pybofh
A Linux system administration automation toolset.
Abstracts common CLIs into python functions and classes.
Current command modules:
- blockdevice
- btrfs
- encryption (cryptsetup)
- drbd
- lvm
- xen
Example
Start all Xen DomUs
from pybofh import xen
for domu in xen.allDomus():
if not xen.isDomuRunning(domu):
xen.startDomu( domu )
Features
Site-specific configuration
Customize site_specific.py to match your local environment
Atomic operations
Having a automated administration tool that leaves a talk half-finished is worse than having no automated administration tool.
pybofh supports context managers:
TMP_MNTS= ["/media/tmp", "/media/tmp2"]
mountpool= blockdevice.MountPool( TMP_MNTS )
with mountpool.mount( '/dev/sda1' ) as sda1_mountpoint:
#/dev/sda1 is now mounted
with mountpoint.mount( '/dev/sda2') as sda2_mountpoint:
#/dev/sda2 is now mounted
with mountpoint.mount( '/dev/sda3') as sda3_mountpoint:
#fails, no more mountpoints available
pass
#/dev/sda1 and /dev/sda2 are now unmounted
But, of course, not all operations make sense as a context manager. Take, for example, creating a new VM from disk on LVM:
lvm.createLV("my_vg", "my_vm", "10gb")
blockdevice.create_filesystem( '/dev/my_vg/my_vm')
#...
What happens if create_filesystem fails? You'll may be left with a inconsistent filesystem on the LV. Worse, once you fix the problem and try to run this again, createLV will fail, because the LV is already there, so you'll have to either create the VM manually or fix your script.
A context manager makes no sense in this case: you don't want to delete the LV if all operations succeed. You have to keep track of the operations you performed, and rollback if something fails. You could do that by hand, of course, but that's no fun:
with Atomic() as atomic:
atomic.lvm.createLV("my_vg", "my_vm", "10gb")
blockdevice.create_filesystem( '/dev/my_vg/my_vm')
Now, the LV will be deleted only if any operation inside the context manager fails. If you have multiple atomic calls, it will keep track of them, and rollback them in the reverse order they were executed on.
While Atomic pre-packages some knowledge, AtomicOperationSequence is operation agnostic - it works by defining rollback functions:
def f1():
print "f1 executed"
def reverse(f, args, kwargs):
if f==f1:
print "f1 reversed"
with AtomicOperationSequence(reverse) as atomic:
atomic.f1()
FAQ
pybofh? What kind of name is that?
It's a tribute to the Bastard Operator From Hell stories
