python-lambda-local 0.1

# python-lambda-local

Run lambda function on local machine

## Prepare development environment

Please use a newly created virtualenv for python2.7.

## Installation

Within virtualenv, run the following command.

``` bash
$ cd $PROJECT_ROOT
$ pip install ./
```

This will install the package with name `python-lambda-local` in the virtualenv.
Now you can use the command `python-lambda-local` to run your AWS Lambda function written in Python on your own machine.

## Usage

Run `python-lambda-local -h` to see the help.

```
usage: python-lambda-local [-h] [-l LIBRARY_PATH] [-f HANDLER_FUNCTION]
[-t TIMEOUT]
FILE EVENT

Run AWS Lambda function written in Python on local machine.

positional arguments:
FILE Lambda function file name
EVENT Event data file name.

optional arguments:
-h, --help show this help message and exit
-l LIBRARY_PATH, --library LIBRARY_PATH
Path of 3rd party libraries.
-f HANDLER_FUNCTION, --function HANDLER_FUNCTION
Lambda function handler name. Default: "handler".
-t TIMEOUT, --timeout TIMEOUT
Seconds until lambda function timeout. Default: 3
```

### Prepare development directory

#### Project directory structure

Suppose your project directory is like this:

```
├── event.json
├── lib
│   ├── rx
│   │   ├── abstractobserver.py
│   │   ├── ... (package content of rx)
...
│   │   └── testscheduler.py
│   └── Rx-1.2.3.dist-info
│   ├── DESCRIPTION.rst
│   ├── METADATA
│   ├── metadata.json
│   ├── pbr.json
│   ├── RECORD
│   ├── top_level.txt
│   ├── WHEEL
│   └── zip-safe
└── test.py
```

In the handler's code is in `test.py` and the function name of the handler is `handler`.
The source depends on 3rd party library `rx` and it is install in the directory `lib`.
The test event of json format is in `event.json` file.

#### Content of `test.py`:

``` python
from rx import Observable


def handler(event, context):
xs = Observable.from_([1, 2, 3, 4, 5, 6])
ys = xs.to_blocking()
zs = (x*x for x in ys if x > 3)
for x in zs:
print x
```

#### Content of `event.json`:

``` json
{
"key": "value"
}
```

#### Run the lambda function

Within the project root directory, you can run the lambda function with the following command

```
python-lambda-local -l lib/ -f handler -t 5 test.py event.json
```

The output will be like:

```
[INFO 2015-10-16 18:21:14,774] Event: {'key': 'value'}
[INFO 2015-10-16 18:21:14,774] START RequestId: 324cb1c5-fa9b-4f39-8ad9-01c95f7d5744
16
25
36
[INFO 2015-10-16 18:21:14,775] END RequestId: 324cb1c5-fa9b-4f39-8ad9-01c95f7d5744
[INFO 2015-10-16 18:21:14,775] RESULT: None
```