diff options
Diffstat (limited to 'tools/rsyslog.conf.5')
| -rw-r--r-- | tools/rsyslog.conf.5 | 728 |
1 files changed, 728 insertions, 0 deletions
diff --git a/tools/rsyslog.conf.5 b/tools/rsyslog.conf.5 new file mode 100644 index 00000000..dd80fca0 --- /dev/null +++ b/tools/rsyslog.conf.5 @@ -0,0 +1,728 @@ +.\" rsyslog.conf - rsyslogd(8) configuration file +.\" Copyright 2003-2008 Rainer Gerhards and Adiscon GmbH. +.\" +.\" This file is part of the rsyslog package, an enhanced system log daemon. +.\" +.\" This program is free software; you can redistribute it and/or modify +.\" it under the terms of the GNU General Public License as published by +.\" the Free Software Foundation; either version 2 of the License, or +.\" (at your option) any later version. +.\" +.\" This program is distributed in the hope that it will be useful, +.\" but WITHOUT ANY WARRANTY; without even the implied warranty of +.\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +.\" GNU General Public License for more details. +.\" +.\" You should have received a copy of the GNU General Public License +.\" along with this program; if not, write to the Free Software +.\" Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA. +.\" +.TH RSYSLOG.CONF 5 "07 April 2008" "Version 3.17.0" "Linux System Administration" +.SH NAME +rsyslog.conf \- rsyslogd(8) configuration file +.SH DESCRIPTION +The +.I rsyslog.conf +file is the main configuration file for the +.BR rsyslogd (8) +which logs system messages on *nix systems. This file specifies rules +for logging. For special features see the +.BR rsyslogd (8) +manpage. Rsyslog.conf is backward-compatible with sysklogd's syslog.conf file. So if you migrate +from sysklogd you can rename it and it should work. + +.B Note that this version of rsyslog ships with extensive documentation in html format. +This is provided in the ./doc subdirectory and probably +in a separate package if you installed rsyslog via a packaging system. +To use rsyslog's advanced features, you +.B need +to look at the html documentation, because the man pages only cover +basic aspects of operation. + + +.SH MODULES + +Rsyslog has a modular design. Consequently, there is a growing number +of modules. See the html documentation for their full description. + +.TP +.I omsnmp +SNMP trap output module +.TP +.I omgssapi +Output module for GSS-enabled syslog +.TP +.I ommysql +Output module for MySQL +.TP +.I omrelp +Output module for the reliable RELP protocol (prevents message loss). +For details, see below at imrelp and the html documentation. +It can be used like this: +.IP +*.* :omrelp:server:port +.IP +*.* :omrelp:192.168.0.1:2514 # actual sample +.TP +.I ompgsql +Output module for PostgreSQL +.TP +.I omlibdbi +Generic database output module (Firebird/Interbase, MS SQL, Sybase, +SQLite, Ingres, Oracle, mSQL) +.TP +.I imfile +Input module for text files +.TP +.I imudp +Input plugin for UDP syslog. Replaces the deprecated -r option. Can be +used like this: +.IP +$ModLoad imudp +.IP +$InputUDPServerRun 514 +.TP +.I imtcp +Input plugin for plain TCP syslog. Replaces the deprecated -t +option. Can be used like this: +.IP +$ModLoad imtcp +.IP +$InputTCPServerRun 514 +.TP +.TP +.I imtcp +Input plugin for the RELP protocol. RELP can be used instead +of UDP or plain TCP syslog to provide reliable delivery of +syslog messages. Please note that plain TCP syslog does NOT +provide truly reliable delivery, with it messages may be lost +when there is a connection problem or the server shuts down. +RELP prevents message loss in those cases. +It can be used like this: +.IP +$ModLoad imrelp +.IP +$InputRELPServerRun 2514 +.TP +.I imgssapi +Input plugin for plain TCP and GSS-enable syslog +.TP +.I immark +Support for mark messages +.TP +.I imklog +Kernel logging. To include kernel log messages, you need to do +.IP +$ModLoad imklog + +Please note that the klogd daemon is no longer necessary and consequently +no longer provided by the rsyslog package. +.TP +.I imuxsock +Unix sockets, including the system log socket. You need to specify +.IP +$ModLoad imudp + +in order to receive log messages from local system processes. This +config directive should only left out if you know exactly what you +are doing. + + +.SH BASIC STRUCTURE + +Lines starting with a hash mark ('#') and empty lines are ignored. +Rsyslog.conf should contain following sections (sorted by recommended order in file): + +.TP +Global directives +Global directives set some global properties of whole rsyslog daemon, for example size of main +message queue ($MainMessageQueueSize), loading external modules ($ModLoad) and so on. +All global directives need to be specified on a line by their own and must start with +a dollar-sign. The complete list of global directives can be found in html documentation in doc +directory or online on web pages. + +.TP +Templates +Templates allow you to specify format of the logged message. They are also used for dynamic +file name generation. They have to be defined before they are used in rules. For more info +about templates see TEMPLATES section of this manpage. + +.TP +Output channels +Output channels provide an umbrella for any type of output that the user might want. +They have to be defined before they are used in rules. For more info about output channels +see OUTPUT CHANNELS section of this manpage. + +.TP +Rules (selector + action) +Every rule line consists of two fields, a selector field and an action field. These +two fields are separated by one or more spaces or tabs. The selector field specifies +a pattern of facilities and priorities belonging to the specified action. + +.SH ACTIONS +The action field of a rule describes what to do with the message. In general, message content +is written to a kind of "logfile". But also other actions might be done, like writing to a +database table or forwarding to another host. + +.SS Regular file +Typically messages are logged to real files. The file has to be specified with full pathname, +beginning with a slash ('/'). + +.B Example: +.RS +*.* /var/log/traditionalfile.log;RSYSLOG_TraditionalFormat # log to a file in the traditional format +.RE + +Note: if you would like to use high-precision timestamps in your log files, +just remove the ";RSYSLOG_TraditionalFormat". That will select the default +template, which, if not changed, uses RFC 3339 timestamps. + +.B Example: +.RS +*.* /var/log/file.log # log to a file with RFC3339 timestamps +.RE + +.SS Named pipes +This version of rsyslogd(8) has support for logging output to named pipes (fifos). A fifo or +named pipe can be used as a destination for log messages by prepending a pipe symbol ('|') +to the name of the file. This is handy for debugging. Note that the fifo must be created with +the mkfifo(1) command before rsyslogd(8) is started. + +.SS Terminal and console +If the file you specified is a tty, special tty-handling is done, same with /dev/console. + +.SS Remote machine +There are three ways to forward message: the traditional UDP transport, which is extremely +lossy but standard, the plain TCP based transport which loses messages only during certain +situations but is widely available and the RELP transport which does not lose messages +but is currently available only as part of rsyslogd 3.15.0 and above. + +To forward messages to another host via UDP, prepend the hostname with the at sign ("@"). +To forward it via plain tcp, prepend two at signs ("@@"). To forward via RELP, prepend the +string ":omrelp:" in front of the hostname. + +.B Example: +.RS +*.* @192.168.0.1 +.RE +.sp +In the example above, messages are forwarded via UDP to the machine 192.168.0.1, the destination +port defaults to 514. Due to the nature of UDP, you will probably lose some messages in transit. +If you expect high traffic volume, you can expect to lose a quite noticeable number of messages +(the higher the traffic, the more likely and severe is message loss). + +.B If you would like to prevent message loss, use RELP: +.RS +*.* :omrelp:192.168.0.1:2514 +.RE +.sp +Note that a port number was given as there is no standard port for relp. + +Keep in mind that you need to load the correct input and output plugins (see "Modules" above). + +Please note that rsyslogd offers a variety of options in regarding to remote +forwarding. For full details, please see the html documentation. + +.SS List of users +Usually critical messages are also directed to ``root'' on that machine. You can specify a list +of users that shall get the message by simply writing the login. You may specify more than one +user by separating them with commas (','). If they're logged in they get the message. Don't +think a mail would be sent, that might be too late. + +.SS Everyone logged on +Emergency messages often go to all users currently online to notify them that something strange +is happening with the system. To specify this wall(1)-feature use an asterisk ('*'). + +.SS Database table +This allows logging of the message to a database table. +By default, a MonitorWare-compatible schema is required for this to work. You can +create that schema with the createDB.SQL file that came with the rsyslog package. You can also +use any other schema of your liking - you just need to define a proper template and assign this +template to the action. + +See the html documentation for further details on database logging. + +.SS Discard +If the discard action is carried out, the received message is immediately discarded. Discard +can be highly effective if you want to filter out some annoying messages that otherwise would +fill your log files. To do that, place the discard actions early in your log files. +This often plays well with property-based filters, giving you great freedom in specifying +what you do not want. + +Discard is just the single tilde character with no further parameters. +.sp +.B Example: +.RS +*.