machined: optionally, allow registration of pre-existing units (scopes

or services) as machine with machined

9 files changed, 220 insertions, 84 deletions

diff --git a/man/systemd-nspawn.xml b/man/systemd-nspawn.xml
index 47c3183eee..9d8db83e81 100644
--- a/man/systemd-nspawn.xml
+++ b/man/systemd-nspawn.xml
@@ -465,8 +465,8 @@
                                 should be enabled when the container
                                 runs a full Operating System (more
                                 specifically: an init system), and is
-                                useful to ensure the container is
-                                accesible via
+                                useful to ensure that the container is
+                                accessible via
                                 <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
                                 and shown by tools such as
                                 <citerefentry><refentrytitle>ps</refentrytitle><manvolnum>1</manvolnum></citerefentry>. If
@@ -478,6 +478,30 @@
                                 <option>--register=no</option>.
                                 </para></listitem>
                         </varlistentry>
+
+                        <varlistentry>
+                                <term><option>--keep-unit</option></term>
+
+                                <listitem><para>Instead of creating a
+                                transient scope unit to run the
+                                container in, simply register the
+                                service or scope unit
+                                <command>systemd-nspawn</command> has
+                                been invoked in in
+                                <citerefentry><refentrytitle>systemd-machined</refentrytitle><manvolnum>8</manvolnum></citerefentry>. This
+                                has no effect if
+                                <option>--register=no</option> is
+                                used. This switch should be used if
+                                <command>systemd-nspawn</command> is
+                                invoked from within an a service unit,
+                                and the service unit's sole purpose
+                                is to run a single
+                                <command>systemd-nspawn</command>
+                                container. This option is not
+                                available if run from a user
+                                session.</para></listitem>
+                        </varlistentry>
+
                 </variablelist>
 
         </refsect1>
diff --git a/src/login/sd-login.c b/src/login/sd-login.c
index c795765620..ef67040ebc 100644
--- a/src/login/sd-login.c
+++ b/src/login/sd-login.c
@@ -630,7 +630,32 @@ _public_ int sd_get_uids(uid_t **users) {
 }
 
 _public_ int sd_get_machine_names(char ***machines) {
-        return get_files_in_directory("/run/systemd/machines/", machines);
+        char **l = NULL, **a, **b;
+        int r;
+
+        r = get_files_in_directory("/run/systemd/machines/", &l);
+        if (r < 0)
+                return r;
+
+        if (l) {
+                r = 0;
+
+                /* Filter out the unit: symlinks */
+                for (a = l, b = l; *a; a++) {
+                        if (startswith(*a, "unit:"))
+                                free(*a);
+                        else {
+                                *b = *a;
+                                b++;
+                                r++;
+                        }
+                }
+
+                *b = NULL;
+        }
+
+        *machines = l;
+        return r;
 }
 
 static inline int MONITOR_TO_FD(sd_login_monitor *m) {
diff --git a/src/machine/machine-dbus.c b/src/machine/machine-dbus.c
index 90eb001bb1..df96ccf9d4 100644
--- a/src/machine/machine-dbus.c
+++ b/src/machine/machine-dbus.c
@@ -132,7 +132,8 @@ const sd_bus_vtable machine_vtable[] = {
         SD_BUS_PROPERTY("Id", "ay", property_get_id, 0, SD_BUS_VTABLE_PROPERTY_CONST),
         BUS_PROPERTY_DUAL_TIMESTAMP("Timestamp", offsetof(Machine, timestamp), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("Service", "s", NULL, offsetof(Machine, service), SD_BUS_VTABLE_PROPERTY_CONST),
-        SD_BUS_PROPERTY("Scope", "s", NULL, offsetof(Machine, scope), SD_BUS_VTABLE_PROPERTY_CONST),
+        SD_BUS_PROPERTY("Unit", "s", NULL, offsetof(Machine, unit), SD_BUS_VTABLE_PROPERTY_CONST),
+        SD_BUS_PROPERTY("Scope", "s", NULL, offsetof(Machine, unit), SD_BUS_VTABLE_PROPERTY_CONST|SD_BUS_VTABLE_HIDDEN),
         SD_BUS_PROPERTY("Leader", "u", NULL, offsetof(Machine, leader), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("Class", "s", property_get_class, offsetof(Machine, class), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("RootDirectory", "s", NULL, offsetof(Machine, root_directory), SD_BUS_VTABLE_PROPERTY_CONST),
diff --git a/src/machine/machine.c b/src/machine/machine.c
index 0791ba8a9a..e45c443495 100644
--- a/src/machine/machine.c
+++ b/src/machine/machine.c
@@ -76,9 +76,9 @@ void machine_free(Machine *m) {
         if (m->in_gc_queue)
                 LIST_REMOVE(gc_queue, m->manager->machine_gc_queue, m);
 
