Creating a Lambda function using CLI

Follow these steps to deploy a Cloudera DataFlow Function using the AWS CLI.

Your Apache NiFi flow definition is stored in the Cloudera DataFlow Catalog and you have the CRN corresponding to the flow version you want to execute as a function
You have created a Machine User with the proper role and you have its Access Key and Private Key credentials
You have installed and configured the AWS CLI on your local machine

Create a role for your Lambda.

aws iam create-role --role-name my_function_role --assume-role-policy-document '{"Version": "2012-10-17","Statement": [{ "Effect": "Allow", "Principal": {"Service": "lambda.amazonaws.com"}, "Action": "sts:AssumeRole"}]}'

Attach the basic AWS Lambda policy to your role.

aws iam attach-role-policy --role-name my_function_role --policy-arn arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole

Copy the following file as a local file named my-function-definition.json.

{
    "FunctionName": "first-cli-function",
    "Description": "my first cli function",
    "Timeout": 300,
    "MemorySize": 1024,
    "Environment": {
        "Variables": {
            "DF_ACCESS_KEY": "00000000-0000-0000-0000-000000000000",
            "DF_PRIVATE_KEY": "00000000000000000000000000000000000",
            "FLOW_CRN": "crn:cdp:df:us-west-1:00000000-0000-0000-0000-000000000000:flow:my-flow/v.1"
        }
    },
    "Tags": {
        "tagKey": "tagValue"
    },


    "EphemeralStorage": {
        "Size": 2048
    },
    "Code": {
        "S3Bucket": "my-bucket",
        "S3Key": "naaf-aws-lambda-1.0.0-bin.zip"
    },
    "Role": "arn:aws:iam::327162129569:role/service-role/My-Role",


    "Runtime": "java11",
    "Handler": "com.cloudera.naaf.aws.lambda.StatelessNiFiFunctionHandler::handleRequest",
    "Publish": false,
    "PackageType": "Zip",
    "Architectures": [
        "x86_64"
    ]
}

Update the three sections of the JSON file.
The JSON file is generally structured into three sections.
1. The first section is expected to be updated with each function. It includes Function Name, Description, Timeout, Memory Size, Tags, and Environment Variables.
  The Environment Variables must include the following 3 environment variables:
  - DF_ACCESS_KEY: The Cloudera DataFlow Access Key
  - DF_PRIVATE_KEY: The Cloudera DataFlow Private Key
  - FLOW_CRN: The CRN of the specific version of the Cloudera DataFlow in the Cloudera DataFlow Catalog. This always ends with /v.<number>.
  Additionally, you can use environment variables to specify parameters for the dataflow.
2. The second section of the JSON file contains fields that will likely be updated once when customizing the template for your particular organization. You should add the ARN of the role you created during the first step.
3. The third section of the JSON file contains fields that will likely remain the same.
Create the Lambda function.
```
aws lambda create-function --cli-input-json file://my-function-definition.json
```
The function is now created. You can check it on the AWS Lambda UI and test the configuration.

Use the AWS Lambda UI or CLI to publish a version of the function.

aws lambda publish-version --function-name <function name or function ARN>

Use the AWS Lambda UI or CLI to specify the appropriate trigger for your published version.