clientupdate1

Usage

Overview

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.

Options

--level

Report the current clientversion.

--update=NEWVERSION

Attempt to update the client to NEWVERSION by fetching this version of the client software from the Xymon server.

--reexec

Used internally during the update process, see OPERATION below.

--remove-self

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 $XYMONTMP.

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 version.

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.

Operation

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.

Environment

clientupdate uses several of the standard Xymon environment variables, including XYMONHOME and XYMONTMP.