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https://github.com/prezi/changelog

"What's changed in the last twenty minutes?"
https://github.com/prezi/changelog

Last synced: 6 days ago
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"What's changed in the last twenty minutes?"

Host: GitHub
URL: https://github.com/prezi/changelog
Owner: prezi
License: wtfpl
Created: 2013-06-09T17:53:36.000Z (over 11 years ago)
Default Branch: master
Last Pushed: 2024-04-24T10:04:40.000Z (7 months ago)
Last Synced: 2024-08-01T19:56:03.269Z (3 months ago)
Language: JavaScript
Homepage:
Size: 1.43 MB
Stars: 248
Watchers: 167
Forks: 26
Open Issues: 8
Metadata Files:
- Readme: README.md
- License: COPYING

Awesome Lists containing this project

README

# changelog

Aims to answer the question "what's changed in the last hour?" in a distributed system. Very useful to have when the
proverbial bad things hit the proverbial ventilation hardware. It can drastically drop mean time to recovery.

## How?

`changelog` provides a simple REST API to post events to, and a web interface where you can quickly see and filter events.
The basic idea is that you'll send any event that has even a remote chance of causing problems to this system. Later,
when something goes wrong, you can quickly check what's changed in the last minutes / hours.

The web interface:
![Web UI](docs/screenshot.png)

Sending events is simple:

```sh
curl http://changelog.awesomecompany.com/api/events \
-X POST \
-H 'Content-Type: application/json' \
-d '{"criticality": 1, "unix_timestamp": 1395334488, "category": "misc", "description": "cli test"}'
```

All four JSON fields are required, and there are no other fields the server understands.

Clients implementing this logic:
- bash: https://github.com/prezi/changelog-client-bash
- python: https://github.com/woohgit/changelog-client-python
- ruby: https://github.com/woohgit/changelog_client
- php: https://github.com/Gerifield/changelog-client-php
- jvm: https://github.com/prezi/changelog-client-java
- go: https://github.com/woohgit/go-changelog

Some ideas for events to send:
- deployment, release
- feature (switch|flag|toggle) changes
- changes to chef / puppet / ansible / ...
- changes to DNS configuration
- cloud instances started, stopped

## Getting started

### Setup - Docker

A public image is available at [prezi/changelog](https://hub.docker.com/r/prezi/changelog/).
It runs `changelog` on Gunicorn with Eventlet workers, and supports SQLite, MySQL and PostgreSQL.
It's not completely production-ready out of the box, see below - you should think about at least SSL termination and authentication.
You can set any of the configuration variables described below as environment variables on the container with the same name as the
configuration variables.

To try it out with an in-container SQLite database:

```sh
sudo docker run -p 5000:5000 -it prezi/changelog
```

### Setup - Manually

Prerequisites:

- a relational database
- python 3
- virtualenv
- optionally: a [Sentry](https://getsentry.com/) server for collecting exceptions; not that there'll be any :)

```sh
git clone https://github.com/prezi/changelog.git
cd changelog

# Install dependencies
./setup.sh

# In on shell, start the server
. virtualenv/bin/activate
python application.py

# In another shell, start the Webpack watcher
npm run watch

# When building for production, create a production frontend bundle
npm run build
```

### Database support

`changelog` uses SQLAlchemy to support a wide range of databases. The client library bindings are not included in
`requirements.txt` to make setup possible in the absence of client libraries on the system. If you want to use
a database other than SQLite (you should), then you'll need to manually install the python bindings. Additional
requirements files are provided to install known good versions of the bindings:

- MySQL: `pip install -r requirements-mysql.txt`
- PostgreSQL: `pip install -r requirements-postgresql.txt`

## Configuration

### Variables

| Variable | Description | Default |
|---------------|----------------------------------------------------------------------------------|----------------|
| `ALCHEMY_URL` | SQL Alchemy connection string. |`sqlite:///changelog.db` |
| `LISTEN_HOST` | IP address where the application will listen when started with `python application.py`.| `127.0.0.1` (`0.0.0.0` in Docker) |
| `LISTEN_PORT` | Port where the application will listen when started with `python application.py`.| `5000` |
| `USE_SENTRY` | Send exceptions to Sentry? | `False` |
| `SENTRY_DSN` | Sentry DSN, used only if `USE_SENTRY` is `True`. | `None` |

The default configuration values defined are in [settings.py](settings.py).

