8. Development¶

This section only needs to be read by developers of the zhmcclient package. 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.

8.1. Code of Conduct¶

Help us keep zhmcclient open and inclusive. Please read and follow our Code of Conduct.

8.2. Repository¶

The repository for zhmcclient is on GitHub:

https://github.com/zhmcclient/python-zhmcclient

8.3. 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 develop:

$ git clone git@github.com:zhmcclient/python-zhmcclient.git
$ cd python-zhmcclient
$ make develop

This will install all prerequisites the package needs to run, as well as all prerequisites that you need for 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.

8.4. Building the documentation¶

The ReadTheDocs (RTD) site is used to publish the documentation for the zhmcclient package at http://python-zhmcclient.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 builddoc

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

8.5. 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.

8.6. Running function tests against a real HMC and CPC¶

The function tests (in tests/function/test_*.py) can be run against a faked HMC/CPC (using the zhmcclient mock support), or against a real HMC/CPC.

By default, the function tests are run against the faked HMC/CPC. To run them against a real HMC/CPC, you must:

Specify the name of the target CPC in the ZHMC_TEST_CPC environment variable. This environment variable is the control point that decides between using a real HMC/CPC and using the faked environment:
```
export ZHMC_TEST_CPC=S67B
```

Have an HMC credentials file at location examples/hmccreds.yaml that specifies the target CPC (among possibly further CPCs) in its cpcs item:

cpcs:

  S67B:
    description: "z13s in DPM mode"
    contact: "Joe"
    hmc_host: "10.11.12.13"
    hmc_userid: myuserid
    hmc_password: mypassword

  # ... more CPCs

There is an example HMC credentials file in the repo, at examples/example_hmccreds.yaml. For a description of its format, see Format of the HMC credentials file.

8.7. Enabling logging for function tests¶

The function tests always log to stderr. What can be logged are the following two components:

api: Calls to and returns from zhmcclient API functions (at debug level).
hmc: Interactions with the HMC (i.e. HTTP requests and responses, at debug level).

By default, the log component and level is set to:

all=warning

meaning that all components log at warning level or higher.

To set different log levels for the log components, set the ZHMC_LOG environment variable as follows:

export ZHMC_LOG=COMP=LEVEL[,COMP=LEVEL[,...]]

Where:

COMP is one of: all, api, hmc.
LEVEL is one of: error, warning, info, debug.

For example, to enable logging of the zhmcclient API calls and the interactions with the HMC, use:

export ZHMC_LOG=api=debug,hmc=debug

or, shorter:

export ZHMC_LOG=all=debug

8.8. Format of the HMC credentials file¶

The HMC credentials file is used for specifying real HMCs/CPCs to be used by function tests. Its syntax is YAML, and the cpcs item relevant for function testing has the following structure:

cpcs:

  "CPC1":
    description: "z13 test system"
    contact: "Amy"
    hmc_host: "10.10.10.11"           # required
    hmc_userid: "myuser1"             # required
    hmc_password: "mypassword1"       # required

  "CPC2":
    description: "z14 development system"
    contact: "Bob"
    hmc_host: "10.10.10.12"
    hmc_userid: "myuser2"
    hmc_password: "mypassword2"

In the example above, any words in double quotes are data and can change, and any words without double quotes are considered keywords and must be specified as shown.

“CPC1” and “CPC2” are CPC names that are used to select an entry in the file. The entry for a CPC contains data about the HMC managing that CPC, with its host, userid and password. If two CPCs are managed by the same HMC, there would be two CPC entries with the same HMC data.

8.9. 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:

8.10. 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
```

8.11. Releasing a version¶

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

Switch to your work directory of the python-zhmcclient Git repo (this is where the Makefile is), and perform the following steps in that directory:

Set a shell variable for the version to be released, e.g.:
```
MNU='0.11.0'
```
Verify that your working directory is in a Git-wise clean state:
```
git status
```
Check out the master branch, and update it from upstream:
```
git checkout master
git pull
```
Create a topic branch for the release, based upon the master branch:
```
git checkout -b release-$MNU
```
Edit the change log (docs/changes.rst) and perform the following changes in the top-most section (that is the section for the version to be released):
- If needed, change the version in the section heading to the version to be released, e.g.:
```
Version 0.11.0
^^^^^^^^^^^^^^
```
- Change the release date to today’s date, e.g.:
```
Released: 2017-03-16
```
- Make sure that the change log entries reflect all changes since the previous version, and make sure they are relevant for and understandable by users.
- In the “Known issues” list item, remove the link to the issue tracker and add any known issues you want users to know about. Just linking to the issue tracker quickly becomes incorrect for released versions:
```
**Known issues:**

* ....
```
- Remove all empty list items in the change log section for this release.

Commit your changes and push them upstream:

git add docs/changes.rst
git commit -sm "Updated change log for $MNU release."
git push --set-upstream origin release-$MNU

On GitHub, create a pull request for branch release-$MNU.
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.
Once the CI tests on GitHub are complete, merge the pull request.
Update your local master branch:
```
git checkout master
git pull
```
Tag the master branch with the release label and push the tag upstream:
```
git tag $MNU
git push --tags
```
On GitHub, edit the new tag, 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.
Upload the package to PyPI:
```
make upload
```
This will show the package version and will ask for confirmation.

Attention!! This only works once for each version. You cannot release the same version twice to PyPI.
Verify that the released version is shown on PyPI:

https://pypi.python.org/pypi/zhmcclient/
Verify that RTD shows the released version as its stable version:

https://python-zhmcclient.readthedocs.io/en/stable/intro.html#versioning

Note: RTD builds the documentation automatically, but it may take a few minutes to do so.
On GitHub, close milestone M.N.U.

8.12. 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 description works for releases that are direct successors of the previous release. It does not cover starting a new version that is a fix release to a version that was released earlier.