late-python
A Python package with OpenStax Lambda@Edge ("lAMBDA at eDGE") utilities.
Overview
late-python provides object overlays
to the JSON containers
inside Lambda@Edge events and responses.
These overlay objects handle the details
of accessing and modifying
the containers they overlay.
All get_* methods
leave the underlying container intact,
and all set_* methods
modify it in place.
Usage
pip install oxlate
Dealing With Request Events
from oxlate import Event, Response
def lambda_handler(event, context):
request = Event(event).request() ## returns Request overlay
## get and set the request uri field
request.get_uri()
request.set_uri('/some/new/uri')
## get the viewer's country code
request.get_viewer_country()
## return Headers overlay
headers = request.get_headers()
## get the Request event header array-of-hash (or None if missing):
## [{name=..., value=...}]
headers.get(name='header-name')
## get the header value only
## (or None if missing and no default given)
headers.get_value(name='header-name', default='some default')
## set or overwrite a header
headers.set(
name = 'header-name',
value = 'some value',
)
## get a request cookie value
## (or None if missing and no default given)
headers.get_request_cookie('cookie_name', default='some default')
## set or overwrite a request cookie value
headers.set_request_cookie('cookie_name', value='some value')
## return a deep copy of the overlaid hashmap
return request.to_dict()Dealing With Response Objects
from oxlate import Response
def request_handler(event, context):
## construct a Response object
response = Response(
status=302,
content_type='text/plain',
body=None,
)
## use method chaining to tweak Response
response.set_status(404) \
.set_content_type('custom/type') \
.set_content_type_json() \
.set_content_type_html() \
.set_body(json.dumps('some body text'))
## get a Headers overlay
headers = response.get_headers()
## get the header value only
## (or None if missing and no default given)
headers.get_value(name='header-name', default='some default')
## set or overwrite a header
headers.set(
name = 'header-name',
value = 'some value',
)
## get a ResponseCookie overlay
cookie = headers.get_response_cookie('cookie-name')
print(cookie.name())
print(cookie.value())
print(cookie.expires_at())
print(cookie.path())
print(cookie.domain())
## set or override a ResponseCookie
cookie = ResponseCookie(
name = 'cookie-name',
value = 'some value',
expires_at = datetime.datetime.utcnow() + datetime.timedelta(days=2),
path = '/',
domain = 'my.domain.com',
)
headers.set_response_cookie(cookie)
return response.to_dict()Development
All development is done inside a docker container. From your host running Docker, in this directory run:
$> ./docker/build
%> ./docker/bashThis will drop you into the running container
Run tests
From within the container, you can run tests with:
$ /code> python -m pytest
For debugging, you can use ipdb, e.g.
import ipdb; ipdb.set_trace()
When running tests with the debugger make sure to use the -s option to prevent pytest from capturing output.
$> python -m pytest -s tests -k 'test_decrypts'
Note that pytest is also on the PATH so you can call it directly.
Distributing
From within the container, build the distributions:
$> python setup.py sdist bdist_wheel
To upload:
$> python -m twine upload dist/*