-        if (m->scope) {
-                hashmap_remove(m->manager->machine_units, m->scope);
-                free(m->scope);
+        if (m->unit) {
+                hashmap_remove(m->manager->machine_units, m->unit);
+                free(m->unit);
         }
 
         free(m->scope_job);
@@ -123,8 +123,8 @@ int machine_save(Machine *m) {
                 "NAME=%s\n",
                 m->name);
 
-        if (m->scope)
-                fprintf(f, "SCOPE=%s\n", m->scope);
+        if (m->unit)
+                fprintf(f, "SCOPE=%s\n", m->unit); /* We continue to call this "SCOPE=" because it is internal only, and we want to stay compatible with old files */
 
         if (m->scope_job)
                 fprintf(f, "SCOPE_JOB=%s\n", m->scope_job);
@@ -159,6 +159,16 @@ int machine_save(Machine *m) {
                 unlink(temp_path);
         }
 
+        if (m->unit) {
+                char *sl;
+
+                /* Create a symlink from the unit name to the machine
+                 * name, so that we can quickly find the machine for
+                 * each given unit */
+                sl = strappenda("/run/systemd/machines/unit:", m->unit);
+                symlink(m->name, sl);
+        }
+
 finish:
         if (r < 0)
                 log_error("Failed to save machine data %s: %s", m->state_file, strerror(-r));
@@ -166,6 +176,21 @@ finish:
         return r;
 }
 
+static void machine_unlink(Machine *m) {
+        assert(m);
+
+        if (m->unit) {
+
+                char *sl;
+
+                sl = strappenda("/run/systemd/machines/unit:", m->unit);
+                unlink(sl);
+        }
+
+        if (m->state_file)
+                unlink(m->state_file);
+}
+
 int machine_load(Machine *m) {
         _cleanup_free_ char *realtime = NULL, *monotonic = NULL, *id = NULL, *leader = NULL, *class = NULL;
         int r;
@@ -173,7 +198,7 @@ int machine_load(Machine *m) {
         assert(m);
 
         r = parse_env_file(m->state_file, NEWLINE,
-                           "SCOPE",     &m->scope,
+                           "SCOPE",     &m->unit,
                            "SCOPE_JOB", &m->scope_job,
                            "SERVICE",   &m->service,
                            "ROOT",      &m->root_directory,
@@ -225,7 +250,7 @@ static int machine_start_scope(Machine *m, sd_bus_message *properties, sd_bus_er
 
         assert(m);
 
-        if (!m->scope) {
+        if (!m->unit) {
                 _cleanup_free_ char *escaped = NULL;
                 char *scope, *description, *job;
 
@@ -245,15 +270,15 @@ static int machine_start_scope(Machine *m, sd_bus_message *properties, sd_bus_er
                         free(scope);
                         return r;
                 } else {
-                        m->scope = scope;
+                        m->unit = scope;
 
                         free(m->scope_job);
                         m->scope_job = job;
                 }
         }
 
