The smtp() sends e-mail messages using SMTP, without needing external applications. The smtp() destination has the following options:
Type: | string |
Default: | n/a |
Description: The BODY field of the e-mail. You can also use macros in the string. Use \n to start a new line. For example:
body("syslog-ng OSE received the following alert from $HOST:\n$MSG")
Type: | string |
Default: | n/a |
Description: The BCC recipient of the e-mail (contents of the BCC field). You can specify the e-mail address, or the name and the e-mail address. Set the bcc() option multiple times to send the e-mail to multiple recipients. For example: bcc("admin@example.com") or bcc("Admin" "admin@example.com") or bcc("Admin" "admin@example.com") bcc("Admin2" "admin2@example.com")
You can also use macros to set the value of this parameter.
Type: | string |
Default: | n/a |
Description: The CC recipient of the e-mail (contents of the CC field). You can specify the e-mail address, or the name and the e-mail address. Set the cc() option multiple times to send the e-mail to multiple recipients. For example: cc("admin@example.com") or cc("Admin" "admin@example.com") or cc("Admin" "admin@example.com") cc("Admin2" "admin2@example.com")
You can also use macros to set the value of this parameter.
Description: This option enables putting outgoing messages into the disk buffer of the destination to avoid message loss in case of a system failure on the destination side. It has the following options:
reliable() | |||
Type: | yes|no | ||
Default: | no | ||
Description: If set to yes, syslog-ng OSE cannot lose logs in case of reload/restart, unreachable destination or syslog-ng OSE crash. This solution provides a slower, but reliable disk-buffer option. It is created and initialized at startup and gradually grows as new messages arrive. If set to no, the normal disk-buffer will be used. This provides a faster, but less reliable disk-buffer option.
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disk-buf-size() | |
Type: | number (bytes) |
Default: | |
Description: This is a required option. The maximum size of the disk-buffer in bytes. The minimum value is 1048576 bytes. If you set a smaller value, the minimum value will be used automatically. It replaces the old log-disk-fifo-size() option. |
mem-buf-length() | |
Type: | number (messages) |
Default: | 10000 |
Description: Use this option if the option reliable() is set to no. This option contains the number of messages stored in overflow queue. It replaces the old log-fifo-size() option. It inherits the value of the global log-fifo-size() option if provided. If it is not provided, the default value is 10000 messages. Note that this option will be ignored if the option reliable() is set to yes. |
mem-buf-size() | |
Type: | number (bytes) |
Default: | 163840000 |
Description: Use this option if the option reliable() is set to yes. This option contains the size of the messages in bytes that is used in the memory part of the disk buffer. It replaces the old log-fifo-size() option. It does not inherit the value of the global log-fifo-size() option, even if it is provided. Note that this option will be ignored if the option reliable() is set to no. |
qout-size() | |
Type: | number (messages) |
Default: | 64 |
Description: The number of messages stored in the output buffer of the destination. Note that if you change the value of this option and the disk-buffer already exists, the change will take effect when the disk-buffer becomes empty. |
Options reliable() and disk-buf-size() are required options.
In the following case reliable disk-buffer() is used.
destination d_demo { network( "127.0.0.1" port(3333) disk-buffer( mem-buf-size(10000) disk-buf-size(2000000) reliable(yes) dir("/tmp/disk-buffer") ) ); };
In the following case normal disk-buffer() is used.
destination d_demo { network( "127.0.0.1" port(3333) disk-buffer( mem-buf-length(10000) disk-buf-size(2000000) reliable(no) dir("/tmp/disk-buffer") ) ); };
Type: | string |
Default: | n/a |
Description: The sender of the e-mail (contents of the FROM field). You can specify the e-mail address, or the name and the e-mail address. For example:
from("admin@example.com")or
from("Admin" "admin@example.com")
If you specify the from() option multiple times, the last value will be used. Instead of the from() option, you can also use sender(), which is just an alias of the from() option.
You can also use macros to set the value of this parameter.
Type: | string |
Default: | n/a |
Description: Adds an extra header to the e-mail with the specified name and content. The first parameter sets the name of the header, the second one its value. The value of the header can contain macros. Set the header() option multiple times to add multiple headers. For example:
header("X-Program", "$PROGRAM")
When using the header option, note the following points:
Do not use the header() option to set the values of headers that have dedicated options. Use it only to add extra headers.
If you set the same custom header multiple times, only the first will be added to the e-mail, other occurrences will be ignored.
It is not possible to set the DATE, Return-Path, Original-Recipient, Content-*, MIME-*, Resent-*, Received headers.
