syslog-ng Premium Edition 7.0.12 - Administration Guide

wildcard-file: Collecting messages from multiple text files

The wildcard-file() source collects log messages from multiple plain-text files from multiple directories. The wildcard-file() source is available in syslog-ng PE version 7.0.3 and later.

The syslog-ng PE application notices if a file is renamed or replaced with a new file, so it can correctly follow the file even if logrotation is used. When syslog-ng PE is restarted, it records the position of the last sent log message in the /opt/syslog-ng/var/syslog-ng.persist file, and continues to send messages from this position after the restart.

Declaration:

wildcard-file(
    base-dir("<pathname>")
    file-pattern("<filename>")
);

Note the following important points:

• You can use the * and ? wildcard characters in the filename (the file-pattern() option), but not in the path (the base-dir() option).

• When using the wildcard-file() source, always set how often syslog-ng PE should check the files for new messages using the follow-freq() parameter.

• If you use multiple wildcard-file() sources in your configuration, make sure that the files and folders that match the wildcards do not overlap. That is, every file and folder should belong to only one file source. Monitoring a file from multiple wildcard sources can lead to data loss.

• When using wildcards, syslog-ng PE monitors every matching file (up to the limit set in the max-files() option), and can receive new log messages from any of the files. However, monitoring (polling) many files (that is, more than ten) has a significant overhead and may affect performance. On Linux this overhead is not so significant, because syslog-ng PE uses the inotify feature of the kernel. Set the max-files() option at least to the number of files you want to monitor. If the wildcard-file source matches more files than the value of the max-files() option, it is random which files will syslog-ng PE actually monitor. The default value of max-files() is 100.

• If the message does not have a proper syslog header, syslog-ng PE treats messages received from files as sent by the kern facility. Use the default-facility() and default-priority() options in the source definition to assign a different facility if needed.

Required parameters: base-dir(), file-pattern(). For the list of available optional parameters, see wildcard-file() source options.

wildcard-file() source options

The wildcard-file() driver has the following options:

base-dir()

Description: The path to the directory that contains the log files to monitor, for example, base-dir("/var/log"). To monitor also the subdirectories of the base directory, use the recursive(yes) option. For details, see recursive().

source s_files {
    wildcard-file(
        base-dir("/var/log")
        file-pattern("*.log")
        recursive(no)
        follow-freq(1)
    );
};

default-facility()

default-priority()

Description: This parameter assigns an emergency level to the messages received from the file source, if the message does not specify one. For example, default-priority(warning)

encoding()

Description: Specifies the characterset (encoding, for example UTF-8) of messages using the legacy BSD-syslog protocol. To list the available character sets on a host, execute the iconv -l command. For details on how encoding affects the size of the message, see Message size and encoding.

file-pattern()

Description: The filename to read messages from, without the path. You can use the * and ? wildcard characters, without regular expression and character range support. You cannot use the * and ? literally in the pattern.

For example, file-pattern("*.log") matches the syslog.log and auth.log files, but does not match the access_log file. The file-pattern("*log") pattern matches all three.

• *

  matches an arbitrary string, including an empty string

• ?

  matches an arbitrary character

source s_files {
    wildcard-file(
        base-dir("/var/log")
        file-pattern("*.log")
        recursive(no)
        follow-freq(1)
    );
};

flags()

Description: Specifies the log parsing options of the source.

• assume-utf8: The assume-utf8 flag assumes that the incoming messages are UTF-8 encoded, but does not verify the encoding. If you explicitly want to validate the UTF-8 encoding of the incoming message, use the validate-utf8 flag.

• empty-lines: Use the empty-lines flag to keep the empty lines of the messages. By default, syslog-ng PE removes empty lines automatically.

• expect-hostname: If the expect-hostname flag is enabled, syslog-ng PE will assume that the log message contains a hostname and parse the message accordingly. This is the default behavior for TCP sources. Note that pipe sources use the no-hostname flag by default.

