Comment 0 for bug 1761140

I've encountered the bug while installing Nova on compute nodes:

Setting up qemu-system-x86 (1:2.11+dfsg-1ubuntu5~cloud0) ...
Setting up qemu-kvm (1:2.11+dfsg-1ubuntu5~cloud0) ...
Setting up qemu-utils (1:2.11+dfsg-1ubuntu5~cloud0) ...
Setting up python-keystone (2:13.0.0-0ubuntu1~cloud0) ...
Processing triggers for initramfs-tools (0.122ubuntu8.11) ...
update-initramfs: Generating /boot/initrd.img-4.4.0-116-generic
Setting up nova-compute-libvirt (2:17.0.1-0ubuntu1~cloud0) ...
adduser: The user `nova' does not exist.
dpkg: error processing package nova-compute-libvirt (--configure):
 subprocess installed post-installation script returned error exit status 1
dpkg: dependency problems prevent configuration of nova-compute-kvm:
 nova-compute-kvm depends on nova-compute-libvirt (= 2:17.0.1-0ubuntu1~cloud0); however:
  Package nova-compute-libvirt is not configured yet.

dpkg: error processing package nova-compute-kvm (--configure):
 dependency problems - leaving unconfigured
Setting up python-os-brick (2.3.0-0ubuntu1~cloud0) ...
No apport report written because the error message indicates its a followup error from a previous failure.
Setting up python-nova (2:17.0.1-0ubuntu1~cloud0) ...
Setting up nova-common (2:17.0.1-0ubuntu1~cloud0) ...
Setting up nova-compute (2:17.0.1-0ubuntu1~cloud0) ...
Processing triggers for libc-bin (2.23-0ubuntu10) ...
Processing triggers for systemd (229-4ubuntu21.2) ...
Processing triggers for ureadahead (0.100.0-19) ...
Processing triggers for dbus (1.10.6-1ubuntu3.3) ...
Errors were encountered while processing:

Installation failed when executing 'post-installation script'.
After some investigation I've found out that if I've create 'nova' user BEFORE running package installation, it's will be succeded.

Steps to reproduce
1. Prepare the node for installing nova-compute packages
2. Run 'apt-get install nova-compute'

Expected result
Nova-compute installed successfully without errors

Actual result
Installation failed with dpkg error

1. Create system user: add to /etc/passwd
2. Create system group: add to /etc/group
3. Run 'apt-get install nova-compute'

My Environment
Ubuntu 16.04.4 LTS, 4.4.0-116-generic
Openstack Queens Release
Nova 17.0.1-0ubuntu1