=======
Logging
=======

Use your Nextcloud log to review system status, or to help debug problems. You may adjust logging levels, and choose between using the Nextcloud log or your syslog. If additional audit information is required, you can optionally activate the **admin_audit** app, which by default generates a separate audit.log file in the data directory.

Log level
---------

Logging levels range from **DEBUG**, which logs all activity, to **FATAL**, which logs only fatal errors.

* **0**: DEBUG: All activity; the most detailed logging.
* **1**: INFO:  Activity such as user logins and file activities, plus warnings, errors, and fatal errors.
* **2**: WARN:  Operations succeed, but with warnings of potential problems, plus errors and fatal errors.
* **3**: ERROR: An operation fails, but other services and operations continue, plus fatal errors.
* **4**: FATAL: The server stops.

By default the log level is set to **2** (WARN). Use **DEBUG** when you have a problem to diagnose, and then reset your log level to a less-verbose level as **DEBUG** outputs a lot of information, and can affect your server performance.

Logging level parameters are set in the :file:`config/config.php` file.

Log type
--------

errorlog
~~~~~~~~

All log information will be sent to PHP ``error_log()``.

::

    "log_type" => "errorlog",

file
~~~~

All log information will be written to a separate log file which can be
viewed using the log viewer on your Admin page. By default, a log
file named **nextcloud.log** will be created in the directory which has
been configured by the **datadirectory** parameter in :file:`config/config.php`.

The desired date format can optionally be defined using the **logdateformat** parameter in :file:`config/config.php`.
By default the `PHP date function`_ parameter ``c`` is used, and therefore the
date/time is written in the format ``2013-01-10T15:20:25+02:00``. By using the
date format in the example below, the date/time format will be written in the format
``January 10, 2013 15:20:25``.

::

    "log_type" => "file",
    "logfile" => "nextcloud.log",
    "loglevel" => 3,
    "logdateformat" => "F d, Y H:i:s",

syslog
~~~~~~

All log information will be sent to your default syslog daemon.

::

    "log_type" => "syslog",
    "syslog_tag" => "Nextcloud",
    "logfile" => "",
    "loglevel" => 3,

systemd
~~~~~~~

All log information will be sent to Systemd journal. Requires `php-systemd <https://github.com/systemd/php-systemd>`_ extension.

::

    "log_type" => "systemd",
    "syslog_tag" => "Nextcloud",

Log fields explained
--------------------

Example log entries
~~~~~~~~~~~~~~~~~~~

::

    {
        "reqId":"TBsuA2uE86DiOD0S8f9j",
        "level":1,
        "time":"April 13, 2021 16:55:37",
        "remoteAddr":"192.168.56.1",
        "user":"admin",
        "app":"admin_audit",
        "method":"GET",
        "url":"/ocs/v1.php/cloud/users?disabled",
        "message":"Login successful: \"admin\"",
        "userAgent":"curl/7.68.0",
        "version":"21.0.1.1"
    }

    {
        "reqId":"ByeDVLuwkXKMfLpBgvxC",
        "level":2,
        "time":"April 14, 2021 09:03:29",
        "remoteAddr":"192.168.56.1",
        "user":"--",
        "app":"no app in context",
        "method":"POST",
        "url":"/login",
        "message":"Login failed: asdf (Remote IP: 192.168.56.1)",
        "userAgent":"Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.114 Safari/537.36",
        "version":"21.0.1.1"
    }

Log field breakdown
~~~~~~~~~~~~~~~~~~~

* **0**: DEBUG: All activity; the most detailed logging.

* **reqId** (request id): any log lines related to a single request have the same value
* **level**: logged incident's level, always 1 in audit.log
* **time**: date and time (format and timezone can be configured in config.php)
* **remoteAddr**: the IP address of the user (if applicable  – empty for occ commands)
* **user**: acting user's id (if applicable)
* **app**: affected app (always admin_audit in audit.log)
* **method**: HTTP method, for example GET, POST, PROPFIND, etc.  – empty on occ calls
* **url**: request path (if applicable – empty on occ calls)
* **message**: event information message
* **userAgent**: user agent (if applicable – empty on occ calls)
* **exception**: Full exception with trace (if applicable)
* **data** additional structured data (if applicable)
* **version**: Nextcloud version at the time of request

Empty value are written as two dashes: "--".

Admin audit log
---------------

If ``loglevel`` in ``config.php`` is set to ``2`` or higher, audit logging needs to be triggered explicitly by adding the following setting to to ``config.php``:

::

	'log.condition' => [
		'apps' => ['admin_audit'],
	],


Similar to the normal logging, the audit log can be written to any of the existing logging mechanism in :file:`config/config.php`:

::

	"log_type_audit" => "syslog",
	"syslog_tag_audit" => "Nextcloud",
	"logfile_audit" => "",

Previously the logfile could be defined in the app config. This config is still used when the system config is not provided:

::

	occ config:app:set admin_audit logfile --value=/var/log/nextcloud/audit.log

Find detailed documentation on auditable events for enterprises in our `customer portal <https://portal.nextcloud.com/article/using-the-audit-log-44.html>`_.

.. _PHP date function: http://www.php.net/manual/en/function.date.php

Temporary overrides
-------------------

You can run override the config.php log level of ``occ`` commands with as :ref:`documented here<occ_debugging>`.
