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client-local.cfg

NAME

client-local.cfg - Local configuration settings for Hobbit clients

SYNOPSIS

~hobbit/server/etc/client-local.cfg

DESCRIPTION

The client-local.cfg file contains settings that are used by each Hobbit client when it runs on a monitored host. It provides a convenient way of configuring clients from a central location without having to setup special configuration maintenance tools on all clients.

The client-local.cfg file is currently used to configure what logfiles the client should fetch data from, to be used as the basis for the "msgs" status column; and to configure which files and directories are being monitored in the "files" status column.

Note that there is a dependency between the client-local.cfg file and the hobbit-clients.cfg(5) file. When monitoring e.g. a logfile, you must first enter it into the client-local.cfg file, to trigger the Hobbit client into reporting any data about the logfile. Next, you must configure hobbit-clients.cfg so the Hobbit server knows what to look for in the file data sent by the client. So: client-local.cfg defines what raw data is collected by the client, and hobbit-clients.cfg defines how to analyze them.

PROPAGATION TO CLIENTS

The client-local.cfg file resides on the Hobbit server.

When clients connect to the Hobbit server to send in their client data, they will receive part of this file back from the Hobbit server. The configuration received by the client is then used the next time the client runs.

This method of propagating the configuration means that there is a delay of up to two poll cycles (i.e. 5-10 minutes) from a configuration change is entered into the client-local.cfg file, and until you see the result in the status messages reported by the client.

FILE FORMAT

The file is divided into sections, delimited by "[name]" lines. A section name can be either an operating system identifier - linux, solaris, hp-ux, aix, freebsd, openbsd, netbsd, darwin - or a hostname. When deciding which section to send to a client, Hobbit will first look for a section named after the hostname of the client; if such a section does not exist, it will look for a section named by the operating system of the client. So you can configure special configurations for individual hosts, and have a default configuration for all other hosts of a certain type.

Apart from the section delimiter, the file format is free-form, or rather it is defined by the tools that make use of the configuration.

LOGFILE CONFIGURATION ENTRIES

A logfile configuration entry looks like this:

    log:/var/log/messages:10240

    ignore MARK

    trigger Oops

The log:FILENAME:SIZE line defines the filename of the log, and the maximum amount of data (in bytes) to send to the Hobbit server. FILENAME is usually an explicit full-path filename on the client. If it is enclosed in backticks, it is a command which the Hobbit client runs and each line of output from this command is then used as a filename. This allows scripting which files to monitor, e.g. if you have logfiles that are named with some sort of timestamp.

The ignore PATTERN line (optional) defines lines in the logfile which are ignored entirely, i.e. they are stripped from the logfile data before sending it to the Hobbit server. It is used to remove completely unwanted "noise" entries from the logdata processed by Hobbit. "PATTERN" is a regular expression.

The trigger PATTERN line (optional) is used only when there is more data in the log than the maximum size set in the "log:FILENAME:SIZE" line. The "trigger" pattern is then used to find particularly interesting lines in the logfile - these will always be sent to the Hobbit server. After picking out the "trigger" lines, any remaining space up to the maximum size is filled in with the most recent entries from the logfile. "PATTERN" is a regular expression.

COUNTING LOGENTRIES

A special type of log-handling is possible, where the number of lines matching a regular expressions are merely counted. This is linecount:FILENAME, followed by a number of lines of the form ID:PATTERN. E.g.

    linecount:/var/log/messages

    diskerrors:I/O error.*device.*hd

    badlogins:Failed login

FILE CONFIGURATION ENTRIES

A file monitoring entry is used to watch the meta-data of a file: Owner, group, size, permissions, checksum etc. It looks like this:

    file:/var/log/messages[:HASH]

The file:FILENAME line defines the filename of the file to monitor. As with the "log:" entries, a filename enclosed in backticks means a command which will generate the filenames dynamically. The optional [:HASH] setting defines what type of hash to compute for the file: md5, sha1 or rmd160. By default, no hash is calculated.
NOTE: If you want to check multiple files using a wildcard, you must use a command to generate the filenames. Putting wildcards directly into the file: entry will not work.

DIRECTORY CONFIGURATION ENTRIES

A directory monitoring entry is used to watch the size of a directory and any sub-directories. It looks like this:

    dir:DIRECTORYNAME

The dir:DIRECTORYNAME line defines the filename of the file to monitor. As with the "log:" entries, a filename enclosed in backticks means a command which will generate the filenames dynamically. The Hobbit client will run the du(1) command with the directoryname as parameter, and send the output back to the Hobbit server.
NOTE: If you want to check multiple directories using a wildcard, you must use a command to generate the directory names. Putting wildcards directly into the dir: entry will not work. E.g. use something like
       dir:`find /var/log -maxdepth 1 -type d`

The "du" command used can be configured through the DU environment variable. On some systems, by default du reports data in disk blocks instead of KB (e.g. Solaris). So you may want to configure the Hobbit client to use a du command which reports data in KB, e.g. by setting

    DU="du -k"
in the hobbitclient.cfg file.

NOTES

The ability of the Hobbit client to calculate file hashes and monitor those can be used for file integrity validation on a small scale. However, there is a significant processing overhead in calculating these every time the Hobbit client runs, so this should not be considered a replacement for host-based intrusion detection systems such as Tripwire or AIDE.

Use of the directory monitoring on directory structures with a large number of files and/or sub-directories can be quite ressource-intensive.

SEE ALSO

hobbit-clients.cfg(5), hobbitd_client(8), hobbitd(8), hobbit(7)