-        if (m->scope)
-                hashmap_put(m->manager->machine_units, m->scope, m);
+        if (m->unit)
+                hashmap_put(m->manager->machine_units, m->unit, m);
 
         return r;
 }
@@ -302,10 +327,10 @@ static int machine_stop_scope(Machine *m) {
 
         assert(m);
 
-        if (!m->scope)
+        if (!m->unit)
                 return 0;
 
-        r = manager_stop_unit(m->manager, m->scope, &error, &job);
+        r = manager_stop_unit(m->manager, m->unit, &error, &job);
         if (r < 0) {
                 log_error("Failed to stop machine scope: %s", bus_error_message(&error, r));
                 return r;
@@ -334,7 +359,7 @@ int machine_stop(Machine *m) {
         if (k < 0)
                 r = k;
 
-        unlink(m->state_file);
+        machine_unlink(m);
         machine_add_to_gc_queue(m);
 
         if (m->started)
@@ -354,7 +379,7 @@ bool machine_check_gc(Machine *m, bool drop_not_started) {
         if (m->scope_job && manager_job_is_active(m->manager, m->scope_job))
                 return true;
 
-        if (m->scope && manager_unit_is_active(m->manager, m->scope))
+        if (m->unit && manager_unit_is_active(m->manager, m->unit))
                 return true;
 
         return false;
@@ -382,10 +407,10 @@ MachineState machine_get_state(Machine *s) {
 int machine_kill(Machine *m, KillWho who, int signo) {
         assert(m);
 
-        if (!m->scope)
+        if (!m->unit)
                 return -ESRCH;
 
-        return manager_kill_unit(m->manager, m->scope, who, signo, NULL);
+        return manager_kill_unit(m->manager, m->unit, who, signo, NULL);
 }
 
 static const char* const machine_class_table[_MACHINE_CLASS_MAX] = {
diff --git a/src/machine/machine.h b/src/machine/machine.h
index 62e4b2b340..f4aefc550f 100644
--- a/src/machine/machine.h
+++ b/src/machine/machine.h
@@ -63,7 +63,7 @@ struct Machine {
         char *service;
         char *root_directory;
 
-        char *scope;
+        char *unit;
         char *scope_job;
 
         pid_t leader;
diff --git a/src/machine/machinectl.c b/src/machine/machinectl.c
index b3a70188a4..703fb3a3a0 100644
--- a/src/machine/machinectl.c
+++ b/src/machine/machinectl.c
@@ -107,7 +107,7 @@ static int list_machines(sd_bus *bus, char **args, unsigned n) {
         return 0;
 }
 
-static int show_scope_cgroup(sd_bus *bus, const char *unit, pid_t leader) {
+static int show_unit_cgroup(sd_bus *bus, const char *unit, pid_t leader) {
         _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
         _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
         _cleanup_free_ char *path = NULL;
@@ -129,7 +129,7 @@ static int show_scope_cgroup(sd_bus *bus, const char *unit, pid_t leader) {
                         bus,
                         "org.freedesktop.systemd1",
                         path,
-                        "org.freedesktop.systemd1.Scope",
+                        endswith(unit, ".scope") ? "org.freedesktop.systemd1.Scope" : "org.freedesktop.systemd1.Service",
                         "ControlGroup",
                         &error,
                         &reply,
@@ -168,7 +168,7 @@ typedef struct MachineStatusInfo {
         sd_id128_t id;
         char *class;
         char *service;
-        char *scope;
+        char *unit;
         char *root_directory;
         pid_t leader;
         usec_t timestamp;
@@ -219,9 +219,9 @@ static void print_machine_status_info(sd_bus *bus, MachineStatusInfo *i) {
         if (i->root_directory)
                 printf("\t    Root: %s\n", i->root_directory);
 
-        if (i->scope) {
-                printf("\t    Unit: %s\n", i->scope);
-                show_scope_cgroup(bus, i->scope, i->leader);
+        if (i->unit) {
+                printf("\t    Unit: %s\n", i->unit);
+                show_unit_cgroup(bus, i->unit, i->leader);
         }
 }
 
