An open API service indexing awesome lists of open source software.

https://github.com/javascript-studio/studio-lambda

🚀 A custom lambda execution environment
https://github.com/javascript-studio/studio-lambda

Last synced: 3 months ago
JSON representation

🚀 A custom lambda execution environment

Awesome Lists containing this project

README

          

# Studio Lambda

🚀 A custom [AWS Lambda][1] execution environment for local testing. Runs
each Lambda function in it's own process. Integrates with [Studio Gateway][2].

## Usage

```js
const Lambda = require('@studio/lambda');

const lambda = Lambda.create();
lambda.invoke('some-lambda', { some: 'event' }, callback);
```

## API

- `lambda = Lambda.create([options])`: Returns a new Lambda controller for
the given options.
- `base_dir`: The base directory to use. Defaults to the current working
directory.
- `lambda_path`: The path to the Lambda function. Replaces `${LAMBDA_NAME}`
with the Lambda name. Defaults to `functions/${LAMBDA_NAME}/`.
- `env`: An object with environment variables to use. Defaults to an empty
object.
- `config_file`: A JSON file with additional `environment` and `timeout`
properties. Defaults to
`functions/${LAMBDA_NAME}/function.${AWS_PROFILE}.json`. Placeholders in
the form of `${ENV_VAR}` are replaced with the corresponding environment
variable.
- `timeout`: The default Lambda timeout to use in milliseconds. Defaults
to 5 seconds.
- `memory`: The default Lambda memory to use in MB. Defaults to 128 MB. This
will set `--max-old-space-size` on Lambda processes.
- `max_idle`: The idle timeout to use in milliseconds. If a function is
not invoked for this time, the process gets destroyed. Defaults to 1 hour.
- `lambda.invoke(lambda_name, event[, options][, callback])`: Invokes the named
Lambda `handle` function. If no callback is given, a promise is returned.
These options are supported:
- `awsRequestId`: The AWS request ID to use in the Lambda `context`.
If a context is given, but one of the above properties is missing, they are
added to the context.
- `lambda.shutdown([options])`: Shut down all processes. These options may be
given:
- `graceful`: Wait for running instances before closing processes. If this
is not set to `true`, all processes are killed immediately.
- `lambda.stats()`: Returns stats for this lambda instance. Returns an object
where the keys are the Lambda function names and each value is an object with
these properties:
- `instances`: The total number of instances running.
- `active`: The number of instances currently handling requests.
- `requests`: The total number of requests received.

## Lambda context

Lambda function are invoked with `(event, context[, callback])` where the
`context` has this interface:

- `functionName`: The name of the Lambda function.
- `invokedFunctionArn`: The function ARN, build from the `AWS_REGION`
(defaulting to `us-east-1`), `STUDIO_AWS_ACCOUNT` (defaulting to
`000000000000`) and the Lambda function name.
- `memoryLimitInMB`: The configured memory limit.
- `awsRequestId`: The AWS request ID, either from `options` or generated.
- `getRemainingTimeInMillis()`: Returns the remaining time until the Lambda
function times out.

If `callback` is not defined (the lambda handler function has an arity < 3), the function is expected to return a promise.

## Debugging Lambda functions

If the environment variable `STUDIO_LAMBDA_INSPECT` is set to the name of a
Lambda function, the node process for that function will be called with
`--inspect` and the timeout value is ignored. This prints a Chrome debugger URL
to the console. With this setup in place, you can add `debugger` statements to
place breakpoints.

[1]: https://aws.amazon.com/lambda/
[2]: https://github.com/javascript-studio/studio-gateway