needed for deployment, including model, code, and environment.

There are many ways to create an Azure Machine Learning online endpoint including the Azure CLI, and visually with the studio. The following example an online endpoint with the REST API.

Create machine learning assets

First, set up your Azure Machine Learning assets to configure your job.

In the following REST API calls, we use SUBSCRIPTION_ID, RESOURCE_GROUP, LOCATION, and WORKSPACE as placeholders. Replace the placeholders with your own values.

Administrative REST requests a service principal authentication token. Replace TOKEN with your own value. You can retrieve this token with the following command:

response=$(curl -H "Content-Length: 0" --location --request POST "https://management.azure.com/subscriptions/$SUBSCRIPTION_ID/resourceGroups/$RESOURCE_GROUP/providers/Microsoft.MachineLearningServices/workspaces/$WORKSPACE/onlineEndpoints/$ENDPOINT_NAME/token?api-version=$API_VERSION" \
--header "Authorization: Bearer $TOKEN")
accessToken=$(echo $response | jq -r '.accessToken')

The service provider uses the api-version argument to ensure compatibility. The api-version argument varies from service to service. Set the API version as a variable to accommodate future versions:

API_VERSION="2022-05-01"

Get storage account details

To register the model and code, first they need to be uploaded to a storage account. The details of the storage account are available in the data store. In this example, you get the default datastore and Azure Storage account for your workspace. Query your workspace with a GET request to get a JSON file with the information.

You can use the tool jq to parse the JSON result and get the required values. You can also use the Azure portal to find the same information:

# Get values for storage account
response=$(curl --location --request GET "https://management.azure.com/subscriptions/$SUBSCRIPTION_ID/resourceGroups/$RESOURCE_GROUP/providers/Microsoft.MachineLearningServices/workspaces/$WORKSPACE/datastores?api-version=$API_VERSION&isDefault=true" \
--header "Authorization: Bearer $TOKEN")
AZUREML_DEFAULT_DATASTORE=$(echo $response | jq -r '.value[0].name')
AZUREML_DEFAULT_CONTAINER=$(echo $response | jq -r '.value[0].properties.containerName')
export AZURE_STORAGE_ACCOUNT=$(echo $response | jq -r '.value[0].properties.accountName')

Upload & register code

Now that you have the datastore, you can upload the scoring script. Use the Azure Storage CLI to upload a blob into your default container:

az storage blob upload-batch -d $AZUREML_DEFAULT_CONTAINER/score -s endpoints/online/model-1/onlinescoring

Tip

You can also use other methods to upload, such as the Azure portal or Azure Storage Explorer.

Once you upload your code, you can specify your code with a PUT request and refer to the datastore with datastoreId:

curl --location --request PUT "https://management.azure.com/subscriptions/$SUBSCRIPTION_ID/resourceGroups/$RESOURCE_GROUP/providers/Microsoft.MachineLearningServices/workspaces/$WORKSPACE/codes/score-sklearn/versions/1?api-version=$API_VERSION" \
--header "Authorization: Bearer $TOKEN" \
--header "Content-Type: application/json" \
--data-raw "{
  \"properties\": {
    \"codeUri\": \"https://$AZURE_STORAGE_ACCOUNT.blob.core.windows.net/$AZUREML_DEFAULT_CONTAINER/score\"
  }
}"

Upload and register model

Similar to the code, Upload the model files:

az storage blob upload-batch -d $AZUREML_DEFAULT_CONTAINER/model -s endpoints/online/model-1/model

Now, register the model:

curl --location --request PUT "https://management.azure.com/subscriptions/$SUBSCRIPTION_ID/resourceGroups/$RESOURCE_GROUP/providers/Microsoft.MachineLearningServices/workspaces/$WORKSPACE/models/sklearn/versions/1?api-version=$API_VERSION" \
--header "Authorization: Bearer $TOKEN" \
--header "Content-Type: application/json" \
--data-raw "{
    \"properties\": {
        \"modelUri\":\"azureml://subscriptions/$SUBSCRIPTION_ID/resourceGroups/$RESOURCE_GROUP/workspaces/$WORKSPACE/datastores/$AZUREML_DEFAULT_DATASTORE/paths/model\"
    }
}"

Create environment

The deployment needs to run in an environment that has the required dependencies. Create the environment with a PUT request. Use a docker image from Microsoft Container Registry. You can configure the docker image with Docker and add conda dependencies with condaFile.

