Deployment with virtualenv¶
First configure the system in accordance with a Common Base Environment to be shared with SAM and POMS projects, and then using a Python virtualenv area to bundle the dependent packages for POMS or SAM etc. along with it. This will also facilitate making
an RPM of the whole virtualenv for production installation via frozen RPMs.
First your base system should be configured per the Common Base Environment, which will use the "softwarecollections" tools to install current versions of python, gcc, etc.
Creating the virtual environment¶
You should pick a location for the virtual environment; by convention this is usually in the home area of the "poms" account; but you can put it in your own home area for a personal development area. We'll be referring to the account area as $HOME.
$ scl enable rh-python36 rh-postgresql96 bash bash-4.1$ which python /opt/rh/rh-python36/root/usr/bin/python bash-4.1$ cd $HOME bash-4.1$ mkdir $HOME/poms_venv bash-4.1$ virtualenv poms_venv New python executable in poms_venv/bin/python2 Also creating executable in poms_venv/bin/python Installing setuptools, pip, wheel...done. bash-4.1$ exit setuptools needed to be upgrade to newer version in order to install packages later $ scl enable rh-python36 rh-postgresql96 bash $ source $HOME/poms_venv/bin/activate $ pip install -U pip setuptools
Optional -- patch up virtual_env and scl enable bits¶
We can now make a script using scl_source that we can source to setup the whole shebang:
echo " scl_source enable rh-python36 scl_source enable rh-postgresql96 source $HOME/poms_venv/bin/activate" > $HOME/poms_venv/bin/scl_activate
setting up the virtual environment¶
[Now if you did the optional previous section, you can skip the 'scl enable' part below]
bash-4.11$ source $HOME/poms_venv/bin/scl_activate (poms_venv)bash-4.11$
pip install dependencies¶
Now with the virtual environment setup, we can install our packages.
If you don't have the libjpeg lib do: sudo yum install libjpeg-turbo-devel check with the command: yum provides */libjpeg.so (poms_venv)bash-4.11$ for pkg in psycopg2 cherrypy sqlalchemy jinja2 python-crontab requests dogpile.cache pytest mock uwsgi do pip install $pkg done Collecting psycopg2 ... Successfully installed Logbook-1.1.0 dowser-py3-0.2.1 emport-1.2.0 infi.pyutils-1.1.3 packaging-16.8 pyparsing-2.2.0 z3c.recipe.scripts-1.0.1 zc.recipe.egg-2.0.3 (poms_venv)bash-4.11$
Now, get a copy of the code from git and let the virtual environment know where it is located.
cd to where ever you want to put the poms code git clone ssh://firstname.lastname@example.org/cvs/projects/prod_mgmt_db poms cd poms pip install -e $PWD
Finally, we can run some tests:
(poms_venv)bash-4.11$ cd poms (poms_venv)bash-4.11$ export POMS_DIR=`pwd` (poms_venv)bash-4.11$ export PYTHONPATH=`pwd`:$PYTHONPATH (poms_venv)bash-4.11$ cd test (poms_venv)bash-4.11$ pytest