Add log handlers syslog and errorlog (#17764)

* Add log handlers syslog and errorlog

Issue#9400

* Add log handlers syslog and errorlog

* syslog/errorlog: fix namespace; add log.syslog.ident

* syslog/errorlog: Document options

* ErrorLogHandler constructor: Avoid null

Avoid null in ErrorLogHandler constructor call: Use level param; default others

* missing comma

* fix two di definitions

Co-authored-by: diosmosis <diosmosis@users.noreply.github.com>

1 files changed, 6 insertions, 2 deletions

diff --git a/core/Log.php b/core/Log.php
index b26101155a..a5eaf44199 100644
--- a/core/Log.php
+++ b/core/Log.php
@@ -38,8 +38,9 @@ use Psr\Log\LoggerInterface;
  * The following configuration options can be set:
  *
  * - `log_writers[]`: This is an array of log writer IDs. The three log writers provided
- *                    by Piwik core are **file**, **screen** and **database**. You can
- *                    get more by installing plugins. The default value is **screen**.
+ *                    by Piwik core are **file**, **screen**, **database**, **errorlog**, 
+ *                    and **syslog**. You can get more by installing plugins. The default 
+ *                    value is **screen**.
  * - `log_level`: The current log level. Can be **ERROR**, **WARN**, **INFO**, **DEBUG**,
  *                or **VERBOSE**. Log entries made with a log level that is as or more
  *                severe than the current log level will be outputted. Others will be
@@ -48,6 +49,9 @@ use Psr\Log\LoggerInterface;
  *                       to log to or a path to a directory to store logs in. If a
  *                       directory, the file name is piwik.log. Can be relative to
  *                       Piwik's root dir or an absolute path. Defaults to **tmp/logs**.
+ * - `logger_syslog_ident`: If configured to log to syslog, mark them with this 
+ *                          identifier string.  This acts as an easy-to-find tag in 
+ *                          the syslog.
  *
  *
  * @deprecated Inject and use Psr\Log\LoggerInterface instead of this class.