Implement clean_chroot to avoid host env variables like TMP to leak into the chroot

[mika]

Some implementation notes:

If we use env -i, then we can no longer export shell functions. So export -f "error_handler" had to be removed.

PATH needs to be set, otherwise clean_chroot "$MNTPOINT" grub-install would fail, because grub-install is in /usr/sbin/grub-install in the chroot.

http_proxy has to be passed otherwise apt-cacher-ng would be broken by this commit. While at it, I completed it and added https_proxy, and ALL_PROXY there too for completeness sake.

Which environment variables are passed into the chroot is currently hardcoded.

FTR, I was also wondering if it was better to use a similar mechanism to the one you're using for CHROOT_VARIABLES, but that would not work because only the chroot-script reads those. But we're not only using that but also other calls from grml-debootstrap to chroot (now clean_chroot), so the environment variables need to be set at the grml-debootstrap level.

Closes: #232

[mika]

This is the result of squashing the commits from #267 and extending the commit message accordingly.

What I'm not entirely sure about yet is the usage of calls like:

clean_chroot "$MNTPOINT" DEBIAN_FRONTEND=$DEBIAN_FRONTEND apt-get [...]

@adrelanos are you sure this behaves as expected? 🤔
Would it make sense to support DEBIAN_FRONTEND via the additional_vars you implemented in clean_chroot()? 🤔

[github-actions]

Remaining comments which cannot be posted as a review comment to avoid GitHub Rate Limit

shellcheck

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📝 [shellcheck] _{reported by reviewdog 🐶}
Double quote to prevent globbing and word splitting. SC2086

grml-debootstrap/grml-debootstrap

Line 1893 in 07a5fe6

cp $VERBOSE "${CHROOT_VARIABLES}" "${MNTPOINT}"/etc/debootstrap/variables

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📝 [shellcheck] _{reported by reviewdog 🐶}
Double quote to prevent globbing and word splitting. SC2086

grml-debootstrap/grml-debootstrap

Line 1895 in 07a5fe6

cp $VERBOSE -a -L "${CONFFILES}"/extrapackages/ "${MNTPOINT}"/etc/debootstrap/

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📝 [shellcheck] _{reported by reviewdog 🐶}
Double quote to prevent globbing and word splitting. SC2086

grml-debootstrap/grml-debootstrap

Line 1898 in 07a5fe6

[ -f "${MNTPOINT}"/etc/resolv.conf ] || cp $VERBOSE /etc/resolv.conf "${MNTPOINT}"/etc/resolv.conf

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📝 [shellcheck] _{reported by reviewdog 🐶}
Double quote to prevent globbing and word splitting. SC2086

grml-debootstrap/grml-debootstrap

Line 1901 in 07a5fe6

[ -n "$LOCALES" ] && cp $VERBOSE "${CONFFILES}"/locale.gen "${MNTPOINT}"/etc/locale.gen

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📝 [shellcheck] _{reported by reviewdog 🐶}
Double quote to prevent globbing and word splitting. SC2086

grml-debootstrap/grml-debootstrap

Line 1904 in 07a5fe6

[ -d "${CONFFILES}"/bin ] && cp $VERBOSE -a -L "${CONFFILES}"/bin/* "${MNTPOINT}"/bin/

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📝 [shellcheck] _{reported by reviewdog 🐶}
Double quote to prevent globbing and word splitting. SC2086

grml-debootstrap/grml-debootstrap

Line 1905 in 07a5fe6

[ -d "${CONFFILES}"/boot ] && cp $VERBOSE -a -L "${CONFFILES}"/boot/* "${MNTPOINT}"/boot/

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📝 [shellcheck] _{reported by reviewdog 🐶}
Double quote to prevent globbing and word splitting. SC2086

grml-debootstrap/grml-debootstrap

Line 1906 in 07a5fe6

[ -d "${CONFFILES}"/etc ] && cp $VERBOSE -a -L "${CONFFILES}"/etc/* "${MNTPOINT}"/etc/

