obs-docker-support should be ported to POSIX shell

[fcrozat]

Dockerfile support in obs-build relies on bash being present on the build container used (as obs-docker-support is written for bash and not POSIX shell).

This breaks building Dockerfile based on opensuse busybox image (and potentially other images not shipping bash).

[fcrozat]

Might interest @dirkmueller

[dirkmueller]

I'm currently fixing things for using, not for building. for building without bash is a whole new challenge imho.

this script in particular.

possible bashism in obs-docker-support line 39 (bash arrays, ${name[0|*|@]}):
            globalopts[${#globalopts[@]}]="$1"
possible bashism in obs-docker-support line 51 (bash arrays, ${name[0|*|@]}):
        /usr/bin/zypper -D $LOCAL_REPOS_D "${globalopts[@]}" "$cmd" "$@"
possible bashism in obs-docker-support line 57 (${[@|*]#[#]pat} or ${[@|*]%[%]pat}):
        exec /usr/bin/zypper "${globalopts[@]}" "$cmd" -C "${@%/*.repo}"
possible bashism in obs-docker-support line 57 (bash arrays, ${name[0|*|@]}):
        exec /usr/bin/zypper "${globalopts[@]}" "$cmd" -C "${@%/*.repo}"
possible bashism in obs-docker-support line 64 (bash arrays, ${name[0|*|@]}):
        exec /usr/bin/zypper "${globalopts[@]}" "$cmd" "$@"
possible bashism in obs-docker-support line 96 (bash arrays, ${name[0|*|@]}):
            globalopts[${#globalopts[@]}]="$1"
possible bashism in obs-docker-support line 111 (bash arrays, ${name[0|*|@]}):
        /usr/bin/apt-get -o Dir::Etc::SourceList=$LOCAL_APTREPOS_D/obssource -o Dir::Etc::SourceParts=$LOCAL_APTREPOS_D --allow-unauthenticated "${globalopts[@]}" "$cmd" "$@"
possible bashism in obs-docker-support line 117 (bash arrays, ${name[0|*|@]}):
        exec /usr/bin/apt-get "${globalopts[@]}" "$cmd" "$@"
possible bashism in obs-docker-support line 128 (bash arrays, ${name[0|*|@]}):
            globalopts[${#globalopts[@]}]="$1"
possible bashism in obs-docker-support line 140 (bash arrays, ${name[0|*|@]}):
        /usr/bin/dnf --setopt=reposdir=$LOCAL_REPOS_D "${globalopts[@]}" "$cmd" "$@"
possible bashism in obs-docker-support line 146 (bash arrays, ${name[0|*|@]}):
        exec /usr/bin/dnf "${globalopts[@]}" "$cmd" "$@"
possible bashism in obs-docker-support line 157 (bash arrays, ${name[0|*|@]}):
            globalopts[${#globalopts[@]}]="$1"
possible bashism in obs-docker-support line 169 (bash arrays, ${name[0|*|@]}):
        /usr/bin/yum --setopt=reposdir=$LOCAL_REPOS_D "${globalopts[@]}" "$cmd" "$@"
possible bashism in obs-docker-support line 175 (bash arrays, ${name[0|*|@]}):
        exec /usr/bin/yum "${globalopts[@]}" "$cmd" "$@"
possible bashism in obs-docker-support line 191 (bash arrays, ${name[0|*|@]}):
                cmd[${#cmd[@]}]="file:$DATA_DIR/build-webcache/$urlsha256"
possible bashism in obs-docker-support line 193 (bash arrays, ${name[0|*|@]}):
                cmd[${#cmd[@]}]="localhost:80/build-webcache/$urlsha256"
possible bashism in obs-docker-support line 203 (bash arrays, ${name[0|*|@]}):
            cmd[${#cmd[@]}]="$1"
possible bashism in obs-docker-support line 209 (bash arrays, ${name[0|*|@]}):
        cmd[${#cmd[@]}]="-o"
possible bashism in obs-docker-support line 210 (bash arrays, ${name[0|*|@]}):
        cmd[${#cmd[@]}]="$oname"
possible bashism in obs-docker-support line 212 (bash arrays, ${name[0|*|@]}):
    exec /usr/bin/curl "${cmd[@]}"
possible bashism in obs-docker-support line 241 (echo -e):
            (echo -n -e "PUT /$n HTTP/1.1\r\nContent-Length: $(wc -c < /tmp/packages)\r\n\r\n" | cat - /tmp/packages && read -t 600 ans ; case "$ans" in *\ 200\ *) ;; *) echo "$ans" >&2 ;; esac) <>/dev/tcp/localhost/80 1>&0
possible bashism in obs-docker-support line 241 (read with option other than -r):
            (echo -n -e "PUT /$n HTTP/1.1\r\nContent-Length: $(wc -c < /tmp/packages)\r\n\r\n" | cat - /tmp/packages && read -t 600 ans ; case "$ans" in *\ 200\ *) ;; *) echo "$ans" >&2 ;; esac) <>/dev/tcp/localhost/80 1>&0
possible bashism in obs-docker-support line 241 (/dev/(tcp|udp)):
            (echo -n -e "PUT /$n HTTP/1.1\r\nContent-Length: $(wc -c < /tmp/packages)\r\n\r\n" | cat - /tmp/packages && read -t 600 ans ; case "$ans" in *\ 200\ *) ;; *) echo "$ans" >&2 ;; esac) <>/dev/tcp/localhost/80 1>&0

