Merge pull request #25004 from keszybz/transient-drop-ins

Allow drop-ins for transient units

3 files changed, 167 insertions, 46 deletions

diff --git a/src/core/dbus-manager.c b/src/core/dbus-manager.c
index 0e57bd92f8..a6b3c7b36b 100644
--- a/src/core/dbus-manager.c
+++ b/src/core/dbus-manager.c
@@ -957,7 +957,7 @@ static int transient_unit_from_message(
 
         if (!unit_is_pristine(u))
                 return sd_bus_error_setf(error, BUS_ERROR_UNIT_EXISTS,
-                                         "Unit %s already exists.", name);
+                                         "Unit %s was already loaded or has a fragment file.", name);
 
         /* OK, the unit failed to load and is unreferenced, now let's
          * fill in the transient data instead */
diff --git a/src/core/unit.c b/src/core/unit.c
index d6bea2080f..d0f7188613 100644
--- a/src/core/unit.c
+++ b/src/core/unit.c
@@ -4844,18 +4844,20 @@ int unit_fail_if_noncanonical(Unit *u, const char* where) {
 bool unit_is_pristine(Unit *u) {
         assert(u);
 
-        /* Check if the unit already exists or is already around,
-         * in a number of different ways. Note that to cater for unit
-         * types such as slice, we are generally fine with units that
-         * are marked UNIT_LOADED even though nothing was actually
-         * loaded, as those unit types don't require a file on disk. */
-
-        return !(!IN_SET(u->load_state, UNIT_NOT_FOUND, UNIT_LOADED) ||
-                 u->fragment_path ||
-                 u->source_path ||
-                 !strv_isempty(u->dropin_paths) ||
-                 u->job ||
-                 u->merged_into);
+        /* Check if the unit already exists or is already around, in a number of different ways. Note that to
+         * cater for unit types such as slice, we are generally fine with units that are marked UNIT_LOADED
+         * even though nothing was actually loaded, as those unit types don't require a file on disk.
+         *
+         * Note that we don't check for drop-ins here, because we allow drop-ins for transient units
+         * identically to non-transient units, both unit-specific and hierarchical. E.g. for a-b-c.service:
+         * service.d/….conf, a-.service.d/….conf, a-b-.service.d/….conf, a-b-c.service.d/….conf.
+         */
+
+        return IN_SET(u->load_state, UNIT_NOT_FOUND, UNIT_LOADED) &&
+               !u->fragment_path &&
+               !u->source_path &&
+               !u->job &&
+               !u->merged_into;
 }
 
 pid_t unit_control_pid(Unit *u) {
diff --git a/test/units/testsuite-15.sh b/test/units/testsuite-15.sh
index f847adac74..079c8b290e 100755
--- a/test/units/testsuite-15.sh
+++ b/test/units/testsuite-15.sh
@@ -3,30 +3,32 @@
 set -eux
 set -o pipefail
 
-_clear_service () {
-    local SERVICE_NAME="${1:?}"
-    systemctl stop "$SERVICE_NAME.service" 2>/dev/null || :
-    rm -f  /{etc,run,usr/lib}/systemd/system/"$SERVICE_NAME".service
-    rm -fr /{etc,run,usr/lib}/systemd/system/"$SERVICE_NAME".service.d
-    rm -fr /{etc,run,usr/lib}/systemd/system/"$SERVICE_NAME".service.{wants,requires}
-    if [[ $SERVICE_NAME == *@ ]]; then
-        systemctl stop "$SERVICE_NAME"*.service 2>/dev/null || :
-        rm -f  /{etc,run,usr/lib}/systemd/system/"$SERVICE_NAME"*.service
-        rm -fr /{etc,run,usr/lib}/systemd/system/"$SERVICE_NAME"*.service.d
-        rm -fr /{etc,run,usr/lib}/systemd/system/"$SERVICE_NAME"*.service.{wants,requires}
+clear_unit () {
+    local UNIT_NAME="${1:?}"
+    systemctl stop "$UNIT_NAME" 2>/dev/null || :
+    rm -f  /{etc,run,usr/lib}/systemd/system/"$UNIT_NAME"
+    rm -fr /{etc,run,usr/lib}/systemd/system/"$UNIT_NAME".d
+    rm -fr /{etc,run,usr/lib}/systemd/system/"$UNIT_NAME".{wants,requires}
+    if [[ $UNIT_NAME == *@ ]]; then
+        local base="${UNIT_NAME%@*}"
+        local suffix="${UNIT_NAME##*.}"
+        systemctl stop "$base@"*."$suffix" 2>/dev/null || :
+        rm -f  /{etc,run,usr/lib}/systemd/system/"$base@"*."$suffix"
+        rm -fr /{etc,run,usr/lib}/systemd/system/"$base@"*."$suffix".d
+        rm -fr /{etc,run,usr/lib}/systemd/system/"$base@"*."$suffix".{wants,requires}
     fi
 }
 