* ~ # discards everything. +.RE + + +.SS Output channel +Binds an output channel definition (see there for details) to this action. Output channel actions +must start with a $-sign, e.g. if you would like to bind your output channel definition "mychannel" +to the action, use "$mychannel". Output channels support template definitions like all all other +actions. + +.SS Shell execute +This executes a program in a subshell. The program is passed the template-generated message as the +only command line parameter. Rsyslog waits until the program terminates and only then continues to run. + +.B Example: +.RS +^program-to-execute;template +.RE + +The program-to-execute can be any valid executable. It receives the template string as a single parameter +(argv[1]). + +.SH FILTER CONDITIONS +Rsyslog offers three different types "filter conditions": +.sp 0 + * "traditional" severity and facility based selectors +.sp 0 + * property-based filters +.sp 0 + * expression-based filters +.RE + +.SS Blocks +Rsyslogd supports BSD-style blocks inside rsyslog.conf. Each block of lines is separated from +the previous block by a program or hostname specification. A block will only log messages +corresponding to the most recent program and hostname specifications given. Thus, a block which +selects "ppp" as the program, directly followed by a block that selects messages from the +hostname "dialhost", then the second block will only log messages from the ppp program on dialhost. + +.SS Selectors +.B Selectors are the traditional way of filtering syslog messages. +They have been kept in rsyslog with their original syntax, because it is well-known, highly +effective and also needed for compatibility with stock syslogd configuration files. If you just +need to filter based on priority and facility, you should do this with selector lines. They are +not second-class citizens in rsyslog and offer the best performance for this job. + +.SS Property-Based Filters +Property-based filters are unique to rsyslogd. They allow to filter on any property, like HOSTNAME, +syslogtag and msg. + +A property-based filter must start with a colon in column 0. This tells rsyslogd that it is the new +filter type. The colon must be followed by the property name, a comma, the name of the compare +operation to carry out, another comma and then the value to compare against. This value must be quoted. +There can be spaces and tabs between the commas. Property names and compare operations are +case-sensitive, so "msg" works, while "MSG" is an invalid property name. In brief, the syntax is as follows: +.sp +.RS +:property, [!]compare-operation, "value" +.RE + +The following compare-operations are currently supported: +.sp +.RS +.B contains +.RS +Checks if the string provided in value is contained in the property +.RE +.sp +.B isequal +.RS +Compares the "value" string provided and the property contents. These two values must be exactly equal to match. +.RE +.sp +.B startswith +.RS +Checks if the value is found exactly at the beginning of the property value +.RE +.sp +.B regex +.RS +Compares the property against the provided regular expression. +.RE + +.SS Expression-Based Filters +See the html documentation for this feature. + + +.SH TEMPLATES + +Every output in rsyslog uses templates - this holds true for files, user +messages and so on. Templates compatible with the stock syslogd +formats are hardcoded into rsyslogd. If no template is specified, we use +one of these hardcoded templates. Search for "template_" in syslogd.c and +you will find the hardcoded ones. + +A template consists of a template directive, a name, the actual template text +and optional options. A sample is: + +.RS +.B $template MyTemplateName,"\\\\7Text %property% some more text\\\\n",<options> +.RE + +The "$template" is the template directive. It tells rsyslog that this line +contains a template. The backslash is an escape character. For example, \\7 rings the +bell (this is an ASCII value), \\n is a new line. The set in rsyslog is a bit restricted +currently. + +All text in the template is used literally, except for things within percent +signs. These are properties and allow you access to the contents of the syslog +message. Properties are accessed via the property replacer and it can for example +pick a substring or do date-specific formatting. More on this is the PROPERTY REPLACER +section of this manpage. + +To escape: +.sp 0 + % = \\% +.sp 0 + \\ = \\\\ --> '\\' is used to escape (as in C) +.sp 0 +$template TraditionalFormat,%timegenerated% %HOSTNAME% %syslogtag%%msg%\n" + +Properties can be accessed by the property replacer (see there for details). + +.B Please note that templates can also by used to generate selector lines with dynamic file names. +For example, if you would like to split syslog messages from different hosts +to different files (one per host), you can define the following template: + +.RS +.B $template DynFile,"/var/log/system-%HOSTNAME%.log" +.RE + +This template can then be used when defining an output selector line. It will +result in something like "/var/log/system-localhost.log" + +.SS Template options +The <options> part is optional. It carries options influencing the template as whole. +See details below. Be sure NOT to mistake template options with property options - the +later ones are processed by the property replacer and apply to a SINGLE property, only +(and not the whole template). + +Template options are case-insensitive. Currently defined are: + +.RS +.TP +sql +format the string suitable for a SQL statement in MySQL format. This will replace single +quotes ("'") and the backslash character by their backslash-escaped counterpart +("\'" and "\\") inside each field. Please note that in MySQL configuration, the NO_BACKSLASH_ESCAPES +mode must be turned off for this format to work (this is the default). + +.TP +stdsql +format the string suitable for a SQL statement that is to be sent to a standards-compliant +sql server. This will replace single quotes ("'") by two single quotes ("''") inside each field. +You must use stdsql together with MySQL if in MySQL configuration the NO_BACKSLASH_ESCAPES +is turned on. +.RE + +Either the +.B sql +or +.B stdsql +option +.B MUST +be specified when a template is used for writing to a database, +otherwise injection might occur. Please note that due to the unfortunate fact +that several vendors have violated the sql standard and introduced their own +escape methods, it is impossible to have a single option doing all the work. +So you yourself must make sure you are using the right format. +.B If you choose the wrong one, you are still vulnerable to sql injection. + +Please note that the database writer *checks* that the sql option is present +in the template. If it is not present, the write database action is disabled. +This is to guard you against accidental forgetting it and then becoming +vulnerable to SQL injection. The sql option can also be useful with files - +especially if you want to import them into a database on another machine for +performance reasons. However, do NOT use it if you do not have a real need for +it - among others, it takes some toll on the processing time. Not much, but on +a really busy system you might notice it ;) + +The default template for the write to database action has the sql option set. + +.SS Template examples +Please note that the samples are split across multiple lines. A template MUST +NOT actually be split across multiple lines. + +A template that resembles traditional syslogd file output: +.sp +.RS +$template TraditionalFormat,"%timegenerated% %HOSTNAME% +.sp 0 +%syslogtag%%msg:::drop-last-lf%\n" +.RE + +A template that tells you a little more about the message: +.sp +.RS +$template precise,"%syslogpriority%,%syslogfacility%,%timegenerated%,%HOSTNAME%, +.sp 0 +%syslogtag%,%msg%\n" +.RE + +A template for RFC 3164 format: +.sp +.RS +$template RFC3164fmt,"<%PRI%>%TIMESTAMP% %HOSTNAME% %syslogtag%%msg%" +.RE + +A template for the format traditionally used for user messages: +.sp +.RS +$template usermsg," XXXX%syslogtag%%msg%\n\r" +.RE + +And a template with the traditional wall-message format: +.sp +.RS +$template wallmsg,"\\r\\n\\7Message from syslogd@%HOSTNAME% at %timegenerated%" +.RE + +.B A template that can be used for writing to a database (please note the SQL template option) +.sp +.RS +.ad l +$template MySQLInsert,"insert iut, message, receivedat values +('%iut%', '%msg:::UPPERCASE%', '%timegenerated:::date-mysql%') +into systemevents\\r\\n", SQL + +NOTE 1: This