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Diffstat (limited to 'doc/rtd/topics/logging.rst')
| -rw-r--r-- | doc/rtd/topics/logging.rst | 37 |
1 files changed, 19 insertions, 18 deletions
diff --git a/doc/rtd/topics/logging.rst b/doc/rtd/topics/logging.rst index b010aa96..c6afca16 100644 --- a/doc/rtd/topics/logging.rst +++ b/doc/rtd/topics/logging.rst @@ -1,15 +1,15 @@ -======= +******* Logging -======= +******* Cloud-init supports both local and remote logging configurable through python's built-in logging configuration and through the cloud-init rsyslog module. Command Output --------------- +============== Cloud-init can redirect its stdout and stderr based on config given under the ``output`` config key. The output of any commands run by cloud-init and any -user or vendor scripts provided will also be included here. The ``output`` -key accepts a dictionary for configuration. Output files may be specified +user or vendor scripts provided will also be included here. The ``output`` key +accepts a dictionary for configuration. Output files may be specified individually for each stage (``init``, ``config``, and ``final``), or a single key ``all`` may be used to specify output for all stages. @@ -31,9 +31,9 @@ stdout and stderr from all cloud-init stages to For a more complex example, the following configuration would output the init stage to ``/var/log/cloud-init.out`` and ``/var/log/cloud-init.err``, for stdout and stderr respectively, replacing anything that was previously there. -For the config stage, it would pipe both stdout and stderr through -``tee -a /var/log/cloud-config.log``. For the final stage it would append the -output of stdout and stderr to ``/var/log/cloud-final.out`` and +For the config stage, it would pipe both stdout and stderr through ``tee -a +/var/log/cloud-config.log``. For the final stage it would append the output of +stdout and stderr to ``/var/log/cloud-final.out`` and ``/var/log/cloud-final.err`` respectively. :: output: @@ -48,8 +48,8 @@ output of stdout and stderr to ``/var/log/cloud-final.out`` and Python Logging -------------- Cloud-init uses the python logging module, and can accept config for this -module using the standard python fileConfig format. Cloud-init looks for config -for the logging module under the ``logcfg`` key. +module using the standard python fileConfig format. Cloud-init looks for +config for the logging module under the ``logcfg`` key. .. note:: the logging configuration is not yaml, it is python ``fileConfig`` format, @@ -67,9 +67,9 @@ Python's fileConfig format consists of sections with headings in the format logging must contain the sections ``[loggers]``, ``[handlers]``, and ``[formatters]``, which name the entities of their respective types that will be defined. The section name for each defined logger, handler and formatter -will start with its type, followed by an underscore (``_``) and the name of the -entity. For example, if a logger was specified with the name ``log01``, config -for the logger would be in the section ``[logger_log01]``. +will start with its type, followed by an underscore (``_``) and the name of +the entity. For example, if a logger was specified with the name ``log01``, +config for the logger would be in the section ``[logger_log01]``. Logger config entries contain basic logging set up. They may specify a list of handlers to send logging events to as well as the lowest priority level of @@ -80,13 +80,13 @@ handlers. A level entry can be any of the following: ``DEBUG``, ``INFO``, the ``NOTSET`` option will allow all logging events to be recorded. Each configured handler must specify a class under the python's ``logging`` -package namespace. A handler may specify a message formatter to use, a priority -level, and arguments for the handler class. Common handlers are +package namespace. A handler may specify a message formatter to use, a +priority level, and arguments for the handler class. Common handlers are ``StreamHandler``, which handles stream redirects (i.e. logging to stderr), and ``FileHandler`` which outputs to a log file. The logging module also -supports logging over net sockets, over http, via smtp, and additional -complex configurations. For full details about the handlers available for -python logging, please see the documentation for `python logging handlers`_. +supports logging over net sockets, over http, via smtp, and additional complex +configurations. For full details about the handlers available for python +logging, please see the documentation for `python logging handlers`_. Log messages are formatted using the ``logging.Formatter`` class, which is configured using ``formatter`` config entities. A default format of @@ -173,3 +173,4 @@ For more information on rsyslog configuration, see :ref:`cc_rsyslog`. .. _python logging config: https://docs.python.org/3/library/logging.config.html#configuration-file-format .. _python logging handlers: https://docs.python.org/3/library/logging.handlers.html .. _python logging formatters: https://docs.python.org/3/library/logging.html#formatter-objects +.. vi: textwidth=78 |