This is a SAM template file to build decimal to roman number function it uses python3.8 docker image and put app.py which contains business logic It includes a decimal number to roman number converter AWS lambda function which works as an image(no zip) and AWS api gateway to test it easier
- Execute sam build and sam deploy in orderly to if code is changed or to create from scratch
- Execute sam local invoke -e ./events/decimal_success.json to test lambda function locally. Docker enginge should be working for local development and testing
- Fill ./tests/test.sh first with api key and execute it. The payload is only data for request body no need to send full http-request here because api gateway will transform it.
- Need api key and will be provided by email due not to add any secret key git history
- Sam Template
- AWS Api Gateway
- AWS Lambda Function
- AWS Elastic Container Registry
- Python3.8
- Docker
Sam is not only resource definition template, it is also build tool and create needing resources
Sam template named as template.yaml and located in ./decimal_to_roman/template.yaml
It has resource definitions of Api Gateway and Lambda Function. Whenever sam build command executed, it builds project and docker image using ./decimal_to_roman/Dockerfile and create .aws-sam folder.
.aws-sam folder includes compiled template.yaml file which merge data from sam build params and build.toml is for image definitions
Sam template create roles under the hood in contrast to native cloudformation.
It is described in template.yaml and binded to lambda function in order to call it. ApiKeyRequired is enabled to prevent abusing api gateway. So api keys created for the users. x-api-key: should be added to header of request. Api has has only 1 endpoint and http-medhod which is post : /decimaltoroman
It is described in template.yaml and binded to api gateway by using Events section
When create_ecr_repo.sh is executed needing ecr repository will be created. Usual deployment progress doesn't to create repo once it is created. When sam deploy is executed sam publish already built docker image to ECR repo by checking build.toml
Even Python is not installed build and deployment phased of project can work due to pulling python runtime docker.
Key point of easy shipment is docker. Even lambda has different virtulization technology than docker it accepts docker images. lambda use use more performant way similar to https://firecracker-microvm.github.io/ because it excluded needless implementation as new containerd is doing
- Api key is not working with postman although it is working with curl
- ECR repo creation could be done by template.yaml
- Prod and test enviroment deployments could be done by using parameters in template.yaml