• kernel: The kernel flag makes the source default to the LOG_KERN | LOG_NOTICE priority if not specified otherwise.

• no-hostname: Enable the no-hostname flag if the log message does not include the hostname of the sender host. That way syslog-ng PE assumes that the first part of the message header is ${PROGRAM} instead of ${HOST}. For example:

  source s_dell {
      network(
          port(2000)
          flags(no-hostname)
      );
  };

• no-multi-line: The no-multi-line flag disables line-breaking in the messages: the entire message is converted to a single line. Note that this happens only if the underlying transport method actually supports multi-line messages. Currently the file() and pipe() drivers support multi-line messages.

• no-parse: By default, syslog-ng PE parses incoming messages as syslog messages. The no-parse flag completely disables syslog message parsing and processes the complete line as the message part of a syslog message. The syslog-ng PE application will generate a new syslog header (timestamp, host, and so on) automatically and put the entire incoming message into the MESSAGE part of the syslog message (available using the ${MESSAGE} macro). This flag is useful for parsing messages not complying to the syslog format.

  If you are using the flags(no-parse) option, then syslog message parsing is completely disabled, and the entire incoming message is treated as the ${MESSAGE} part of a syslog message. In this case, syslog-ng PE generates a new syslog header (timestamp, host, and so on) automatically. Note that since flags(no-parse) disables message parsing, it interferes with other flags, for example, disables flags(no-multi-line).

• dont-store-legacy-msghdr: By default, syslog-ng stores the original incoming header of the log message. This is useful if the original format of a non-syslog-compliant message must be retained (syslog-ng automatically corrects minor header errors, for example, adds a whitespace before msg in the following message: Jan 22 10:06:11 host program:msg). If you do not want to store the original header of the message, enable the dont-store-legacy-msghdr flag.

• sanitize-utf8: When using the sanitize-utf8 flag, syslog-ng PE converts non-UTF-8 input to an escaped form, which is valid UTF-8.

• store-raw-message: Save the original message as received from the client in the ${RAWMSG} macro. You can forward this raw message in its original form to another syslog-ng node using the syslog-ng() destination, or to a SIEM system, ensuring that the SIEM can process it. Available only in 7.0.9 and later.

• syslog-protocol: The syslog-protocol flag specifies that incoming messages are expected to be formatted according to the new IETF syslog protocol standard (RFC5424), but without the frame header. Note that this flag is not needed for the syslog driver, which handles only messages that have a frame header.

• validate-utf8: The validate-utf8 flag enables encoding-verification for messages formatted according to the new IETF syslog standard (for details, see IETF-syslog messages). If theBOM1character is missing, but the message is otherwise UTF-8 compliant, syslog-ng automatically adds the BOM character to the message.

follow-freq()

Description: Indicates that the source should be checked periodically. This is useful for files which always indicate readability, even though no new lines were appended. If this value is higher than zero, syslog-ng will not attempt to use poll() on the file, but checks whether the file changed every time the follow-freq() interval (in seconds) has elapsed. Floating-point numbers (for example 1.5) can be used as well.

keep-timestamp()

Description: Specifies whether syslog-ng should accept the timestamp received from the sending application or client. If disabled, the time of reception will be used instead. This option can be specified globally, and per-source as well. The local setting of the source overrides the global option if available.

log-fetch-limit()

Description: The maximum number of messages fetched from a source during a single poll loop. The destination queues might fill up before flow-control could stop reading if log-fetch-limit() is too high.

log-iw-size()

Description: The size of the initial window, this value is used during flow control. Make sure that log-iw-size() is larger than the value of log-fetch-limit().

When using wildcards in the filenames, syslog-ng PE attempts to read log-fetch-limit() number of messages from each file. For optimal performance, make sure that log-iw-size() is greater than log-fetch-limit()*max-files(). Note that to avoid performance problems, if log-iw-size()/max-files() is smaller than 100, syslog-ng PE automatically sets log-iw-size() to max-files()*100.

log-msg-size()

Description: Maximum length of a message in bytes. This length includes the entire message (the data structure and individual fields). The maximal value that can be set is 268435456 bytes (256MB). For messages using the IETF-syslog message format (RFC5424), the maximal size of the value of an SDATA field is 64kB.

