Development¶

This section only needs to be read by developers of the zhmc-ansible-modules project. People that want to make a fix or develop some extension, and people that want to test the project are also considered developers for the purpose of this section.

Repository¶

The repository for the zhmc-ansible-modules project is on GitHub:

https://github.com/zhmcclient/zhmc-ansible-modules

Setting up the development environment¶

The development environment is pretty easy to set up.

Besides having a supported operating system with a supported Python version (see Supported environments), it is recommended that you set up a virtual Python environment.

Then, with a virtual Python environment active, clone the Git repo of this project and prepare the development environment with make setup:

$ git clone git@github.com:zhmcclient/zhmc-ansible-modules.git
$ cd zhmc-ansible-modules
$ make setup

This will install all prerequisites the project needs for its development.

Generally, this project uses Make to do things in the currently active Python environment. The command make help (or just make) displays a list of valid Make targets and a short description of what each target does.

Building the documentation¶

The ReadTheDocs (RTD) site is used to publish the documentation for the zhmc-ansible-modules project at http://zhmc-ansible-modules.readthedocs.io/

This page automatically gets updated whenever the master branch of the Git repo for this package changes.

In order to build the documentation locally from the Git work directory, issue:

$ make docs

The top-level document to open with a web browser will be build/docs/html/index.html.

Testing¶

To run unit tests in the currently active Python environment, issue one of these example variants of make test:

$ make test                                  # Run all unit tests
$ TESTCASES=test_resource.py make test       # Run only this test source file
$ TESTCASES=TestInit make test               # Run only this test class
$ TESTCASES="TestInit or TestSet" make test  # py.test -k expressions are possible

To run the unit tests and some more commands that verify the project is in good shape in all supported Python environments, use Tox:

$ tox                              # Run all tests on all supported Python versions
$ tox -e py27                      # Run all tests on Python 2.7
$ tox -e py27 test_resource.py     # Run only this test source file on Python 2.7
$ tox -e py27 TestInit             # Run only this test class on Python 2.7
$ tox -e py27 TestInit or TestSet  # py.test -k expressions are possible

The positional arguments of the tox command are passed to py.test using its -k option. Invoke py.test --help for details on the expression syntax of its -k option.

Contributing¶

Third party contributions to this project are welcome!

In order to contribute, create a Git pull request, considering this:

Test is required.
Each commit should only contain one “logical” change.
A “logical” change should be put into one commit, and not split over multiple commits.
Large new features should be split into stages.
The commit message should not only summarize what you have done, but explain why the change is useful.
The commit message must follow the format explained below.

What comprises a “logical” change is subject to sound judgement. Sometimes, it makes sense to produce a set of commits for a feature (even if not large). For example, a first commit may introduce a (presumably) compatible API change without exploitation of that feature. With only this commit applied, it should be demonstrable that everything is still working as before. The next commit may be the exploitation of the feature in other components.

For further discussion of good and bad practices regarding commits, see:

Format of commit messages¶

A commit message must start with a short summary line, followed by a blank line.

Optionally, the summary line may start with an identifier that helps identifying the type of change or the component that is affected, followed by a colon.

It can include a more detailed description after the summary line. This is where you explain why the change was done, and summarize what was done.

It must end with the DCO (Developer Certificate of Origin) sign-off line in the format shown in the example below, using your name and a valid email address of yours. The DCO sign-off line certifies that you followed the rules stated in DCO 1.1. In short, you certify that you wrote the patch or otherwise have the right to pass it on as an open-source patch.

We use GitCop during creation of a pull request to check whether the commit messages in the pull request comply to this format. If the commit messages do not comply, GitCop will add a comment to the pull request with a description of what was wrong.

Example commit message:

cookies: Add support for delivering cookies

Cookies are important for many people. This change adds a pluggable API for
delivering cookies to the user, and provides a default implementation.

Signed-off-by: Random J Developer <random@developer.org>

Use git commit --amend to edit the commit message, if you need to.

Use the --signoff (-s) option of git commit to append a sign-off line to the commit message with your name and email as known by Git.

If you like filling out the commit message in an editor instead of using the -m option of git commit, you can automate the presence of the sign-off line by using a commit template file:

Create a file outside of the repo (say, ~/.git-signoff.template) that contains, for example:

<one-line subject>

<detailed description>

Signed-off-by: Random J Developer <random@developer.org>

Configure Git to use that file as a commit template for your repo:
```
git config commit.template ~/.git-signoff.template
```

Releasing a version¶

This section shows the steps for releasing a version to PyPI.

It covers all variants of versions that can be released:

Releasing the master branch as a new major or minor version (M+1.0.0 or M.N+1.0)
Releasing a stable branch as a new update version (M.N.U+1)

This description assumes that you are authorized to push to the upstream repo at https://github.com/zhmcclient/zhmc-ansible-modules and that the upstream repo has the remote name origin in your local clone.

Switch to your work directory of your local clone of the zhmc-ansible-modules Git repo and perform the following steps in that directory.
Set shell variables for the version and branch to be released:
- MNU - Full version number M.N.U this release should have
- MN - Major and minor version numbers M.N of that full version
- BRANCH - Name of the branch to be released
When releasing the master branch (e.g. as version 0.6.0):
```
MNU=0.6.0
MN=0.6
BRANCH=master
```
When releasing a stable branch (e.g. as version 0.5.1):
```
MNU=0.5.1
MN=0.5
BRANCH=stable_$MN
```
Check out the branch to be released, make sure it is up to date with upstream, and create a topic branch for the version to be released:
```
git status  # Double check the work directory is clean
git checkout $BRANCH
git pull
git checkout -b release_$MNU
```
Edit the change log:
```
vi docs/changes.rst
```
and make the following changes in the section of the version to be released:
- Finalize the version to the version to be released.
- Remove the statement that the version is in development.
- Change the release date to today´s date.
- Make sure that all changes are described.
- Make sure the items shown in the change log are relevant for and understandable by users.
- In the “Known issues” list item, remove the link to the issue tracker and add text for any known issues you want users to know about.
- Remove all empty list items in that section.