-clear_services () {
+clear_units () {
     for u in "$@"; do
-        _clear_service "$u"
+        clear_unit "$u"
     done
     systemctl daemon-reload
 }
 
 create_service () {
     local SERVICE_NAME="${1:?}"
-    clear_services "$SERVICE_NAME"
+    clear_units "${SERVICE_NAME}".service
 
     cat >/etc/systemd/system/"$SERVICE_NAME".service <<EOF
 [Unit]
@@ -119,7 +121,7 @@ EOF
     check_ok test15-b ExecCondition "/bin/echo test15-b"
     rm -rf /usr/lib/systemd/system/service.d
 
-    clear_services test15-a test15-b test15-c test15-c1
+    clear_units test15-{a,b,c,c1}.service
 }
 
 test_linked_units () {
@@ -146,7 +148,7 @@ test_linked_units () {
                                           # Make sure it is completely ignored.
 
     rm /test15-a@.scope
-    clear_services test15-a test15-b
+    clear_units test15-{a,b}.service
 }
 
 test_template_alias() {
@@ -172,32 +174,147 @@ test_template_alias() {
     check_ko test15-b@other Names test15-a@other.service
     check_ok test15-b@other Names test15-b@other.service
 
-    clear_services test15-a@ test15-b@
+    clear_units test15-{a,b}@.service
 }
 
-test_hierarchical_dropins () {
-    echo "Testing hierarchical dropins..."
+test_hierarchical_service_dropins () {
+    echo "Testing hierarchical service dropins..."
     echo "*** test service.d/ top level drop-in"
     create_services a-b-c
-    check_ko a-b-c ExecCondition "/bin/echo service.d"
-    check_ko a-b-c ExecCondition "/bin/echo a-.service.d"
-    check_ko a-b-c ExecCondition "/bin/echo a-b-.service.d"
-    check_ko a-b-c ExecCondition "/bin/echo a-b-c.service.d"
+    check_ko a-b-c ExecCondition "echo service.d"
+    check_ko a-b-c ExecCondition "echo a-.service.d"
+    check_ko a-b-c ExecCondition "echo a-b-.service.d"
+    check_ko a-b-c ExecCondition "echo a-b-c.service.d"
 
     for dropin in service.d a-.service.d a-b-.service.d a-b-c.service.d; do
         mkdir -p /usr/lib/systemd/system/$dropin
         echo "
 [Service]
-ExecCondition=/bin/echo $dropin
+ExecCondition=echo $dropin
         " >/usr/lib/systemd/system/$dropin/override.conf
         systemctl daemon-reload
-        check_ok a-b-c ExecCondition "/bin/echo $dropin"
+        check_ok a-b-c ExecCondition "echo $dropin"
+
+        # Check that we can start a transient service in presence of the drop-ins
+        systemd-run -u a-b-c2.service -p Description='sleepy' sleep infinity
+
+        # The transient setting replaces the default
+        check_ok a-b-c2.service Description "sleepy"
+
+        # The override takes precedence for ExecCondition
+        # (except the last iteration when it only applies to the other service)
+        if [ "$dropin" != "a-b-c.service.d" ]; then
+            check_ok a-b-c2.service ExecCondition "echo $dropin"
+        fi
+
+        # Check that things are the same after a reload
+        systemctl daemon-reload
+        check_ok a-b-c2.service Description "sleepy"
+        if [ "$dropin" != "a-b-c.service.d" ]; then
+            check_ok a-b-c2.service ExecCondition "echo $dropin"
+        fi
+
+        systemctl stop a-b-c2.service
     done
     for dropin in service.d a-.service.d a-b-.service.d a-b-c.service.d; do
         rm -rf /usr/lib/systemd/system/$dropin
     done
 
