Image administration

In SkyHiGh all virtual machines boots from images which is stored in the openstack image service (glance). Manipulation of these images is done trough the use of the glance client or trough the web interface. This page explains the glance client:

Image formats

As SkyHiGh utilizes KVM for the virtualization, a large range of image formats are supportet (vhd, vmdk, vdi, iso, qcow2, aki, ari, ami, raw). The preferred format is however raw images, as this enables the compute-node to create a root-disk for the virtual machine which is a COW (Copy-on-write) snapshot of the original image. This way it is not needed to take a full image before the virtual machine is booted. This speeds up the VM boot process a lot.

Determine image format

To determine what format a certain image is, qemu-img can be used like so:

$ qemu-img info trusty-server-cloudimg-amd64-disk1.img 
image: trusty-server-cloudimg-amd64-disk1.img
file format: qcow2
virtual size: 2.2G (2361393152 bytes)
disk size: 248M
cluster_size: 65536
Format specific information:
    compat: 0.10
    refcount bits: 16

Converting images

To convert images to the raw format, the utility "qemu-img" can be used:

$ qemu-img convert -f <original_image_type> -O <converted_image_type> <original_image> <converted_image>

So, to convert the qcow2 image "debian-8.2.0-openstack-amd64.qcow2" to a raw image, the following command could be used:

$ qemu-img convert -f qcow2 -O raw debian-8.2.0-openstack-amd64.qcow2 debian-8.2.0-openstack-amd64.raw

Uploading new images

To upload a new image to glance, the following command can be useful:

glance image-create --name <image_name> --file <image_location> --disk-format raw --container-format bare --visibility public --progress 
openstack image create --file <image_location> --disk-format raw --container-format bare [--public|--private] <image_name>

For example, the following command would upload an ubuntu image:

glance image-create --name "Ubuntu Server 16.04 (Xenial) amd64" --file xenial-server-cloudimg-amd64-disk1.img.raw --disk-format raw --container-format bare --is-public True --progress
openstack image create --file xenial-server-cloudimg-amd64-disk1.img.raw --disk-format raw --container-format bare --public "Ubuntu Server 16.04 (Xenial) amd64"

The "–visibility public" flag is used to indicate that all projects should have access to this image, and the upload would then require admin credentials. In the case of an image upload which should only be accessible to the project uploading it, that flag can be omitted.

Manipulate image-init images

Required packages for ubuntu, other OS might have different names. The procedure is tested with raw and qcow2 images.

• qemu-utils
• guestfish
• libguestfs-tools
• working sudo for your user

Verify that the cloud-init image is ok.

:~$  qemu-img check <image name>
No errors were found on the image.
14510/36032 = 40.27% allocated, 98.23% fragmented, 98.04% compressed clusters
Image end offset: 289210368

Manipulate the image with guestfish

# Mounting the filesystem
:~$ sudo guestfish

Welcome to guestfish, the guest filesystem shell for
editing virtual machine filesystems and disk images.

Type: 'help' for help on commands
      'man' to read the manual
      'quit' to quit the shell

><fs> add <path to image>
><fs> run
><fs> list-filesystems 
/dev/sda1: ext4
><fs> mount /dev/sda1 /

# Editing a file
><fs> vi /etc/fstab

#Copying in a file from outside the image
><fs> copy-in <file outside the image> <pat to where to put it>

# Commiting and exiting guestfish. Exit does both
><fs> exit

Change existing images

Creating Windows Images

Cloudbase.it provides tools for creating OpenStack-ready cloud images. They've created a Windows Server 2012R2 images, which is ready for use (download and instructions here). This image is already imported into our environment.

If you need an another Windows Version, you must build the image yourself, with good help from the automated cloudbase-scripts. It is recommended to create the image on a Windows 10 host or VM. The following examples is a list of what we did to create a cloud ready Windows 10 image.

1. Install the Windows 10 ADK (download) and choose only Deployment Tools
2. Download the Windows 10 Enterprise Evaluation ISO, and mount it in your host/VM (you need to login with your Microsoft account to download ISOs)
3. Download the stable amd64 virto-win iso, following this link
4. Download the Windows OpenStack Imaging Tools
5. Change the following:

   1. UnattendTemplate.xml: Change InputLocale and UserLocale from en-US to nb-NO

   2. Added ntnu_wallpaper.png to the UnattendResources-folder
   3. UnattendResources\Specialize.ps1:
      1. Change the line with Wallpaper.png to ntnu_wallpaper.png (do not change the destination filename in the copy-command, as the wallpaper is set through an imported local GPO)
   4. UnattendResources\Logon.ps1:
      1. Add the following to commands: netsh advfirewall firewall add rule name="All ICMP V4" protocol=icmpv4:any,any dir=in action=allow and netsh advfirewall firewall add rule name="All ICMP V6" protocol=icmpv6:any,any dir=in action=allow
6. Create the following powershell-script, modify the three path-variables, and run it:
7. CreateOpenStackImage.ps1

   Import-Module .\windows-openstack-imaging-tools-master\WinImageBuilder.psm1
   $virtualDiskPath = "C:\path\to\diskfile.raw"
   $wimFilePath     = "<windowsiso-mountpoint>\sources\install.wim>"
   $virtIOISOPath   = "C:\path\to\virtio-win-x.x.xxx.iso"
   $images = Get-WimFileImagesInfo -WimFilePath $wimFilePath
   $image = $images[0]
   New-WindowsCloudImage -WimFilePath $wimFilePath -ImageName $image.ImageName -VirtualDiskFormat RAW -VirtualDiskPath $virtualDiskPath -SizeBytes 18GB -VirtIOISOPath $virtIOISOPath -InstallUpdates

8. You now have a .raw diskfile, which contains a Windows 10-installation that will automatically run sysprep once booted. Now you have to choices:

   1. Import the .raw file to glance (see Upload new images), and spawn an instance from the new image
   2. Create a new local KVM-vm (on a Linux host), be sure to choose a virtio NIC, attach the .raw-file, boot the VM
9. Wait for the instance to shutdown (it will install updates, run the powershellscripts Logon.ps1, FirstLogon.ps1 and Specialize.ps1 and finally run sysprep
10. If you chose 8a, create a public snapshot of the instance. This snapshot is your new cloud ready Windows 10 image.
11. If you chose 8b, upload the .raw-file to glance (Upload new images)

When you spawn a Windows instance, be sure to attach a keypair. Cloudbase-init will generate a random password for the user Admin, which can be retrieved with:

nova get-password <instance-id> <private-key-file>

NOTE: There is a known issue with Windows 10 - the hostname will not be set to wahtever you chose for instance name. This might be fixed in the future... (Link)