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📝 [shellcheck] _{reported by reviewdog 🐶}
Double quote to prevent globbing and word splitting. SC2086

grml-debootstrap/grml-debootstrap

Line 1907 in 07a5fe6

[ -d "${CONFFILES}"/sbin ] && cp $VERBOSE -a -L "${CONFFILES}"/sbin/* "${MNTPOINT}"/sbin/

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📝 [shellcheck] _{reported by reviewdog 🐶}
Double quote to prevent globbing and word splitting. SC2086

grml-debootstrap/grml-debootstrap

Line 1908 in 07a5fe6

[ -d "${CONFFILES}"/share ] && cp $VERBOSE -a -L "${CONFFILES}"/share/* "${MNTPOINT}"/share/

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📝 [shellcheck] _{reported by reviewdog 🐶}
Double quote to prevent globbing and word splitting. SC2086

grml-debootstrap/grml-debootstrap

Line 1909 in 07a5fe6

[ -d "${CONFFILES}"/usr ] && cp $VERBOSE -a -L "${CONFFILES}"/usr/* "${MNTPOINT}"/usr/

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📝 [shellcheck] _{reported by reviewdog 🐶}
Double quote to prevent globbing and word splitting. SC2086

grml-debootstrap/grml-debootstrap

Line 1910 in 07a5fe6

[ -d "${CONFFILES}"/var ] && cp $VERBOSE -a -L "${CONFFILES}"/var/* "${MNTPOINT}"/var/

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📝 [shellcheck] _{reported by reviewdog 🐶}
Double quote to prevent globbing and word splitting. SC2086

grml-debootstrap/grml-debootstrap

Line 1965 in 07a5fe6

cp $VERBOSE /etc/network/interfaces "${MNTPOINT}/etc/network/interfaces"

[github-actions]

📝 [shellcheck] _{reported by reviewdog 🐶}
Note that A && B || C is not if-then-else. C may run when A is true. SC2015

[github-actions]

📝 [shellcheck] _{reported by reviewdog 🐶}
Note that A && B || C is not if-then-else. C may run when A is true. SC2015

[github-actions]

📝 [shellcheck] _{reported by reviewdog 🐶}
Possible misspelling: PACKAGES may not be assigned. Did you mean KPACKAGE? SC2153

grml-debootstrap/chroot-script

Line 272 in 07a5fe6

if [ "$PACKAGES" = 'yes' ] ; then

[github-actions]

📝 [shellcheck] _{reported by reviewdog 🐶}
Double quote to prevent globbing and word splitting. SC2086

grml-debootstrap/grml-debootstrap

Line 817 in 07a5fe6

RELEASE="$(dialog --stdout --title "${PN}" --default-item $DEFAULT_RELEASE --menu \

[github-actions]

📝 [shellcheck] _{reported by reviewdog 🐶}
Double quote to prevent globbing and word splitting. SC2086

grml-debootstrap/grml-debootstrap

Line 869 in 07a5fe6

CHOOSE_MIRROR=$(dialog --stdout --title "$PN" --default-item $DEFAULT_MIRROR \

[github-actions]

📝 [shellcheck] _{reported by reviewdog 🐶}
Double quote to prevent globbing and word splitting. SC2086

grml-debootstrap/grml-debootstrap

Line 879 in 07a5fe6

0 0 $MIRROR)" || bailout

[github-actions]

📝 [shellcheck] _{reported by reviewdog 🐶}
Double quote to prevent globbing and word splitting. SC2086

grml-debootstrap/grml-debootstrap

Line 885 in 07a5fe6

0 0 $ISO)" || bailout

[github-actions]

📝 [shellcheck] _{reported by reviewdog 🐶}
Double quote to prevent globbing and word splitting. SC2086

grml-debootstrap/grml-debootstrap

Line 1852 in 07a5fe6

cp $VERBOSE "${CONFFILES}"/chroot-script "${MNTPOINT}"/bin/chroot-script

[github-actions]

📝 [shellcheck] _{reported by reviewdog 🐶}
Double quote to prevent globbing and word splitting. SC2086

grml-debootstrap/grml-debootstrap

Line 1857 in 07a5fe6

cp $VERBOSE "${CONFFILES}/config" "${MNTPOINT}"/etc/debootstrap/

[github-actions]

