Mock ALB for invoking AWS Lambda's over HTTP using express.
npm install lambda-alb
A mock ALB using express that enables invoking a lambda locally using HTTP.
It supports multple lambda's mapped to various routes. Can be configured to use either a mock AWS setup, such as localstack, or an actual AWS region.
GitHub Repo: https://github.com/djfdyuruiry/lambda-alb
Docker Hub: https://hub.docker.com/r/djfdyuruiry/lambda-alb
Read the full typedoc documentation: https://djfdyuruiry.github.io/lambda-alb/
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- Install this package using npm
``shell`
npm install -g lambda-alb
- Deploy some code to an AWS Lambda Function that processes ALB or API Gateway request events (see here)
- Create a new JSON file config.json, add the following:
`json`
{
"region": "eu-west-1",
"targets": {
"some-lambda":{
"lambdaName": "some-lambda-function"
},
"another-lambda":{
"lambdaName": "another-lambda-function"
}
}
}
Ensure the region of your function is correct when copying the above
- Ensure that your AWS credentials are set up correctly, see here if you need help doing this
- Start the ALB mock using your new config file:
`shell`
lambda-alb --config config.json
- Start making requests using the target routes:
`
curl http://localhost:8080/some-lambda/
curl http://localhost:8080/another-lambda/
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If you are using a local AWS Mock to run your lambda's, specify it's endpoint in the JSON configuration file:
`json`
{
"lambdaEndpoint": "http://localhost:4574",
"targets": {
"some-lambda":{
"lambdaName": "some-lambda-function"
}
}
}
If you get errors similar to Missing credentials in config, run the below to set mock credential env vars before starting lambda-alb:
`bash`
export AWS_ACCESS_KEY_ID=MOCK
export AWS_SECRET_ACCESS_KEY=MOCK
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To use the image:
- Place a config.json file in the current directory containing your setup
- Run the below commands:
`bash`
dokcer run --rm -v $(pwd):/etc/lambda-alb -p 8080:8080 djfdyuruiry/lambda-alb
Don't forget to pass your AWS credentials in as environment variables, or mount a volume to supply a credentials file. See here for more info.
- You can now access your lambda-alb on http://localhost:8080
If you are using docker-compose it's very simple to add lambda-alb to your stack:
`yaml
version: "3"
services:
alb:
image: djfdyuruiry/lambda-alb.git
ports:
- 8080:8080
volumes:
- ${PWD}/config.json:/etc/lambda-alb/config.json
`
A Dockerfile is provided in this repository that will create an image containing the latest version of this package on the global path.
`bash`
docker build --tag djfdyuruiry/lambda-alb .
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lambda-alb supports several command line parameters:
- -c or --config: Path to JSON configuration file-p
- or --port: (Optional) Port to listen on, defaults to 8080
- or --host: (Optional) Host to accept requests on, defaults to * (any hostname/ip)-o
- or --cors-origin: (Optional) CORS origins to allow, defaults to * (any origin)-d
- or --debug: (Optional) Enable debug logging
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Below is an overview of the JSON configuration file schema:
| Key | Description | Example | Required? |
|----------------|-----------------------------------------------------------|----------------------------------------------------------------|-----------|
| region | AWS region that your Lambda targets have been deployed to | eu-west-1 | ✘ |http://localhost:4574
| lambdaEndpoint | Custom service endpoint for AWS Lambda | | ✘ | { "some-lambda": { "lambdaName": "some-lambda-function "} }
| targets | Map of target route to AWS Lambda definition | | ✔ |
AWS Lambda Definition (targets) schema:
| Key | Description | Example | Required? |
|----------------|----------------------------------------------|-----------------|-----------|
| lambdaName | Name of the target Lambda function | a-lambda-name | ✔ |DEV
| versionOrAlias | A version or alias of the function to invoke | | ✘ |/special-route`| ✘ |
| routeUrl | Override the target route for this Lambda |