Welcome to Brewtils’s documentation!

Contents:

Brewtils

Brewtils is the Python library for interfacing with Beergarden systems. If you are planning on writing beer-garden plugins, this is the correct library for you. In addition to writing plugins, it provides simple ways to query the API and is officially supported by the beer-garden team.

Features

Brewtils helps you interact with beer-garden.

• Easy way to create beer-garden plugins
• Full support of the entire Beer-Garden API
• Officially supported by the beer-garden team

Installation

To install brewtils, run this command in your terminal:

$ pip install brewtils

Or add it to your requirements.txt

$ cat brewtils >> requirements.txt
$ pip install -r requirements.txt

Quick Start

You can create your own beer-garden plugins without much problem at all. To start, we’ll create the obligatory hello-world plugin. Creating a plugin is as simple as:

from brewtils.decorators import system, parameter, command
from brewtils.plugin import RemotePlugin

@system
class HelloWorld(object):

    @parameter(key="message", description="The message to echo", type="String")
    def say_hello(self, message="World!"):
        print("Hello, %s!" % message)
        return "Hello, %s!" % message

if __name__ == "__main__":
    client = HelloWorld()
    plugin = RemotePlugin(client,
                          name="hello",
                          version="0.0.1",
                          bg_host='127.0.0.1',
                          bg_port=2337)
    plugin.run()

Assuming you have a Beer Garden running on port 2337 on localhost, running this will register and start your plugin! You now have your first plugin running in beer-garden. Let’s use another part of the brewtils library to exercise your plugin from python.

The SystemClient is designed to help you interact with registered Systems as if they were native Python objects.

from brewtils.rest.system_client import SystemClient

hello_client = SystemClient('localhost', 2337, 'hello')

request = hello_client.say_hello(message="from system client")

print(request.status) # 'SUCCESS'
print(request.output) # Hello, from system client!

In the background, the SystemClient has executed an HTTP POST with the payload required to get beer-garden to execute your command. The SystemClient is how most people interact with beer-garden when they are in the context of python and want to be making requests.

Of course, the rest of the API is accessible through the brewtils package. The EasyClient provides simple convenient methods to call the API and auto-serialize the responses. Suppose you want to get a list of all the commands on all systems:

from brewtils.rest.easy_client import EasyClient

client = EasyClient('localhost', 2337)

systems = client.find_systems()

for system in systems:
    for command in system.commands:
        print(command.name)

This is just a small taste of what is possible with the EasyClient. Feel free to explore all the methods that are exposed.

For more detailed information and better walkthroughs, checkout the full documentation!

Documentation

• Full Beer Garden documentation is available at https://beer-garden.io
• Brewtils Documentation is available at https://brewtils.readthedocs.io

Installation

Stable release

To install Brewtils, run this command in your terminal:

$ pip install brewtils

This is the preferred method to install Brewtils, as it will always install the most recent stable release.

If you don’t have pip installed, this Python installation guide can guide you through the process.

From sources

The sources for Brewtils can be downloaded from the Github repo.

You can either clone the public repository:

$ git clone git@github.com/beer-garden/brewtils.git

Or download the tarball:

$ curl  -OL https://github.com/beer-garden/brewtils/tarball/master

Once you have a copy of the source, you can install it with:

$ python setup.py install

Usage

Brewtils

Brewtils is the Python library for interfacing with Beergarden systems. If you are planning on writing beer-garden plugins, this is the correct library for you. In addition to writing plugins, it provides simple ways to query the API and is officially supported by the beer-garden team.

Features

Brewtils helps you interact with beer-garden.

