Build an HTTP API Endpoint

HTTP endpoints have become one of the most ubiquitous ways of delivering software to end users. Cdev provides a simple interface for creating HTTP APIs and connecting them to Serverless Functions. You can find more information about HTTP in the official documentation.

Create an API and Route

    

        
            
            
    
    import json

from cdev.aws.api import Api
from cdev.aws.lambda_function import ServerlessFunction

from cdev import Project as cdev_project

myProject = cdev_project.instance()

myApi = Api("demoApi")

hello_world_get_route = DemoApi.route("/hello_world", "GET")

Integrate GET route with a Serverless Function

    

        
            
            
    
    import json

from cdev.aws.api import Api
from cdev.aws.lambda_function import ServerlessFunction

from cdev import Project as cdev_project

myProject = cdev_project.instance()

myApi = Api("demoApi")

hello_world_get_route = myApi.route("/hello_world", "GET")


@ServerlessFunction("demo_function", events=[hello_world_get_route.event()])
def hello_world(event, context):
    """
    This is an example function connected to an example API route
    """
    message = {
        "message": "Hello World from Lambda!"
    }

    return {
        "isBase64Encoded": False,
        "status_code": 200, 
        "body": json.dumps(message),
        "headers": {
            "Content-Type": "application/json"
        }
    }


myProject.display_output("Base API URL", myApi.output.endpoint)
myProject.display_output("Routes", myApi.output.endpoints)

Get your endpoint

Get the live url for your endpoint:

cdev output <component_name>.api.demoApi.endpoint

You can test the endpoint with the following commands from your terminal:

curl <your_endpoint>/hello_world

Integrate POST route with data to a Serverless function

    

        
            
            
    
    import json

from cdev.aws.api import Api
from cdev.aws.lambda_function import ServerlessFunction

from cdev import Project as cdev_project

myProject = cdev_project.instance()

myApi = Api("demoApi")

send_data_route = myApi.route("/send_data", "POST")


@ServerlessFunction("send_data_handler", events=[send_data_route.event()])
def hello_world(event, context):
    
    """
    This is an example function connected to an example POST API route that can receive data
    """

    print(event)

    data = json.loads(event.get("body"))

    print(data)
    message = {
        "message": "Handled Data"
    }

    return {
        "isBase64Encoded": False,
        "status_code": 200, 
        "body": json.dumps(message),
        "headers": {
            "Content-Type": "application/json"
        }
    }


myProject.display_output("Base API URL", myApi.output.endpoint)
myProject.display_output("Routes", myApi.output.endpoints)

Test your POST endpoint

Save and deploy your endpoint with the following commands:

cdev plan

cdev deploy

Get the live url for your endpoint:

cdev output <component_name>.api.demoApi.endpoint

You can test the endpoint with the follow commands from your terminal:

curl -X POST <your_endpoint>/send_data -H 'Content-Type: application/json' -d "{\"login\":\"my_login\"}"

Check the logs of your function

cdev run function.logs <component_name>.send_data_handler

Return Values from Function

From the AWS Documentation, API Gateway makes the following assumptions if your Lambda function returns valid JSON and does not return a statusCode:

• isBase64Encoded is false.
• statusCode is 200.
• content-type is application/json.
• body is the function's response.

Examples:

Function Response

return "Hello from Lambda!"

API Gateway Response

{
  "isBase64Encoded": false,
  "statusCode": 200,
  "body": "Hello from Lambda!",
  "headers": {
    "content-type": "application/json"
  }
}

Function Response

return { "message": "Hello from Lambda!" }

API Gateway Response

{
  "isBase64Encoded": false,
  "statusCode": 200,
  "body": "{ \"message\": \"Hello from Lambda!\" }",
  "headers": {
    "content-type": "application/json"
  }
}

If you want to customize your return value completely, it should have the form:

return {
    "cookies" : ["cookie1", "cookie2"],
    "isBase64Encoded": True|False,
    "statusCode": httpStatusCode,
    "headers": { "headername": "headervalue", ... },
    "body": "Hello from Lambda!"
}

return {
    "cookies" : ["cookie1", "cookie2"],
    "isBase64Encoded": True|False,
    "statusCode": httpStatusCode,
    "headers": { "headername": "headervalue", ... },
    "body": json.dumps({
        "message" :"Hello from Lambda!"
    })
}