| commit | author | age | ||
| b731b5 | 1 | .. _qtut_logging: |
| PE | 2 | |
| b1b922 | 3 | ============================================ |
| PE | 4 | 16: Collecting Application Info With Logging |
| 5 | ============================================ | |
| 6 | ||
| e672bd | 7 | Capture debugging and error output from your web applications using standard |
| SP | 8 | Python logging. |
| 9 | ||
| b1b922 | 10 | |
| PE | 11 | Background |
| 12 | ========== | |
| 13 | ||
| e672bd | 14 | It's important to know what is going on inside our web application. In |
| SP | 15 | development we might need to collect some output. In production, we might need |
| 16 | to detect problems when other people use the site. We need *logging*. | |
| b1b922 | 17 | |
| b52d1a | 18 | Fortunately Pyramid uses the normal Python approach to logging. The project |
| e672bd | 19 | generated in your ``development.ini`` has a number of lines that configure the |
| SP | 20 | logging for you to some reasonable defaults. You then see messages sent by |
| 21 | Pyramid, for example, when a new request comes in. | |
| 22 | ||
| b1b922 | 23 | |
| PE | 24 | Objectives |
| 25 | ========== | |
| 26 | ||
| e672bd | 27 | - Inspect the configuration setup used for logging. |
| b1b922 | 28 | |
| e672bd | 29 | - Add logging statements to your view code. |
| SP | 30 | |
| b1b922 | 31 | |
| PE | 32 | Steps |
| 33 | ===== | |
| 34 | ||
| 35 | #. First we copy the results of the ``view_classes`` step: | |
| 36 | ||
| 37 | .. code-block:: bash | |
| 38 | ||
| 187104 | 39 | $ cd ..; cp -r view_classes logging; cd logging |
| 14fd6d | 40 | $ $VENV/bin/pip install -e . |
| b1b922 | 41 | |
| PE | 42 | #. Extend ``logging/tutorial/views.py`` to log a message: |
| 43 | ||
| 44 | .. literalinclude:: logging/tutorial/views.py | |
| 45 | :linenos: | |
| 46 | ||
| e672bd | 47 | #. Finally let's edit ``development.ini`` configuration file to enable logging |
| SP | 48 | for our Pyramid application: |
| a42397 | 49 | |
| AB | 50 | .. literalinclude:: logging/development.ini |
| 51 | :language: ini | |
| 52 | ||
| b1b922 | 53 | #. Make sure the tests still pass: |
| PE | 54 | |
| 55 | .. code-block:: bash | |
| 56 | ||
| e672bd | 57 | $ $VENV/bin/py.test tutorial/tests.py -q |
| SP | 58 | .... |
| 59 | 4 passed in 0.41 seconds | |
| b1b922 | 60 | |
| PE | 61 | #. Run your Pyramid application with: |
| 62 | ||
| 63 | .. code-block:: bash | |
| 64 | ||
| 187104 | 65 | $ $VENV/bin/pserve development.ini --reload |
| b1b922 | 66 | |
| e672bd | 67 | #. Open http://localhost:6543/ and http://localhost:6543/howdy in your browser. |
| SP | 68 | Note, both in the console and in the debug toolbar, the message that you |
| 69 | logged. | |
| 70 | ||
| b1b922 | 71 | |
| PE | 72 | Analysis |
| 73 | ======== | |
| 74 | ||
| e672bd | 75 | In our configuration file ``development.ini``, our ``tutorial`` Python package |
| SP | 76 | is set up as a logger and configured to log messages at a ``DEBUG`` or higher |
| 77 | level. When you visit http://localhost:6543, your console will now show: | |
| b1b922 | 78 | |
| e672bd | 79 | .. code-block:: text |
| SP | 80 | |
| 81 | 2013-08-09 10:42:42,968 DEBUG [tutorial.views][MainThread] In home view | |
| b1b922 | 82 | |
| PE | 83 | Also, if you have configured your Pyramid application to use the |
| 84 | ``pyramid_debugtoolbar``, logging statements appear in one of its menus. | |
| 85 | ||
| 2033ee | 86 | .. seealso:: See also :ref:`logging_chapter`. |
