Tag Archives: openSUSE

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Install OpenSUSE MicroOS in KVM with Ignition

Install OpenSUSE MicroOS in KVM with Ignition. A step-by-step guide to provision container specific OS instances really fast.

About OpenSUSE MicroOS

I needed a container specific OS since I converted my docker-compose services to pods with Podman. Fedora CoreOS looks promising. However I have been using OpenSUSE for years, so it was convenient for me to try MicroOS which is derived from Tumbleweed.

These are the features which I like the most.

Install OpenSUSE MicroOS in KVM with Ignition

There are documentations about MicroOS, but I could not find a complete guide about how to install OpenSUSE MicroOS in KVM. Also its Ignition guide directly redirects to CoreOS’s git repo for documentation. The information is there but putting it together takes time.
As I already managed to do it then why not to share it? ūüôā

In my guide I will use virsh (libvirt) and virt-install (virt-manager) to provision headless MicroOS VMs based on the downloadable KVM images they made available. Both tools are higher lever APIs to KVM / QEMU.

Installing libvirt to make using QEMU easy

OpenSUSE has a package pattern for turning your OS into a virtualization host. Following the Virtualization Guide will definitely help. But if you do not want to read it all then just run the following command.

zypper in -t pattern kvm_server kvm_tools

Should you want to read more about managing virtual machines with libvirt then there is a documentation for that too. I will not go into details this time.

Downloading and verify installation media of MicroOS

Once the tools are ready then download the installation media and verify the checksum and signature.

# cd /var/lib/libvirt/images
# curl -LO http://download.opensuse.org/tumbleweed/appliances/openSUSE-MicroOS.x86_64-ContainerHost-kvm-and-xen.qcow2
# curl -LO http://download.opensuse.org/tumbleweed/appliances/openSUSE-MicroOS.x86_64-ContainerHost-kvm-and-xen.qcow2.sha256
# curl -LO http://download.opensuse.org/tumbleweed/appliances/openSUSE-MicroOS.x86_64-ContainerHost-kvm-and-xen.qcow2.sha256.asc

Note that sha256 checksum and signature was made for a snapshot whose name is different from the file we downloaded, though the content is the same. Probably the other files on their webserver are just symbolic links.

# sha256sum openSUSE-MicroOS.x86_64-ContainerHost-kvm-and-xen.qcow2
# gpg --search-keys B88B2FD43DBDC284
# gpg --recv-keys 0x22C07BA534178CD02EFE22AAB88B2FD43DBDC284
# gpg --verify openSUSE-MicroOS.x86_64-ContainerHost-kvm-and-xen.qcow2.sha256.asc

Creating Ignition configuration for VM

Ignition expect its configuration to be in JSON. However one just not create a JSON file by hand. But creates a YML file and convert it with semantic checks (and some boilerplate) to JSON by using CoreOS’s fcct. Here is my example. It is pretty straight forward.

variant: fcos
version: 1.0.0
passwd:
  users:
    - name: root
      ssh_authorized_keys:
        - ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDHj2D8PAxz0MKV9UJ8dxavlVzdAvMBrfGp38sj4q/aRbkcuYVNHAQh+xXHI0VcPEtu9rqZbvqfmQt0DFhsdf938W6r3y6mLp4+6KIDgb4Jj2B3zlzBIF0haAFi/GZAp4dh4uuhHsVvZGqsdqCglxUnIPb+i8IyYA8GGU+3IOgRfjjtpMfDJcWZTzGm56yDsBYORX3EckkGcWTN4/oW0SKWoO9zf/887/CvVZF/0V7corEAdMyTCiSSqqUjIDLAZpCMU4czadZop7cvVjGT6WLmyGDuTBruvjsMwxYA/OMAZrUuOEoAW0bf/QZRZ4tO7ku+o0oqwca5uwVbuouAFovJ [email protected]
      password_hash: "$1$salt$qJH7.N4xYta3aEG/dfqo/0"
storage:
  files:
    - path: /etc/sysconfig/network/ifcfg-eth0
      mode: 0600
      overwrite: true
      contents:
        inline: |
          BOOTPROTO='static'
          STARTMODE='auto'
          BROADCAST=''
          ETHTOOL_OPTIONS=''
          IPADDR='192.168.0.10/24'
          MTU=''
          NAME=''
          NETWORK=''
          REMOTE_IPADDR=''
          ZONE=public
    - path: /etc/sysconfig/network/routes
      mode: 0644
      overwrite: true
      contents:
        inline: |
          default 192.168.0.254 - -
    - path: /etc/hostname
      mode: 0644
      overwrite: true
      contents:
        inline: |
          example.com

