clientupdate - Xymon client update utility
clientupdate is part of the Xymon client. It is responsible for updating
an existing client installation from a central repository of client packages
stored on the Xymon server.
When the Xymon client sends a normal client report to the Xymon
server, the server responds with the section of the
client-local.cfg(5) file that is relevant to this client. Included in
this may be a "clientversion" value. The clientversion received
from the server is compared against the current clientversion installed on
the client, as determined by the contents of the
$XYMONHOME/etc/clientversion.cfg file. If the two versions are not
identical, clientupdate is launched to update the client installation.
- Report the current clientversion.
- Attempt to update the client to NEWVERSION by fetching this version of the
client software from the Xymon server.
- Used internally during the update process, see OPERATION below.
- Used internally during the update process. This option causes the running
clientupdate utility to delete itself - it is used during the update to
purge a temporary copy of the clientupdate utility that is installed in
USING CLIENTUPDATE IN XYMON¶
To manage updating clients without having to logon to each server, you can use
the clientupdate utility. This is how you setup the release of a new client
- Create the new client
- Setup the new client $XYMONHOME directory, e.g. by copying an existing
client installation to an empty directory and modifying it for your needs.
It is a good idea to delete all files in the tmp/ and logs/ directories,
since there is no need to copy these over to all of the clients. Pay
attention to the etc/ files, and make sure that they are suitable for the
systems where you want to deploy this new client. You can add files - e.g.
extension scripts in the ext/ directory - but the clientupdate utility
cannot delete or rename files.
- Package the client
- When your new client software is ready, create a tar-file of the new
client. All files in the tar archive must have file names relative to the
clients' $XYMONHOME (usually, ~xymon/client/). Save the tar file on the
Xymon server in ~xymon/server/download/somefile.tar. Don't compress it. It
is recommended that you use some sort of operating-system and
version-numbering scheme for the filename, but you can choose whatever
filename suits you - the only requirement is that it must end with
".tar". The part of the filename preceding ".tar" is
what Xymon will use as the "clientversion" ID.
- Configure which hosts receive the new client
- In the client-local.cfg(5) file, you must now setup a
clientversion:ID line where the ID matches the filename you
used for the tar-file. So if you have packaged the new client into the
file linux.v2.tar, then the corresponding entry in client-local.cfg
would be clientversion:linux.v2.
- Wait for xymond to reload client-local.cfg
- xymond will automatically reload the client-local.cfg file after at most
10 minutes. If you want to force an immediate reload, send a SIGHUP signal
to the xymond process.
- Wait for the client to update
- The next time the client contacts the Xymon server to send the client
data, it will notice the new clientversion setting in client-local.cfg,
and will run clientupdate to install the new client software. So
when the client runs the next time, it will use the new client software.
clientupdate runs in two steps:
- Re-exec step
- The first step is when clientupdate is first invoked from the
xymonclient.sh script with the "--re-exec" option. This step
copies the clientupdate program from $XYMONHOME/bin/ to a temporary file
in the $XYMONTMP directory. This is to avoid conflicts when the update
procedure installs a new version of the clientupdate utility itself. Upon
completion of this step, the clientupdate utility automatically launches
the next step by running the program from the file in $XYMONTMP.
- Update step
- The second step downloads the new client software from the Xymon server.
The new software must be packed into a tar file, which clientupdate then
unpacks into the $XYMONHOME directory.
clientupdate uses several of the standard Xymon environment variables, including
XYMONHOME and XYMONTMP.