Using Imagefactory to build Vagrant images

Fedora Koji buildsystem and CentOS Community build system i.e. cbs  uses  imagefactory at the back-end of Koji to build Vagrant images.  I have used it as through cbs/koji but wanted to give it a try as I am looking for  easier methods to build adb-atomic-developer-bundle . Specially for developers who don’t have access to Fedora or CentOS build system.

Imagefactory needs a kvm/libvirt hypervisor to build images and it converts them for other providers e.g. Virtualbox or VMware Fusion

Setup:

I have used my laptop (which runs Fedora 23) for this. As I have plan to hack imagefactory and I did not want to damage my laptop’s kvm setup.  So I have used nested virtualization for this. Which means I have a CentOS 7 VM which can run virtual machines.

All below steps are done on a CentOS 7 VM which has a kvm setup in place.

Installation:

Imagefactory is available in Fedora and EPEL repo. But I wanted to try/test the latest code, so I generated RPMs from latest code and then installed the RPMs.

$yum install  rpmdevtools epel-release
$git clone https://github.com/redhat-imaging/imagefactory.git
$cd imagefactory
$make rpm
$cd imagefactory_plugins
$make rpm
$cd ~/rpmbuild/RPMS/noarch/
$sudo yum localinstall ./*

Building Vagrant Images:

For building Vagrant box I have used Ian’s example git repo. He is the maintainer and one of the primary developer for imagefactory.

Below commands are copied from imagefactory-examples git repo.

$ git clone https://github.com/imcleod/imagefactory-examples.git
$ cd imagefactory-examples/vagrant/

Once you are in the “imagefactory-examples/vagrant/” directory, you can see the required files are already there for running commands to generate image for Fedora 22. So we can start running required commands.

For getting a working Vagrant box we need to run three commands (as mentioned below) to create appropriate OVA image. Each command will give a UUID for the intermediate image file name and we need to use the UUID in the next command.

$ sudo imagefactory --debug base_image \
  --file-parameter install_script ./f22-vagrant.ks \
  --parameter offline_icicle true \
  ./f22-minimal-40g.tdl
Output:
xxxxxxxxxxxxxxxxxxxxxxxxxxx
============ Final Image Details ============
UUID: 109cb45f-bbd2-4a27-ba5f-42e2d368be32
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Image build completed SUCCESSFULLY!
$ sudo imagefactory --debug target_image --id 109cb45f-bbd2-4a27-ba5f-42e2d368be32  rhevm

Output:
============ Final Image Details ============
UUID: ce0dce5f-a1d1-4c1a-8e9b-fc56e022a1bc
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Image build completed SUCCESSFULLY!
$ sudo imagefactory --debug target_image --parameter rhevm_ova_format vagrant-libvirt --id ce0dce5f-a1d1-4c1a-8e9b-fc56e022a1bc ova

Output:
============ Final Image Details ============
UUID: 36fcb589-06b8-447b-85bf-ed4715bd2a93
Type: target_image
Image filename: /var/lib/imagefactory/storage/36fcb589-06b8-447b-85bf-ed4715bd2a93.body
Image build completed SUCCESSFULLY!

The last step will generate the F22 image for libvirt provider. You can rename it as f22.libvirt.box (usually Vagrant images have .box extension) and start using it.

$ cp /var/lib/imagefactory/storage/36fcb589-06b8-447b-85bf-ed4715bd2a93.body ./f22.libvirt.box

[1] http://imgfac.org/
[2] https://github.com/redhat-imaging/imagefactory
[3] https://lalatendumohanty.wordpress.com/2015/11/01/kvm-nested-virtualization-in-fedora-23/
[4] https://lalatendumohanty.wordpress.com/2015/05/28/installing-vagrant-in-centos7/

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KVM Nested Virtualization In Fedora 23

Nested virtualization allows you to run a virtual machine (VM) inside another VM [1]. Both Intel and AMD supports nested virtualization.

