AWS Chalice
AWS Chalice is a serverless micro framework used to develop and deploy your serverless applications on AWS resources. Chalice provides integrated functionality with most of the AWS Toolings like S3 Storage, Simple Queue Service, API Gateway and more. It offers a handy CLI interface that allows you to easily create, develop & deploy your serverless applications.
LocalStack offers an AWS Chalice client that allows you to interact with your Chalice applications locally. Using LocalStack, you can kick-start your development process, create a new Chalice application, and test it application locally.
Creating a new Chalice project
Section titled “Creating a new Chalice project”Start LocalStack inside a Docker container by running:
localstack start -d
Install the chalice-local
package by running:
pip install chalice-local
You can now create a new Chalice project by running:
chalice-local new-project
You will be prompted with an interactive menu where you can choose the name of your project and the project type.
In this example, we are using localstack-test
as the project name and REST API
as the project type:
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The python serverless microframework for AWS allowsyou to quickly create and deploy applications usingAmazon API Gateway and AWS Lambda.
Please enter the project name[?] Enter the project name: localstack-test[?] Select your project type: REST API > REST API S3 Event Handler Lambda Functions only Legacy REST API Template [CDK] Rest API with a DynamoDB table
Your project has been generated in ./localstack-test
Let’s take a look inside the project structure:
- app.py
Directorychalicelib
- __init__.py
- requirements-dev.txt
- requirements.txt
Directorytests
- __init__.py
- test_app.py
The app.py
is our main API file.
It has only one Route that would assign the URL of the application to the function.
The decorators here primarily “wrap” functions here which makes it easy to write Code Logic by breaking them down into separate routes.
For now, our Application is serving only a JSON Message which is {'hello': 'world'}
.
Testing the Chalice API
Section titled “Testing the Chalice API”Just as with AWS, you can now test your API using chalice-local local
:
chalice-local localServing on http://127.0.0.1:8000
You can also do a curl
to test the API:
curl -X GET http://127.0.0.1:8000{"hello":"world"}
Deploying the Chalice API
Section titled “Deploying the Chalice API”You can use chalice-local deploy
to deploy the REST API now:
chalice-local deploy
Creating deployment package.Creating IAM role: localstack-test-devCreating lambda function: localstack-test-devCreating Rest APIResources deployed:- Lambda ARN: arn:aws:lambda:us-east-1:000000000000:function:localstack-test-dev- Rest API URL: https://y5iuni004m.execute-api.us-east-1.amazonaws.com/api/
We now have our Chalice Application deployed on a Lambda Amazon Resource Name (ARN) along with a REST API URL.