This project implements a set of microservices that coordinate in order to guarantee data consistency using AWS Lambda and the AWS serverless application model (SAM).
For this project we will use AWS Lambdas to implement several microservices that will run code in response to HTTP requests (using the Amazon API Gateway) and will coordinate in order to achieve data consistency. Below we provide some useful links with more information about the AWS systems being used for this project.
For developing microservices using lambdas AWS offers a set of command line interface tools and editor plugins that make development and deployment easier.
The setup process for configuring an AWS account with all the required prerequisits in order to start developing with AWS Lambdas can be found here. The guidelines below assume you have configured your AWS CLI credentials and have installed the AWS CDK CLI. Note: most of the provided code snippets work on Linux and MacOS, however the setup is very similar for Windows as well.
This is a blank project for Python development with CDK. The cdk.json file tells the CDK Toolkit how to execute your app. This project is set up like a standard Python project. The initialization process also creates a virtualenv within this project, stored under the .env directory. To create the virtualenv it assumes that there is a python3 (or python for Windows) executable in your path with access to the venv package. If for any reason the automatic creation of the virtualenv fails, you can create the virtualenv manually.
To manually create a virtualenv on MacOS and Linux:
$ python3 -m venv .env
After the init process completes and the virtualenv is created, you can use the following step to activate your virtualenv.
$ source .env/bin/activate
If you are a Windows platform, you would activate the virtualenv like this:
% .env\Scripts\activate.bat
Once the virtualenv is activated, you can install the required dependencies.
$ pip install -r requirements.txt
Note: for packaging external libraries used in our lambda functions the pip modules poetry and docker are used. When running any cdk commands, a .build folder will be created together with a .zip for any lambda that uses external libraries. Any externals should be added to setup.py and will automatically be picked up by the zip_asset_code.py script when creating the .build folder and will be shipped with the lambdas once the cloud stack is brought up.
At this point you can now synthesize the CloudFormation template for this code.
$ cdk synth
To add additional dependencies, for example other CDK libraries, just add them to your setup.py file and rerun the pip install -r requirements.txt command.
cdk lslist all stacks in the appcdk synthemits the synthesized CloudFormation templatecdk deploydeploy this stack to your default AWS account/regioncdk diffcompare deployed stack with current statecdk docsopen CDK documentation