In an AWS lambda written in Node.js, I want to extract the following part of a URL when I do a GET call through the API gateway:
/devices/{id} --> {id} will be replaced by a value, and that is the value I want!
I know that to get QueryStringParameters you just use
event.queryStringParameters.[parameter name]
But how will I do this for path parameters, like for {id} above.
Also is there a good place where I can comprehensively learn about writing lambdas for APIs in Node.js?
Short answer:
const { id } = event.pathParameters;
I recently released a short training video that demonstrates in detail how to create API Gateway REST APIs and integrate them with AWS Lambda (NodeJS). Please check it out here:
I'm assuming you are using lambda proxy here i'm pasting the event object sample for lambda proxy.
{
"message": "Good day, John of Seattle. Happy Friday!",
"input": {
"resource": "/{proxy+}",
"path": "/Seattle",
"httpMethod": "POST",
"headers": {
"day": "Friday"
},
"queryStringParameters": {
"time": "morning"
},
"pathParameters": {
"proxy": "Seattle"
},
"stageVariables": null,
"requestContext": {
"path": "/{proxy+}",
"accountId": "123456789012",
"resourceId": "nl9h80",
"stage": "test-invoke-stage",
"requestId": "test-invoke-request",
"identity": {
"cognitoIdentityPoolId": null,
"accountId": "123456789012",
"cognitoIdentityId": null,
"caller": "AIDXXX...XXVJZG",
"apiKey": "test-invoke-api-key",
"sourceIp": "test-invoke-source-ip",
"accessKey": "ASIXXX...XXDQ5A",
"cognitoAuthenticationType": null,
"cognitoAuthenticationProvider": null,
"userArn": "arn:aws:iam::123456789012:user/kdeding",
"userAgent": "Apache-HttpClient/4.5.x (Java/1.8.0_131)",
"user": "AIDXXX...XXVJZG"
},
"resourcePath": "/{proxy+}",
"httpMethod": "POST",
"apiId": "r275xc9bmd"
},
"body": "{ \"callerName\": \"John\" }",
"isBase64Encoded": false
}
}
the path can be extracted from "path" key in event object, it can be accessed from event.path and after that you can use string manipulation function to further manipulate it.
I hope it helps !
Use brackets in the resource path, as image above. Then in node.js user the code below:
exports.handler = async function(event) {
let serviceId = event.pathParameters.id;
}
The solution is very similar to what you mentioned in the first place. Just use event.pathParameters instead of event.queryStringParameters.
Here I'm using /api/test/{id} as my resource path and using Lambda Proxy integration. I'm getting the following event when I hit https://www.dummyapi.com/dev/api/test/id-123456