• Easy way to create beer-garden plugins
• Full support of the entire Beer-Garden API
• Officially supported by the beer-garden team

Installation

To install brewtils, run this command in your terminal:

$ pip install brewtils

Or add it to your requirements.txt

$ cat brewtils >> requirements.txt
$ pip install -r requirements.txt

Quick Start

You can create your own beer-garden plugins without much problem at all. To start, we’ll create the obligatory hello-world plugin. Creating a plugin is as simple as:

from brewtils.decorators import system, parameter, command
from brewtils.plugin import RemotePlugin

@system
class HelloWorld(object):

    @parameter(key="message", description="The message to echo", type="String")
    def say_hello(self, message="World!"):
        print("Hello, %s!" % message)
        return "Hello, %s!" % message

if __name__ == "__main__":
    client = HelloWorld()
    plugin = RemotePlugin(client,
                          name="hello",
                          version="0.0.1",
                          bg_host='127.0.0.1',
                          bg_port=2337)
    plugin.run()

Assuming you have a Beer Garden running on port 2337 on localhost, running this will register and start your plugin! You now have your first plugin running in beer-garden. Let’s use another part of the brewtils library to exercise your plugin from python.

The SystemClient is designed to help you interact with registered Systems as if they were native Python objects.

from brewtils.rest.system_client import SystemClient

hello_client = SystemClient('localhost', 2337, 'hello')

request = hello_client.say_hello(message="from system client")

print(request.status) # 'SUCCESS'
print(request.output) # Hello, from system client!

In the background, the SystemClient has executed an HTTP POST with the payload required to get beer-garden to execute your command. The SystemClient is how most people interact with beer-garden when they are in the context of python and want to be making requests.

Of course, the rest of the API is accessible through the brewtils package. The EasyClient provides simple convenient methods to call the API and auto-serialize the responses. Suppose you want to get a list of all the commands on all systems:

from brewtils.rest.easy_client import EasyClient

client = EasyClient('localhost', 2337)

systems = client.find_systems()

for system in systems:
    for command in system.commands:
        print(command.name)

This is just a small taste of what is possible with the EasyClient. Feel free to explore all the methods that are exposed.

For more detailed information and better walkthroughs, checkout the full documentation!

Documentation

• Full Beer Garden documentation is available at https://beer-garden.io
• Brewtils Documentation is available at https://brewtils.readthedocs.io

Contributing

Contributions are welcome, and they are greatly appreciated! Every little bit helps, and credit will always be given.

You can contribute in many ways:

Types of Contributions

Report Bugs

Report bugs at https://github.com/beer-garden/brewtils/issues.

If you are reporting a bug, please include:

• Your operating system name and version.
• Any details about your local setup that might be helpful in troubleshooting.
• Detailed steps to reproduce the bug.

Fix Bugs

Look through the GitHub issues for bugs. Anything tagged with “bug” and “help wanted” is open to whoever wants to implement it.

Implement Features

Look through the GitHub issues for features. Anything tagged with “enhancement” and “help wanted” is open to whoever wants to implement it.

Write Documentation

Brewtils could always use more documentation, whether as part of the official Brewtils docs, in docstrings, or even on the web in blog posts, articles, and such.

Submit Feedback

The best way to send feedback is to file an issue at https://github.com/beer-garden/brewtils/issues.

If you are proposing a feature:

• Explain in detail how it would work.
• Keep the scope as narrow as possible, to make it easier to implement.
• Remember that this is a volunteer-driven project, and that contributions are welcome :)

Get Started!

Ready to contribute? Here’s how to set up brewtils for local development.

1. Fork the brewtils repo on GitHub.

2. Clone your fork locally:

   $ git clone git@github.com:your_name_here/brewtils.git
   

3. Install your local copy into a virtualenv. Assuming you have virtualenvwrapper installed, this is how you set up your fork for local development:

   $ mkvirtualenv brewtils
   $ cd brewtils/
   $ python setup.py develop
   

4. Create a branch for local development:

   $ git checkout -b name-of-your-bugfix-or-feature
   

   Now you can make your changes locally.

5. When you’re done making changes, check that your changes pass flake8 and the tests, including testing other Python versions with tox:

   $ flake8 brewtils test
   $ nosetests
   $ tox
   

   To get flake8 and tox, just pip install them into your virtualenv.