@@ -231,7 +231,7 @@ static int show_info(const char *verb, sd_bus *bus, const char *path, bool *new_
                 { "Name",          "s",  NULL,          offsetof(MachineStatusInfo, name) },
                 { "Class",         "s",  NULL,          offsetof(MachineStatusInfo, class) },
                 { "Service",       "s",  NULL,          offsetof(MachineStatusInfo, service) },
-                { "Scope",         "s",  NULL,          offsetof(MachineStatusInfo, scope) },
+                { "Unit",          "s",  NULL,          offsetof(MachineStatusInfo, unit) },
                 { "RootDirectory", "s",  NULL,          offsetof(MachineStatusInfo, root_directory) },
                 { "Leader",        "u",  NULL,          offsetof(MachineStatusInfo, leader) },
                 { "Timestamp",     "t",  NULL,          offsetof(MachineStatusInfo, timestamp) },
@@ -264,7 +264,7 @@ static int show_info(const char *verb, sd_bus *bus, const char *path, bool *new_
         free(info.name);
         free(info.class);
         free(info.service);
-        free(info.scope);
+        free(info.unit);
         free(info.root_directory);
 
         return r;
diff --git a/src/machine/machined-dbus.c b/src/machine/machined-dbus.c
index 7c7293b29d..4a75c34dd0 100644
--- a/src/machine/machined-dbus.c
+++ b/src/machine/machined-dbus.c
@@ -169,9 +169,8 @@ static int method_list_machines(sd_bus *bus, sd_bus_message *message, void *user
         return sd_bus_send(bus, reply, NULL);
 }
 
-static int method_create_machine(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) {
+static int method_create_or_register_machine(Manager *manager, sd_bus_message *message, Machine **_m, sd_bus_error *error) {
         const char *name, *service, *class, *root_directory;
-        Manager *manager = userdata;
         MachineClass c;
         uint32_t leader;
         sd_id128_t id;
@@ -180,9 +179,9 @@ static int method_create_machine(sd_bus *bus, sd_bus_message *message, void *use
         size_t n;
         int r;
 
-        assert(bus);
-        assert(message);
         assert(manager);
+        assert(message);
+        assert(_m);
 
         r = sd_bus_message_read(message, "s", &name);
         if (r < 0)
@@ -218,10 +217,6 @@ static int method_create_machine(sd_bus *bus, sd_bus_message *message, void *use
         if (!isempty(root_directory) && !path_is_absolute(root_directory))
                 return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Root directory must be empty or an absolute path");
 
-        r = sd_bus_message_enter_container(message, 'a', "(sv)");
-        if (r < 0)
-                return r;
-
         if (leader == 0) {
                 _cleanup_bus_creds_unref_ sd_bus_creds *creds = NULL;
 
@@ -263,17 +258,70 @@ static int method_create_machine(sd_bus *bus, sd_bus_message *message, void *use
                 }
         }
 
+        *_m = m;
+
+        return 1;
+
+fail:
+        machine_add_to_gc_queue(m);
+        return r;
+}
+
+static int method_create_machine(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) {
+        Manager *manager = userdata;
+        Machine *m = NULL;
+        int r;
+
+        r = method_create_or_register_machine(manager, message, &m, error);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_enter_container(message, 'a', "(sv)");
+        if (r < 0)
+                goto fail;
+
         r = machine_start(m, message, error);
         if (r < 0)
                 goto fail;
 
         m->create_message = sd_bus_message_ref(message);
-
         return 1;
 
 fail:
         machine_add_to_gc_queue(m);
+        return r;
+}
+
+static int method_register_machine(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) {
+        Manager *manager = userdata;
+        _cleanup_free_ char *p = NULL;
+        Machine *m = NULL;
+        int r;
+
+        r = method_create_or_register_machine(manager, message, &m, error);
+        if (r < 0)
+                return r;
+
+        r = cg_pid_get_unit(m->leader, &m->unit);
+        if (r < 0) {
+                r = sd_bus_error_set_errnof(error, r, "Failed to determine unit of process "PID_FMT" : %s", m->leader, strerror(-r));
+                goto fail;
+        }
 
