lambda-proxy 5.2.1
Simple AWS Lambda proxy to handle API Gateway request
License: BSD
Requires Python: >=3
Keywords: AWS-Lambda API-Gateway Request Proxy

# lambda-proxy

[![Packaging status](https://badge.fury.io/py/lambda-proxy.svg)](https://badge.fury.io/py/lambda-proxy)
[![CircleCI](https://circleci.com/gh/vincentsarago/lambda-proxy.svg?style=svg)](https://circleci.com/gh/vincentsarago/lambda-proxy)
[![codecov](https://codecov.io/gh/vincentsarago/lambda-proxy/branch/master/graph/badge.svg)](https://codecov.io/gh/vincentsarago/lambda-proxy)

A zero-requirement proxy linking AWS API Gateway `{proxy+}` requests and AWS Lambda.

<img width="600" alt="" src="https://user-images.githubusercontent.com/10407788/58742966-6ff50480-83f7-11e9-81f7-3ba7aa2310bb.png">

## Install

```bash
$ pip install -U pip
$ pip install lambda-proxy
```

Or install from source:

```bash
$ git clone https://github.com/vincentsarag/lambda-proxy.git
$ cd lambda-proxy
$ pip install -U pip
$ pip install -e .
```

# Usage

Lambda proxy is designed to work well with both API Gateway's REST API and the
newer and cheaper HTTP API. If you have issues using with the HTTP API, please
open an issue.

With GET request

```python
from lambda_proxy.proxy import API

APP = API(name="app")

@APP.route('/test/tests/<id>', methods=['GET'], cors=True)
def print_id(id):
    return ('OK', 'plain/text', id)
```

With POST request

```python
from lambda_proxy.proxy import API

APP = API(name="app")

@APP.route('/test/tests/<id>', methods=['POST'], cors=True)
def print_id(id, body):
    return ('OK', 'plain/text', id)
```

**Note**

Starting in version 5.2.0, users can now add route using `@APP.get` and `@APP.post` removing the need to add `methods=[**]`

## Binary body

Starting from version 5.0.0, lambda-proxy will decode base64 encoded body on POST message.

Pre 5.0.0
```python
from lambda_proxy.proxy import API

APP = API(name="app")

@APP.route('/test', methods=['POST']e)
def print_id(body):
    body = json.loads(base64.b64decode(body).decode())
```

Post 5.0.0
```python
from lambda_proxy.proxy import API

APP = API(name="app")

@APP.route('/test', methods=['POST']e)
def print_id(body):
    body = json.loads(body)
```

# Routes

Route schema is simmilar to the one used in [Flask](http://flask.pocoo.org/docs/1.0/api/#url-route-registrations)

> Variable parts in the route can be specified with angular brackets `/user/<username>`. By default a variable part in the URL accepts any string without a slash however a different converter can be specified as well by using `<converter:name>`.

Converters:
- `int`: integer
- `string`: string
- `float`: float number
- `uuid`: UUID

example:
- `/app/<user>/<id>` (`user` and `id` are variables)
- `/app/<string:value>/<float:num>` (`value` will be a string, while `num` will be a float)

## Regex
You can also add regex parameters descriptions using special converter `regex()`

example:
```python
@APP.get("/app/<regex([a-z]+):regularuser>")
def print_user(regularuser):
    return ('OK', 'plain/text', f"regular {regularuser}")

@APP.get("/app/<regex([A-Z]+):capitaluser>")
def print_user(capitaluser):
    return ('OK', 'plain/text', f"CAPITAL {capitaluser}")
```

#### Warning

when using **regex()** you must use different variable names or the route might not show up in the documentation.

```python
@APP.get("/app/<regex([a-z]+):user>")
def print_user(user):
    return ('OK', 'plain/text', f"regular {user}")

@APP.get("/app/<regex([A-Z]+):user>")
def print_user(user):
    return ('OK', 'plain/text', f"CAPITAL {user}")
```
This app will work but the documentation will only show the second route because in `openapi.json`, route names will be `/app/{user}` for both routes.

# Route Options

- **path**: the URL rule as string
- **methods**: list of HTTP methods allowed, default: ["GET"]
- **cors**: allow CORS, default: `False`
- **token**: set `access_token` validation
- **payload_compression_method**: Enable and select an output body compression
- **binary_b64encode**: base64 encode the output body (API Gateway)
- **ttl**: Cache Control setting (Time to Live) **(Deprecated in 6.0.0)**
- **cache_control**: Cache Control setting
- **description**: route description (for documentation)
- **tag**: list of tags (for documentation)

## Cache Control

Add a Cache Control header with a Time to Live (TTL) in seconds.

```python
from lambda_proxy.proxy import API
APP = API(app_name="app")

@APP.get('/test/tests/<id>', cors=True, cache_control="public,max-age=3600")
def print_id(id):
   return ('OK', 'plain/text', id)
```

Note: If function returns other then "OK", Cache-Control will be set to `no-cache`

## Binary responses

When working with binary on API-Gateway we must return a base64 encoded string

```python
from lambda_proxy.proxy import API

APP = API(name="app")

@APP.get('/test/tests/<filename>.jpg', cors=True, binary_b64encode=True)
def print_id(filename):
    with open(f"{filename}.jpg", "rb") as f:
        return ('OK', 'image/jpeg', f.read())
```

## Compression

Enable compression if "Accept-Encoding" if found in headers.

```python
from lambda_proxy.proxy import API

APP = API(name="app")

@APP.get(
   '/test/tests/<filename>.jpg',
   cors=True,
   binary_b64encode=True,
   payload_compression_method="gzip"
)
def print_id(filename):
    with open(f"{filename}.jpg", "rb") as f:
       return ('OK', 'image/jpeg', f.read())
```

## Simple Auth token

Lambda-proxy provide a simple token validation system.

