Re: [Libguestfs] [PATCH v3 0/3] Install QEMU-GA from oVirt guest tools ISO on Linux
On Wed, 07 Nov 2018 13:32:45 +0100
Pino Toscano <ptoscano(a)redhat.com> wrote:
On Wednesday, 7 November 2018 12:53:17 CET Tomáš Golembiovský wrote:
> - support for Debian is missing
> I don't know how to install the package only when all it's dependencies
are
> already installed.
dpkg -i foo.deb
If it were as easy as this. :)
> dpkg cannot be used to check that (simulate the install).
dpkg --dry-run (the man page lists also --no-act, and --simulate)
The --dry-run does not seem to do much. It does not verify dependencies.
See below.
> And attempting to install the package will leave it half-installed (dpkg
> cannot roll-back).
`dpkg -i` performs a complete installation, doing all the steps needed,
and leaving the package properly configured if the process is succesfull.
That is assuming everything is OK and the package can be installed. If
there are missing dependencies it leaves the package unpacked in the
system but in un-configured state. This would have to be fixed after next
boot of the guest.
See this:
root@8e59267e1b89:/# dpkg -l qemu-guest-agent
dpkg-query: no packages found matching qemu-guest-agent
root@8e59267e1b89:/# dpkg --simulate --refuse-downgrade --skip-same-version --install
/var/tmp/qemu-guest-agent_1%3a2.8+dfsg-6+deb9u4_amd64.deb
Selecting previously unselected package qemu-guest-agent.
(Reading database ... 6498 files and directories currently installed.)
Preparing to unpack .../qemu-guest-agent_1%3a2.8+dfsg-6+deb9u4_amd64.deb ...
root@8e59267e1b89:/# echo $?
0
root@8e59267e1b89:/# dpkg --refuse-downgrade --skip-same-version --install
/var/tmp/qemu-guest-agent_1%3a2.8+dfsg-6+deb9u4_amd64.deb
Selecting previously unselected package qemu-guest-agent.
(Reading database ... 6498 files and directories currently installed.)
Preparing to unpack .../qemu-guest-agent_1%3a2.8+dfsg-6+deb9u4_amd64.deb ...
Unpacking qemu-guest-agent (1:2.8+dfsg-6+deb9u4) ...
dpkg: dependency problems prevent configuration of qemu-guest-agent:
qemu-guest-agent depends on libglib2.0-0 (>= 2.37.1); however:
Package libglib2.0-0 is not installed.
dpkg: error processing package qemu-guest-agent (--install):
dependency problems - leaving unconfigured
Errors were encountered while processing:
qemu-guest-agent
root@8e59267e1b89:/# dpkg -l qemu-guest-agent
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name Version Architecture Description
+++-===============-============-============-====================================
iU qemu-guest-agen 1:2.8+dfsg-6 amd64 Guest-side qemu-system agent
root@8e59267e1b89:/#
Sadly, dpkg cannot even roll-back in case of errors.
So far I haven't found any way to check dependencies in advance.
Tomas
--
Pino Toscano
--
Tomáš Golembiovský <tgolembi(a)redhat.com>