[coolo]

If you wanted this to be portable you would avoid shell to begin with and write it in a compiled programming language. Perhaps you can interest ... Alberto :)

[aplanas]

cc: @aplanas

[mlschroe]

I tried that a couple of weeks ago but not having array support makes things super ugly.

[dirkmueller]

If you wanted this to be portable you would avoid shell to begin with and write it in a compiled programming language. Perhaps you can interest ... Alberto :)

a compiled language makes multiple architecture support and cross compiling not really any easier.

@fcrozat can you give a self contained example that you'd like to see working? maybe we can find a shortcut by fixing only the breaking cases.

[fcrozat]

I was trying to build https://github.com/fcrozat/rclone-container/blob/master/Dockerfile.busybox on OBS (I've switched to another base container for now..)

[coolo]

The problem here is that the obs-docker-support shouldn't even run on your target, but within the builder. Because obs-docker-support fails to add a zypper repo - which you don't even want in your target.

[coolo]

If you remove the bashisms by brute force you see what it's trying to do:

[   15s] [1/3] STEP 1/4: FROM opensuse/busybox AS target
[   15s] [1/3] STEP 2/4: COPY .obs-docker-support /usr/local/sbin/obs-docker-support
[   15s] [1/3] STEP 3/4: RUN obs-docker-support --install
[   16s] [1/3] STEP 4/4: RUN obs-docker-support --uninstall

Pretty useless if you ask me. So possibly not copying obs-docker-support into the target if there are no zypper actions is the easier goal

[coolo]

Or split obs-docker-support --install from the remains. I.e. make it 2 scripts. If you need zypper/apt-get you will need to have bash as well.

[mlschroe]

obs-docker-support does more than intercept zypper.

[mlschroe]

I wonder if just changing the shebang to /bin/sh would be enough.

[coolo]

No, busybox-sh also takes offense on the cmd=() and globalopts=() declarations

[coolo]

https://github.com/openSUSE/obs-build/pull/806 pushes it a little further

[mlschroe]

(Unrelated: currently you need to use zypper --installroot=/tmp/chroot to make the parsing work. I'll add support to make it also work without the =)

[coolo]

And btw: the way you copy the chroot, you will have glibc and busybox in both the base layer and in your rclone layer.

[fcrozat]

And btw: the way you copy the chroot, you will have glibc and busybox in both the base layer and in your rclone layer.

thanks, I'll try to fix that (I was initially using BCI micro image, which doesn't have busybox)

[coolo]

Just for PoC this saves 12MB in the final layer without impacting the actual container image:

RUN mkdir /tmp/newroot
RUN for f in usr/bin/rclone usr/lib/sysimage/rpm/Index.db usr/lib/sysimage/rpm/Packages.db usr/share/licenses/rclone/COPYING; do mkdir -p /tmp/newroot/$(dirname $f); cp -a /tmp/chroot/$f /tmp/newroot/$f; done