| Message ID | 20220502183920.88982-4-carenas@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | fix `sudo make install` regression in maint | expand |
Carlo Marcelo Arenas Belón <carenas@gmail.com> writes: > +# 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? > +# 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 $SHELL to run our script (which write_script may help). > diff --git a/t/t0034-root-safe-directory.sh b/t/t0034-root-safe-directory.sh > index 67dd96b9321..0f79648a2fb 100755 > --- a/t/t0034-root-safe-directory.sh > +++ b/t/t0034-root-safe-directory.sh > @@ -3,6 +3,19 @@ > test_description='verify safe.directory checks while running as root' > > . ./test-lib.sh > +. "$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. > @@ -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. > @@ -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. > +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 > +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 $SUDO_UID; whoami' 0 root So that gives us another workaround, I guess, which might be even simpler. > +test_expect_success SUDO 'can access using a workaround' ' > + # provide explicit GIT_DIR > + ( > + cd root/p && > + run_with_sudo <<-END > + GIT_DIR=.git > + GIT_WORK_TREE=. > + export GIT_DIR GIT_WORK_TREE > + git status > + END > + ) && > + # discard SUDO_UID > + ( > + cd root/p && > + run_with_sudo <<-END > + unset SUDO_UID > + git status > + END > + ) # double sudo ( cd root/p && sudo sudo git status ) I do not know if it is worth adding this third workaround. > +' > + > # this MUST be always the last test > test_expect_success SUDO 'cleanup' ' > sudo rm -rf root Looking much better otherwise.
On Mon, May 2, 2022 at 3:10 PM Junio C Hamano <gitster@pobox.com> wrote: > > Carlo Marcelo Arenas Belón <carenas@gmail.com> writes: > > > +# Runs a scriplet passed through stdin under sudo. > > +run_with_sudo () { > > + local ret > > + local SH=${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? correct, I tried to use write_script initially, but I thought that since I needed to inject code at the beginning for env, I could also inject "set -e" and make sure that any scriplet used would work (and more importantly fail when not) even without the "&&". so the scriptlets themselves would be more readable. My function is just a slightly modified version of wrte_script for that reason, as making write_script do that seemed more complicated than what I ended up doing. > +# 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). makes sense, would prepare a formal v3 with those changes and that should be safe to queue. > > +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 my only concern doing that would be that then could confuse people adding new tests later that might also not need SUDO and that would be skipped because they were added at the end, but I agree it is overall cleaner so would also include in the reroll > > +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? funny enough sudo itself doesn't honour SUDO_UID. > ... goes and checks ... > $ sudo sudo sh -c 'echo $SUDO_UID; whoami' > 0 > root > > So that gives us another workaround, I guess, which might be even > simpler. correct. > > +test_expect_success SUDO 'can access using a workaround' ' > > + # provide explicit GIT_DIR > > + ( > > + cd root/p && > > + run_with_sudo <<-END > > + GIT_DIR=.git > > + GIT_WORK_TREE=. > > + export GIT_DIR GIT_WORK_TREE > > + git status > > + END > > + ) && > > + # discard SUDO_UID > > + ( > > + cd root/p && > > + run_with_sudo <<-END > > + unset SUDO_UID > > + git status > > + END > > + ) > > # double sudo > ( > cd root/p && > sudo sudo git status > ) > > I do not know if it is worth adding this third workaround. I think it is, as it helps document them, and makes sure they remain viable, but still think that the one added to the documentation is "better", because it is direct and not an implementation detail removing SUDO_UID from your environment "means" you want to be identified as root by git from then on, and that the fact that you might have become root through sudo is no longer relevant. Carlo
diff --git a/t/lib-sudo.sh b/t/lib-sudo.sh new file mode 100644 index 00000000000..60046927f3b --- /dev/null +++ b/t/lib-sudo.sh @@ -0,0 +1,31 @@ +# Helpers for running git commands under sudo. + +# Runs a scriplet passed through stdin under sudo. +run_with_sudo () { + local ret + local SH=${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 +} + +# 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" >>"$HOME/env" + shift + done +} diff --git a/t/t0034-root-safe-directory.sh b/t/t0034-root-safe-directory.sh index 67dd96b9321..0f79648a2fb 100755 --- a/t/t0034-root-safe-directory.sh +++ b/t/t0034-root-safe-directory.sh @@ -3,6 +3,19 @@ test_description='verify safe.directory checks while running as root' . ./test-lib.sh +. "$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 # this prerequisite should be added to all the tests, it not only prevents # the test from failing but also warms up any authentication cache sudo @@ -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 && @@ -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 +' + +test_expect_success SUDO 'cannot access if owned by root' ' + ( + cd root/p && + test_must_fail git status + ) +' + +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 + ) +' + +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 + ) +' + # this MUST be always the last test test_expect_success SUDO 'cleanup' ' sudo rm -rf root
When running under sudo, the environment gets altered in significant ways, so make sure that PATH is respected by comparing the full path to git outside and inside sudo and disabling the tests if they don't match. Additionally, invent a way to inject environment variables into that environment and create a helper function to facilitate running more than one command under sudo, while using those variables. Add additional negative tests as suggested by Junio and export the GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME variable that will be used when running init in one of those. Note that in order to be able to call `test_must_fail sudo git status` or an equivalent test_must_fail will need to be enhanced or be able to run under sudo, so fixing that has been punted, since the only protection it affords is for `git status` not crashing, and that is covered already by other tests. Helped-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com> --- t/lib-sudo.sh | 31 ++++++++++++++++++ t/t0034-root-safe-directory.sh | 58 ++++++++++++++++++++++++++++++++++ 2 files changed, 89 insertions(+) create mode 100644 t/lib-sudo.sh