-    clear_services a-b-c
+    clear_units a-b-c.service
+}
+
+test_hierarchical_slice_dropins () {
+    echo "Testing hierarchical slice dropins..."
+    echo "*** test slice.d/ top level drop-in"
+    # Slice units don't even need a fragment, so we test the defaults here
+    check_ok a-b-c.slice Description "Slice /a/b/c"
+    check_ok a-b-c.slice MemoryMax "infinity"
+
+    # Test drop-ins
+    for dropin in slice.d a-.slice.d a-b-.slice.d a-b-c.slice.d; do
+        mkdir -p /usr/lib/systemd/system/$dropin
+        echo "
+[Slice]
+MemoryMax=1000000000
+        " >/usr/lib/systemd/system/$dropin/override.conf
+        systemctl daemon-reload
+        check_ok a-b-c.slice MemoryMax "1000000000"
+
+        busctl call \
+               org.freedesktop.systemd1 \
+               /org/freedesktop/systemd1 \
+               org.freedesktop.systemd1.Manager \
+               StartTransientUnit 'ssa(sv)a(sa(sv))' \
+               'a-b-c.slice' 'replace' \
+               2 \
+               'Description' s 'slice too' \
+               'MemoryMax' t 1000000002 \
+               0
+
+        # The override takes precedence for MemoryMax
+        check_ok a-b-c.slice MemoryMax "1000000000"
+        # The transient setting replaces the default
+        check_ok a-b-c.slice Description "slice too"
+
+        # Check that things are the same after a reload
+        systemctl daemon-reload
+        check_ok a-b-c.slice MemoryMax "1000000000"
+        check_ok a-b-c.slice Description "slice too"
+
+        busctl call \
+               org.freedesktop.systemd1 \
+               /org/freedesktop/systemd1 \
+               org.freedesktop.systemd1.Manager \
+               StopUnit 'ss' \
+               'a-b-c.slice' 'replace'
+
+        rm /usr/lib/systemd/system/$dropin/override.conf
+    done
+
+    # Test unit with a fragment
+    echo "
+[Slice]
+MemoryMax=1000000001
+        " >/usr/lib/systemd/system/a-b-c.slice
+    systemctl daemon-reload
+    check_ok a-b-c.slice MemoryMax "1000000001"
+
+    clear_units a-b-c.slice
+}
+
+test_transient_service_dropins () {
+    echo "Testing dropins for a transient service..."
+    echo "*** test transient service drop-ins"
+
+    mkdir -p /etc/systemd/system/service.d
+    mkdir -p /etc/systemd/system/a-.service.d
+    mkdir -p /etc/systemd/system/a-b-.service.d
+    mkdir -p /etc/systemd/system/a-b-c.service.d
+
+    echo -e '[Service]\nStandardInputText=aaa' >/etc/systemd/system/service.d/drop1.conf
+    echo -e '[Service]\nStandardInputText=bbb' >/etc/systemd/system/a-.service.d/drop2.conf
+    echo -e '[Service]\nStandardInputText=ccc' >/etc/systemd/system/a-b-.service.d/drop3.conf
+    echo -e '[Service]\nStandardInputText=ddd' >/etc/systemd/system/a-b-c.service.d/drop4.conf
+
+    # There's no fragment yet, so this fails
+    systemctl cat a-b-c.service && exit 1
+
+    # xxx → eHh4Cg==
+    systemd-run -u a-b-c.service -p StandardInputData=eHh4Cg== sleep infinity
+
+    data=$(systemctl show -P StandardInputData a-b-c.service)
+    # xxx\naaa\n\bbb\nccc\nddd\n → eHh4…
+    test "$data" = "eHh4CmFhYQpiYmIKY2NjCmRkZAo="
+
+    # Do a reload and check again
+    systemctl daemon-reload
+    data=$(systemctl show -P StandardInputData a-b-c.service)
+    test "$data" = "eHh4CmFhYQpiYmIKY2NjCmRkZAo="
+
+    clear_units a-b-c.service
+    rm /etc/systemd/system/service.d/drop1.conf \
+       /etc/systemd/system/a-.service.d/drop2.conf \
+       /etc/systemd/system/a-b-.service.d/drop3.conf
 }
 
 test_template_dropins () {
@@ -346,7 +463,7 @@ EOF
     check_ok bar-alias@3 Requires yup-template-requires.device
     check_ok bar-alias@3 Requires yup-3-requires.device
 
-    clear_services foo {bar,yup,bar-alias}@{,1,2,3}
+    clear_units foo.service {bar,yup,bar-alias}@{,1,2,3}.service
 }
 
 test_alias_dropins () {
@@ -361,7 +478,7 @@ test_alias_dropins () {
     systemctl --quiet is-active test15-b
     systemctl stop test15-a test15-b
     rm /etc/systemd/system/test15-b1.service
-    clear_services test15-a test15-b
+    clear_units test15-{a,b}.service
 
     # Check that dependencies don't vary.
     echo "*** test 2"
@@ -378,7 +495,7 @@ test_alias_dropins () {
     systemctl stop test15-a test15-x test15-y
     rm /etc/systemd/system/test15-a1.service
 
-    clear_services test15-a test15-x test15-y
+    clear_units test15-{a,x,y}.service
 }
 
 test_masked_dropins () {
@@ -499,7 +616,7 @@ EOF
     ln -sf /dev/null /etc/systemd/system/test15-a.service.requires/test15-b.service
     check_ok test15-a Requires test15-b
 
-    clear_services test15-a test15-b
+    clear_units test15-{a,b}.service
 }
 
 test_invalid_dropins () {
@@ -511,7 +628,7 @@ test_invalid_dropins () {
     # Assertion failed on earlier versions, command exits unsuccessfully on later versions
     systemctl cat a@.service || true
     systemctl stop a
-    clear_services a
+    clear_units a.service
     return 0
 }
 
@@ -531,13 +648,15 @@ EOF
     ln -s /tmp/testsuite-15-test15-a-dropin-directory-regular /usr/lib/systemd/system/test15-a.service.d
     check_ok test15-a Description hogehoge
 
-    clear_services test15-a
+    clear_units test15-a.service
 }
 
 test_basic_dropins
 test_linked_units
 test_template_alias
-test_hierarchical_dropins
+test_hierarchical_service_dropins
+test_hierarchical_slice_dropins
+test_transient_service_dropins
 test_template_dropins
 test_alias_dropins
 test_masked_dropins