+        r = machine_start(m, NULL, error);
+        if (r < 0)
+                goto fail;
+
+        p = machine_bus_path(m);
+        if (!p) {
+                r = -ENOMEM;
+                goto fail;
+        }
+
+        return sd_bus_reply_method_return(message, "o", p);
+
+fail:
+        machine_add_to_gc_queue(m);
         return r;
 }
 
@@ -347,6 +395,7 @@ const sd_bus_vtable manager_vtable[] = {
         SD_BUS_METHOD("GetMachineByPID", "u", "o", method_get_machine_by_pid, SD_BUS_VTABLE_UNPRIVILEGED),
         SD_BUS_METHOD("ListMachines", NULL, "a(ssso)", method_list_machines, SD_BUS_VTABLE_UNPRIVILEGED),
         SD_BUS_METHOD("CreateMachine", "sayssusa(sv)", "o", method_create_machine, 0),
+        SD_BUS_METHOD("RegisterMachine", "sayssus", "o", method_register_machine, 0),
         SD_BUS_METHOD("KillMachine", "ssi", NULL, method_kill_machine, SD_BUS_VTABLE_CAPABILITY(CAP_KILL)),
         SD_BUS_METHOD("TerminateMachine", "s", NULL, method_terminate_machine, SD_BUS_VTABLE_CAPABILITY(CAP_KILL)),
         SD_BUS_SIGNAL("MachineNew", "so", 0),
diff --git a/src/nspawn/nspawn.c b/src/nspawn/nspawn.c
index 0a81f97298..97ef6c799d 100644
--- a/src/nspawn/nspawn.c
+++ b/src/nspawn/nspawn.c
@@ -120,6 +120,7 @@ static char **arg_setenv = NULL;
 static bool arg_quiet = false;
 static bool arg_share_system = false;
 static bool arg_register = true;
+static bool arg_keep_unit = false;
 
 static int help(void) {
 
@@ -152,6 +153,8 @@ static int help(void) {
                "     --bind-ro=PATH[:PATH]  Similar, but creates a read-only bind mount\n"
                "     --setenv=NAME=VALUE    Pass an environment variable to PID 1\n"
                "     --register=BOOLEAN     Register container as machine\n"
+               "     --keep-unit            Do not register a scope for the machine, reuse\n"
+               "                            the service unit nspawn is running in\n"
                "  -q --quiet                Do not show status information\n",
                program_invocation_short_name);
 
@@ -172,7 +175,8 @@ static int parse_argv(int argc, char *argv[]) {
                 ARG_BIND_RO,
                 ARG_SETENV,
                 ARG_SHARE_SYSTEM,
-                ARG_REGISTER
+                ARG_REGISTER,
+                ARG_KEEP_UNIT
         };
 
         static const struct option options[] = {
@@ -197,6 +201,7 @@ static int parse_argv(int argc, char *argv[]) {
                 { "quiet",                 no_argument,       NULL, 'q'                 },
                 { "share-system",          no_argument,       NULL, ARG_SHARE_SYSTEM    },
                 { "register",              required_argument, NULL, ARG_REGISTER        },
+                { "keep-unit",             no_argument,       NULL, ARG_KEEP_UNIT       },
                 {}
         };
 
@@ -410,6 +415,10 @@ static int parse_argv(int argc, char *argv[]) {
                         arg_register = r;
                         break;
 
+                case ARG_KEEP_UNIT:
+                        arg_keep_unit = true;
+                        break;
+
                 case '?':
                         return -EINVAL;
 
@@ -426,6 +435,11 @@ static int parse_argv(int argc, char *argv[]) {
                 return -EINVAL;
         }
 