In most cases, it is not recommended to set log-msg-size() higher than 10 MiB.

For details on how encoding affects the size of the message, see Message size and encoding.

Uses the value of the global option if not specified.

log-prefix() (DEPRECATED)

Description: A string added to the beginning of every log message. It can be used to add an arbitrary string to any log source, though it is most commonly used for adding kernel: to the kernel messages on Linux. NOTE: This option is deprecated. Use program-override() instead.

max-files()

Description: Limits the number of files that the wildcard-file source monitors.

When using wildcards, syslog-ng PE monitors every matching file (up to the limit set in the max-files() option), and can receive new log messages from any of the files. However, monitoring (polling) many files (that is, more than ten) has a significant overhead and may affect performance. On Linux this overhead is not so significant, because syslog-ng PE uses the inotify feature of the kernel. Set the max-files() option at least to the number of files you want to monitor. If the wildcard-file source matches more files than the value of the max-files() option, it is random which files will syslog-ng PE actually monitor. The default value of max-files() is 100.

monitor-method()

Description: If the platform supports inotify, syslog-ng PE uses it automatically to detect changes to the source files. If inotify is not available, syslog-ng PE polls the files as set in the follow-freq() option. To force syslog-ng PE poll the files even if inotify is available, set this option to poll.

multi-line-garbage()

Description: Use the multi-line-garbage() option when processing multi-line messages that contain unneeded parts between the messages. Specify a string or regular expression that matches the beginning of the unneeded message parts. If the multi-line-garbage() option is set, syslog-ng PE ignores the lines between the line matching the multi-line-garbage() and the next line matching multi-line-prefix(). See also the multi-line-prefix() option.

When receiving multi-line messages from a source when the multi-line-garbage() option is set, but no matching line is received between two lines that match multi-line-prefix(), syslog-ng PE will continue to process the incoming lines as a single message until a line matching multi-line-garbage() is received.

To use the multi-line-garbage() option, set the multi-line-mode() option to prefix-garbage.

multi-line-mode()

Description: Use the multi-line-mode() option when processing multi-line messages. The syslog-ng PE application provides the following methods to process multi-line messages: multi-line-mode(indented), and multi-line-mode(prefix-garbage).

• The indented mode can process messages where each line that belongs to the previous line is indented by whitespace, and the message continues until the first non-indented line. For example, the Linux kernel (starting with version 3.5) uses this format for /dev/log, as well as several applications, like Apache Tomcat.

  Example: Processing indented multi-line messages

  source s_tomcat {
      file("/var/log/tomcat/xxx.log"
          multi-line-mode(indented)
      );
  };

• The prefix-garbage mode uses a string or regular expression (set in multi-line-prefix()) that matches the beginning of the log messages, ignores newline characters from the source until a line matches the regular expression again, and treats the lines between the matching lines as a single message. For details on using multi-line-mode(prefix-garbage), see the multi-line-prefix() and multi-line-garbage() options.

• The prefix-suffix mode uses a string or regular expression (set in multi-line-prefix()) that matches the beginning of the log messages, ignores newline characters from the source until a line matches the regular expression set in multi-line-suffix(), and treats the lines between multi-line-prefix() and multi-line-suffix() as a single message. Any other lines between the end of the message and the beginning of a new message (that is, a line that matches the multi-line-prefix() expression) are discarded. For details on using multi-line-mode(prefix-suffix), see the multi-line-prefix() and multi-line-suffix() options.