This is very helpful when you are experimenting with the hypervisor related technologies. Example: I will be able to run KVM and Virtualbox both on my laptop but in different VMs. Also I will be able to run local installation of imagefactory to build Vagrant images in a VM  as imagefactory need a hypervisor to run the build . The best part is, I can experiment with all of these inside different VMs without damaging my primary workstation’s hypervisor.

The below steps are done on a Fedora 23 running a Lenovo Thinkpad with Intel chipset.

Step 1: Make sure Intel virtualization (VT) is enabled for the host machine.

$ cat /proc/cpuinfo | grep vmx

flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm epb tpr_shadow vnmi flexpriority ept vpid fsgsbase smep erms xsaveopt dtherm ida arat pln pts
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm epb tpr_shadow vnmi flexpriority ept vpid fsgsbase smep erms xsaveopt dtherm ida arat pln pts
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm epb tpr_shadow vnmi flexpriority ept vpid fsgsbase smep erms xsaveopt dtherm ida arat pln pts
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm epb tpr_shadow vnmi flexpriority ept vpid fsgsbase smep erms xsaveopt dtherm ida arat pln pts

The output should contain vmx else Intel virtualization (VT) is not enabled on the machine. You should first fix the setting in the BIOS.

Step 2: Install KVM on the F23 host.

$ dnf install @virtualization

Nested virtualization should be disabled bydefault

$ cat /sys/module/kvm_intel/parameters/nested
 N

Step 3: Enable nested virtualization.  Run below commands as root

  • Temporarily remove the kvm kernel module
      $ sudo rmmod kvm-intel
  • Add the following directive to /etc/modprobe.d/dist.conf
    $ sudo sh -c "echo 'options kvm-intel nested=y' >> /etc/modprobe.d/dist.conf"
  • Insert the kvm module back in the kernel
     $ sudo modprobe kvm-intel

There is alternative way to do the same i.e. pass  kvm-intel.nested=1 on kernel commandline [3]

Step 4: Reboot and verify that nested virtualization is enabled

  • Check that nested virt is enabled
$ sudo cat /sys/module/kvm_intel/parameters/nested
 Y

Step 5: Install the beefy VM. (Lets call it parent VM)

  • I used CentOS 7 minimal ISO i.e. CentOS-7-x86_64-Minimal-1503-01.iso to install the VM through Virtual Machine Manger.
  • Parent VM configuration : 50GB disk, 4GB RAM and 4 vCPUs

Step 6: Enable the VM to use nested virt

  • Go to -> Virtual Machine Manger GUI -> CPU properties -> select “Copy host CPU configuration”

There is also another option i.e. host-passthrough [1] . It is supposed to be more stable then “Copy host CPU configuration” but I have not tried that yet.

Step 7:  Check that Intel virtualization (VT) is enabled in the VM

$ cat /proc/cpuinfo | grep vmx

Step 8: Install KVM inside the VM  [4]

$ yum install qemu-kvm qemu-img
$ yum install libvirt libvirt-python python-virtinst

$ systemctl enable libvirtd
$ systemctl start libvirtd
$ systemctl status libvirtd

Step 9:  Install the child VM inside the parent VM

  • I used Virtual Machine Manger to connect to the parent VM and then install the child VM.
  • Used the same CentOS 7 minimal ISO i.e. CentOS-7-x86_64-Minimal-1503-01.iso to install  the child VM.

[1] https://fedoraproject.org/wiki/How_to_enable_nested_virtualization_in_KVM

[2] http://docs.openstack.org/developer/devstack/guides/devstack-with-nested-kvm.html

[3] http://kashyapc.com/2012/01/14/nested-virtualization-with-kvm-intel/

[4] https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Virtualization_Host_Configuration_and_Guest_Installation_Guide/chap-Virtualization_Host_Configuration_and_Guest_Installation_Guide-Guest_Installation.html