Re: [PATCH v2] classes/image-postproc: Add image version

[Henning Schild <henning.schild@siemens.com>]

On Wed, 22 Apr 2020 10:36:32 +0200
Gylstorff Quirin <quirin.gylstorff@siemens.com> wrote:

> On 4/21/20 9:28 PM, cedric_hombourger@mentor.com wrote:
> > 
> > 
> > On Tuesday, April 21, 2020 at 8:49:43 PM UTC+2, Henning Schild
> > wrote:
> > 
> >     On Tue, 21 Apr 2020 17:01:34 +0200
> >     "[ext] Q. Gylstorff" <Quirin....@siemens.com <javascript:>>
> > wrote: 
> >      > From: Quirin Gylstorff <quirin....@siemens.com <javascript:>>
> >      >
> >      > Add the image version as additional identifier to
> >      > /etc/os-release. This allows in a update scenario an easier
> >      > identification of the the currently used image.
> >      >
> >      > Signed-off-by: Quirin Gylstorff <quirin....@siemens.com  
> >     <javascript:>>  
> >      > ---
> >      >  meta/classes/image-postproc-extension.bbclass | 9 ++++++++-
> >      >  1 file changed, 8 insertions(+), 1 deletion(-)
> >      >
> >      > diff --git a/meta/classes/image-postproc-extension.bbclass
> >      > b/meta/classes/image-postproc-extension.bbclass index
> >      > 7280202..1091fa4 100644 ---
> >      > a/meta/classes/image-postproc-extension.bbclass +++
> >      > b/meta/classes/image-postproc-extension.bbclass @@ -4,10
> >      > +4,12 @@ update_etc_os_release() {
> >      >      OS_RELEASE_BUILD_ID=""
> >      >      OS_RELEASE_VARIANT=""
> >      > +    OS_RELEASE_VARIANT_VERSION=""
> >      >      while true; do
> >      >          case "$1" in
> >      >          --build-id) OS_RELEASE_BUILD_ID=$2; shift ;;
> >      >          --variant) OS_RELEASE_VARIANT=$2; shift ;;
> >      > +        --version) OS_RELEASE_VARIANT_VERSION=$2; shift ;;
> >      >          -*) bbfatal "$0: invalid option specified: $1" ;;
> >      >          *) break ;;
> >      >          esac
> >      > @@ -24,6 +26,11 @@ update_etc_os_release() {
> >      >          echo "VARIANT=\"${OS_RELEASE_VARIANT}\"" | \
> >      >              sudo tee -a '${IMAGE_ROOTFS}/etc/os-release'
> >      >      fi
> >      > +    if [ -n "${OS_RELEASE_VARIANT_VERSION}" ]; then
> >      > +        sudo sed -i '/^ISAR_IMAGE_VERSION=.*/d'
> >      > '${IMAGE_ROOTFS}/etc/os-release'
> >      > +        echo "VARIANT_VERSION=\"${PV}\"" | \
> >      > +            sudo tee -a '${IMAGE_ROOTFS}/etc/os-release'  
> > 
> >     Looking at
> >     https://www.freedesktop.org/software/systemd/man/os-release.html
> >     <https://www.freedesktop.org/software/systemd/man/os-release.html>
> > 
> >     VARIANT_VERSION does not show up in the list of
> >     "The following OS identifications parameters may be set using
> >     os-release"
> > 
> >     So i would conclude we may not use it. I would suggest either
> > finding a variable that we may use and debian does not use yet.
> > 
> > 
> > for everyone's benefits, Henning and I were discussing this
> > offline. from my perspective, the freedesktop folks aren't that
> > rigid. 2 quotes from them:
> > 
> > (1) The file is extensible? Awesome! I want a new field XYZ= in it! 
> > Sure, it's extensible, and we are happy if distributions extend it. 
> > Please prefix your keys with your distribution's name however.
> > 
> > (2) If you are working on a small/embedded distribution, or a 
> > legacy-free distribution we encourage you to adopt only this file
> > and not establish any other per-distro release file.
> > 
> > I am guilty of adding custom fields in the Debian-based distro we
> > are producing over here. I had missed the recommendation to prefix
> > new keys with the name of the distro. That's a good thing to do for
> > sure.
> > 
> > With that said, I am not saying that Isar should or should not add 
> > custom entries there. Just wanted to say that it is not forbidden
> > Ref: http://0pointer.de/blog/projects/os-release (link found from: 
> > http://0pointer.de/blog/projects/os-release)
> > 
> > Cedric  
> 
> I see that as a human readable version identifier for an
> image. Not every one has git at hand ;-). 

The CMD can be anything, use "hg" or "echo 42".

> We can add our own ids with 
> ISAR_ in front of it, if it is better
> that way as written in [1]:
> 
> `Operating system vendors may extend the file format and introduce
> new fields. It is highly recommended to prefix new fields with an OS 
> specific name in order to avoid name clashes. Applications reading
> this file must ignore unknown fields. Example: 
> "DEBIAN_BTS="debbugs://bugs.debian.org/""`
> 
> As the only hard requirement regarding this file is that application
> ignore unknown items.
> 
> [1]: https://www.freedesktop.org/software/systemd/man/os-release.html

True, my interpretation of the "opposite" of "may" might be too harsh
when i suggest that opposite to be "must not".

I just wanted to raise awareness that this is a "standardized" file and
care needs to be taken.

There probably are a lot of scripts out there, that "source" the file
and could get very confused when they loose their own variables or env
that way, because the file is full of unexpected stuff. And yes, they
technically "must ignore" ... still another reason to be careful.

Henning

> Quirin
> 
> > 
> > 
> >     Or the layer with the requirement looks at BUILD_ID and sets a
> > custom ISAR_RELEASE_CMD to inject their clue.
> >     Here is an example where people decided to include the date of
> > a build
> > 
> >     ISAR_RELEASE_CMD = "echo $(git -C ${LAYERDIR_isar-XXX} describe
> > --long --dirty --always) $(date --utc --rfc-3339=seconds)"
> > 
> >     Henning
> >   
> >      > +    fi
> >      >  }
> >      >
> >      >  ROOTFS_POSTPROCESS_COMMAND =+ "image_postprocess_configure"
> >      > @@ -43,7 +50,7 @@ ROOTFS_POSTPROCESS_COMMAND =+
> >      > "image_postprocess_mark" image_postprocess_mark() {
> >      >      BUILD_ID=$(get_build_id)
> >      >      update_etc_os_release \
> >      > -        --build-id "${BUILD_ID}" --variant "${DESCRIPTION}"
> >      > +        --build-id "${BUILD_ID}" --variant "${DESCRIPTION}"
> >      > --version "${PV}" }
> >      >
> >      >  ROOTFS_POSTPROCESS_COMMAND =+
> >      > "image_postprocess_machine_id"  
> > 
> > -- 
> > You received this message because you are subscribed to the Google 
> > Groups "isar-users" group.
> > To unsubscribe from this group and stop receiving emails from it,
> > send an email to isar-users+unsubscribe@googlegroups.com 
> > <mailto:isar-users+unsubscribe@googlegroups.com>.
> > To view this discussion on the web visit 
> > https://groups.google.com/d/msgid/isar-users/f8bdcad7-3efe-485a-85ee-fda69c2d616f%40googlegroups.com 
> > <https://groups.google.com/d/msgid/isar-users/f8bdcad7-3efe-485a-85ee-fda69c2d616f%40googlegroups.com?utm_medium=email&utm_source=footer>.
> >  
>