Commit your changes and push them upstream:

git add docs/changes.rst
git commit -sm "Release $MNU"
git push --set-upstream origin release_$MNU

On GitHub, create a Pull Request for branch release_$MNU. This will trigger the CI runs in Travis and Appveyor.

Important: When creating Pull Requests, GitHub by default targets the master branch. If you are releasing a stable branch, you need to change the target branch of the Pull Request to stable_M.N.
On GitHub, close milestone M.N.U.
Perform a complete test:
```
tox
```
This should not fail because the same tests have already been run in the Travis CI. However, run it for additional safety before the release.
- If this test fails, fix any issues until the test succeeds. Commit the changes and push them upstream:
```
git add <changed-files>
git commit -sm "<change description with details>"
git push
```
  Wait for the automatic tests to show success for this change.
On GitHub, once the checks for this Pull Request succeed:
- Merge the Pull Request (no review is needed).
  
  Because this updates the stable_M.N branch, it triggers an RTD docs build of its stable version. However, because the git tag for this version is not assigned yet, this RTD build will show an incorrect version (a dev version based on the previous version tag). This will be fixed in a subsequent step.
- Delete the branch of the Pull Request (release_M.N.U)
Checkout the branch you are releasing, update it from upstream, and delete the local topic branch you created:
```
git checkout $BRANCH
git pull
git branch -d release_$MNU
```
Tag the version:

Important: This is the basis on which ‘pbr’ determines the package version. The tag string must be exactly the version string M.N.U.

Create a tag for the new version and push the tag addition upstream:
```
git status    # Double check the branch to be released is checked out
git tag $MNU
git push --tags
```
The pushing of the tag triggers another RTD docs build of its stable version, this time with the correct version as defined in the tag.

If the previous commands fail because this tag already exists for some reason, delete the tag locally and remotely:
```
git tag --delete $MNU
git push --delete origin $MNU
```
and try again.
On RTD, verify that it shows the correct version for its stable version:

RTD stable version: https://zhmc-ansible-modules.readthedocs.io/en/stable.

If it does not, trigger a build of RTD version “stable” on the RTD project page:

RTD build page: https://readthedocs.org/projects/zhmc-ansible-modules/builds/

Once that build is complete, verify again.
On GitHub, edit the new tag M.N.U, and create a release description on it. This will cause it to appear in the Release tab.

You can see the tags in GitHub via Code -> Releases -> Tags.
Do a fresh install of this version in your active Python environment. This ensures that ‘pbr’ determines the correct version. Otherwise, it may determine some development version.
```
make clobber install
make help    # Double check that it shows version ``M.N.U``
```
Upload the package to PyPI:
```
make upload
```
This will show the package version and will ask for confirmation.

Important: Double check that the correct package version (M.N.U, without any development suffix) is shown.

Attention!! This only works once for each version. You cannot re-release the same version to PyPI, or otherwise update it.

Verify that the released version arrived on PyPI: https://pypi.python.org/pypi/zhmc-ansible-modules/
If you released the master branch, it needs a new fix stream.

Create a branch for its fix stream and push it upstream:
```
git status    # Double check the branch to be released is checked out
git checkout -b stable_$MN
git push --set-upstream origin stable_$MN
```
Log on to the RTD project zhmc-ansible-modules and activate the new version (=branch) stable_M.N as a version to be built.

Starting a new version¶

This section shows the steps for starting development of a new version.

These steps may be performed right after the steps for Releasing a version, or independently.

This section covers all variants of new versions:

A new major or minor version for new development based upon the master branch.
A new update (=fix) version based on a stable branch.

This description assumes that you are authorized to push to the upstream repo at https://github.com/zhmcclient/zhmc-ansible-modules and that the upstream repo has the remote name origin in your local clone.

Switch to your work directory of your local clone of the zhmc-ansible-modules Git repo and perform the following steps in that directory.
Set shell variables for the version to be started and its base branch:
- MNU - Full version number M.N.U of the new version to be started
- MN - Major and minor version numbers M.N of that full version
- BRANCH - Name of the branch the new version is based upon
When starting a (major or minor) version (e.g. 0.6.0) based on the master branch:
```
MNU=0.6.0
MN=0.6
BRANCH=master
```
When starting an update (=fix) version (e.g. 0.5.1) based on a stable branch:
```
MNU=0.5.1
MN=0.5
BRANCH=stable_$MN
```
Check out the branch the new version is based on, make sure it is up to date with upstream, and create a topic branch for the new version:
```
git status  # Double check the work directory is clean
git checkout $BRANCH
git pull
git checkout -b start_$MNU
```

Edit the change log:

vi docs/changes.rst

and insert the following section before the top-most section:

Version 0.6.0
^^^^^^^^^^^^^

Released: not yet

**Incompatible changes:**

**Deprecations:**

**Bug fixes:**

**Enhancements:**

**Known issues:**

* See `list of open issues`_.

.. _`list of open issues`: https://github.com/zhmcclient/zhmc-ansible-modules/issues