Instead of hardcoding the location of perl (assuming it is installed in
/usr), use /usr/bin/env to run it, and thus picking it from $PATH.
This makes it possible to run these scripts also on installations with
perl in a different prefix than /usr.
Also, given that we want enable warnings on scripts, turn the -w
previously in shebang to explicit "use warnings;" in scripts which
didn't have it before.
Review every test(!) to ensure that it:
- Doesn't use a generic name (eg. "test1.img", "test.out") for any
temporary file it needs.
- Does instead use a unique name or a temporary name (eg. a name like
"name-of-the-test.img", or a scratch disk).
- Does not use 'rm -f' to clean up its temporary files (so we can
detect errors if the wrong temporary file is created or removed).
This allows tests to be run in parallel, so they don't stomp on each
other's temporary files.
This large, but mainly mechanical commit, renames "attach method"
everywhere to "backend".
Backwards compatibility of the API (guestfs_{set,get}_attach_method)
and environment (LIBGUESTFS_ATTACH_METHOD) is maintained, but in new
code use guestfs_{set,get}_backend and LIBGUESTFS_BACKEND instead.
The default backend (launching qemu directly) is now called 'direct'
instead of 'appliance', although you can still use 'appliance' as a
synonym.
When libvirt is used, we can allow disks to be hotplugged.
guestfs_add_drive can be called after launch to hot-add a disk.
When a disk is hot-added, we first ask libvirt to add the disk to the
appliance, then we make an internal call into the appliance to get it
to wait for the disk to appear (ie. udev_settle ()).
Hot-added disks are tracked in the g->drives array.
This also adds a test.