  The prefix-suffix mode is similar to the prefix-garbage mode, but it appends the garbage part to the message instead of discarding it.

multi-line-prefix()

Description: Use the multi-line-prefix() option to process multi-line messages, that is, log messages that contain newline characters (for example, Tomcat logs). Specify a string or regular expression that matches the beginning of the log messages (always start with the ^ character). Use as simple regular expressions as possible, because complex regular expressions can severely reduce the rate of processing multi-line messages. If the multi-line-prefix() option is set, syslog-ng PE ignores newline characters from the source until a line matches the regular expression again, and treats the lines between the matching lines as a single message. See also the multi-line-garbage() option.

2010.06.09. 12:07:39 org.apache.catalina.startup.Catalina start
SEVERE: Catalina.start:
LifecycleException:  service.getName(): "Catalina";  Protocol handler start failed: java.net.BindException: Address already in use null:8080
       at org.apache.catalina.connector.Connector.start(Connector.java:1138)
       at org.apache.catalina.core.StandardService.start(StandardService.java:531)
       at org.apache.catalina.core.StandardServer.start(StandardServer.java:710)
       at org.apache.catalina.startup.Catalina.start(Catalina.java:583)
       at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
       at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
       at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
       at java.lang.reflect.Method.invoke(Method.java:597)
       at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:288)
       at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
       at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
       at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
       at java.lang.reflect.Method.invoke(Method.java:597)
       at org.apache.commons.daemon.support.DaemonLoader.start(DaemonLoader.java:177)
2010.06.09. 12:07:39 org.apache.catalina.startup.Catalina start
INFO: Server startup in 1206 ms
2010.06.09. 12:45:08 org.apache.coyote.http11.Http11Protocol pause
INFO: Pausing Coyote HTTP/1.1 on http-8080
2010.06.09. 12:45:09 org.apache.catalina.core.StandardService stop
INFO: Stopping service Catalina

source s_file{file("/var/log/tomcat6/catalina.2010-06-09.log" follow-freq(0) multi-line-prefix("[0-9]{4}\.[0-9]{2}\.[0-9]{2}\.") flags(no-parse));};
};

multi-line-suffix()

Description: Use the multi-line-suffix() option when processing multi-line messages. Specify a string or regular expression that matches the end of the multi-line message.

To use the multi-line-suffix() option, set the multi-line-mode() option to prefix-suffix. See also the multi-line-prefix() option.

pad-size()

Description: Specifies input padding. Some operating systems (such as HP-UX) pad all messages to block boundary. This option can be used to specify the block size. The syslog-ng PE application will pad reads from the associated device to the number of bytes set in pad-size(). Mostly used on HP-UX where /dev/log is a named pipe and every write is padded to 2048 bytes. If pad-size() was given and the incoming message does not fit into pad-size(), syslog-ng will not read anymore from this pipe and displays the following error message:

Padding was set, and couldn't read enough bytes

program-override()

Description: Replaces the ${PROGRAM} part of the message with the parameter string. For example, to mark every message coming from the kernel, include the program-override("kernel") option in the source containing /proc/kmsg.

recursive()

Description: When enabled, syslog-ng PE monitors every subdirectory of the path set in the base-dir() option, and reads log messages from files with matching filenames. The recursive option can be used together with wildcards in the filename.

source s_file_subdirectories {
    wildcard-file(
        base-dir("/var/log")
        file-pattern("*.log")
        recursive(yes)
        follow-freq(1)
        log-fetch-limit(100)
    );
};

tags()

Description: Label the messages received from the source with custom tags. Tags must be unique, and enclosed between double quotes. When adding multiple tags, separate them with comma, for example tags("dmz", "router"). This option is available only in syslog-ng 3.1 and later.

time-zone()

Description: The default timezone for messages read from the source. Applies only if no timezone is specified within the message itself.

The timezone can be specified as using the name of the (for example time-zone("Europe/Budapest")), or as the timezone offset in +/-HH:MM format (for example +01:00). On Linux and UNIX platforms, the valid timezone names are listed under the /usr/share/zoneinfo directory.

network: Collecting messages using the RFC3164 protocol (network() driver)

The network() source driver can receive syslog messages conforming to RFC3164 from the network using the TCP, TLS, and UDP networking protocols.

