wiki:cereal

Version 26 (modified by dkg, 10 years ago) (diff)

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cereal

cereal is a serial terminal management system. cereal provides a framework to easily set up and maintain automated, timestamped logs of serial lines, while simultaneously allowing end user access to them. This is probably most useful for providing automated, logged access to remote serial consoles.

cereal can control an arbitrary number of independently monitored and logged lines. Direct access to the monitored lines is allowed only to a specific user (who doesn't necessarily otherwise have access to the direct serial line), but logs can be made available to any group. Logs are rotated automatically and their total space can be limited in size.

cereal uses GNU screen as the terminal interface to the serial lines. cereal attaches a screen session to a specified serial terminal, and then monitors the screen session with runit. Any activity on that screen session is written to a log file.

cereal was conceived as a way to manage the monitoring of serial consoles on other machines. Other than network connections, serial lines are the most useful way to interact with a machine. All legitimate BIOS, bootloaders, and operating systems can provide console/terminal access through a serial line. In a high-density environment, such as a rack, all machines can be configured with their consoles on a serial line. A serial console server can then be setup with a high number of serial ports to monitor the serial consoles of all the machines in the rack. Serial monitoring requires less space, and is more flexible and convenient that typical KVM systems. cereal can be used on the serial console server to manage all the serial connections to the machines in the rack.

cereal is available under the GNU General Public License, v3 or later.

terminology

  • a "session" connects a "terminal", with screen, to a "host" (serial console) via serial "line"
  • one can "attach" to enabled session
  • one can "follow" enabled session (read logs)

dependencies

cereal depends on runit and GNU screen.

download

cereal is now a part of Debian!

The latest version of cereal is available from CMRG in source or .deb form, or from the CMRG apt repository by adding the following to your /etc/apt/sources.list:

deb http://cmrg.fifthhorseman.net/debian unstable cereal
deb-src http://cmrg.fifthhorseman.net/debian unstable cereal

The latest version of cereal no longer works on etch because of changes in runit. If you want to use cereal on an etch, please put the following lines in /etc/apt/sources.list instead:

deb http://cmrg.fifthhorseman.net/debian etch cereal
deb-src http://cmrg.fifthhorseman.net/debian etch cereal

Note: these repositories are signed by dkg's GPG key. You can import this key for apt if you want cryptographic verification of these packages.

Anonymous, read-only access to the source is available via svn:

svn co http://cmrg.fifthhorseman.net/svn/trunk/cereal

You can also browse the source on this site.

open issues

#5
coax screen into logging to stdout or stderr
#8
cereal bash completion
#27
create /usr/bin/cereal-shell
#96
cereal attach fails if there are other sessions named similarly
#97
cereal failing to destroy stopped sessions
#104
add ability to change session parameters