📝 [shellcheck] _{reported by reviewdog 🐶}
Double quote to prevent globbing and word splitting. SC2086

grml-debootstrap/grml-debootstrap

Line 1876 in 07a5fe6

cp $VERBOSE "${_opt_packages:-$CONFFILES/$PACKAGES_FILE}" \

[github-actions]

📝 [shellcheck] _{reported by reviewdog 🐶}
Double quote to prevent globbing and word splitting. SC2086

grml-debootstrap/grml-debootstrap

Line 1883 in 07a5fe6

cp $VERBOSE "${_opt_debconf}" "${MNTPOINT}"/etc/debootstrap/debconf-selections

[github-actions]

📝 [shellcheck] _{reported by reviewdog 🐶}
Double quote to prevent globbing and word splitting. SC2086

grml-debootstrap/grml-debootstrap

Line 1889 in 07a5fe6

cp -a $VERBOSE "${_opt_chroot_scripts}"/* "${MNTPOINT}"/etc/debootstrap/chroot-scripts/

[github-actions]

Remaining comments which cannot be posted as a review comment to avoid GitHub Rate Limit

shellcheck (suggestion)

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[shellcheck (suggestion)] _{reported by reviewdog 🐶}

grml-debootstrap/grml-debootstrap

Line 1895 in 07a5fe6

cp $VERBOSE -a -L "${CONFFILES}"/extrapackages/ "${MNTPOINT}"/etc/debootstrap/

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[shellcheck (suggestion)] _{reported by reviewdog 🐶}

grml-debootstrap/grml-debootstrap

Line 1898 in 07a5fe6

[ -f "${MNTPOINT}"/etc/resolv.conf ] || cp $VERBOSE /etc/resolv.conf "${MNTPOINT}"/etc/resolv.conf

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[shellcheck (suggestion)] _{reported by reviewdog 🐶}

grml-debootstrap/grml-debootstrap

Line 1901 in 07a5fe6

[ -n "$LOCALES" ] && cp $VERBOSE "${CONFFILES}"/locale.gen "${MNTPOINT}"/etc/locale.gen

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[shellcheck (suggestion)] _{reported by reviewdog 🐶}

grml-debootstrap/grml-debootstrap

Lines 1904 to 1910 in 07a5fe6

	[ -d "${CONFFILES}"/bin ] && cp $VERBOSE -a -L "${CONFFILES}"/bin/* "${MNTPOINT}"/bin/
	[ -d "${CONFFILES}"/boot ] && cp $VERBOSE -a -L "${CONFFILES}"/boot/* "${MNTPOINT}"/boot/
	[ -d "${CONFFILES}"/etc ] && cp $VERBOSE -a -L "${CONFFILES}"/etc/* "${MNTPOINT}"/etc/
	[ -d "${CONFFILES}"/sbin ] && cp $VERBOSE -a -L "${CONFFILES}"/sbin/* "${MNTPOINT}"/sbin/
	[ -d "${CONFFILES}"/share ] && cp $VERBOSE -a -L "${CONFFILES}"/share/* "${MNTPOINT}"/share/
	[ -d "${CONFFILES}"/usr ] && cp $VERBOSE -a -L "${CONFFILES}"/usr/* "${MNTPOINT}"/usr/
	[ -d "${CONFFILES}"/var ] && cp $VERBOSE -a -L "${CONFFILES}"/var/* "${MNTPOINT}"/var/

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[shellcheck (suggestion)] _{reported by reviewdog 🐶}

grml-debootstrap/grml-debootstrap

Line 1965 in 07a5fe6

cp $VERBOSE /etc/network/interfaces "${MNTPOINT}/etc/network/interfaces"

[github-actions]

[shellcheck (suggestion)] _{reported by reviewdog 🐶}

grml-debootstrap/grml-debootstrap

Line 817 in 07a5fe6

RELEASE="$(dialog --stdout --title "${PN}" --default-item $DEFAULT_RELEASE --menu \

[github-actions]

