<title>Logging</title>
<section>
- <title>Logging configuration</title>
+ <title>Logging Configuration</title>
<para>
</section>
<section>
- <title>Example Logger configurations</title>
+ <title>Example Logger Configurations</title>
<para>
In this example we want to set the global logging to
</section>
<section>
- <title>Environment variables and initial logging</title>
+ <title>Logging During Kea Startup</title>
<para>
- Logging configuration is specified in the configuration file. However,
- there are several early initialization routines that are conducted even
- before configuration file is read and applied. They also apply if
- the new configuration does not configure any logging.
+ The logging configuration is specified in the configuration file.
+ However, when Kea starts, the file is not read until some way into the
+ initialization process. Prior to that, the logging settings are
+ set to default values, although it is possible to modify some
+ aspects of the settings by means of environment variables. Note
+ that in the absence of any logging configuration in the configuration
+ file, the settings of (possibly modified) default configuration will
+ persist while the program is running.
+ </para>
+ <para>
+ The following environment variables can be used to control the
+ behavio of logging during startup:
</para>
- <para>There are several environment variables that control logging
- behavior in the early phase of the bring up. Once configuration that hold
- logging configuration is parsed and applied they no longer apply.</para>
<variablelist>
<varlistentry>
<term>KEA_LOCKFILE_DIR</term>
<listitem><para>
Specifies a directory where logging system should create its
- lock file. If not specified, it is ${prefix}/var/run/kea, where
- prefix defaults to /usr/local. This variable must not end
+ lock file. If not specified, it is
+ <replaceable>prefix</replaceable>/var/run/kea, where
+ <replaceable>prefix</replaceable> defaults to /usr/local.
+ This variable must not end
with a slash. There is one special value: "none", which
instructs Kea to not create lock file at all. This may cause
issues if several processes log to the same file.
<term>KEA_LOGGER_DESTINATION</term>
<listitem><para>
Specifies logging output. There are several special values.
- "stdout" means standard output. "stderr" means standard error.
- "syslog" means logging using syslog and a default name.
- "syslog:foo" syntax is also permitted. It will log via syslog
- using "foo" as a name. Any other value is treated as a name
+ <variablelist>
+ <varlistentry>
+ <term>stdout</term>
+ <listitem><para>
+ Log to standard output.
+ </para></listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>stderr</term>
+ <listitem><para>
+ Log to standard error.
+ </para></listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>syslog<optional>:<replaceable>fac</replaceable></optional></term>
+ <listitem><para>
+ Log via syslog. The optional
+ <replaceable>fac</replaceable> (which is
+ separated from the word "syslog" by a colon)
+ specifies the
+ facility to be used for the log messages. Unless
+ specified, messages will be logged using the
+ facility "local0".
+ </para></listitem>
+ </varlistentry>
+ </variablelist>
+ Any other value is treated as a name
of the output file. If not specified otherwise, Kea will log to
standard output.
</para></listitem>