AWS Serverless Image Handler Lambda wrapper for Thumbor

A solution to dynamically handle images on the fly, utilizing Thumbor (thumbor.org). Published version, additional details and documentation are available here: https://aws.amazon.com/answers/web-applications/serverless-image-handler/

Docker Environment Setup

In order to build the package locally, you'll need to build the docker image. In order to do so, run the following command:

docker build -t serverless-image-handler .

This will build a docker image that has the following properties:

• pinned to the amazonlinux version that Lambda runs on
• pinned yum repository to releasever=2017.03
  • this is important when building pycurl so that the compiled version of libcurl does not differ from the runtime version on the Lambda AMI
• has all of the base requirements installed
  • libpng
  • libjpeg
  • pngcrush
  • gifsicle
  • optipng
  • pngquant

Building Lambda Package

To build the Lambda package, use the serverless-image-handler image that was built earlier. The following command will build the deployment packages:

• Now build the distributable

docker run -it --rm --volume $PWD:/lambda serverless-image-handler source-bucket-base-name $VERSION

source-bucket-base-name should be the base name for the S3 bucket location where the template will source the Lambda code from. The template will append '-[region_name]' to this value. For example: ./build-s3-dist.sh solutions The template will then expect the source code to be located in the solutions-[region_name] bucket

Located in deployment/dist

deployment/dist/
├── [2.0M]  serverless-image-handler-custom-resource.zip
├── [6.4M]  serverless-image-handler-ui.zip
├── [ 23K]  serverless-image-handler.template
└── [ 48M]  serverless-image-handler.zipN

• Deploy the distributable to an Amazon S3 bucket in your account. Note: you must have the AWS Command Line Interface installed.

aws s3 cp ./dist/ s3://$DIST_OUTPUT_BUCKET-[region_name]/serverless-image-handler/$VERSION/ --recursive --exclude "*" --include "*.zip"
aws s3 cp ./dist/serverless-image-handler.template s3://$TEMPLATE_OUTPUT_BUCKET/serverless-image-handler/$VERSION/

Note: In the above example, the solution template will expect the source code to be located in the my-bucket-name-[region_name] with prefix serverless-image-handler/my-version/serverless-image-handler.zip

• Get the link of the serverless-image-handler.template uploaded to your Amazon S3 bucket.
• Deploy the Serverless Image Handler solution to your account by launching a new AWS CloudFormation stack using the link of the serverless-image-handler.template

https://s3.amazonaws.com/my-bucket-name/serverless-image-handler/my-version/serverless-image-handler.template

SafeURL hash calculation

• For hash calculation with safe URL, use following snippet to find signed_path value

http_key='mysecuritykey' # security key provided to lambda env variable
http_path='200x200/smart/sub-folder/myimage.jpg' # sample options for myimage
hashed = hmac.new(str(http_key),str(http_path),sha1)
encoded = base64.b64encode(hashed.digest())
signed_path = encoded.replace('/','_').replace('+','-')

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Copyright 2017 Amazon.com, Inc. or its affiliates. All Rights Reserved.

Licensed under the Amazon Software License (the "License"). You may not use this file except in compliance with the License. A copy of the License is located at

http://aws.amazon.com/asl/

or in the "license" file accompanying this file. This file is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, express or implied. See the License for the specific language governing permissions and limitations under the License.