You can use the ALTP protocol as well. For details about the ALTP protocol, see Advanced Log Transfer Protocol .

• UDP is a simple datagram oriented protocol, which provides "best effort service" to transfer messages between hosts. It may lose messages, and no attempt is made to retransmit lost messages. The BSD-syslog protocol traditionally uses UDP.

  Use UDP only if you have no other choice.

• TCP provides connection-oriented service: the client and the server establish a connection, each message is acknowledged, and lost packets are resent. TCP can detect lost connections, and messages are lost, only if the TCP connection breaks. When a TCP connection is broken, messages that the client has sent but were not yet received on the server are lost.

• The syslog-ng application supports TLS (Transport Layer Security, also known as SSL) over TCP. For details, see Encrypting log messages with TLS.

network([options]);

By default, the network() driver binds to 0.0.0.0, meaning that it listens on every available IPV4 interface on the TCP/601 port. To limit accepted connections to only one interface, use the localip() parameter. To listen on IPv6 addresses, use the ip-protocol(6) option.

source s_network {
    network();
};

source s_network {
    network(
        ip("192.168.1.1")
        transport("udp")
    );
};

source s_network6 {
    network(
        ip("::1")
        transport("tcp")
        port(2222)
        ip-protocol(6)
    );
};

source s_network {
    network(
        transport("tcp")
        port(2222)
        tls(
            peer-verify("required-trusted")
            key-file("/opt/syslog-ng/etc/syslog-ng/syslog-ng.key")
            cert-file("/opt/syslog-ng/etc/syslog-ng/syslog-ng.crt")
        );
    );
};

source s_tcp_syslog {
    network(
        ip("127.0.0.1")
        flags(syslog-protocol)
    );
};

For details on the options of the network() source, see network() source options.

network() source options

The network() driver has the following options.

encoding()

Description: Specifies the characterset (encoding, for example UTF-8) of messages using the legacy BSD-syslog protocol. To list the available character sets on a host, execute the iconv -l command. For details on how encoding affects the size of the message, see Message size and encoding.

host-override()

Description: Replaces the ${HOST} part of the message with the parameter string.

ip() or localip()

Description: The IP address to bind to. By default, syslog-ng PE listens on every available interface. Note that this is not the address where messages are accepted from.

If you specify a multicast bind address and use the udp transport, syslog-ng PE automatically joins the necessary multicast group. TCP does not support multicasting.

ip-protocol()

Description: Determines the internet protocol version of the given driver (network() or syslog()). The possible values are 4 and 6, corresponding to IPv4 and IPv6. The default value is ip-protocol(4).

Note that listening on a port using IPv6 automatically means that you are also listening on that port using IPv4. That is, if you want to have receive messages on an IP-address/port pair using both IPv4 and IPv6, create a source that uses the ip-protocol(6). You cannot have two sources with the same IP-address/port pair, but with different ip-protocol() settings (it causes an Address already in use error).

For example, the following source receives messages on TCP, using the network() driver, on every available interface of the host on both IPv4 and IPv6.

source s_network_tcp {
    network(
        transport("tcp")
        ip("::")
        ip-protocol(6)
        port(601)
    );
};

ip-tos()

Description: Specifies the Type-of-Service value of outgoing packets.

ip-ttl()

Description: Specifies the Time-To-Live value of outgoing packets.

keep-alive()

Description: Specifies whether connections to sources should be closed when syslog-ng is forced to reload its configuration (upon the receipt of a SIGHUP signal). Note that this applies to the server (source) side of the syslog-ng connections, client-side (destination) connections are always reopened after receiving a HUP signal unless the keep-alive option is enabled for the destination.

keep-hostname()

Description: Enable or disable hostname rewriting.

• If enabled (keep-hostname(yes)), syslog-ng PE assumes that the incoming log message was sent by the host specified in the HOST field of the message.

