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 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 config/config.php.

The desired date format can optionally be defined using the logdateformat parameter in 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 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
userAgent: user agent (if applicable – empty on occ calls)
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'],
],

If required, the name and path of the audit log file can be customized by using the following command:

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.

Temporary overrides

You can run override the config.php log level of occ commands with as documented here.