Starting, Updating & Extending the Agent

Starting, Updating & Extending the Agent

The purpose of this section is to familiarize the user with updating and extending the enStratus agent, as well as starting from scratch.

Updating

Updating the agent on a Ubuntu/Debian server can be accomplished by using the .deb package. The installation routine will detect previously installed versions and do a backup, preserving any customizations by preserving the contents of the /enstratus/custom/bin directory.

Extending the Agent

Agent scripts are designed to be extended and customized. The scripts located in /enstratus/bin are not designed to be edited directly as these scripts are overwritten during an upgrade. Instead, use the /enstratus/custom/bin directory to run custom scripts before, in place of, and/or after the provided scripts.

To run a script before the default enStratus script, place a script called $scriptName-pre in the /enstratus/custom/bin directory. To run a script in place of the default enStratus script, place a script of the same name in the /enstratus/custom/bin directory. To run a script after the default enStratus script, place a script called $scriptName-post in the /enstratus/custom/bin directory.

For example to modify the /enstratus/bin/addUser script do the following:

$ apt-get install gcc sun-java6-jdk sysstat sudo secure-delete $ sudo dpkg -i enstratus-latest.deb/enstratus/custom/bin/addUser - if exists, will completely replace this script /enstratus/custom/bin/addU pre - if exists, will be executed before this script /enstratus/custom/bin/addUser-post - if exists, will be executed after this script.

Starting from Scratch

At enStratus we use the EC2 images supplied by Alestic www.alestic.com with success. The .deb installer has been tested with the latest releases of Ubuntu (10.04) and Debian (5.0).

The installation process should work on most flavors of Ubuntu and Debian, if you have trouble installing on your own, please contact support at enStratus.