Please note that on OpenSUSE you cannot just provide static DNS information by overwriting /etc/resolv.conf. Because the content of /etc/resolv.conf is managed by netconfig. And it configuration file bigger than optimal to include it in a YML file. Though you can configure it manually after the first run.

Once you are ready, put the contents into config.fcc and convert it to JSON by using fcct.

# podman run -i --rm quay.io/coreos/fcct:release --pretty --strict < config.fcc > config.ign

Create a KVM host with virt-install

The Ignition file can be specified via QEMU command line. Adjust the specification of the VM according to your needs.

# virt-install --import --connect qemu:///system --name example \
    --ram 1024 --vcpus 1 \
    --disk size=20,backing_store=/var/lib/libvirt/images/openSUSE-MicroOS.x86_64-ContainerHost-kvm-and-xen.qcow2,bus=virtio \
    --os-variant=opensusetumbleweed \
    --network bridge=br0,model=virtio \
    --noautoconsole \
    --graphics spice,listen=127.0.0.1 \
    --qemu-commandline="-fw_cfg name=opt/com.coreos/config,file=/path/to/config.ign"

No you have just installed OpenSUSE MicroOS in KVM with Ignition. Enjoy.

Managing VM with Virsh

Virsh is another tool to manage your VMs. Here I provide some examples I frequently use. They could be useful.

Console access

You can attach to the serial console of the VM with the following command.

# virsh console example

Disconnecting from Virsh console is possible with SHIFT+5.

Remote console access

Remote access to the console is possible with Spice. If you are not in production then you can easily access the remote Spice port without TLS via SSH port forward.

Delete virtual machines

This can be useful when you are not satisfied with the result and want to start over from scratch. Storage files are not automatically deleted.

# virsh dumpxml --domain example | grep 'source file'
      <source file='/var/lib/libvirt/images/example.qcow2'/>
        <source file='/var/lib/libvirt/images/openSUSE-MicroOS.x86_64-ContainerHost-kvm-and-xen.qcow2'/>
# virsh destroy example
# virsh undefine example
# rm -f /var/lib/libvirt/images/example.qcow2

I hope you will enjoy your shiny new container host. ūüôā

Docker failed to restart after upgrade

I already had plans to write about Docker. However a recent system update caused issues and Docker failed to restart. This service outage made me think and write about such a typical maintenance task.

 

Docker logo upside downI know that I created the issue at the first place. However I could fix it and I will show you how I did it and how can I avoid that in the future.

Continue reading

Mounting NFS exports by using autofs

When I created a central file sever, I mentioned that some of the problems with the solution are yet to be resolved.

autofs better than manual

  1. YaST created an import rule in file /etc/fstab, which is the de-facto place for storing such information. Its content and the mounts are usually static in server environments. On most client (in term of using an export of an NFS server) the network connectivity rarely or never changes in traditional environments.
    However in case of mobile devices like on laptops, the network state could vary a lot. It can be offline, or on WiFi, or on wired connection, maybe using VPNs. We need much more flexibility than a mostly static file.
  2. Users would like to mount exports on their own. The system should be as transparent as possible to the end users.

Lucky for us, mounting NFS exports by using autofs service help us and gives the following advantages too. Continue reading

Creating an NFS file server

In 2019 almost everyone has a digital life, so as I. Having digital photos or videos taken with our smartphones is an every day action.
Year by year the number of smart phones and computers rises in households. Files started to be found everywhere. In your computers, in the cloud, everywhere
Why do not we store them in one place and access them from everywhere?

creating and nfs server

I wanted to create a file server providing a central location for all our digital data. Creating an NFS file server looked promising.
Continue reading