AWS Serverless

Introduction

This is an example of how to set up a serverless framework function within AWS

Setup

Within AWS there are example templates for each piece of the infrastructure. For this we need to create a

• S3 Bucket to hold the code
• IAM::Role to describe the permissions
• Lambda The function to run

Templates

I have copied the example templates for each component and highlighted the ones we need to change

S3 Bucket

Example can be found here

{
    "Resources": {
        "cowsayBucket": {
            "Type": "AWS::S3::Bucket",
            "DeletionPolicy": "Retain", // No required
            "Properties": {
                "BucketName": "cowsayBucket"
            }
        }
    }
}

IAM::Role

Example can be found here

{
   "AWSTemplateFormatVersion": "2010-09-09",
   "Resources": {
      "RootRole": {
         "Type": "AWS::IAM::Role",
         "Properties": {
            "AssumeRolePolicyDocument": {
               "Version" : "2012-10-17",
               "Statement": [ {
                  "Effect": "Allow",
                  "Principal": {
                     "Service": [ "ec2.amazonaws.com" ]
                  },
                  "Action": [ "sts:AssumeRole" ]
               } ]
            },
            "Path": "/"
         }
      },
      "RolePolicies": {
         "Type": "AWS::IAM::Policy",
         "Properties": {
            "PolicyName": "root",
            "PolicyDocument": {
               "Version" : "2012-10-17",
               "Statement": [ {
                  "Effect": "Allow",
                  "Action": "*",
                  "Resource": "*"
               } ]
            },
            "Roles": [ {
               "Ref": "RootRole"
            } ]
         }
      },
      "RootInstanceProfile": {
         "Type": "AWS::IAM::InstanceProfile",
         "Properties": {
            "Path": "/",
            "Roles": [ {
               "Ref": "RootRole"
            } ]
         }
      }
   }
}

Lambda Function

Example can be found here

"AMIIDLookup": {
    "Type": "AWS::Lambda::Function",
    "Properties": {
        "Handler": "index.handler",
        "Role": {
            "Fn::GetAtt": [
                "LambdaExecutionRole",
                "Arn"
            ]
        },
        "Code": {
            "S3Bucket": "lambda-functions",
            "S3Key": "amilookup.zip"
        },
        "Runtime": "nodejs12.x",
        "Timeout": 25,
        "TracingConfig": {
            "Mode": "Active"
        }
    }
}