[shellcheck (suggestion)] _{reported by reviewdog 🐶}

grml-debootstrap/grml-debootstrap

Line 869 in 07a5fe6

CHOOSE_MIRROR=$(dialog --stdout --title "$PN" --default-item $DEFAULT_MIRROR \

[github-actions]

[shellcheck (suggestion)] _{reported by reviewdog 🐶}

grml-debootstrap/grml-debootstrap

Line 879 in 07a5fe6

0 0 $MIRROR)" || bailout

[github-actions]

[shellcheck (suggestion)] _{reported by reviewdog 🐶}

grml-debootstrap/grml-debootstrap

Line 885 in 07a5fe6

0 0 $ISO)" || bailout

[github-actions]

[shellcheck (suggestion)] _{reported by reviewdog 🐶}

grml-debootstrap/grml-debootstrap

Line 1852 in 07a5fe6

cp $VERBOSE "${CONFFILES}"/chroot-script "${MNTPOINT}"/bin/chroot-script

[github-actions]

[shellcheck (suggestion)] _{reported by reviewdog 🐶}

grml-debootstrap/grml-debootstrap

Line 1857 in 07a5fe6

cp $VERBOSE "${CONFFILES}/config" "${MNTPOINT}"/etc/debootstrap/

[github-actions]

[shellcheck (suggestion)] _{reported by reviewdog 🐶}

grml-debootstrap/grml-debootstrap

Line 1876 in 07a5fe6

cp $VERBOSE "${_opt_packages:-$CONFFILES/$PACKAGES_FILE}" \

[github-actions]

[shellcheck (suggestion)] _{reported by reviewdog 🐶}

grml-debootstrap/grml-debootstrap

Line 1883 in 07a5fe6

cp $VERBOSE "${_opt_debconf}" "${MNTPOINT}"/etc/debootstrap/debconf-selections

[github-actions]

[shellcheck (suggestion)] _{reported by reviewdog 🐶}

grml-debootstrap/grml-debootstrap

Line 1889 in 07a5fe6

cp -a $VERBOSE "${_opt_chroot_scripts}"/* "${MNTPOINT}"/etc/debootstrap/chroot-scripts/

[github-actions]

[shellcheck (suggestion)] _{reported by reviewdog 🐶}

grml-debootstrap/grml-debootstrap

Line 1893 in 07a5fe6

cp $VERBOSE "${CHROOT_VARIABLES}" "${MNTPOINT}"/etc/debootstrap/variables

[adrelanos]

This is the result of squashing the commits from #267 and extending the commit message accordingly.

Thank you!

What I'm not entirely sure about yet is the usage of calls like:

clean_chroot "$MNTPOINT" DEBIAN_FRONTEND=$DEBIAN_FRONTEND apt-get [...]

@adrelanos are you sure this behaves as expected? 🤔

I've built several releases using that line. It is functional because we are using /usr/bin/env -i and are therefore allowed to extend that.

chroot bookworm /usr/bin/env -i testvar=test env | grep testvar

testvar=test

Would it make sense to support DEBIAN_FRONTEND via the additional_vars you implemented in clean_chroot()? 🤔

It would make sense but I did not include it to keep this PR smaller. It wasn't strictly required, I thought. And it made the diff look simpler. I could be done in a follow-up.

[mika]

What I'm not entirely sure about yet is the usage of calls like:

clean_chroot "$MNTPOINT" DEBIAN_FRONTEND=$DEBIAN_FRONTEND apt-get [...]

@adrelanos are you sure this behaves as expected? 🤔

I've built several releases using that line. It is functional because we are using /usr/bin/env -i and are therefore allowed to extend that.

Ahhhh right, now I see the magic in Capture additional environment variables passed as arguments that makes that possible, thanks :)

chroot bookworm /usr/bin/env -i testvar=test env | grep testvar

testvar=test

Would it make sense to support DEBIAN_FRONTEND via the additional_vars you implemented in clean_chroot()? 🤔

It would make sense but I did not include it to keep this PR smaller. It wasn't strictly required, I thought. And it made the diff look simpler. I could be done in a follow-up.

Ok :)