.. _installing_chapter: Installing :mod:`repoze.bfg` ============================ Before You Install ------------------ You will need `Python `_ version 2.4 or better to run :mod:`repoze.bfg`. It has been tested under Python 2.4.5, Python 2.5.2 and Python 2.6. Development of :mod:`repoze.bfg` is currently done primarily under Python 2.4. :mod:`repoze.bfg` does *not* run under any version of Python before 2.4, and does *not* run under Python 3.X. .. warning:: To succesfully install :mod:`repoze.bfg`, you will need an environment capable of compiling C code (e.g. ``XCode Tools`` will need to be installed if you're using MacOS X, and ``gcc`` and other build tools will need to be installed if you're using other UNIXlike systems). See the system's documentation about installing this software. Additionally, the Python development libraries for your Python version will need to be installed and the ``lixbml2`` and ``libxslt`` development libraries will need to be installed. These requirements are often satisfied by installing the ``python-devel``, ``libxml2-devel`` and ``libxslt-devel`` packages into your system. You will also need :term:`setuptools` installed on within your Python system in order to run the ``easy_install`` command. At the time of this writing, ``repoze.bfg`` will not install on Windows systems unless you have development tools (e.g. *Visual C++*) installed. .. note:: If you'd like to help produce and maintain a version of :mod:`repoze.bfg` that works on Windows, we'd love to hear from you. There's nothing intrinsic about :mod:`repoze.bfg` that would prevent it from running on Windows, but none of the current developers use the platform. Please contact us via the `repoze.dev maillist `_ if you'd like to try to tackle the job of compilation and maintenance. Installing :mod:`repoze.bfg` ---------------------------- It is advisable to install :mod:`repoze.bfg` into a :term:`virtualenv` in order to obtain isolation from any "system" packages you've got installed in your Python version (and likewise, to prevent :mod:`repoze.bfg` from globally installing versions of packages that are not compatible with your system Python). To set up a virtualenv to install :mod:`repoze.bfg` within, first ensure that setuptools is installed. Invoke ``import setuptools`` within the Python interpreter you'd like to run :mod:`repoze.bfg` under. .. code-block:: bash [chrism@vitaminf bfg]$ python Python 2.4.5 (#1, Aug 29 2008, 12:27:37) [GCC 4.0.1 (Apple Inc. build 5465)] on darwin Type "help", "copyright", "credits" or "license" for more information. >>> import setuptools If ``import setuptools`` does not raise an ``ImportError``, it means that setuptools is already installed into your Python interpreter. If ``import setuptools`` fails, you will need to install setuptools manually. If you are using a "system" Python (one installed by your OS distributor or a 3rd-party packager such as Fink or MacPorts), you can usually install a setuptools package using your system's package manager. If you cannot do this, or if you're using a self-installed version of Python, you will need to install setuptools "by hand". Installing setuptools "by hand" is always a reasonable thing to do, even if your package manager already has a prechewed version of setuptools for installation. To install setuptools by hand, first download `ez_setup.py `_ then invoke it using the Python interpreter you want to install setuptools into. .. code-block:: bash $ python ez_setup.py Once this command is invoked, setuptools should be installed on your system. If the command fails due to permission errors, you may need to be the administrative user on your system to successfully invoke the script. Installing the ``virtualenv`` Package ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Once you've got setuptools installed, you should install the :term:`virtualenv` package. To install the :term:`virtualenv` package into your setuptools-enabled Python interpreter, use the ``easy_install`` command. .. code-block:: bash $ easy_install virtualenv This command should succeed, and tell you that the virtualenv package is now installed. If it fails due to permission errors, you may need to install it as your system's administrative user. Creating the Virtual Python Environment ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Once the :term:`virtualenv` package is installed in your Python, you can actually create a virtual environment. To do so, invoke the following: .. code-block:: bash :linenos: $ virtualenv --no-site-packages bfgenv New python executable in bfgenv/bin/python Installing setuptools.............done. .. warning:: Using ``--no-site-packages`` when generating your virtualenv is *very important*. This flag provides the necessary isolation for running the set of packages required by :mod:`repoze.bfg`. If you do not specify ``--no-site-packages``, it's possible that :mod:`repoze.bfg` will not install properly into the virtualenv, or, even if it does, may not run properly, depending on the packages you've already got installed into your Python's "main" site-packages dir. You should perform any following commands that mention a "bin" directory from within the ``bfgenv`` virtualenv dir. Installing :mod:`repoze.bfg` Into the Virtual Python Environment ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ After you've got your ``bfgenv`` virtualenv installed, you may install :mod:`repoze.bfg` itself using the following commands from within the virtualenv (``bfgenv``) directory: .. code-block:: bash :linenos: $ bin/easy_install -i http://dist.repoze.org/bfg/current/simple repoze.bfg .. warning:: Note carefully the ``-i http://dist.repoze.org/bfg/current/simple`` above. It is required. :mod:`repoze.bfg` software is maintained in its own index; :mod:`repoze.bfg` cannot be installed from PyPI. This command will take longer than the previous ones to complete, as it compiles a number of dependencies. What Gets Installed ~~~~~~~~~~~~~~~~~~~ When you ``easy_install`` :mod:`repoze.bfg`, various Zope libraries, WebOb, Paste, PasteScript, and PasteDeploy libraries are installed. Additionally, as shown in the next section, PasteScript (aka *paster*) templates will be registered that make it easy to start a new :mod:`repoze.bfg` project. Troubleshooting --------------- If ``lxml`` Fails to Compile During ``easy_install`` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ If the installation of :mod:`repoze.bfg` fails due to problems compiling ``lxml``, you should try installing ``lxml`` before installing :mod:`repoze.bfg`. To do so, invoke ``easy_install``, instructing ``lxml`` to download its own copy of ``libxml2``:: $ STATIC_DEPS=true bin/easy_install lxml Once that completes, you can start a subsequent ``easy_install`` of :mod:`repoze.bfg` as per the instructions above; it should then work. If You Can't Install Via ``easy_install`` (Alternate Installation) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ If you can't get :mod:`repoze.bfg` installed using ``easy_install`` because ``lxml`` fails to compile on your system, you can try the `repoze.bfg buildout `_. This installation mechanism builds known-compatible ``libxml2`` and ``libxslt`` from source and causes ``lxml`` to link against these instead of your system packages, as version incompatibilities between system packages and ``lxml`` versions are typically to blame for compilation problems.