[yocto] Identifying image in os-release

[Randy Witt]

On 02/03/2015 11:42 AM, Moore, Thomas (FtWorth) wrote:
> For my system, we are generating two images: a release image and a debug image. The debug image simply adds the debug image features (tools-debug, eclipse-debug, and dbg-pkgs). This approach looks like it is going to work well for our needs. However, the one issue that I have is that there doesn't appear to be a way to easily tell which image is running. My current plan for version identification is to make use of the /etc/os-release file that is generated during the build, which is suitable for determining the version of the base distribution. However, I can't find a way to influence any of those values from within my image recipes, which I image is by design.
>
> It would seem to me that having a way to assign a version, or some other identifying information, to a final image would be very important. The DISTRO_VERSION is nice, but it doesn't seem like it's enough considering that you can write an image recipe to add any number of additional packages.
>
> Any suggestions on how I can achieve this?

If you are willing to use a file other than os-release, I've often seen this 
done using a function in ROOTFS_POSTPROCESS_COMMAND 
https://www.yoctoproject.org/docs/1.7/ref-manual/ref-manual.html#var-ROOTFS_POSTPROCESS_COMMAND. 
For example:

add_releaseinfo () {
     echo "foo: ${FOOVAR}" > ${IMAGE_ROOTFS}/${sysconfdir}/somefile
     echo "bar: ${BARVAR}" >> ${IMAGE_ROOTFS}/${sysconfdir}/somefile
}

ROOTFS_POSTPROCESS_COMMAND += " add_releaseinfo ; "
> Thanks,
>
> Thomas
>
>