Re: [RFC PATCH v3 3/3] t0034: enhance framework to allow testing more commands under sudo
- From
Junio C Hamano <gitster@pobox.com>
- Date
- May 2, 2022, 22:10 UTC
- Message-ID
- <xmqqo80fvb5q.fsf@gitster.g>
- In-Reply-To
- <20220502183920.88982-4-carenas@gmail.com>
Carlo Marcelo Arenas Belón <carenas@gmail.com> writes:
Show 17 quoted lines
> +# Runs a scriplet passed through stdin under sudo.
> +run_with_sudo () {
> + local ret
> + local SH=${1-"$TEST_SHELL_PATH"}
> + local RUN="$HOME/$$.sh"
> + {
> + echo "#!$SH"
> + echo "set -e"
> + echo ". \"$HOME/env\""
> + cat
> + } >"$RUN" &&
> + chmod +x "$RUN" &&
> + sudo "$SH" -c "\"$RUN\""
> + ret=$?
> + rm -f "$RUN"
> + return $ret
> +}I wonder if write_script can be used for better readability. It is especially true as I am going to suggest ripping out $HOME/env stuff that is not absolutely needed (and its support with this patch looks inadequate when we do need one).
local RUN=$HOME/$$.sh && write_script "$RUN" "$TEST_SHELL_PATH" && sudo "$RUN"
or something?
Show 11 quoted lines
> +# Makes all variables passed as parameters available to the scriplet that
> +# run under sudo with run_with_sudo
> +export_to_sudo () {
> + while test -n "$1"
> + do
> + local v
> + eval v="\$$1"
> + echo "$1=$v" >>"$HOME/env"
> + shift
> + done
> +}Two potential issues:
- This forces the caller to list _all_ the relevant environment variables that would ever matter, which would not be feasible and would not be maintainable. For example, by forgetting to export GIT_TEST_DISALLOW_ABBREVIATED_OPTIONS, "git" commands run in the sudo tests change their behaviour. Whoever writing a new test need to see what obscure GIT_TEST_* thing may affect the test they want to write, and whoever enhancing the test framework to add new GIT_TEST_* knob need to pay attention to the users of export_to_sudo if their new knob need to be exported.
- I think the assignment to $v under eval is correct, but I am not sure the string accumulated in the $HOME/env file is safe to eval. We can pass TEST_DIRECTORY via this mechanism, where the value deliberately has a whitespace in it, but if the leading path to our source directory had a single-quote in it, it probably would not work well. Of course, any variable that has LF in its value would not work without proper quoting.
I think both are not impossible but are hard to do right. Because I do not see anything that absolutely needs the $HOME/env mechanism to work in the rest of the tests in this patch, I am inclined to say that I'd prefer keeping things simple and only make sure we use the right $SHELL to run our script (which write_script may help).
Show 21 quoted lines
> diff --git a/t/t0034-root-safe-directory.sh b/t/t0034-root-safe-directory.sh > index 67dd96b9321..0f79648a2fb 100755 > --- a/t/t0034-root-safe-directory.sh > +++ b/t/t0034-root-safe-directory.sh > @@ -3,6 +3,19 @@ > test_description='verify safe.directory checks while running as root' > > . ./test-lib.sh > +. "$TEST_DIRECTORY"/lib-sudo.sh > + > +if [ "$IKNOWWHATIAMDOING" != "YES" ] > +then > + skip_all="You must set env var IKNOWWHATIAMDOING=YES in order to run this test" > + test_done > +fi > + > +if ! test_have_prereq NOT_ROOT > +then > + skip_all="No, you don't; these tests can't run as root" > + test_done > +fi
OK.
Show 8 quoted lines
> @@ -19,6 +32,7 @@ test_lazy_prereq SUDO ' > test_expect_success SUDO 'setup' ' > sudo rm -rf root && > mkdir -p root/r && > + export_to_sudo GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME && > sudo chown root root && > ( > cd root/r &&
I know I brought up the "git init" during the previous review, but as long as the test does not depend on the GIT_TEST_* knob (i.e. either we say "git init --initial-branch" explicitly, or we do not rely on the initial branch having a certain name), we do not have to worry. We do not check what branch we are on after we do this test, we do not check what branch "git status" reports that we are on in later tests, we obviously do not care between main and master in this test script.
I am tempted to suggest dropping the whole $HOME/env business.
Show 10 quoted lines
> @@ -34,6 +48,50 @@ test_expect_success SUDO 'sudo git status as original owner' ' > ) > ' > > +test_expect_success SUDO 'setup root owned repository' ' > + sudo mkdir -p root/p && > + run_with_sudo <<-END > + git init root/p > + END > +'
OK.
Show 6 quoted lines
> +test_expect_success SUDO 'cannot access if owned by root' ' > + ( > + cd root/p && > + test_must_fail git status > + ) > +'
OK, but strictly speaking, we do not need the SUDO prerequisite for this one. It still need it for the test directories prepared in previous steps anyway, so perhaps we want one check upfront, just like we do for NOT_ROOT?
if ! test_have_prereq SUDO then skip_all="You do not seem to have a working 'sudo'" test_done fi
Show 8 quoted lines
> +test_expect_success SUDO 'cannot access with sudo' ' > + ( > + # TODO: test_must_fail needs additional functionality > + # 6a67c759489 blocks its use with sudo > + cd root/p && > + ! sudo git status > + ) > +'
OK. So we cannot by default access root-owned repository by default, which is OK. I wonder what happens if we did "sudo sudo git status". Perhaps the inner sudo will notice that SUDO_UID is set in its environment and does not update it to 0?
... goes and checks ... $ sudo sudo sh -c 'echo $SUDO_UID; whoami' 0 root
So that gives us another workaround, I guess, which might be even simpler.
Show 19 quoted lines
> +test_expect_success SUDO 'can access using a workaround' ' > + # provide explicit GIT_DIR > + ( > + cd root/p && > + run_with_sudo <<-END > + GIT_DIR=.git > + GIT_WORK_TREE=. > + export GIT_DIR GIT_WORK_TREE > + git status > + END > + ) && > + # discard SUDO_UID > + ( > + cd root/p && > + run_with_sudo <<-END > + unset SUDO_UID > + git status > + END > + )
# double sudo ( cd root/p && sudo sudo git status )
I do not know if it is worth adding this third workaround.
Show 5 quoted lines
> +' > + > # this MUST be always the last test > test_expect_success SUDO 'cleanup' ' > sudo rm -rf root
Looking much better otherwise.