+        if (arg_keep_unit && cg_pid_get_owner_uid(0, NULL) >= 0) {
+                log_error("--keep-unit may not be used when invoked from a user session.");
+                return -EINVAL;
+        }
+
         return 1;
 }
 
@@ -1086,22 +1100,41 @@ static int register_machine(pid_t pid) {
                 return r;
         }
 
-        r = sd_bus_call_method(
-                        bus,
-                        "org.freedesktop.machine1",
-                        "/org/freedesktop/machine1",
-                        "org.freedesktop.machine1.Manager",
-                        "CreateMachine",
-                        &error,
-                        NULL,
-                        "sayssusa(sv)",
-                        arg_machine,
-                        SD_BUS_MESSAGE_APPEND_ID128(arg_uuid),
-                        "nspawn",
-                        "container",
-                        (uint32_t) pid,
-                        strempty(arg_directory),
-                        !isempty(arg_slice), "Slice", "s", arg_slice);
+        if (arg_keep_unit) {
+                r = sd_bus_call_method(
+                                bus,
+                                "org.freedesktop.machine1",
+                                "/org/freedesktop/machine1",
+                                "org.freedesktop.machine1.Manager",
+                                "RegisterMachine",
+                                &error,
+                                NULL,
+                                "sayssus",
+                                arg_machine,
+                                SD_BUS_MESSAGE_APPEND_ID128(arg_uuid),
+                                "nspawn",
+                                "container",
+                                (uint32_t) pid,
+                                strempty(arg_directory));
+        } else {
+                r = sd_bus_call_method(
+                                bus,
+                                "org.freedesktop.machine1",
+                                "/org/freedesktop/machine1",
+                                "org.freedesktop.machine1.Manager",
+                                "CreateMachine",
+                                &error,
+                                NULL,
+                                "sayssusa(sv)",
+                                arg_machine,
+                                SD_BUS_MESSAGE_APPEND_ID128(arg_uuid),
+                                "nspawn",
+                                "container",
+                                (uint32_t) pid,
+                                strempty(arg_directory),
+                                !isempty(arg_slice), "Slice", "s", arg_slice);
+        }
+
         if (r < 0) {
                 log_error("Failed to register machine: %s", bus_error_message(&error, r));
                 return r;
diff --git a/src/shared/cgroup-util.c b/src/shared/cgroup-util.c
index e6ceb99454..9692a07f56 100644
--- a/src/shared/cgroup-util.c
+++ b/src/shared/cgroup-util.c
@@ -1282,39 +1282,18 @@ int cg_pid_get_user_unit(pid_t pid, char **unit) {
 }
 
 int cg_path_get_machine_name(const char *path, char **machine) {
-        const char *e, *n, *x;
-        char *s, *r;
-        size_t l;
-
-        assert(path);
-        assert(machine);
-
-        /* Skip slices, if there are any */
-        e = skip_slices(path);
-
-        n = strchrnul(e, '/');
-        if (e == n)
-                return -ENOENT;
-
-        s = strndupa(e, n - e);
-        s = cg_unescape(s);
-
-        x = startswith(s, "machine-");
-        if (!x)
-                return -ENOENT;
-        if (!endswith(x, ".scope"))
-                return -ENOENT;
+        _cleanup_free_ char *u = NULL, *sl = NULL;
+        int r;
 
-        l = strlen(x);
-        if (l <= 6)
-                return -ENOENT;
+        r = cg_path_get_unit(path, &u);
+        if (r < 0)
+                return r;
 
-        r = strndup(x, l - 6);
-        if (!r)
+        sl = strjoin("/run/systemd/machines/unit:", u, NULL);
+        if (!sl)
                 return -ENOMEM;
 
-        *machine = r;
-        return 0;
+        return readlink_malloc(sl, machine);
 }
 
 int cg_pid_get_machine_name(pid_t pid, char **machine) {