Modularity/Development/Setting up PDC locally

Setting up PDC locally for Modularity development

To develop tooling for Modularity and test it, we want to have a local instance of PDC installed. The upstream documentation describes a couple of ways of doing that, this document describes how it can be done using a Python virtualenv, with some notable differences:

• The virtualenv won't have system-wide packages enabled. This is so that OS updates or upgrades have a reduced impact on the development environment, "reduced" because neither koji nor rpm Python modules lend themselves well to be installed into a virtualenv, so for the sake of simplicity we'll symlink the system-wide installed modules.
• We'll use the modularity branch of productmd, not the version that's available on PyPI.

Walkthrough

1. Install the necessary system-wide packages (if missing) using dnf, yum or similar:

   koji
   python-virtualenvwrapper
   rpm-python

   Some development packages of libraries are needed for the Python module dependencies to be installed as well. Here's the list of development packages needed on Fedora 23:

   cyrus-sasl-devel
   glibc-devel
   graphviz-devel
   keyutils-libs-devel
   krb5-devel
   libcom_err-devel
   libffi-devel
   libgcrypt-devel
   libgpg-error-devel
   libselinux-devel
   libxml2-devel
   libxslt-devel
   nspr-devel
   nss-devel
   nss-softokn-freebl-devel
   nss-util-devel
   openldap-devel
   openssl-devel
   pcre-devel
   python-devel
   xz-devel
   zlib-devel
   

2. Create a workspace directory where all the checked out code repositories live, if you haven't done so already. We'll refer to that as $WORKSPACE.
3. Make a virtualenv pdc for PDC development. This is one point where we deviate from the upstream docs:

   mkvirtualenv pdc

   This activates the pdc virtualenv right away, leave it using the deactivate command, and activate it again with workon pdc later on.

4. Optional: Upgrade pip so it doesn't complain about the old version being installed all the time:

   pip install --upgrade pip

5. Make the modularity branch of productmd available in the virtualenv.
   1. Clone the repository into your workspace:

      cd "$WORKSPACE"
      git clone --branch modularity https://github.com/lkocman/productmd.git

   2. Make the virtualenv use the checked out source:

      cd productmd
      python setup.py develop

6. Symlink the koji and rpm Python packages from the system into the virtualenv:

   cdvirtualenv
   cd lib/python2.7/site-packages
   ln -s /usr/lib/python2.7/site-packages/koji koji
   ln -s /usr/lib64/python2.7/site-packages/rpm rpm

   If you use a 32bit system, the last line must be changed to:

   ln -s /usr/lib/python2.7/site-packages/rpm rpm

7. Install Python dependencies needed by koji into the virtualenv:

   pip install pyOpenSSL python-krbV

8. Get PDC and set it up.
   1. Clone the PDC repository into your workspace:

      cd "$WORKSPACE"
      git clone https://github.com/product-definition-center/product-definition-center.git

   2. Install the dependencies needed for PDC development:

      cd product-definition-center
      pip install -r requirements/devel.txt

   3. Create the database and schema inside, this command also would migrate the schema to a new version if subsequent changes in PDC make this necessary:

      ./manage.py migrate

   4. Create a superuser for PDC:

      ./manage.py createsuperuser

      This will ask you for a user name, email address and password. Going forward, we'll assume the user name is superuser.

   5. Set up local configuration so testing doesn't require authentication etc. for what would be privileged operations in a productive environment.
      1. Copy the local configuration file from the template:

         cd pdc
         cp settings_local.py.dist settings_local.py

      2. Make some changes in settings_local.py:
         1. Enable debugging, change this line:

            DEBUG = False

            to this one:

            DEBUG = True

         2. Don't restrict connecting to PDC (it listens on the loopback device only, anyway), comment out the ALLOWED_HOSTS line:

            #ALLOWED_HOSTS = [...]

         3. Make unauthenticated access user the superuser account, forego permissions checking. Add these lines to the end of the file:

            # mock login for debugging
            DEBUG_USER = "superuser"
            
            DISABLE_RESOURCE_PERMISSION_CHECK = True
            
            del get_setting('REST_FRAMEWORK')['DEFAULT_PERMISSION_CLASSES']

   6. Start up the local PDC instance:

      cd "$WORKSPACE"/product-definition-center
      ./manage.py runserver

   7. Manually create the module Variant Type in the PDC interface.
      1. Go to http://127.0.0.1:8000 with your web browser, then go the administrative interface 👤 superuser → PDC Administration interface.
      2. Locate Release → Variant types, click on + Add, enter module as the name, click on Save.

At this point, PDC should be set up and ready for working with modules.