In the following snippet, the contents of a Conda environment (YAML file) has been read into an environment variable:

ENV_VERSION=$RANDOM
curl --location --request PUT "https://management.azure.com/subscriptions/$SUBSCRIPTION_ID/resourceGroups/$RESOURCE_GROUP/providers/Microsoft.MachineLearningServices/workspaces/$WORKSPACE/environments/sklearn-env/versions/$ENV_VERSION?api-version=$API_VERSION" \
--header "Authorization: Bearer $TOKEN" \
--header "Content-Type: application/json" \
--data-raw "{
    \"properties\":{
        \"condaFile\": \"$CONDA_FILE\",
        \"image\": \"mcr.microsoft.com/azureml/openmpi3.1.2-ubuntu18.04:20210727.v1\"
    }
}"

Create endpoint

Create the online endpoint:

response=$(curl --location --request PUT "https://management.azure.com/subscriptions/$SUBSCRIPTION_ID/resourceGroups/$RESOURCE_GROUP/providers/Microsoft.MachineLearningServices/workspaces/$WORKSPACE/onlineEndpoints/$ENDPOINT_NAME?api-version=$API_VERSION" \
--header "Content-Type: application/json" \
--header "Authorization: Bearer $TOKEN" \
--data-raw "{
    \"identity\": {
       \"type\": \"systemAssigned\"
    },
    \"properties\": {
        \"authMode\": \"AMLToken\"
    },
    \"location\": \"$LOCATION\"
}")

Create deployment

Create a deployment under the endpoint:

response=$(curl --location --request PUT "https://management.azure.com/subscriptions/$SUBSCRIPTION_ID/resourceGroups/$RESOURCE_GROUP/providers/Microsoft.MachineLearningServices/workspaces/$WORKSPACE/onlineEndpoints/$ENDPOINT_NAME/deployments/blue?api-version=$API_VERSION" \
--header "Content-Type: application/json" \
--header "Authorization: Bearer $TOKEN" \
--data-raw "{
    \"location\": \"$LOCATION\",
    \"sku\": {
        \"capacity\": 1,
        \"name\": \"Standard_DS2_v2\"
    },
    \"properties\": {
        \"endpointComputeType\": \"Managed\",
        \"scaleSettings\": {
            \"scaleType\": \"Default\"
        },
        \"model\": \"/subscriptions/$SUBSCRIPTION_ID/resourceGroups/$RESOURCE_GROUP/providers/Microsoft.MachineLearningServices/workspaces/$WORKSPACE/models/sklearn/versions/1\",
        \"codeConfiguration\": {
            \"codeId\": \"/subscriptions/$SUBSCRIPTION_ID/resourceGroups/$RESOURCE_GROUP/providers/Microsoft.MachineLearningServices/workspaces/$WORKSPACE/codes/score-sklearn/versions/1\",
            \"scoringScript\": \"score.py\"
        },
        \"environmentId\": \"/subscriptions/$SUBSCRIPTION_ID/resourceGroups/$RESOURCE_GROUP/providers/Microsoft.MachineLearningServices/workspaces/$WORKSPACE/environments/sklearn-env/versions/$ENV_VERSION\"
    }
}")

Invoke the endpoint to score data with your model

We need the scoring uri and access token to invoke the endpoint. First get the scoring uri:

response=$(curl --location --request GET "https://management.azure.com/subscriptions/$SUBSCRIPTION_ID/resourceGroups/$RESOURCE_GROUP/providers/Microsoft.MachineLearningServices/workspaces/$WORKSPACE/onlineEndpoints/$ENDPOINT_NAME?api-version=$API_VERSION" \
--header "Content-Type: application/json" \
--header "Authorization: Bearer $TOKEN")

scoringUri=$(echo $response | jq -r '.properties.scoringUri')

Get the endpoint access token:

response=$(curl -H "Content-Length: 0" --location --request POST "https://management.azure.com/subscriptions/$SUBSCRIPTION_ID/resourceGroups/$RESOURCE_GROUP/providers/Microsoft.MachineLearningServices/workspaces/$WORKSPACE/onlineEndpoints/$ENDPOINT_NAME/token?api-version=$API_VERSION" \
--header "Authorization: Bearer $TOKEN")
accessToken=$(echo $response | jq -r '.accessToken')

Now, invoke the endpoint using curl:

curl --location --request POST $scoringUri \
--header "Authorization: Bearer $accessToken" \
--header "Content-Type: application/json" \
--data-raw @endpoints/online/model-1/sample-request.json

Check the logs

Check the deployment logs:

curl --location --request POST "https://management.azure.com/subscriptions/$SUBSCRIPTION_ID/resourceGroups/$RESOURCE_GROUP/providers/Microsoft.MachineLearningServices/workspaces/$WORKSPACE/onlineEndpoints/$ENDPOINT_NAME/deployments/blue/getLogs?api-version=$API_VERSION" \
--header "Authorization: Bearer $TOKEN" \
--header "Content-Type: application/json" \
--data-raw "{ \"tail\": 100 }"

Delete the endpoint

If you aren't going use the deployment, you should delete it with the below command (it deletes the endpoint and all the underlying deployments):

curl --location --request DELETE "https://management.azure.com/subscriptions/$SUBSCRIPTION_ID/resourceGroups/$RESOURCE_GROUP/providers/Microsoft.MachineLearningServices/workspaces/$WORKSPACE/onlineEndpoints/$ENDPOINT_NAME?api-version=$API_VERSION" \
--header "Content-Type: application/json" \
--header "Authorization: Bearer $TOKEN" || true

Next steps