serverless-offline-direct-lambda

A Serverless Offline plugin that exposes lambdas with no API Gateway event via HTTP, to allow offline direct lambda-to-lambda interactions.

Setup

Note - this requires the plugin 'serverless-offline'.

To include in your project, add the following to the plugins section in serverless.yml:

``
- serverless-offline-direct-lambda
`

You may also want to change the port that the plugin runs on - you can do this by specifying the following custom config in your serverless yml file:

`yml
custom:
serverless-offline:
port: 4000
`

Running & Calling

To run:

`
servlerless offline start
`

(calling the command 'start' is necessary to trigger the plugin, simply running 'serverless online' does not trigger the start hooks).

The plugin will create api-gateway proxies for all lambdas with no triggering events.

You will see output like this:

`bash
export AWS_SDK_USED=node

sls offline start

Serverless: Running Serverless Offline with direct lambda support
Serverless: Starting Offline: dev/us-east-1.

Serverless: Routes for myLambda:
Serverless: (none)

Serverless: Routes for my-project-dev-myLambda_proxy:
Serverless: POST /proxy/my-project-dev-myLambda
Serverless: POST /2015-03-31/functions/my-project-dev-myLambda/invocations
`

$3

The body of the POST should match the JSON data that would ordinarily be passed in a lambda-to-lambda call. i.e.

`bash
curl -X POST \
http://localhost:4000/proxy/my-project-dev-myLambda \
-H 'Cache-Control: no-cache' \
-H 'Content-Type: application/json' \
-d '{
"some-key": "some-value",
"other-key": false
}'
`

$3

You may also invoke the function by using the AWS SDK on your client side...
This can be done by specifying a custom "endpoint" in your Lambda configuration like so:

Note: the AWS SDK for NodeJS actually sends a different content type header on it's request to the Lambda API then all the other AWS SDK's (Python, Rails etc).. You will need to export AWS_SDK_USED=node before running the serverless offline if you wish to use this with the NodeJS AWS SDK.

`javascript

var AWS = require('aws-sdk');
AWS.config.region = 'us-east-1';

let lambda = new AWS.Lambda({
region: 'us-east-1',
endpoint: 'http://localhost:4000'
})

var lambda_args = {
"some-key": "some-value",
"other-key": false
}

var params = {
FunctionName: 'my-project-dev-myLambda', // the lambda function we are going to invoke
Payload: JSON.stringify(lambda_args)
};

lambda.invoke(params, function(err, data) {
if (err) {
console.error(err);
} else {
console.dir(data);
}
})

``