maintenance: `git maintenance run` learned `--scheduler=<scheduler>`

Depending on the system, different schedulers can be used to schedule
the hourly, daily and weekly executions of `git maintenance run`:
* `launchctl` for MacOS,
* `schtasks` for Windows and
* `crontab` for everything else.

`git maintenance run` now has an option to let the end-user explicitly
choose which scheduler he wants to use:
`--scheduler=auto|crontab|launchctl|schtasks`.

When `git maintenance start --scheduler=XXX` is run, it not only
registers `git maintenance run` tasks in the scheduler XXX, it also
removes the `git maintenance run` tasks from all the other schedulers to
ensure we cannot have two schedulers launching concurrent identical
tasks.

The default value is `auto` which chooses a suitable scheduler for the
system.

`git maintenance stop` doesn't have any `--scheduler` parameter because
this command will try to remove the `git maintenance run` tasks from all
the available schedulers.

Signed-off-by: Lénaïc Huard <lenaic@lhuard.fr>
Acked-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 51 insertions, 4 deletions

diff --git a/t/t7900-maintenance.sh b/t/t7900-maintenance.sh
index b93ae014ee..b36b7f5fb0 100755
--- a/t/t7900-maintenance.sh
+++ b/t/t7900-maintenance.sh
@@ -494,8 +494,21 @@ test_expect_success !MINGW 'register and unregister with regex metacharacters' '
 		maintenance.repo "$(pwd)/$META"
 '
 
+test_expect_success 'start --scheduler=<scheduler>' '
+	test_expect_code 129 git maintenance start --scheduler=foo 2>err &&
+	test_i18ngrep "unrecognized --scheduler argument" err &&
+
+	test_expect_code 129 git maintenance start --no-scheduler 2>err &&
+	test_i18ngrep "unknown option" err &&
+
+	test_expect_code 128 \
+		env GIT_TEST_MAINT_SCHEDULER="launchctl:true,schtasks:true" \
+		git maintenance start --scheduler=crontab 2>err &&
+	test_i18ngrep "fatal: crontab scheduler is not available" err
+'
+
 test_expect_success 'start from empty cron table' '
-	GIT_TEST_MAINT_SCHEDULER="crontab:test-tool crontab cron.txt" git maintenance start &&
+	GIT_TEST_MAINT_SCHEDULER="crontab:test-tool crontab cron.txt" git maintenance start --scheduler=crontab &&
 
 	# start registers the repo
 	git config --get --global --fixed-value maintenance.repo "$(pwd)" &&
@@ -518,7 +531,7 @@ test_expect_success 'stop from existing schedule' '
 
 test_expect_success 'start preserves existing schedule' '
 	echo "Important information!" >cron.txt &&
-	GIT_TEST_MAINT_SCHEDULER="crontab:test-tool crontab cron.txt" git maintenance start &&
+	GIT_TEST_MAINT_SCHEDULER="crontab:test-tool crontab cron.txt" git maintenance start --scheduler=crontab &&
 	grep "Important information!" cron.txt
 '
 
@@ -547,7 +560,7 @@ test_expect_success 'start and stop macOS maintenance' '
 	EOF
 
 	rm -f args &&
-	GIT_TEST_MAINT_SCHEDULER=launchctl:./print-args git maintenance start &&
+	GIT_TEST_MAINT_SCHEDULER=launchctl:./print-args git maintenance start --scheduler=launchctl &&
 
 	# start registers the repo
 	git config --get --global --fixed-value maintenance.repo "$(pwd)" &&
@@ -598,7 +611,7 @@ test_expect_success 'start and stop Windows maintenance' '
 	EOF
 
 	rm -f args &&
-	GIT_TEST_MAINT_SCHEDULER="schtasks:./print-args" git maintenance start &&
+	GIT_TEST_MAINT_SCHEDULER="schtasks:./print-args" git maintenance start --scheduler=schtasks &&
 
 	# start registers the repo
 	git config --get --global --fixed-value maintenance.repo "$(pwd)" &&
@@ -621,6 +634,40 @@ test_expect_success 'start and stop Windows maintenance' '
 	test_cmp expect args
 '
 
+test_expect_success 'start and stop when several schedulers are available' '
+	write_script print-args <<-\EOF &&
+	printf "%s\n" "$*" | sed "s:gui/[0-9][0-9]*:gui/[UID]:; s:\(schtasks /create .* /xml\).*:\1:;" >>args
+	EOF
+
+	rm -f args &&
+	GIT_TEST_MAINT_SCHEDULER="launchctl:./print-args launchctl,schtasks:./print-args schtasks" git maintenance start --scheduler=launchctl &&
+	printf "schtasks /delete /tn Git Maintenance (%s) /f\n" \
+		hourly daily weekly >expect &&
+	for frequency in hourly daily weekly
+	do
+		PLIST="$pfx/Library/LaunchAgents/org.git-scm.git.$frequency.plist" &&
+		echo "launchctl bootout gui/[UID] $PLIST" >>expect &&
+		echo "launchctl bootstrap gui/[UID] $PLIST" >>expect || return 1
+	done &&
+	test_cmp expect args &&
+
+	rm -f args &&
+	GIT_TEST_MAINT_SCHEDULER="launchctl:./print-args launchctl,schtasks:./print-args schtasks" git maintenance start --scheduler=schtasks &&
+	printf "launchctl bootout gui/[UID] $pfx/Library/LaunchAgents/org.git-scm.git.%s.plist\n" \
+		hourly daily weekly >expect &&
+	printf "schtasks /create /tn Git Maintenance (%s) /f /xml\n" \
+		hourly daily weekly >>expect &&
+	test_cmp expect args &&
+
+	rm -f args &&
+	GIT_TEST_MAINT_SCHEDULER="launchctl:./print-args launchctl,schtasks:./print-args schtasks" git maintenance stop &&
+	printf "launchctl bootout gui/[UID] $pfx/Library/LaunchAgents/org.git-scm.git.%s.plist\n" \
+		hourly daily weekly >expect &&
+	printf "schtasks /delete /tn Git Maintenance (%s) /f\n" \
+		hourly daily weekly >>expect &&
+	test_cmp expect args
+'
+
 test_expect_success 'register preserves existing strategy' '
 	git config maintenance.strategy none &&
 	git maintenance register &&