ValueError: need more than 0 values to unpack

[hillbicks]

Hey,

first of all, thanks for the script. Unfortunately though, it is not working for me. When starting the virtual machine it fails with error code 256. Starting the script from the shell results in the following error:

root@debiantest:/etc/libvirt/hooks# ./qemu
Traceback (most recent call last):
File "./qemu", line 96, in
vir_domain, action = sys.argv[1:3]
ValueError: need more than 0 values to unpack

This is on a debian wheezy machine with python 2.7.3.

oh, and test_qemu.py also fails:

root@debiantest:~/libvirt-hook-qemu-master# python test_qemu.py
Traceback (most recent call last):
File "test_qemu.py", line 5, in
import qemu # Our local libvirt hooks module
ImportError: No module named qemu

Could you give me a hint what is going on here?

Thanks!

[gtirloni]

You need the libvirt-python package.

[hillbicks]

I guess you mean python-libvirt, right? I had that installed already

dpkg -s python-libvirt
Package: python-libvirt
Status: install ok installed
Priority: optional
Section: python
Installed-Size: 2177
Maintainer: Debian Libvirt Maintainers [email protected]
Architecture: amd64
Source: libvirt
Version: 0.9.12.3-1+deb7u1
Provides: python2.6-libvirt, python2.7-libvirt

[gtirloni]

First error is because you didn't pass all the argument on the command-line (as libvirtd would) and the hook's code failed to validate that before unpacking.

Second error is because it's trying to import the hook's code as a python module. ln -s qemu qemu.py and try again please.

[hillbicks]

Yeah, well, that makes sense now that you say it ;)

linking qemu.py to qemu and starting test_qemu.py again finishes without any error, or any other message for that matter.

I tried to lookup the arguments that qemu passes on and I thought this is what the arguments should look like, but that also fails.

./qemu debian7 prepare begin -

Unfortunately the libvirt.log only states:
Hook script /etc/libvirt/hooks/qemu qemu failed with error code 256

My understanding was the exit code of the hook script != 0 wil result in error code 256 with the output of stderr, but there is no additional information that indicates what is wrong. Btw. this is how the qemu.json file looks:

{
"debian7": {
"interface": "virbr0",
"private_ip": "192.168.122.216",
"port_map": {
"tcp": [[2222, 22]]
}
}

hhttps://www.libvirt.org/hooks.html#structure

[gtirloni]

You might be missing an extra "}" at the end. I usually like to run my json files through jq: cat file.son | jq '.'

[hillbicks]

sigh

Sorry that I wasted your time with this nonsense, of course I was missing an extra } at the end. Thanks for your help.

Although the machine starts up and I can see the iptable rules, the port forwarding still isn't working, which is the same issue I had with the other solutions that you can find on the internet. Damn it...

[gtirloni]

No worries! I got it to work here pretty much painlessly (for a change). My setup was using a single bridge, where I got the public IPs (actually, my lab's private IPs) and from there it would forward to the VM. It might be worth running tcpdump on the bridge interface and inside the guests to see what's arriving (and if the packets are mangled or not).

[extr3mal]

[root@CentOS-71-64-minimal hooks]# virsh start Guest --console
error: Failed to start domain Guest
error: Hook script execution failed: internal error: Child process (LC_ALL=C PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin /etc/libvirt/hooks/qemu StageMain prepare begin -) unexpected exit status 1: Traceback (most recent call last):
File "/etc/libvirt/hooks/qemu", line 97, in
domain = config().get(vir_domain)
File "/etc/libvirt/hooks/qemu", line 51, in config
config._conf = json.load(f)
File "/usr/lib64/python2.7/json/init.py", line 290, in load
**kw)
File "/usr/lib64/python2.7/json/init.py", line 338, in loads
return _default_decoder.decode(s)
File "/usr/lib64/python2.7/json/decoder.py", line 365, in decode
obj, end = self.raw_decode(s, idx=_w(s, 0).end())
File "/usr/lib64/python2.7/json/decoder.py", line 381, in raw_decode
obj, end = self.scan_once(s, idx)
ValueError: Expecting property name: line 7 column 8 (char 115)

[bronson]

Just filed a PR that addresses the unit test part of this issue: https://github.com/saschpe/libvirt-hook-qemu/pull/6/files

Yes, running the test script should produce output:

----------------------------------------------------------------------
Ran 3 tests in 0.026s

OK

If not, the tests didn't run.

@extr3mal it looks like you have an error in your JSON file (or did, 6 months ago...)

[bronson]

#6 is in. @hillbicks, is there anything more that needs to be done to address this PR?