Introduction

This page was started to encapsulate the results of reverse-engineering the as-installed /etc/xen/scripts/* scripts

Calling the scripts

Normally the scripts are called by xl (and thence libxenlight?) because the are named in /etc/xen/<DomU name>.cfg.

Developing the scripts

In case of syntax errors, the error messages do not appear when running xl -vvv create <dom-name>.cfg so it may be necessary to run the scripts at a command prompt, in which case some run time values must be given ...

Runtime values

The script's arguments and environment can be found by inserting this code at the beginning of a script:

log_fn=/tmp/${0##*/}.$$
exec >>$log_fn 2>&1
i=0
for arg in "$@"
do
    echo "Arg $((i++)): '$arg'"
done
echo "env output: $(env)"
unset i arg

In case you want to trace a script, the usual technique of adding +x to the shebang line was found not to work on Debian 7 wheezy.   Adding set +x after the code above puts trace into the log file.

Functions