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diff --git a/doc/source/usage.rst b/doc/source/usage.rst index a1e9e92..8c84163 100644 --- a/doc/source/usage.rst +++ b/doc/source/usage.rst @@ -2,6 +2,123 @@ Usage ======= -To use oslo.context in a project:: +oslo.context is used in conjunction with `oslo.log`_ to provide context +aware log records when specifying a :class:`~oslo_context.context.RequestContext` +object. - from oslo_context import context +This code example demonstrates two INFO log records with varying output +format due to the use of RequestContext. + +.. _oslo.log: http://docs.openstack.org/developer/oslo.log/ + +.. highlight:: python +.. literalinclude:: examples/usage_simple.py + :linenos: + :lines: 28-42 + :emphasize-lines: 2,14 + +Source: :ref:`example_usage_simple.py` + +**Example Logging Output:** + +:: + + 2016-01-20 21:56:29.283 8428 INFO __main__ [-] Message without context + 2016-01-20 21:56:29.284 8428 INFO __main__ [req-929d23e9-f50e-46ae-a8a7-02bc8c3fd2c8 - - - - -] Message with context + +The format of these log records are defined by the +`logging_default_format_string`_ and `logging_context_format_string`_ +configuration options respectively. The `logging_user_identity_format`_ option +also provides further context aware definition flexibility. + +.. _logging_default_format_string: http://docs.openstack.org/developer/oslo.log/opts.html#logging_default_format_string +.. _logging_context_format_string: http://docs.openstack.org/developer/oslo.log/opts.html#logging_context_format_string +.. _logging_user_identity_format: http://docs.openstack.org/developer/oslo.log/opts.html#logging_user_identity_format + +----------------- +Context Variables +----------------- + +The oslo.context variables used in the **logging_context_format_string** and +**logging_user_identity_format** configuration options include: + +* request_id - A request id (e.g. req-9f2c484a-b504-4fd9-b44c-4357544cca50) +* user - A user id (e.g. e5bc7033e6b7473c9fe8ee1bd4df79a3) +* tenant - A tenant/project id (e.g. 79e338475db84f7c91ee4e86b79b34c1) +* domain - A domain id +* user_domain - A user domain id +* project_domain - A project domain id + + +This code example demonstrates defining a context with specific attributes +that are presented in the output log record. + +.. literalinclude:: examples/usage.py + :linenos: + :lines: 28-46 + :emphasize-lines: 2,16-18 + +Source: :ref:`example_usage.py` + +**Example Logging Output:** + +:: + + 2016-01-21 17:30:50.263 12201 INFO __main__ [-] Message without context + 2016-01-21 17:30:50.264 12201 INFO __main__ [req-e591e881-36c3-4627-a5d8-54df200168ef 6ce90b4d d6134462 - - a6b9360e] Message with context + +A context object can also be passed as an argument to any logging level +message. + +.. literalinclude:: examples/usage.py + :linenos: + :lines: 48-51 + :emphasize-lines: 4 + +**Example Logging Output:** + +:: + + 2016-01-21 22:43:55.621 17295 INFO __main__ [req-ac2d4a3a-ff3c-4c2b-97a0-2b76b33d9e72 ace90b4d b6134462 - - c6b9360e] Message with passed context + +.. note:: + + To maintain consistent log messages for operators across multiple + OpenStack projects it is highly recommended that + **logging_default_format_string** and **logging_context_format_string** are + not modified from oslo.log default values. + + +-------------------------- +Project Specific Variables +-------------------------- + +Individual projects can also subclass :class:`~oslo_context.context.RequestContext` +to provide additional attributes that can be using with oslo.log. The Nova +`RequestContext`_ class for example provides additional variables including +user_name and project_name. + +.. _RequestContext: http://git.openstack.org/cgit/openstack/nova/tree/nova/context.py + +This can for example enable the defining of **logging_user_identity_format = +%(user_name)s %(project_name)s** which would produce a log record +containing a context portion using names instead of ids such as +**[req-e4b9a194-a9b1-4829-b7d0-35226fc101fc admin demo]** + +This following code example shows how a modified **logging_user_identity_format** +configuration alters the context portion of the log record. + +.. literalinclude:: examples/usage_user_identity.py + :linenos: + :lines: 28-48 + :emphasize-lines: 9 + +Source: :ref:`example_usage_user_identity.py` + + +**Example Logging Output:** + +:: + + 2016-01-21 20:56:43.964 14816 INFO __main__ [-] Message without context + 2016-01-21 20:56:43.965 14816 INFO __main__ [req-abc 6ce90b4d/d6134462@a6b9360e] Message with context |