Contributing¶

Get Source Code¶

Clone the repo from github:

$ git clone git@github.com:tomcatmanager/tomcatmanager.git

Create Python Environments¶

tomcatamanger uses tox to run the test suite against multiple python versions. I recommend using pyenv with the pyenv-virtualenv plugin to manage these various versions. If you are a Windows user, pyenv won’t work for you, you’ll probably have to use conda.

This distribution includes a shell script build-pyenvs.sh which automates the creation of these environments.

If you prefer to create these virtual envs by hand, do the following:

$ cd tomcatmanager
$ pyenv install 3.7.0
$ pyenv virtualenv -p python3.7 3.7.0 tomcatmanager-3.7
$ pyenv install 3.6.5
$ pyenv virtualenv -p python3.6 3.6.5 tomcatmanager-3.6
$ pyenv install 3.5.5
$ pyenv virtualenv -p python3.5 3.5.5 tomcatmanager-3.5
$ pyenv install 3.4.8
$ pyenv virtualenv -p python3.4 3.4.8 tomcatmanager-3.4

Now set pyenv to make all three of those available at the same time:

$ pyenv local tomcatmanager-3.7 tomcatmanager-3.6 tomcatmanager-3.5 tomcatmanager-3.4

Whether you ran the script, or did it by hand, you now have isolated virtualenvs just for tomcatmanager for each of the three python versions. This table shows various python commands, the version of python which will be executed, and the virtualenv it will utilize.

Command	python	virtualenv
`python`	3.7.0	tomcatmanager-3.6
`python3`	3.7.0	tomcatmanager-3.6
`python3.7`	3.7.0	tomcatmanager-3.7
`python3.6`	3.6.5	tomcatmanager-3.6
`python3.5`	3.5.5	tomcatmanager-3.5
`python3.4`	3.4.8	tomcatmanager-3.4
`pip`	3.7.0	tomcatmanager-3.6
`pip3`	3.7.0	tomcatmanager-3.6
`pip3.7`	3.7.0	tomcatmanager-3.7
`pip3.6`	3.6.5	tomcatmanager-3.6
`pip3.5`	3.5.5	tomcatmanager-3.5
`pip3.4`	3.4.8	tomcatmanager-3.4

Install Dependencies¶

Now install all the development dependencies:

$ pip install -e .[dev]

This installs the tomcatmanager package “in-place”, so the package points to the source code instead of copying files to the python site-packages folder.

All the dependencies now have been installed in the tomcatmanager-3.6 virtualenv. If you want to work in other virtualenvs, you’ll need to manually select it, and install again:

$ pyenv shell tomcatmanager-3.4
$ pip install -e .[dev]

Branches, Tags, and Versions¶

This project uses a simplified version of the git flow branching strategy. We don’t use release branches, and we generally don’t do hotfixes, so we don’t have any of those branches either. The master branch always contains the latest release of the code uploaded to PyPI, with a tag for the version number of that release.

The develop branch is where all the action occurs. Feature branches are welcome. When it’s time for a release, we merge develop into master.

This project uses semantic versioning.

Invoking Common Development Tasks¶

This project uses many other python modules for various development tasks, including testing, rendering documentation, and building and distributing releases. These modules can be configured many different ways, which can make it difficult to learn the specific incantations required for each project you are familiar with.

This project uses invoke to provide a clean, high level interface for these development tasks. To see the full list of functions available:

$ invoke -l

You can run multiple tasks in a single invocation, for example:

$ invoke clean docs sdist wheel

That one command will remove all superflous cache, testing, and build files, render the documentation, and build a source distribution and a wheel distribution.

You probably won’t need to read further in this document unless you want more information about the specific tools used.

Testing¶

To ensure the tests can run without an external dependencies, tests/mock_server80.py contains a HTTP server which emulates the behavior of Tomcat Manager 8.0. There is a test fixture to start this server, and all the tests run against this fixture. I created this fixture to speed up testing time. It doesn’t do everything a real Tomcat server does, but it’s close enough for the tests to run, and it allows you to parallelize the test suite using python-xdist.

You can run the tests against all the supported versions of python using tox:

$ tox

tox expects that when it runs python3.4 it will actually get a python from the 3.4.x series. That’s why we set up the various python environments earlier.