template is embedded into core application under name +.B StdDBFmt +, so you don't need to define it. +.sp +NOTE 2: You have to have MySQL module installed to use this template. +.ad +.RE + +.SH OUTPUT CHANNELS + +Output Channels are a new concept first introduced in rsyslog 0.9.0. As of this writing, +it is most likely that they will be replaced by something different in the future. +So if you use them, be prepared to change you configuration file syntax when you upgrade +to a later release. + +Output channels are defined via an $outchannel directive. It's syntax is as follows: +.sp +.RS +.B $outchannel name,file-name,max-size,action-on-max-size +.RE + +name is the name of the output channel (not the file), file-name is the file name to be +written to, max-size the maximum allowed size and action-on-max-size a command to be issued +when the max size is reached. This command always has exactly one parameter. The binary is +that part of action-on-max-size before the first space, its parameter is everything behind +that space. + +Keep in mind that $outchannel just defines a channel with "name". It does not activate it. +To do so, you must use a selector line (see below). That selector line includes the channel +name plus an $ sign in front of it. A sample might be: +.sp +.RS +*.* $mychannel +.RE + +.SH PROPERTY REPLACER +The property replacer is a core component in rsyslogd's output system. A syslog message has +a number of well-defined properties (see below). Each of this properties can be accessed and +manipulated by the property replacer. With it, it is easy to use only part of a property value +or manipulate the value, e.g. by converting all characters to lower case. + +.SS Accessing Properties +Syslog message properties are used inside templates. They are accessed by putting them between +percent signs. Properties can be modified by the property replacer. The full syntax is as follows: +.sp +.RS +.B %propname:fromChar:toChar:options% +.RE + +propname is the name of the property to access. +.B It is case-sensitive. + +.SS Available Properties +.TP +.B msg +the MSG part of the message (aka "the message" ;)) +.TP +.B rawmsg +the message exactly as it was received from the socket. Should be useful for debugging. +.TP +.B HOSTNAME +hostname from the message +.TP +.B FROMHOST +hostname of the system the message was received from (in a relay chain, this is the system immediately +in front of us and not necessarily the original sender) +.TP +.B syslogtag +TAG from the message +.TP +.B programname +the "static" part of the tag, as defined by BSD syslogd. For example, when TAG is "named[12345]", +programname is "named". +.TP +.B PRI +PRI part of the message - undecoded (single value) +.TP +.B PRI-text +the PRI part of the message in a textual form (e.g. "syslog.info") +.TP +.B IUT +the monitorware InfoUnitType - used when talking to a MonitorWare backend (also for phpLogCon) +.TP +.B syslogfacility +the facility from the message - in numerical form +.TP +.B syslogfacility-text +the facility from the message - in text form +.TP +.B syslogseverity +severity from the message - in numerical form +.TP +.B syslogseverity-text +severity from the message - in text form +.TP +.B timegenerated +timestamp when the message was RECEIVED. Always in high resolution +.TP +.B timereported +timestamp from the message. Resolution depends on what was provided in the message (in most cases, only seconds) +.TP +.B TIMESTAMP +alias for timereported +.TP +.B PROTOCOL-VERSION +The contents of the PROTOCOL-VERSION field from IETF draft draft-ietf-syslog-protocol +.TP +.B STRUCTURED-DATA +The contents of the STRUCTURED-DATA field from IETF draft draft-ietf-syslog-protocol +.TP +.B APP-NAME +The contents of the APP-NAME field from IETF draft draft-ietf-syslog-protocol +.TP +.B PROCID +The contents of the PROCID field from IETF draft draft-ietf-syslog-protocol +.TP +.B MSGID +The contents of the MSGID field from IETF draft draft-ietf-syslog-protocol +.TP +.B $NOW +The current date stamp in the format YYYY-MM-DD +.TP +.B $YEAR +The current year (4-digit) +.TP +.B $MONTH +The current month (2-digit) +.TP +.B $DAY +The current day of the month (2-digit) +.TP +.B $HOUR +The current hour in military (24 hour) time (2-digit) +.TP +.B $MINUTE +The current minute (2-digit) + +.P +Properties starting with a $-sign are so-called system properties. These do NOT stem from the +message but are rather internally-generated. + +.SS Character Positions +FromChar and toChar are used to build substrings. They specify the offset within the string that +should be copied. Offset