It’s now possible to run Bash scripts in AWS Lambda functions & the steps to do so are rather simple. Just create a Lambda function as shown below:

This will create a Lambda with a hello.sh file:

function handler () {
    EVENT_DATA=$1

    RESPONSE="{\"statusCode\": 200, \"body\": \"Hello from Lambda!\"}"
    echo $RESPONSE
}

Add your Bash code to it & run:

function handler () {
    EVENT_DATA=$1
    DATA=`ls` # "ls" is in backticks
    RESPONSE="{\"statusCode\": 200, \"body\": \"$DATA\"}"
    echo $RESPONSE
}

Response:
{
  "statusCode": 200,
  "body": "bootstrap hello.sh README.md"
}