If you just want to run the tests in your current python environment, use pytest:

$ pytest

This runs all the test in tests/ and also runs doctests in tomcatmanager/ and docs/.

You can speed up the test suite by using pytest-xdist to parallelize the tests across the number of cores you have:

$ pip install pytest-xdist
$ pytest -n8

In many of the doctests you’ll see something like:

>>> tomcat = getfixture('tomcat')

This getfixture() helper imports fixtures defined in conftest.py, which has several benefits:

reduces the amount of redundant code in doctests which shows connecting to a tomcat server and handling exceptions
allows doctests to execute against a mock tomcat server

You can run all the tests against a real Tomcat Server by utilizing the following command line options:

$ pytest --url=http://localhost:8080/manager --user=ace \
--password=newenglandclamchowder --warfile=/tmp/sample.war \
--contextfile=/tmp/context.xml

Running the test suite will deploy and undeploy an app hundreds of times, and will definitely trigger garbage collection, so you might not want to run it against a production server. When I run the test suite against a stock Tomcat on a Linode with 2 cores and 4GB of memory it takes approximately 30 minutes to complete.

Note

If you test against a real Tomcat server, you should not use the pytest-xdist plugin to parallelize testing across multiple CPUs or many platforms. Many of the tests depend on deploying and undeploying an app at a specific path, and that path is shared across the entire test suite. It wouldn’t help much anyway because the testing is constrained by the speed of the Tomcat server.

If you kill the test suite in the middle of a run, you may leave the test application deployed in your tomcat server. If this happens, you must undeploy it before rerunning the test suite or you will get lots of errors.

When the test suite deploys applications, it will be at the path returned by the safe_path fixture in conftest.py. You can modify that fixture if for some reason you need to deploy at a different path.

The url, user, and password options describe the location and credentials for the Tomcat server you wish to use.

The warfile parameter is the full path to a war file on the server. There is a simple war file in tests/war/sample.war which you can copy to the server if you don’t have a war file you want to use. If you don’t copy the war file, or if you don’t specify the warfile parameter, or the path you provide doesn’t point to a valid war file, several of the tests will fail.

The contextfile parameter is the full path to a context XML file, which gives you an alternative way to specify additional deployment information to the Tomcat Server. There is a simple context file in tests/war/context.xml which you can copy to the server if you don’t have a context file you want to use. If you don’t copy the context file, or if you don’t specify the contextfile parameter, or the path you provide doesn’t point to a valid context file, several of the tests will fail. The path in your context file will be ignored, but you must specify a docBase attribute which points to a real war file.

Code Quality¶

Use pylint to check code quality. There is a pylint config file for the tests and for the main module:

$ pylint --rcfile=tests/pylintrc tests
$ pylint --rcfile=tomcatmanager/pylintrc tomcatmanager

You are welcome to use the pylint comment directives to disable certain messages in the code, but pull requests containing these directives will be carefully scrutinized.

As allowed by PEP 8 this project uses a nominal line length of 100 characters.

Documentation¶

The documentation is written in reStructured Test, and turned into HTML using Sphinx:

$ cd docs
$ make html

The output will be in docs/build/html.

If you are doing a lot of documentation work, the sphinx-autobuild module has been integrated. Type:

$ cd docs
$ make livehtml

Then point your browser at http://localhost:8000 to see the documentation automatically rebuilt as you save your changes.

Make a Release¶

To make a release and deploy it to PyPI, do the following:

Merge everything to be included in the release into the develop branch.
Run tox to make sure the tests pass in all the supported python versions.
Review and update CHANGELOG.rst.
Update the milestone corresponding to the release at https://github.com/tomcatmanager/tomcatmanager/milestones
Push the develop branch to github.
Create a pull request on github to merge the develop branch into master. Wait for the checks to pass.
Merge the develop branch into the master branch and close the pull request.
Tag the master branch with the new version number, and push the tag.
Build source distribution, wheel distribution, and upload them to pypi:
```
$ invoke distribute
```
Docs are automatically deployed to http://tomcatmanager.readthedocs.io/en/stable/.

Make sure they look good.

Switch back to the develop branch. Add an Unreleased section to the top of CHANGELOG.rst. Push the change to github.