6. Commit your changes and push your branch to GitHub:

   $ git add .
   $ git commit -m "Your detailed description of your changes."
   $ git push origin name-of-your-bugfix-or-feature
   

7. Submit a pull request through the GitHub website.

Pull Request Guidelines

Before you submit a pull request, check that it meets these guidelines:

1. The pull request should include tests.
2. If the pull request adds functionality, the docs should be updated. Put your new functionality into a function with a docstring, and add the feature to the list in README.rst.
3. The pull request should work for Python 2.7, 3.5, and 3.6. Check https://travis-ci.org/beer-garden/brewtils/pull_requests and make sure that the tests pass for all supported Python versions.

Tips

To run a subset of tests:

$ nosetests test/models_test.py:SystemTest.test_instance_names

Credits

Development Leads

• Logan Asher Jones <loganasherjones@gmail.com>
• Matt Patrick

Contributors

None yet. Why not be the first?

Brewtils Changelog

2.3.4

Date: 4/5/18

New Features

• Python 3.4 is now supported (#43)
• Now using Yapconf for configuration parsing (#34)
• Parameter types can now be specified as native Python types (#29)
• Added flag to raise an exception if a request created with SystemClient completes with an ‘ERROR’ status (#28)

Other Changes

• All exceptions now inherit from BrewtilsException (#45)
• Removed references to Brewmaster exception classes (#44)
• Requests with JSON command_type are smarter about formatting exceptions (#27)
• Decorators, RemotePlugin, and SystemClient can now be imported directly from the brewtils package

2.3.3

Date: 3/20/18

Bug Fixes

• Fixed bug where request updating could retry forever (#39)

2.3.2

Date: 3/7/18

Bug Fixes

• Fixed issue with multi-instance remote plugins failing to initialize (#35)

2.3.1

Date: 2/22/18

New Features

• Added description keyword argument to @command decorator

2.3.0

Date: 1/26/18

New Features

• Added methods for interacting with the Queue API to RestClient and EasyClient
• Clients and Plugins can now be configured to skip server certificate verification when making HTTPS requests
• Timestamps now have true millisecond precision on platforms that support it
• Added form_input_type to Parameter model
• Plugins can now be stopped correctly by calling their _stop method
• Added Event model

Bug Fixes

• Plugins now additionally look for ca_cert and client_cert in BG_CA_CERT and BG_CLIENT_CERT

Other Changes

• Better data integrity by only allowing certain Request status transitions

2.2.1

Date: 1/11/18

Bug Fixes

• Nested requests that reference a different beer-garden no longer fail

2.2.0

Date: 10/23/17

New Features

• Command descriptions can now be changed without updating the System version
• Standardized Remote Plugin logging configuration
• Added domain-specific language for dynamic choices configuration
• Added metadata field to Instance model

Bug Fixes

• Removed some default values from model __init__ functions
• System descriptors (description, display name, icon name, metadata) now always updated during startup
• Requests with output type ‘JSON’ will now have JSON error messages

Other changes

• Added license file

2.1.1

Date: 8/25/17

New Features

• Added updated_at field to Request model
• SystemClient now allows specifying a client_cert
• RestClient now reuses the same session for subsequent connections
• SystemClient can now make non-blocking requests
• RestClient and EasyClient now support PATCHing a System

Deprecations / Removals

• multithreaded argument to PluginBase has been superseded by max_concurrent
• These decorators are now deprecated - @command_registrar, instead use @system - @plugin_param, instead use @parameter - @register, instead use @command
• These classes are now deprecated - BrewmasterSchemaParser, instead use SchemaParser - BrewmasterRestClient, instead use RestClient - BrewmasterEasyClient, instead use EasyClient - BrewmasterSystemClient, instead use SystemClient

Bug Fixes

• Reworked message processing to remove the possibility of a failed request being stuck in IN_PROGRESS
• Correctly handle custom form definitions with a top-level array
• Smarter reconnect logic when the RabbitMQ connection fails

Other changes

• Removed dependency on pyopenssl so there’s need to compile any Python extensions
• Request processing now occurs inside of a ThreadPoolExecutor thread
• Better serialization handling for epoch fields