Category: Software Development

Makefile

I use Make to create a package (i.e “sample-app.zip”). The dependencies are installed into a virtualenv which are appended to the package.

make build-dev
make create-dev

make build-dev
make update-dev

Lambda deployment package

Make sure you include all the dependencies in the package. You need to copy the contents of site-packages, NOT the directory itself. If you copy site-packages itself, lambda will not be able to find the modules.

The contents will look something similar to:

Testing locally

Instead of constantly deploying the function, I wanted to test my changes locally.

When creating an AWS lambda function, you need to specify the handler gets executes. In the gist above, I specify it with –handler main.lambda_handler. So testing locally is simple as:

if __name__ == "__main__":
    lambda_handler(None, None)

Basic Setup

Our process is managed by supervisor and it logs to stdout. Supervisor logging plugin sends logs to our centralized syslog collector, which forwards the logs to Sumologic. We then configure alerts based off of search results.

Configuring the alert

First, create your search (here’s a cheatsheet). Next, configure it:

• Library -> Edit Search
• Scheduled this Search
• Number of results Equal to = 0

Screenshot:

That’s it. You can integrate this with your Pager Duty account or just have it send directly to an e-mail address.

Configure tox + coverage

Since tox does NOT play nicely with pipes (|), this simple shell scripts checks for 100% test coverage:

#!/bin/sh

coverage run --source speedcurve -m py.test
coverage report | tail -n 1 | grep '^TOTAL.*100%$'

This goes in tox.ini

[testenv:coverage]
commands =
    ./coverage-check.sh

Recommended Links:

• Tox tricks and patterns

Testing manually first

Before any implementation, I always like to get a better understanding of the API by using good ol’ fashion curl.

curl https://api.github.com/licenses \
-H "Accept: application/vnd.github.drax-preview+json"

Sending a custom Accept: Header

In the code base, most classes inherit from github3.GitHubCore, which inherits from requests.Session. We can pass in**kwargs, and requests.Session.get accepts a headers as a kwarg. So, we can pass a custom Accept: header like so:

headers = {
    'Accepts': 'application/vnd.github.drax-preview+json'
}

url = self._build_url('license')
json = self._json(self._get(url, headers=headers))

How to add attributes to License model

By default, the model will not expose any attributes. How do we do that? The key is implementing __update_attributesmethod.

github3.licenses.License inherits from github3.models.GitHubObject, which calls __update_attriubtes in its__init__.

class GitHubObject(object):
    """The :class:`GitHubObject <GitHubObject>` object. A basic class to be
    subclassed by GitHubCore and other classes that would otherwise subclass
    object."""
    def __init__(self, json):
        super(GitHubObject, self).__init__()
        if json is not None:
            self.etag = json.pop('ETag', None)
            self.last_modified = json.pop('Last-Modified', None)
            self._uniq = json.get('url', None)
        self._json_data = json
        self._update_attributes(json)

So, let’s add License attributes

def _update_attributes(self, license):
    self.name = license.get('name')
    self.permitted = license.get('permitted')
    self.category = license.get('category')
    self.forbidden = license.get('forbidden')
    self.featured = license.get('featured')
    self.html_url = license.get('html_url')
    self.body = license.get('body')
    self.key = license.get('key')
    self.description = license.get('description')
    self.implementation = license.get('implementation')
    self.required = license.get('required')

Writing test

This guide is a great place to start. But, just a few pointers. For unit tests, copy/paste example data the API docs. For example, grab the JSON data from the license documentation. Save it under tests/unit/.

For integration tests, you’ll need to perform HTTP request(s). The betamax wrapper will record it to tests/cassettes.

Summary

This feature was merged in this pull request. I really enjoy contributing to this project. Primarily since sigmavirus24 is a pleasure to work with and extremely helpful. He’s super patient and I appreciate he takes the time onboarding new contributors.

Order of decorator

Also, pay attention to the order of parameters. My assertions were failing left and right.