Description: This option makes it possible to execute external programs when the relevant driver is initialized or torn down. The hook-commands() can be used with all source and destination drivers with the exception of the usertty() and internal() drivers.
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NOTE: The syslog-ng OSE application must be able to start and restart the external program, and have the necessary permissions to do so. For example, if your host is running AppArmor or SELinux, you might have to modify your AppArmor or SELinux configuration to enable syslog-ng OSE to execute external applications. |
To execute an external program when syslog-ng OSE starts or stops, use the following options:
startup() | |
Type: | string |
Default: | N/A |
Description: Defines the external program that is executed as syslog-ng OSE starts. |
shutdown() | |
Type: | string |
Default: | N/A |
Description: Defines the external program that is executed as syslog-ng OSE stops. |
To execute an external program when the syslog-ng OSE configuration is initiated or torn down, for example, on startup/shutdown or during a syslog-ng OSE reload, use the following options:
setup() | |
Type: | string |
Default: | N/A |
Description: Defines an external program that is executed when the syslog-ng OSE configuration is initiated, for example, on startup or during a syslog-ng OSE reload. |
teardown() | |
Type: | string |
Default: | N/A |
Description: Defines an external program that is executed when the syslog-ng OSE configuration is stopped or torn down, for example, on shutdown or during a syslog-ng OSE reload. |
In the following example, the hook-commands() is used with the network() driver and it opens an iptables port automatically as syslog-ng OSE is started/stopped.
The assumption in this example is that the LOGCHAIN chain is part of a larger ruleset that routes traffic to it. Whenever the syslog-ng OSE created rule is there, packets can flow, otherwise the port is closed.
source { network(transport(udp) hook-commands( startup("iptables -I LOGCHAIN 1 -p udp --dport 514 -j ACCEPT") shutdown("iptables -D LOGCHAIN 1") ) ); };
Type: | hostname or IP address |
Default: | n/a |
Description: Hostname or IP address of the SMTP server.
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NOTE:
If you specify host="localhost", syslog-ng OSE will use a socket to connect to the local SMTP server. Use host="127.0.0.1" to force TCP communication between syslog-ng OSE and the local SMTP server. |
Type: | number |
Default: | Use global setting. |
Description: The number of messages that the output queue can store.
Type: | number |
Default: | 25 |
Description: The port number of the SMTP server.
Type: | string |
Default: | n/a |
Description: Replies of the recipient will be sent to this address (contents of the REPLY-TO field). You can specify the e-mail address, or the name and the e-mail address. Set the reply-to() option multiple times to send the e-mail to multiple recipients. For example: reply-to("admin@example.com") or reply-to("Admin" "admin@example.com") or reply-to("Admin" "admin@example.com") reply-to("Admin2" "admin2@example.com")
You can also use macros to set the value of this parameter.
Type: | number (of attempts) |
Default: | 3 |
Description: The number of times syslog-ng OSE attempts to send a message to this destination. If syslog-ng OSE could not send a message, it will try again until the number of attempts reaches retries, then drops the message.
Type: | string |
Default: | n/a |
Description: The SUBJECT field of the e-mail. You can also use macros. For example:
subject("[SYSLOG ALERT]: Critical error message received from $HOST")
If you specify the subject() option multiple times, the last value will be used.
Type: | number |
Default: | 0 |
Description: Sets the maximum number of messages sent to the destination per second. Use this output-rate-limiting functionality only when using disk-buffer as well to avoid the risk of losing messages. Specifying 0 or a lower value sets the output limit to unlimited.
Type: | string |
Default: | localhost |
Description: The recipient of the e-mail (contents of the TO field). You can specify the e-mail address, or the name and the e-mail address. Set the to() option multiple times to send the e-mail to multiple recipients. For example: to("admin@example.com") or to("Admin" "admin@example.com") or to("Admin" "admin@example.com") to("Admin2" "admin2@example.com")
You can also use macros to set the value of this parameter.
Although syslog-ng OSE currently does not have any built-in integration with Splunk, the existing message-formatting features and flexibility of syslog-ng OSE allows you to forward your log messages to Splunk. In syslog-ng OSE version
For details on forwarding log messages to Splunk with syslog-ng OSE see the following posts on the Splunk blog:
The sql() driver sends messages into an SQL database. Currently the Microsoft SQL (MSSQL), MySQL, Oracle, PostgreSQL, and SQLite databases are supported.
sql(database_type host_parameters database_parameters [options]);
The sql() driver has the following required parameters: type(), database(), table(), columns(), and values().
