| 7 | | == Python 2 |
| 8 | | |
| 9 | | === Difficulties |
| 10 | | |
| 11 | | This installations is made more difficult by 3 things: |
| 12 | | |
| 13 | | 1. Suse Linux does not have mod_wsgi in its repositories, so you're going to have to compile it. |
| 14 | | 2. mod_wsgi seems picky about where it picks python apps and libraries from |
| 15 | | 3. The LAMP servers don't put things where you'd expect them to be. |
| 16 | | 4. Some other stuff that I don't quite understand |
| 17 | | |
| 18 | | === Requirements |
| 19 | | |
| 20 | | Before installation can start, the following packages will have to be installed by IT services: |
| 21 | | |
| 22 | | - libmysqlclient-dev |
| 23 | | - python-dev |
| 24 | | |
| 25 | | === Start Services |
| 26 | | |
| 27 | | Start the Apache and MySQL and make sure that they are restarted when the server is rebooted. |
| 28 | | |
| 29 | | {{{ |
| 30 | | sudo /sbin/chkconfig uol.apache2 on |
| 31 | | sudo /etc/init.d/uol.apache2 start |
| 32 | | sudo /sbin/chkconfig uol.mysql on |
| 33 | | sudo /etc/init.d/uol.mysql start |
| 34 | | }}} |
| 35 | | |
| 36 | | === Proceduce |
| 37 | | |
| 38 | | 1. Install {{{mod_wsgi.so}}} into the directory {{{/local/apache2/etc/}}} |
| 39 | | 1. Compile `mod_wsgi`. See: [[HowTo Compile mod_wsgi for LAMP servers]] |
| 40 | | 2. Copy `mod_wsgi.so` from the directory {{{/local/apache2/etc/}}} of an existing UoL LAMP python Flask application. |
| 41 | | 2. Clone the application from the `git` repository into `/local/` directory. |
| 42 | | 3. Install virtualenv: |
| 43 | | a. First switch to python 2.7 by running the command `source /opt/python2/etc/python-env.sh` |
| 44 | | |
| 45 | | {{{ |
| 46 | | easy_install --install-dir=/local/python virtualenv |
| 47 | | }}} |
| 48 | | |
| 49 | | ''For some reason that I can't work out (point 4. above), it would only pick up some of the python libraries from a virtual env and not when they were installed in `/local/python/`. Maybe this was because of the order that I installed things, but I couldn't get it to work without the virtual environment.'' |
| 50 | | 4. Create a virtual environment in the application directory. |
| 51 | | |
| 52 | | {{{ |
| 53 | | cd /local/{application directory} |
| 54 | | /local/python/virtualenv --no-site-packages BASELINE |
| 55 | | }}} |
| 56 | | |
| 57 | | ''`BASELINE` is the name of the virtual environment. It could be called anything, but it's called that! Also note that you need to use the full path to the `virtualenv` utility, since `/local/python` isn't in `$PATH`.'' |
| 58 | | |
| 59 | | 5. Activate the environment, install the required packages, then deactivate. This example shows some common requirements: |
| 60 | | |
| 61 | | {{{ |
| 62 | | source BASELINE/bin/activate |
| 63 | | easy_install flask |
| 64 | | easy_install flask-sqlalchemy |
| 65 | | easy_install mysql-python |
| 66 | | easy_install flask-wtf |
| 67 | | easy_install WTForms-Components |
| 68 | | deactivate |
| 69 | | }}} |
| 70 | | |
| 71 | | 6. Load the WSGI module into Apache, by editing the file `/local/apache2/etc/loadmodule.conf` by adding this line at the end. |
| 72 | | |
| 73 | | {{{ |
| 74 | | LoadModule wsgi_module /local/apache2/etc/mod_wsgi.so |
| 75 | | }}} |
| 76 | | |
| 77 | | 7. Add the WSGI config to the Apache config file `/local/apache2/etc/httpd.conf`: |
| 78 | | |
| 79 | | {{{ |
| 80 | | <Directory /local/{application directory}> |
| 81 | | WSGIProcessGroup {application name} |
| 82 | | WSGIApplicationGroup %{GLOBAL} |
| 83 | | Order deny,allow |
| 84 | | Allow from all |
| 85 | | </Directory> |
| 86 | | |
| 87 | | WSGIDaemonProcess {application name} user=wwwrun threads=5 python-path=/local/{application directory}/BASELINE/lib/python2.6/site-packages:/local/python:/usr/lib64/python2.6/site-packages:/usr/share/doc/packages/ home=/local/{application directory}/ |
| 88 | | WSGIScriptAlias / /local/{application directory}/{path to *.wsgi} |
| 89 | | }}} |
| 90 | | |
| 91 | | ''The two hard won things here are the values for the `python-path` and `home` arguments. The `python-path` must contain every directory where python libraries are installed, including a sub-directory of the virtualenv directory you created earlier. The `home` must point to your application directory, or you won't be able to pick up your own modules.'' |
| 92 | | |
| 93 | | 8. Restart apache: |
| 94 | | |
| 95 | | {{{ |
| 96 | | sudo /etc/init.d/uol.apache2 restart |
| 97 | | }}} |
| 98 | | |
| 99 | | 9. Create any databases that are required and given the appropriate user permissions. |
| 100 | | |
| 101 | | 10. Update the application settings in {{{/local/{application directory} }}} |
| 102 | | |
| 103 | | 10. Pray. |
| 104 | | |
| 105 | | == Other Possible Stuff (**Not required last time used!**) |
| 106 | | |
| 107 | | 1. You may need to give `wwwrun` extra permissions to the `/local/{application directory}` directory. |
| 108 | | 2. You might need to pray a bit more. |
| 109 | | |
| 110 | | {{{ |
| 111 | | setfacl -m u:wwwrun:rwx /local/{application directory} |
| 112 | | setfacl -m d:u:wwwrun:rwx /local/telomere/{application directory} |
| 113 | | }}} |
| 114 | | |
| 115 | | === Gotchas |
| 116 | | |
| 117 | | - [[Python Flask Gotchas Import Database Module Fails]] |
| 118 | | |
| 119 | | |
| 120 | | |
| 121 | | == Python 3 |
| | 6 | This page is for python 3, for python 2 see [[UoL LAMP HowTo Install Legacy Python Flask Applications]] |