counting starts at 1, so if you need to obtain the first 2 characters of +the message text, you can use this syntax: "%msg:1:2%". If you do not wish to specify from and to, +but you want to specify options, you still need to include the colons. For example, if you would +like to convert the full message text to lower case, use "%msg:::lowercase%". If you would like to +extract from a position until the end of the string, you can place a dollar-sign ("$") in toChar +(e.g. %msg:10:$%, which will extract from position 10 to the end of the string). + +There is also support for +.B regular expressions. +To use them, you need to place a "R" into FromChar. +This tells rsyslog that a regular expression instead of position-based extraction is desired. The +actual regular expression +.B must +then be provided in toChar. The regular expression must be followed +by the string "--end". It denotes the end of the regular expression and will not become part of it. +If you are using regular expressions, the property replacer will return the part of the property text +that matches the regular expression. An example for a property replacer sequence with a regular +expression is: "%msg:R:.*Sev:. \\(.*\\) \\[.*--end%" + +Also, extraction can be done based on so-called "fields". To do so, place a "F" into FromChar. A field +in its current definition is anything that is delimited by a delimiter character. The delimiter by +default is TAB (US-ASCII value 9). However, if can be changed to any other US-ASCII character by +specifying a comma and the decimal US-ASCII value of the delimiter immediately after the "F". For example, +to use comma (",") as a delimiter, use this field specifier: "F,44". If your syslog data is delimited, +this is a quicker way to extract than via regular expressions (actually, a *much* quicker way). Field +counting starts at 1. Field zero is accepted, but will always lead to a "field not found" error. The same +happens if a field number higher than the number of fields in the property is requested. The field number +must be placed in the "ToChar" parameter. An example where the 3rd field (delimited by TAB) from the msg +property is extracted is as follows: "%msg:F:3%". The same example with semicolon as delimiter is +"%msg:F,59:3%". + +Please note that the special characters "F" and "R" are case-sensitive. Only upper case works, lower case +will return an error. There are no white spaces permitted inside the sequence (that will lead to error +messages and will NOT provide the intended result). + +.SS Property Options +Property options are case-insensitive. Currently, the following options are defined: +.TP +uppercase +convert property to lowercase only +.TP +lowercase +convert property text to uppercase only +.TP +drop-last-lf +The last LF in the message (if any), is dropped. Especially useful for PIX. +.TP +date-mysql +format as mysql date +.TP +date-rfc3164 +format as RFC 3164 date +.TP +date-rfc3339 +format as RFC 3339 date +.TP +escape-cc +replace control characters (ASCII value 127 and values less then 32) with an escape sequence. The sequence is "#<charval>" where charval is the 3-digit decimal value of the control character. For example, a tabulator would be replaced by "#009". +.TP +space-cc +replace control characters by spaces +.TP +drop-cc +drop control characters - the resulting string will neither contain control characters, escape sequences nor any other replacement character like space. + +.SH QUEUED OPERATIONS +Rsyslogd supports queued operations to handle offline outputs +(like remote syslogd's or database servers being down). When running in +queued mode, rsyslogd buffers messages to memory and optionally to disk +(on an as-needed basis). Queues survive rsyslogd restarts. + +It is highly suggested to use remote forwarding and database writing +in queued mode, only. + +To learn more about queued operations, see the html documentation. + +.SH FILES +.PD 0 +.TP +.I /etc/rsyslog.conf +Configuration file for +.B rsyslogd + +.SH SEE ALSO +.BR rsyslogd (8), +.BR logger (1), +.BR syslog (3) + +The complete documentation can be found in the doc folder of the rsyslog distribution or online at + +.RS +.B http://www.rsyslog.com/doc + +.RE +Please note that the man page reflects only a subset of the configuration options. Be sure to read +the html documentation for all features and details. This is especially vital if you plan to set +up a more-then-extremely-simple system. + +.SH AUTHORS +.B rsyslogd +is taken from sysklogd sources, which have been heavily modified +by Rainer Gerhards (rgerhards@adiscon.com) and others. |