Azure Functions

This section helps you to check the list of actions you must perfom before you start working on your function.

You have the latest version of the Azure Functions CLI.
You have jq installed to extract some information from the JSON responses when executing commands.

Start by setting all the parameters required for deploying your function using the Azure CLI.

# Name of the binary you download from the Cloudera Public Cloud control plane.
FILEKEY="NaafAzureFunctions.zip"

# Location where the function will be deployed. Change this value to match your needs/requirements.
LOCATION=francecentral

# Name of the file share where the binary will be uploaded. Change this value to match your needs/requirements.
BUCKET_NAME=mydffresizeimagebucket

# Name of the function (only lower case letters). Change this value to match your needs/requirements.
FUNCTIONNAME=resizeimageabc

# Flow CRN. Add the Customer Resource Number you obtained from the Cloudera DataFlow Catalog.
FLOW_CRN=***YOUR VALUE HERE***

# Credentials of the machine user
DF_ACCESS_KEY=***YOUR VALUE HERE***
DF_PRIVATE_KEY=***YOUR VALUE HERE***

# Name of the resource group that is going to be created for the function. Change this value to match your needs/requirements.
RESOURCEGROUP=MyDFFResourceGroup

# Subscription ID to use. Change this value to match your needs/requirements.
SUBSCRIPTIONID=***YOUR VALUE HERE***

# Name of the hosting plan that is going to be created for the function. Change this value to match your needs/requirements.
HOSTINGPLANNAME=MyHostingPlanDFF

# Name of the storage account that is going to be created (only lower case letters). Change this value to match your needs/requirements.
STORAGEACCOUNTNAME=mydffstorageaccountname

Download the deployment template from here.

Execute the below commands:

Create a resource group.

az group create -l $LOCATION -n $RESOURCEGROUP

echo "please

Deploy the Function App.


az deployment group create --resource-group $RESOURCEGROUP \
	--template-file template.json \
	--parameters \
	    subscriptionId=$SUBSCRIPTIONID \
	    name=$FUNCTIONNAME \
	    location=$LOCATION \
	    hostingPlanName=$HOSTINGPLANNAME \
	    resourceGroup=$RESOURCEGROUP \
	    storageAccountName=$STORAGEACCOUNTNAME \
	    FLOW_CRN=$FLOW_CRN \
	    DF_ACCESS_KEY=$DF_ACCESS_KEY \
	    DF_PRIVATE_KEY=$DF_PRIVATE_KEY

echo "please wait a bit more (10 sec)..."
sleep 10

Retrieve the file share name created in the previous step.

FILESHARE=`az storage share list --account-name $STORAGEACCOUNTNAME | jq -r '.[0].name'`

Create the right directories for the binary.

az storage directory create --account-name $STORAGEACCOUNTNAME --share-name $FILESHARE --name data
az storage directory create --account-name $STORAGEACCOUNTNAME --share-name $FILESHARE --name data/SitePackages

Upload the binary and the metadata file.

az storage file upload -s $FILESHARE --source $FILEKEY --path data/SitePackages/ --account-name $STORAGEACCOUNTNAME

echo "$FILEKEY" > /tmp/packagename.txt && az storage file upload -s $FILESHARE --source /tmp/packagename.txt --path data/SitePackages/ --account-name $STORAGEACCOUNTNAME && rm /tmp/packagename.txt

When the execution is complete (it takes a few minutes), the function will be publicly listening on:

https://<function
        name>.azurewebsites.net/api/StatelessNiFiHttpBinaryTriggerFunction

You can now use a tool like Postman to send your picture.

Make sure to override the Content-Type header with application/octet-stream.

You can add two custom headers (resize-width and resize-height) to specify the resizing dimensions. If not specified, the default values of the NiFi flow parameters are used.

It is possible to send a request to your function using curl.

For example:

curl -X POST https://myresizeimage.azurewebsites.net/api/StatelessNiFiHttpBinaryTriggerFunction \
-H "Content-Type: application/octet-stream" \
-H "resize-width: 400" \
-H "resize-height: 200" \
--data-binary "@/Users/pierre/Desktop/test.png" \
--output /tmp/my_resized_image.png

You can delete the function using the following command: az group delete --name $RESOURCEGROUP --yes