### With Docker

You can pass in any of these variables as an environment variable to the Docker container. Additional, docker-specific variables:

| Variable | Description | Default |
|-------------------------|--------------------------------------------------|---------|
| `GUNICORN_WORKER_COUNT` | Number of worker processes started by Gunicorn. | `2` |

For example, to use a PostgreSQL database:

```sh
sudo docker run -d --name changelog-db postgres
sudo docker run --rm --link changelog-db:db postgres psql -h db -U postgres -c 'CREATE DATABASE changelog'
sudo docker run -it -p 5000:5000 --link changelog-db:db -e ALCHEMY_URL=postgres://postgres@db/changelog prezi/changelog
```

### Without Docker

You can set the environment variable `CHANGELOG_SETTINGS_PATH` to point to a python file. That file can set the values detailed
below. The application prints the final configuration at startup to make debugging this easier (not that there's anything
to debug, but configuration always needs debugging). The file pointed to by `CHANGELOG_SETTINGS_PATH` can, for example,
look like this:

```python
LISTEN_PORT = 8080
ALCHEMY_URL = 'sqlite:////opt/foo/bar/local/changelog.db'
```

## Considerations for running in production

- Running under a WSGI server is highly recommended. This project uses the Flask framework, see their documentation for
running under [Apache](http://flask.pocoo.org/docs/deploying/mod_wsgi/) or [Standalone WSGI containers](http://flask.pocoo.org/docs/deploying/wsgi-standalone/) (Uses Gunicorn with Eventlet workers in the provided Docker image)
- No authentication is provided, you'll probably want to put some authenticating proxy in front of this application.
Pull requests for adding authentication support are of course welcome.
- Similarly, no HTTPS termination is provided. Ideally the WSGI container will take care of that.
- Once you have a good number of events, enabling response compression (think `mod_deflate`) can speed things up.

## Contributing

Feature requests are welcome, bug reports are especially welcome, and pull requests are super welcome. Please make sure
to use a feature branch in your fork. Don't look too hard for tests, there are none - not for a lack of belief in tests,
but because the application is almost trivial. Please make sure you also update the README to reflect your changes. While you're there you may as well add yourself to the Credits section too :)

## Credits

- Roy Rapoport (@royrapoport) for inspiring this tool with his talk at the
[SF Metrics Meetup](http://blog.librato.com/posts/2013/6/12/sf-metrics-meetup-change-reporting-and-building-metrics-from-log-data)
- Zoltan Nagy (@abesto): initial implementation, current maintainer
- Ryan Bowlby (@rbowlby)
- Bálint Csergő (@deathowl) for adding SQLAlchemy support
- Charles Hooper (@chooper)

## Awesome tools used
These tools made it possible to write `changelog` in a weekend. Huge thanks.

- [Flask](http://flask.pocoo.org/), the lightweight Python web framework and
[Flask-RESTful](http://flask-restful.readthedocs.org/en/latest/) for making the REST api trivial to write
- [Bootstrap](http://getbootstrap.com/), for making the whole UI look not terrible
and [bootstrap-datetimepicker](http://bootstrap-datepicker.readthedocs.org/en/release/) for making the date chooser
pretty awesome
- [jQuery](http://jquery.com/), because obviously
- [jQuery BBQ](http://benalman.com/code/projects/jquery-bbq/docs/files/jquery-ba-bbq-js.html) and
[jQuery hashchange](http://benalman.com/code/projects/jquery-hashchange/docs/files/jquery-ba-hashchange-js.html)
for making the permalink simple to implement
- [Sentry](http://getsentry.com/) for simple-to-use, awesome error reporting / collection / aggregation
- [cdnjs](http://cdnjs.com/) for hosting all the client-side libraries above
- [SQLAlchemy](http://www.sqlalchemy.org/)
- [Flask-SQLAlchemy](https://github.com/mitsuhiko/flask-sqlalchemy) SQLAlchemy support for Flask
- Those that we take for granted: sqlite3, python, virtualenv, and the list goes on...

![Changelog](docs/changelog.jpg)

^{Image gleefully copied from [Android Police](http://www.androidpolice.com/2011/03/07/cyanogenmod-7-rc2-rolling-out-now-packing-android-2-3-3-new-features-bugfixes/)}