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https://github.com/ashiina/lambda-local
Commandline tool to run Amazon Lambda function on local machines.
https://github.com/ashiina/lambda-local
amazon-lambda aws-sdk lambda nodejs
Last synced: about 2 months ago
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Commandline tool to run Amazon Lambda function on local machines.
- Host: GitHub
- URL: https://github.com/ashiina/lambda-local
- Owner: ashiina
- License: mit
- Created: 2015-01-17T21:05:17.000Z (over 9 years ago)
- Default Branch: develop
- Last Pushed: 2024-04-13T22:00:21.000Z (5 months ago)
- Last Synced: 2024-05-01T14:59:54.878Z (5 months ago)
- Topics: amazon-lambda, aws-sdk, lambda, nodejs
- Language: JavaScript
- Homepage:
- Size: 316 KB
- Stars: 726
- Watchers: 19
- Forks: 101
- Open Issues: 10
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE
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README
# Lambda-local
[](https://www.npmjs.com/package/lambda-local)
[](https://github.com/ashiina/lambda-local/actions?query=event%3Apush)
Lambda-local lets you test **NodeJS Amazon Lambda functions** on your local machine, by providing a simplistic API and command-line tool.
It does not aim to be perfectly feature proof as projects like [serverless-offline](https://github.com/dherault/serverless-offline) or [docker-lambda](https://github.com/lambci/docker-lambda), but rather to remain **very light** (it still provides a fully built `Context`, handles all of its parameters and functions, and everything is customizable easily).
The main target are unit tests and running lambda functions locally.
## Install
```bash
npm install -g lambda-local
```
## Build
```bash
make build
```
Or
```bash
npm install
npm install --only=dev
npm run build
```
## Usage
- **As an API:** You can also use Lambda local directly in a script. For instance, it is interesting in a [MochaJS][1] test suite in order to get test coverage.
- **As a command line tool:** You can use Lambda-local as a command line tool.
If you're unsure about some definitions, see [Definitions](#about-definitions) for terminology.
## About: API
### LambdaLocal
API accessible with:
```js
const lambdaLocal = require("lambda-local");
```
Or on TypeScript (supported on 1.7.0+):
```js
import lambdaLocal = require("lambda-local");
```
#### `lambdaLocal.execute(options)`
Executes a lambda given the `options` object, which is a dictionary where the keys may be:
| Key name | Description |
| --- | --- |
| `event`|requested event as a json object|
| `lambdaPath`|requested path to the lambda function|
| `lambdaFunc`|pass the lambda function. You cannot use it at the same time as lambdaPath|
| `profilePath`|optional, path to your AWS credentials file|
| `profileName`|optional, aws profile name. Must be used with |
| `lambdaHandler`|optional handler name, default to `handler`|
| `region`|optional, AWS region, default to `us-east-1`|| `callbackWaitsForEmptyEventLoop`|optional, default to `false`. Setting it to True will wait for an empty loop before returning.|
| `timeoutMs`|optional, timeout, default to 3000 ms|
| `esm`|boolean, marks that the script is an ECMAScript module (use import), default false|
| `environment`|optional, extra environment variables for the lambda|
| `envfile`|optional, load an environment file before booting|
| `envdestroy`|optional, destroy added environment on closing, default to false|
| `verboseLevel`|optional, default 3. Level 2 dismiss handler() text, level 1 dismiss lambda-local text and level 0 dismiss also the result. Level -1 only displays handler() text.|
| `callback`|optional, lambda third parameter [callback][1]. When left out a Promise is returned|
| `onInvocationEnd`|optional. called once the invocation ended. useful when awslambda.streamifyResponse is used to distinguish between end of response stream and end of invocation. |
| `clientContext`|optional, used to populated clientContext property of lambda second parameter (context)
| `contextOverwrite`| optional, a function that overwrites the context object. It can get and overwrite the values of the context (such as awsRequestId). |
#### `lambdaLocal.setLogger(logger)`
#### `lambdaLocal.getLogger()`
Those functions allow to access the [winston](https://www.npmjs.com/package/winston) logger used by lambda-local.