-  a "TOKEN" variable must be set in the environment
-  each request must provide a "access_token" params (e.g curl
   http://myurl/test/tests/myid?access_token=blabla)

```python
from lambda_proxy.proxy import API

APP = API(name="app")

@APP.get('/test/tests/<id>', cors=True, token=True)
def print_id(id):
    return ('OK', 'plain/text', id)
```

## URL schema and request parameters

QueryString parameters are passed as function's options.

```python
from lambda_proxy.proxy import API

APP = API(name="app")

@APP.get('/<id>', cors=True)
def print_id(id, name=None):
    return ('OK', 'plain/text', f"{id}{name}")
```

requests:

```bash
$ curl /000001
   0001

$ curl /000001?name=vincent
   0001vincent
```

## Multiple Routes

```python
from lambda_proxy.proxy import API
APP = API(name="app")

@APP.get('/<id>', cors=True)
@APP.get('/<id>/<int:number>', cors=True)
def print_id(id, number=None, name=None):
    return ('OK', 'plain/text', f"{id}-{name}-{number}")
```
requests:

```bash

$ curl /000001
   0001--

$ curl /000001?name=vincent
   0001-vincent-

$ curl /000001/1?name=vincent
   0001-vincent-1
```

# Advanced features

## Context and Event passing

Pass event and context to the handler function.

```python
from lambda_proxy.proxy import API

APP = API(name="app")

@APP.get("/<id>", cors=True)
@APP.pass_event
@APP.pass_context
def print_id(ctx, evt, id):
    print(ctx)
    print(evt)
    return ('OK', 'plain/text', f"{id}")
```

# Automatic OpenAPI documentation

By default the APP (`lambda_proxy.proxy.API`) is provided with three (3) routes:
- `/openapi.json`: print OpenAPI JSON definition

- `/docs`: swagger html UI
![swagger](https://user-images.githubusercontent.com/10407788/58707335-9cbb0480-8382-11e9-927f-8d992cf2531a.jpg)

- `/redoc`: Redoc html UI
![redoc](https://user-images.githubusercontent.com/10407788/58707338-9dec3180-8382-11e9-8dec-18173e39258f.jpg)

**Function annotations**

To be able to render full and precise API documentation, lambda_proxy uses python type hint and annotations [link](https://www.python.org/dev/peps/pep-3107/).

```python
from lambda_proxy.proxy import API

APP = API(name="app")

@APP.route('/test/<int:id>', methods=['GET'], cors=True)
def print_id(id: int, num: float = 0.2) -> Tuple(str, str, str):
    return ('OK', 'plain/text', id)
```

In the example above, our route `/test/<int:id>` define an input `id` to be a `INT`, while we also add this hint to the function `print_id` we also specify the type (and default) of the `num` option.

# Custom Domain and path mapping

Since version 4.1.1, lambda-proxy support custom domain and path mapping (see https://github.com/vincentsarago/lambda-proxy/issues/16).

Note: When using path mapping other than `root` (`/`), `/` route won't be available.

```python
from lambda_proxy.proxy import API

api = API(name="api", debug=True)


# This route won't work when using path mapping
@api.get("/", cors=True)
# This route will work only if the path mapping is set to /api
@api.get("/api", cors=True)
def index():
    html = """<!DOCTYPE html>
    <html>
        <header><title>This is title</title></header>
        <body>
            Hello world
        </body>
    </html>"""
    return ("OK", "text/html", html)


@api.get("/yo", cors=True)
def yo():
    return ("OK", "text/plain", "YOOOOO")
```

# Plugin

- Add cache layer: https://github.com/vincentsarago/lambda-proxy-cache


# Examples

-  https://github.com/vincentsarago/lambda-proxy/tree/master/example
-  https://github.com/RemotePixel/remotepixel-tiler


# Contribution & Devellopement

Issues and pull requests are more than welcome.

**Dev install & Pull-Request**

```bash
$ git clone https://github.com/vincentsarago/lambda-proxy.git
$ cd lambda-proxy
$ pip install -e .[dev]
```

**Python3.7 only**

This repo is set to use pre-commit to run *mypy*, *flake8*, *pydocstring* and *black* ("uncompromising Python code formatter") when committing new code.

```bash
$ pre-commit install
$ git add .
$ git commit -m'my change'
   black.........................Passed
   Flake8........................Passed
   Verifying PEP257 Compliance...Passed
   mypy..........................Passed
$ git push origin
```

### License

See [LICENSE.txt](/LICENSE.txt>).

### Authors

See [AUTHORS.txt](/AUTHORS.txt>).

### Changes

See [CHANGES.txt](/CHANGES.txt>).