Fai-updater

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fai-updater - run and supervise softupdates on many machines at the same time

Screenshots

Everybody likes screenshots, so here are two. Note: they were done using fai-updater's dry-run mode, which does not touch the hosts, but feeds fai-updater with random log snippets instead to test the updaters log parser.

General logic is the following:

  • clients are put into the "waiting" queue (the right column), by default in randomized order
  • as soon as a slot in the "running" queue gets free (the second column from the right), the first "waiting" client gets updated/put into the "running" status and stays there until the update task finished
  • Depending on the outcome, the client is sorted in one of the first three columns:
    • Unreachable: the host was unreachable or the fai softupdate could not be started there
    • Error: the updater detected an error during the update (basically, it parses for the error string produced by a logcheck script such as hooks/savelog.LAST in the simple example)
    • Success: the update finished and no error was detected

Fai-updater in its basic mode

Fai-updater.png

Fai-updater with an open logfile viewer

Fai-updater-viewer.png

License

I put this code under the GPLv2

Download

You can download the FAI updater from here: media:fai-updater-20060321.tgz

Required packages

for the frontend, you need the Curses::UI perl module, in Debian you get it via

apt-get install libcurses-ui-perl

On the client side, fai-client is needed and of course a FAI configuration which is update-safe.

Install

Just unpack the tarball.

Command line options

 updater-curses [options] <netgroup|-H host1,host2,...>
 --help            display this help message
 --version         print version
 -o                ordered mode: don't randomize order of hosts
 -s <number>       number of updates running simultanously
 -n                dryrun mode: use a dummy-script instead of really 
                   contacting the clients

Connecting to the clients

A script using ssh is included, but of course you can edit it to match your own needs.

To be able to connect to the clients using the provided libexec/faiupdate, you need to have some way to access them via ssh as root without entering a password.

A solution for this is to install a matching file as /root/.ssh/authorized_keys, start ssh-agent and load the private key into it _before_ starting fai-updater.

Another, but from a security point of view dangerous, possibility is to use a passphrase-less ssh private key into the account under which you run fai-updater.

Some comments on the code

I know the code is quite rough, as though I tried programming cleanly, a lot of hacks have slipped in, and I don't have the time to clean up the code right now due to my diploma thesis' deadline ;)

If you have any questions or suggestions, feel free to write me.

Henning Glawe <glaweh (at) debian (dot) org>

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