## API examples
A lot of examples, especially used among Mocha, may be found in the test files over: [here](https://github.com/ashiina/lambda-local/tree/develop/test)
##### Basic usage: Using Promises
```js
const lambdaLocal = require('lambda-local');
var jsonPayload = {
'key': 1,
'another_key': "Some text"
}
lambdaLocal.execute({
event: jsonPayload,
lambdaPath: path.join(__dirname, 'path_to_index.js'),
profilePath: '~/.aws/credentials',
profileName: 'default',
timeoutMs: 3000
}).then(function(done) {
console.log(done);
}).catch(function(err) {
console.log(err);
});
```
#### Basic usage: using callbacks
```js
const lambdaLocal = require('lambda-local');
var jsonPayload = {
'key': 1,
'another_key': "Some text"
}
lambdaLocal.execute({
event: jsonPayload,
lambdaPath: path.join(__dirname, 'path_to_index.js'),
profilePath: '~/.aws/credentials',
profileName: 'default',
timeoutMs: 3000,
callback: function(err, data) {
if (err) {
console.log(err);
} else {
console.log(data);
}
},
clientContext: JSON.stringify({clientId: 'xxxx'})
});
```
## About: CLI
### Available Arguments
* `-l, --lambda-path ` (required) Specify Lambda function file name.
* `-e, --event-path ` (required --watch is not in use) Specify event data file name.
* `-h, --handler ` (optional) Lambda function handler name. Default is "handler".
* `-t, --timeout ` (optional) Seconds until lambda function timeout. Default is 3 seconds.
* `--esm` (optional) Load lambda function as ECMAScript module.
* `-r, --region ` (optional) Sets the AWS region, defaults to us-east-1.
* `-P, --profile-path ` (optional) Read the specified AWS credentials file.
* `-p, --profile ` (optional) Use with **-P**: Read the AWS profile of the file.
* `-E, --environment ` (optional) Set extra environment variables for the lambda
* `--wait-empty-event-loop` (optional) Sets callbackWaitsForEmptyEventLoop=True => will wait for an empty loop before returning. This is false by default because our implementation isn\'t perfect and only "emulates" it.
* `--envdestroy` (optional) Destroy added environment on closing. Defaults to false
* `-v, --verboselevel <3/2/1/0>` (optional) Default 3. Level 2 dismiss handler() text, level 1 dismiss lambda-local text and level 0 dismiss also the result.
* `--envfile ` (optional) Set extra environment variables from an env file
* `--inspect [[host:]port]` (optional) Starts lambda-local using the NodeJS inspector (available in nodejs > 8.0.0)
* `-W, --watch [port]` (optional) Starts lambda-local in watch mode listening to the specified port [1-65535].
### CLI examples
```bash
# Simple usage
lambda-local -l index.js -h handler -e examples/s3-put.js
# Input environment variables
lambda-local -l index.js -h handler -e examples/s3-put.js -E '{"key":"value","key2":"value2"}'
```
#### Running lambda functions as a HTTP Server (Amazon API Gateway payload format version 2.0.)
A simple way you can run lambda functions locally, without the need to create any special template files (like Serverless plugin and SAM requires), just adding the parameter `--watch`. It will raise a http server listening to the specified port (default is 8008). You can then call the lambda as mentionned here:
https://docs.aws.amazon.com/lambda/latest/dg/urls-invocation.html
```bash
lambda-local -l examples/handler_gateway2.js -h handler --watch 8008
curl --request POST \
--url http://localhost:8008/ \
--header 'content-type: application/json' \
--data '{
"key1": "value1",
"key2": "value2",
"key3": "value3"
}'
{"message":"This is a response"}
```
You can also use the following format for your event, in order to avoid using the Amazon API Gateway format:
```
{
"event": {
"key1": "value1",
"key2": "value2",
"key3": "value3"
}
}
```
In this case, the event will be passed directly to the handler.
## About: Definitions
### Event data
Event sample data are placed in `examples` folder - feel free to use the files in here, or create your own event data.
Event data are just JSON objects exported:
```js
// Sample event data
module.exports = {
foo: "bar"
};
```
### Context
The `context` object has been sampled from what's visible when running an actual Lambda function on AWS, and the [available documentation](https://docs.aws.amazon.com/lambda/latest/dg/nodejs-prog-model-context.html)
They may change the internals of this object, and Lambda-local does not guarantee that this will always be up-to-date with the actual context object.
### AWS-SDK
As of version 2.0.0, lambda-local no longer packages AWS-SDK in its dependencies. To run a function that makes use of this module, make sure to install it as a dependency in your project.
## Other links
- If you are willing to test an app based on the ASK-SDK, have a look at https://github.com/taimos/ask-sdk-test
## Development
* Run `make` to install npm modules. (Required to develop & test lambda-local)
* Run `make test` to execute the mocha test.
* Run `make clean` to reset the repository.
## License
This library is released under the MIT license.
[1]: http://docs.aws.amazon.com/lambda/latest/dg/nodejs-prog-model-handler.html