• If disabled (keep-hostname(no)), syslog-ng PE rewrites the HOST field of the message, either to the IP address (if the use-dns() parameter is set to no), or to the hostname (if the use-dns() parameter is set to yes and the IP address can be resolved to a hostname) of the host sending the message to syslog-ng PE. For details on using name resolution in syslog-ng PE, see Using name resolution in syslog-ng.

This option can be specified globally, and per-source as well. The local setting of the source overrides the global option if available.

keep-timestamp()

Description: Specifies whether syslog-ng should accept the timestamp received from the sending application or client. If disabled, the time of reception will be used instead. This option can be specified globally, and per-source as well. The local setting of the source overrides the global option if available.

log-fetch-limit()

Description: The maximum number of messages fetched from a source during a single poll loop. The destination queues might fill up before flow-control could stop reading if log-fetch-limit() is too high.

log-msg-size()

Description: Maximum length of a message in bytes. This length includes the entire message (the data structure and individual fields). The maximal value that can be set is 268435456 bytes (256MB). For messages using the IETF-syslog message format (RFC5424), the maximal size of the value of an SDATA field is 64kB.

In most cases, it is not recommended to set log-msg-size() higher than 10 MiB.

For details on how encoding affects the size of the message, see Message size and encoding.

Uses the value of the global option if not specified.

max-connections()

Description: Specifies the maximum number of simultaneous connections.

pad-size()

Description: Specifies input padding. Some operating systems (such as HP-UX) pad all messages to block boundary. This option can be used to specify the block size. The syslog-ng PE application will pad reads from the associated device to the number of bytes set in pad-size(). Mostly used on HP-UX where /dev/log is a named pipe and every write is padded to 2048 bytes. If pad-size() was given and the incoming message does not fit into pad-size(), syslog-ng will not read anymore from this pipe and displays the following error message:

Padding was set, and couldn't read enough bytes

program-override()

Description: Replaces the ${PROGRAM} part of the message with the parameter string. For example, to mark every message coming from the kernel, include the program-override("kernel") option in the source containing /proc/kmsg.

so-broadcast()

Description: This option controls the SO_BROADCAST socket option required to make syslog-ng send messages to a broadcast address. For details, see the socket(7) manual page.

so-keepalive()

Description: Enables keep-alive messages, keeping the socket open. This only effects TCP and UNIX-stream sockets. For details, see the socket(7) manual page.

so-rcvbuf()

Description: Specifies the size of the socket receive buffer in bytes. For details, see the socket(7) manual page.

so-sndbuf()

Description: Specifies the size of the socket send buffer in bytes. For details, see the socket(7) manual page.

tags()

Description: Label the messages received from the source with custom tags. Tags must be unique, and enclosed between double quotes. When adding multiple tags, separate them with comma, for example tags("dmz", "router"). This option is available only in syslog-ng 3.1 and later.

time-zone()

Description: The default timezone for messages read from the source. Applies only if no timezone is specified within the message itself.

The timezone can be specified as using the name of the (for example time-zone("Europe/Budapest")), or as the timezone offset in +/-HH:MM format (for example +01:00). On Linux and UNIX platforms, the valid timezone names are listed under the /usr/share/zoneinfo directory.

transport()

Description: Specifies the protocol used to receive messages from the source.

tls()

Description: This option sets various options related to TLS encryption, for example, key/certificate files and trusted CA locations. TLS can be used only with tcp-based transport protocols. For details, see TLS options.

use-dns()

Description: Enable or disable DNS usage. The persist_only option attempts to resolve hostnames locally from file (for example from /etc/hosts). The syslog-ng PE application blocks on DNS queries, so enabling DNS may lead to a Denial of Service attack. To prevent DoS, protect your syslog-ng network endpoint with firewall rules, and make sure that all hosts which may get to syslog-ng are resolvable. This option can be specified globally, and per-source as well. The local setting of the source overrides the global option if available.

use-fqdn()

Description: Add Fully Qualified Domain Name instead of short hostname. This option can be specified globally, and per-source as well. The local setting of the source overrides the global option if available.