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Building an image in a VM

The makefile configuration supports running OSbuild inside a VM. There are two scenarios in which this is beneficial:

  • Standard OSBuild requires root/sudo permissions, because it performs some system-level operations such as loopback mounts. Running OSBuild in a VM allows you to run it non-privileged.
  • When you build an image for a different architecture, you can use QEMU software emulation to make this work. Software emulation is slower than native, but for some use cases it is sufficient.

Running make osbuildvm-images uses OSBuild on the host to build the supporting image files, _build/osbuildvm-*. These files are required to build an image in a VM. The supporting image files can later be used to build other images from the same architecture inside a VM by passing VM=1 to make.

To build images from a different architecture in a VM, there are two options:

  • Copy the output of make osbuildvm-images from a build on a different architecture into _build. For example, the contents of _build/osbuildvm-* from an aarch64 machine into _build/ on an x86_64 machine.

  • Use pre-built osbuildvm images. To build for aarch64 on an x86_64 host, follow the steps outlined below.

Change to the sample-images directory

cd sample-images/

Retrieve the nightly osbuildvm* files and place them into the _build folder

wget -r -l 1 -nH -nd -np -A 'osbuildvm*' -P _build https://autosd.sig.centos.org/AutoSD-9/nightly/osbuildvm-images/

After the _build folder is populated with the relevant osbuildvm-* files, you may then run make with a target that has an architecture different to the host system, for example, make cs9-qemu-minimal-ostree.aarch64.qcow2.

Note

You can download pre-built osbuildvm-images files for the aarch64 architecture from the nightly folder at: https://autosd.sig.centos.org/AutoSD-9/nightly/osbuildvm-images/

Note

If you have a previous version of osbuildvm-images for a different architecture, rebuild or refresh them by using VM=1 on your architecture.

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