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virtualenv: for the better
It's better (and frankly super easy) to use a virtual environment for your server's python stuff. For hosting mdid3, it carries at least these benefits:
- Allows the mdid-application user (referred to as
mdid) to manage python without having to use sudo - Protects your mdid installation from a unwitting system wide upgrade to django 1.4 hosing your server
- Removes the need to type python26 in front of everything (rhel 5)
- If needed, you can make multiple virtualenvs to be able to test some change
Here's how to set it up - this can be done whether you've already setup or not
It's not a problem to set up retroactively. Before you begin, install yolk:
[sudo] easy_install yolk
and after that completes, you type
yolk -l
and you should get a list of the libraries you had installed anyway:
MySQL-python - 1.2.3c1 - active
PIL - 1.1.7 - active
Pygments - 1.4 - active
Python - 2.6.5 - active development (/usr/lib/python2.6/lib-dynload)
Werkzeug - 0.8.2 - active
distribute - 0.6.10 - active
flickrapi - 1.2 - active
pyodbc - 3.0.3 - active
python-dateutil - 2.0 - active
python-ldap - 2.3.12 - active
python-memcached - 1.43 - active
reportlab - 2.5 - active
setuptools - 0.6c11 - active
virtualenv - 1.5.1 - active
wsgiref - 0.1.2 - active development (/usr/lib/python2.6)
yolk - 0.4.3 - active
which you can use to make sure you put all of your dependencies in your virtualenv. Speaking of virtualenv...
easy_install virtualenv
note-if setting up an rhel server, you need to install python26 & setuptools first (walkthrough) and use easy_install with python26, i.e.
sudo python26 /usr/lib/python2.6/site-packages/easy_install.py virtualenv
Once installed, make a directory for storing your virtualenv - if you've installed mdid to /var/local/mdid consider putting your virtualenv in /var/local/virt to keep things close, but remember to chown/chgrp the directory so the user mdid can use it
sudo mkdir /var/local/virt
sudo chown mdid:staff virt
virtualenv-2.6 -v --no-site-packages virt/mdid3
Ok, so now all you have to do is switch to the virtualenv:
source /var/local/virt/mdid3/bin/activate
and your terminal prompt should go from $ to this: (mdid3)$ (if your prompt is just $)
To switch back to your default system python, just type deactivate and you'll be back to normal.
Add this to your .bash_profile to activate by typing mdid3:
alias mdid3='source /var/local/virt/mdid3-py26/bin/activate'
then type
source ~/.bash_profile
to activate your new command.
Before you activate (just type deactivate if you already did) you want to make an install file for re-getting your python libraries:
pip freeze > /var/local/virt/mdid3-py26/mdid-dep.txt
If you have an already working mdid3 server this will generate a file containing something like:
MySQL-python==1.2.3c1
PIL==1.1.7
Pygments==1.4
Werkzeug==0.8.2
distribute==0.6.28
flickrapi==1.2
pyodbc==3.0.3
python-dateutil==2.0
python-ldap==2.3.12
python-memcached==1.43
reportlab==2.5
virtualenv==1.5.1
wsgiref==0.1.2
yolk==0.4.3
You can probably delete the virtualenv==1.5.1 line, but otherwise this should be good.
Now activate
source /var/local/virt/mdid3-py26/bin/activate
or
mdid3
(if you listened to my advice about adding the alias to your bash shell)
This is awesome =)
pip install -r mdid-dep.txt- Sip coffee
- (optional, not your choice) Curse when you realize it didn't work exactly.
You'll need to add something like this to your wsgi script and then restart your webserver (safety note: a typo or wrong path will result in downtime)
See http://code.google.com/p/modwsgi/wiki/VirtualEnvironments for more information.
It's better (and frankly super easy) to use a virtual environment for your server's python stuff. For hosting mdid3, it carries at least these benefits:
- Allows the mdid-application user (referred to as
mdid) to manage python without having to use sudo - Protects your mdid installation from a unwitting system wide upgrade to django 1.4 hosing your server
- Removes the need to type python26 in front of everything (rhel 5)
- If needed, you can make multiple virtualenvs to be able to test some change
Here's how to set it up - this can be done whether you've already setup or not
It's not a problem to set up retroactively. Before you begin, install yolk:
[sudo] easy_install yolk
and after that completes, you type
yolk -l
and you should get a list of the libraries you had installed anyway:
MySQL-python - 1.2.3c1 - active
PIL - 1.1.7 - active
Pygments - 1.4 - active
Python - 2.6.5 - active development (/usr/lib/python2.6/lib-dynload)
Werkzeug - 0.8.2 - active
distribute - 0.6.10 - active
flickrapi - 1.2 - active
pyodbc - 3.0.3 - active
python-dateutil - 2.0 - active
python-ldap - 2.3.12 - active
python-memcached - 1.43 - active
reportlab - 2.5 - active
setuptools - 0.6c11 - active
virtualenv - 1.5.1 - active
wsgiref - 0.1.2 - active development (/usr/lib/python2.6)
yolk - 0.4.3 - active
which you can use to make sure you put all of your dependencies in your virtualenv. Speaking of virtualenv...
easy_install virtualenv
note-if setting up an rhel server, you need to install python26 & setuptools first (walkthrough) and use easy_install with python26, i.e.
sudo python26 /usr/lib/python2.6/site-packages/easy_install.py virtualenv
Once installed, make a directory for storing your virtualenv - if you've installed mdid to /var/local/mdid consider putting your virtualenv in /var/local/virt to keep things close, but remember to chown/chgrp the directory so the user mdid can use it
sudo mkdir /var/local/virt
sudo chown mdid:staff virt
virtualenv-2.6 -v --no-site-packages virt/mdid3
Ok, so now all you have to do is switch to the virtualenv:
source /var/local/virt/mdid3/bin/activate
and your terminal prompt should go from $ to this: (mdid3)$ (if your prompt is just $)
To switch back to your default system python, just type deactivate and you'll be back to normal.
Add this to your .bash_profile to activate by typing mdid3:
alias mdid3='source /var/local/virt/mdid3-py26/bin/activate'
then type
source ~/.bash_profile
to activate your new command.
Before you activate (just type deactivate if you already did) you want to make an install file for re-getting your python libraries:
pip freeze > /var/local/virt/mdid3-py26/mdid-dep.txt
If you have an already working mdid3 server this will generate a file containing something like:
MySQL-python==1.2.3c1
PIL==1.1.7
Pygments==1.4
Werkzeug==0.8.2
distribute==0.6.28
flickrapi==1.2
pyodbc==3.0.3
python-dateutil==2.0
python-ldap==2.3.12
python-memcached==1.43
reportlab==2.5
virtualenv==1.5.1
wsgiref==0.1.2
yolk==0.4.3
You can probably delete the virtualenv==1.5.1 line, but otherwise this should be good.
Now activate
source /var/local/virt/mdid3-py26/bin/activate
or
mdid3
(if you listened to my advice about adding the alias to your bash shell)
This is awesome =)
pip install -r mdid-dep.txt- Sip coffee
- (optional, not your choice) Curse when you realize it didn't work exactly.
You'll need to add something like this to your wsgi script and then restart your webserver (safety note: a typo or wrong path will result in downtime)
See http://code.google.com/p/modwsgi/wiki/VirtualEnvironments for more information.
WSGIPythonHome /var/local/virt/mdid3-py26/
import site
site.addsitedir('/var/local/virt/mdid3-py26/lib/python2.6/site-packages')