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Caution:
The syslog-ng application requires read and write access to the SQL table, otherwise it cannot verify that the destination table exists. Currently the syslog-ng application has default schemas for the different databases and uses these defaults if the database schema (for example columns and column types) is not defined in the configuration file. However, these schemas will be deprecated and specifying the exact database schema will be required in later versions of syslog-ng. |
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NOTE:
In addition to the standard syslog-ng packages, the sql() destination requires database-specific packages to be installed. These packages are automatically installed by the binary syslog-ng installer. |
The table and value parameters can include macros to create tables and columns dynamically (for details, see Macros of syslog-ng OSE).
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Caution:
When using macros in table names, note that some databases limit the maximum allowed length of table names. Consult the documentation of the database for details. |
Inserting the records into the database is performed by a separate thread. The syslog-ng application automatically performs the escaping required to insert the messages into the database.
The following example sends the log messages into a PostgreSQL database running on the logserver host. The messages are inserted into the logs database, the name of the table includes the exact date and the name of the host sending the messages. The syslog-ng application automatically creates the required tables and columns, if the user account used to connect to the database has the required privileges.
destination d_sql { sql(type(pgsql) host("logserver") username("syslog-ng") password("password") database("logs") table("messages_${HOST}_${R_YEAR}${R_MONTH}${R_DAY}") columns("datetime", "host", "program", "pid", "message") values("{$R_DATE}", "${HOST}", "${PROGRAM}", "${PID}", "${MSGONLY}") indexes("datetime", "host", "program", "pid", "message")); };
The following example specifies the type of the database columns as well:
destination d_sql { sql(type(pgsql) host("logserver") username("syslog-ng") password("password") database("logs") table("messages_${HOST}_${R_YEAR}${R_MONTH}${R_DAY}") columns("datetime varchar(16)", "host varchar(32)", "program varchar(20)", "pid varchar(8)", "message varchar(200)") values("${R_DATE}", "${HOST}", "${PROGRAM}", "${PID}", "${MSGONLY}") indexes("datetime", "host", "program", "pid", "message")); };
The Oracle sql destination has some special aspects that are important to note.
The hostname of the database server is set in the tnsnames.ora file, not in the host parameter of the sql() destination.
If the tnsnames.ora file is not located in the /etc directory (or in the /var/opt/oracle directory on Solaris), set the following Oracle-related environment variables, so syslog-ng OSE will find the file: ORACLE_BASE, ORACLE_HOME, and ORACLE_SID. For details, see the documentation of the Oracle Instant Client.
You cannot use the same database() settings in more than one destination, because the database() option of the SQL driver is just a reference to the connection string of the tnsnames.ora file. To overcome this problem, you can duplicate the connections in the tnsnames.ora file under a different name, and use a different table in each Oracle destination in syslog-ng OSE.
As certain database versions limit the maximum length of table names, macros in the table names should be used with care.
In the current version of syslog-ng OSE, the types of database columns must be explicitly set for the Oracle destination. The column used to store the text part of the syslog messages should be able to store messages as long as the longest message permitted by syslog-ng, therefore it is usually recommended to use the varchar2 or clob column type. (The maximum length of the messages can be set using the log-msg-size() option.) For details, see the following example.
The Oracle Instant Client used by syslog-ng OSE supports only the following character sets:
Single-byte character sets: US7ASCII, WE8DEC, WE8MSWIN1252, and WE8ISO8859P1
Unicode character sets: UTF8, AL16UTF16, and AL32UTF8
The following example sends the log messages into an Oracle database running on the logserver host, which must be set in the /etc/tnsnames.ora file. The messages are inserted into the LOGS database, the name of the table includes the exact date when the messages were sent. The syslog-ng application automatically creates the required tables and columns, if the user account used to connect to the database has the required privileges.
destination d_sql { sql(type(oracle) username("syslog-ng") password("password") database("LOGS") table("msgs_${R_YEAR}${R_MONTH}${R_DAY}") columns("datetime varchar(16)", "host varchar(32)", "program varchar(32)", "pid varchar(8)", "message varchar2") values("${R_DATE}", "${HOST}", "${PROGRAM}", "${PID}", "${MSGONLY}") indexes("datetime", "host", "program", "pid", "message")); };
The Oracle Instant Client retrieves the address of the database server from the /etc/tnsnames.ora file. Edit or create this file as needed for your configuration. A sample is provided below.
LOGS = (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP) (HOST = logserver) (PORT = 1521)) ) (CONNECT_DATA = (SERVICE_NAME = EXAMPLE.SERVICE) ) )
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