Automated Resize & GreyScale Images in S3 with Lambda

export AWS_ACCESS_KEY_ID=my access key id
export AWS_SECRET_ACCESS_KEY=my secret key
export AWS_DEFAULT_REGION=region

# Change to your own unique S3 bucket name:
source_bucket=sas-image-upload-bucket

# Do not change this. Walkthrough code assumes this name
target_bucket=${source_bucket}resized

function=CreateThumbnailImage
lambda_execution_role_name=lambda-$function-execution
lambda_execution_access_policy_name=lambda-$function-execution-access
lambda_invocation_role_name=lambda-$function-invocation
lambda_invocation_access_policy_name=lambda-$function-invocation-access
log_group_name=/aws/lambda/$function

# Create S3 buckets
aws s3 mb s3://$source_bucket
aws s3 mb s3://$target_bucket

# Upload sample photo
wget -q -OHappyFace.jpg \
  https://c3.staticflickr.com/7/6209/6094281702_d4ac7290d3_b.jpg

aws s3 cp HappyFace.jpg s3://$source_bucket/

# JavaScript code as listed in walkthrough
#wget -q -O $function.js \
# http://run.alestic.com/lambda/aws-examples/CreateThumbnail.js

zip -r $function.zip $function.js node_modules

# Create IAM Role
lambda_execution_role_arn=$(aws iam create-role \
  --role-name "$lambda_execution_role_name" \
  --assume-role-policy-document '{
      "Version": "2012-10-17",
      "Statement": [
        {
          "Sid": "",
          "Effect": "Allow",
          "Principal": {
            "Service": "lambda.amazonaws.com"
          },
          "Action": "sts:AssumeRole"
        }
      ]
    }' \
  --output text \
  --query 'Role.Arn'
)
echo lambda_execution_role_arn=$lambda_execution_role_arn

aws iam put-role-policy \

  --role-name "$lambda_execution_role_name" \

  --policy-name "$lambda_execution_access_policy_name" \

  --policy-document '{

    "Version": "2012-10-17",

    "Statement": [

      {

        "Effect": "Allow",

        "Action": [

          "logs:*"

        ],

        "Resource": "arn:aws:logs:*:*:*"

      },

      {

        "Effect": "Allow",

        "Action": [

          "s3:GetObject"

        ],

        "Resource": "arn:aws:s3:::'$source_bucket'/*"

      },

      {

        "Effect": "Allow",

        "Action": [

          "s3:PutObject"

        ],

        "Resource": "arn:aws:s3:::'$target_bucket'/*"

      }

    ]

  }'

sleep 10

aws lambda create-function --function-name "$function" --zip-file "fileb://./$function.zip"   --role "$lambda_execution_role_arn"    --handler "$function.handler"   --timeout 30 --runtime nodejs8.10

cat > $function-data.json <<EOM

{

   "Records":[

      {

         "eventVersion":"2.0",

         "eventSource":"aws:s3",

         "awsRegion":"us-east-1",

         "eventTime":"1970-01-01T00:00:00.000Z",

         "eventName":"ObjectCreated:Put",

         "userIdentity":{

            "principalId":"AIDAJDPLRKLG7UEXAMPLE"

         },

         "requestParameters":{

            "sourceIPAddress":"127.0.0.1"

         },

         "responseElements":{

            "x-amz-request-id":"C3D13FE58DE4C810",

            "x-amz-id-2":"FMyUVURIY8/IgAtTv8xRjskZQpcIZ9KG4V5Wp6S7S/JRWeUWerMUE5JgHvANOjpD"

         },

         "s3":{

            "s3SchemaVersion":"1.0",

            "configurationId":"testConfigRule",

            "bucket":{

               "name":"$source_bucket",

               "ownerIdentity":{

                  "principalId":"A3NL1KOZZKExample"

               },

               "arn":"arn:aws:s3:::$source_bucket"

            },

            "object":{

               "key":"HappyFace.jpg",

               "size":1024,

               "eTag":"d41d8cd98f00b204e9800998ecf8427e",

               "versionId":"096fKKXTRTtl3on89fVO.nfljtsv6qko"

            }

         }

      }

   ]

}

EOM