Unify shallow clone options across rootfs scripts to reduce traffic and storage requirements

[pawiecz]

Are clone options intended to reduce traffic or do they serve some additional purpose?

Yes, to help reduce network traffic and speed up clones in CI systems, where complete history is not required.

Originally posted by @vigneshraman in #2826 (comment)

Rootfs builder scripts use various approaches to running shallow clones. This task focuses on providing a set of sane defaults for such an operation.

• Check git clones across rootfs scripts
• Extract optimum set of git options
• Document it as a best practice
• (Optionally) Provide it as a shell function shared across scripts

[pawiecz]

config/rootfs/debos/scripts$ find . -name "*sh" -exec grep -h "git clone" {} + | sed 's/\$[^\s]*/$VAR/g' | sort -u
git clone $VAR
git clone $VARsingle-branch --no-checkout
git clone -b master $VAR
git clone --depth 1 $VAR
git clone --depth=1 "$VAR
git clone --depth=1 $VAR
git clone --depth=1 -b main $VAR
git clone --depth=1 git://linuxtv.org/v4l-utils.git .
git clone https://github.com/libhugetlbfs/libhugetlbfs
git clone https://github.com/linux-test-project/kirk /opt/kirk
git clone https://github.com/nathanlynch/vdsotest
git clone https://github.com/nuclearcat/nvmetcli
git clone https://github.com/open-iscsi/configshell-fb

There's also a single fetch:

config/rootfs/debos/scripts$ find . -name "*sh" -exec grep "git fetch" {} + 
./install-firmware.sh:git fetch --depth 1 origin $version

[khanheric2003]

Hi, could I try on this issue @pawiecz

[pawiecz]

Hi @khanheric2003 👋 Sure, please do - let me know if you'd need any support

[khanheric2003]

Hi @pawiecz , regards to this PR, and for this optional task, "Provide it as a shell function shared across scripts", should I change all of the git clone command to my function instead (would be too much of changes in 1 issue alone),.
And also this is my first time contributing to open-source, so feel free to have any comments to me. I'm open to learn from my mistake.