How to add a user to a list of groups using an Ansible playbook using the user module:
- name: Add Users to libvirt action: user name=myuser groups="adm,sudo,kvm,libvirtd" append=yes
If you have set append to yes – the groups will be added to the list of existing groups. If append = no then just the list in groups with a set for the user.
I’ve been developing Ansible playbooks to help manage our Ubuntu servers. I wanted to install a list of package on a server using Ansible:
The old syntax:
- name: Install list of packages
action: apt pkg={{item}} state=installed
with_items:
- package1
- package2
- package3
- etc
The new syntax:
- name: Install list of packages
apt: name={{item}} state=installed
with_items:
- package1
- package2
- package3
- etc
Qpress is a fast compression tool. It isn’t in the Ubuntu repositories but it very easy to install. Download it from the website: http://www.quicklz.com/
You will notice that there is a download link near the bottom of the page for Linux 64 bit. Copy the binary to /usr/bin/qpress .
chmod 755 qpress
chown root:root qpress
To make it owned by root but it readable and executable by everyone.
If you try apt-get install apt-add-repository on Ubuntu 13.04 it will say:
E: Unable to locate package apt-add-repository
You need to install python-software-properties-common.
sudo apt-get install python-software-properties-common
I’ve just been setting up Ansible and needed to find a download of the Percona RPM GPG APT-KEY so that I could use the apt_key module. You can download the Percona apt-key here: http://www.percona.com/redir/downloads/RPM-GPG-KEY-percona
With Ansible you can add this key to a server via the play:
tasks:
- name: Add Percona apt-key
action: apt_key url=http://www.percona.com/redir/downloads/RPM-GPG-KEY-percona state=present
I’m just starting to use Ansible to automate the configuration of some of our servers. Therefore, I need to stop sudo asking for a password. You need to edit /etc/sudoers . However, you can’t do this with your usual text editor. You need to use visudo
sudo visudo
To add a your user add the following line:
username ALL=(ALL) NOPASSWD: ALL
I just upgrade Ubuntu on one of my virtual machines and for some reason the file system was corrupted after I rebooted the server. I got errors like:
ext4-fs error ext4_lookup deleted inode referenced
Great. Here is how I fixed the problem.
I found the solution was to attach the qcow2 file as a device on the host and then use fsck. Obviously, you will need to shutdown the virtual machine before doing this.
On the host, enable the nbd (network block device) kernel module. This should be available on all Ubuntu servers after Intrepid.
sudo modprobe nbd max_part=8
You can this use qemu-nbd to connect your qcow2 file as a network block device.
sudo qemu-nbd --connect=/dev/nbd0 /mnt/kvm/wordpress-sites.qcow2
You can then find the partitions using
sudo fdisk /dev/nbd0
On the virtual machine, partition 1 was corrupted, so here is the command I ran:
sudo fsck /dev/nbd0p1
Then disconnect the disk:
sudo qemu-nbd --disconnect /dev/nbd0
Everything seemed to be fine and so I started the domain up again.
I just exported / copied a virtual machine from one of our servers (a HP Proliant) to my laptop so that I could to mess around with it offline. I used the following commands to export the domain.
On the server:
virsh dumpxml wordpress > /tmp/wordpress.xml
On the laptop:
virsh define wordpress.xml
virsh wordpress start
However, I got this error on the laptop:
error: unsupported configuration: guest and host CPU are not compatible: Host CPU does not provide required features: rdtscp, popcnt, sse4.2, dca
The HP server has xeon processors and my laptop has a little core two duo. Obviously the CPU’s had different capabilities. You can see the cpu definitions in the wordpress.xml file were:
less wordpress.xml
<cpu match='exact'> <model>Nehalem</model> <vendor>Intel</vendor> <feature policy='require' name='tm2'/> <feature policy='require' name='est'/> <feature policy='require' name='monitor'/> <feature policy='require' name='ds'/> <feature policy='require' name='ss'/> <feature policy='require' name='vme'/> <feature policy='require' name='rdtscp'/> <feature policy='require' name='ht'/> <feature policy='require' name='dca'/> <feature policy='require' name='pbe'/> <feature policy='require' name='tm'/> <feature policy='require' name='vmx'/> <feature policy='require' name='ds_cpl'/> <feature policy='require' name='xtpr'/> <feature policy='require' name='acpi'/> </cpu>
You can also view the same information using virsh capabilities command. It is worth piping it through less because the command produces alot of output and the host cpu information is at the top.
For the laptop:
virsh capabilities | less
<cpu> <arch>x86_64</arch> <model>Penryn</model> <vendor>Intel</vendor> <topology sockets='1' cores='2' threads='1'/> <feature name='pdcm'/> <feature name='xtpr'/> <feature name='tm2'/> <feature name='est'/> <feature name='smx'/> <feature name='vmx'/> <feature name='ds_cpl'/> <feature name='monitor'/> <feature name='dtes64'/> <feature name='pbe'/> <feature name='tm'/> <feature name='ht'/> <feature name='ss'/> <feature name='acpi'/> <feature name='ds'/> <feature name='vme'/> </cpu>
So, to fix the issue, I just edited the domains xml definition and put in the correct features.
virsh edit wordpress
Note – if you are using ubuntu on your desktop and have virt-manager installed (which is an awesome gui application which runs on Linux and Macs). You can run virt-manager, open the virtual machine, go to the information tab, select the processor and then “copy host cpu configuration”. I’ve attached a screenshot of how to do this.
I hope this helps someone.
I was trying to setup a KVM host with some KVM virtual machines on Ubuntu 13.04 Server. It was a fresh install on a HP DL360. However, there seemed to be a fundamental problem with KVM / virsh / virt-install.
When trying to install a virtual machine using virt-install with this command.
virt-install --accelerate -v -w bridge:br0 -m DE:AD:BE:EF:04:7B -n test1 --vcpus=2 -r 4096 --os-variant=ubuntuprecise --vnc --import --disk path=/home/me/vm.qcow2
I get this error:
ERROR internal error process exited while connecting to monitor: W: kvm binary is deprecated, please use qemu-system-x86_64 instead
It seems like a serious problem but it isn’t. I just should have put sudo in the front.
<strong>sudo</strong> virt-install --accelerate -v -w bridge:br0 -m DE:AD:BE:EF:04:7B -n test1 --vcpus=2 -r 4096 --os-variant=ubuntuprecise --vnc --import --disk path=/home/me/vm.qcow2
I hope this helps you because I wasted quite some time reading Ubuntu bug reports. Why can’t the system designers detect that the user didn’t have permissions and throw sensible errors?
Just trying to upgrade the server (sudo apt-get upgrade) and it says:
dpkg: error: parsing file ‘/var/lib/dpkg/available’ near line 0
Turns out that /var/lib/dpkg/available is broken. To fix just run:
sudo dpkg –clear-avail
Then get the latest updates:
sudo apt-get update