run: add support for executing commands remotely via SSH or in a container

Also, unify the transport logic a bit, since we reuse the same scheme in
many of our client tools.

man/systemd-run.xml

@@ -112,6 +112,27 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>.
         </listitem>
       </varlistentry>
 
+      <varlistentry>
+              <term><option>-H</option></term>
+              <term><option>--host=</option></term>
+
+              <listitem><para>Execute operation
+              remotely. Specify a hostname, or
+              username and hostname separated by <literal>@</literal>,
+              to connect to. This will use SSH to
+              talk to the remote machine manager
+              instance.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+              <term><option>-M</option></term>
+              <term><option>--machine=</option></term>
+
+              <listitem><para>Execute operation on a
+              local container. Specify a container
+              name to connect to.</para></listitem>
+      </varlistentry>
+
       <varlistentry>
         <term><option>--scope</option></term>
 
@@ -212,7 +233,8 @@ Sep 08 07:37:21 bupkis env[19948]: BOOT_IMAGE=/vmlinuz-3.11.0-0.rc5.git6.2.fc20.
       <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
       <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
       <citerefentry><refentrytitle>systemd.scope</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
-      <citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
+      <citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
     </para>
   </refsect1>
 

src/libsystemd-bus/bus-container.c

@@ -44,6 +44,8 @@ int bus_container_connect(sd_bus *b) {
                 return -ENOMEM;
 
         r = parse_env_file(p, NEWLINE, "LEADER", &s, "CLASS", &class, NULL);
+        if (r == -ENOENT)
+                return -EHOSTDOWN;
         if (r < 0)
                 return r;
         if (!s)

src/libsystemd-bus/bus-util.c

@@ -594,3 +594,38 @@ int bus_generic_print_property(const char *name, sd_bus_message *property, bool
 
         return 0;
 }
+
+int bus_open_transport(BusTransport transport, const char *host, bool user, sd_bus **bus) {
+        int r;
+
+        assert(transport >= 0);
+        assert(transport < _BUS_TRANSPORT_MAX);
+        assert(bus);
+
+        assert_return((transport == BUS_TRANSPORT_LOCAL) == !host, -EINVAL);
+        assert_return(transport == BUS_TRANSPORT_LOCAL || !user, -ENOTSUP);
+
+        switch (transport) {
+
+        case BUS_TRANSPORT_LOCAL:
+                if (user)
+                        r = sd_bus_open_user(bus);
+                else
+                        r = sd_bus_open_system(bus);
+
+                break;
+
+        case BUS_TRANSPORT_REMOTE:
+                r = sd_bus_open_system_remote(host, bus);
+                break;
+
+        case BUS_TRANSPORT_CONTAINER:
+                r = sd_bus_open_system_container(host, bus);
+                break;
+
+        default:
+                assert_not_reached("Hmm, unknown transport type.");
+        }
+
+        return r;
+}

src/libsystemd-bus/bus-util.h

@@ -27,6 +27,14 @@
 #include "time-util.h"
 #include "util.h"
 
+typedef enum BusTransport {
+        BUS_TRANSPORT_LOCAL,
+        BUS_TRANSPORT_REMOTE,
+        BUS_TRANSPORT_CONTAINER,
+        _BUS_TRANSPORT_MAX,
+        _BUS_TRANSPORT_INVALID = -1
+} BusTransport;
+
 int bus_async_unregister_and_quit(sd_event *e, sd_bus *bus, const char *name);
 
 int bus_event_loop_with_idle(sd_event *e, sd_bus *bus, const char *name, usec_t timeout);
@@ -39,6 +47,8 @@ void bus_verify_polkit_async_registry_free(sd_bus *bus, Hashmap *registry);
 
 int bus_open_system_systemd(sd_bus **_bus);
 
+int bus_open_transport(BusTransport transport, const char *host, bool user, sd_bus **bus);
+
 int bus_generic_print_property(const char *name, sd_bus_message *property, bool all);
 
 DEFINE_TRIVIAL_CLEANUP_FUNC(sd_bus*, sd_bus_unref);

src/machine/machinectl.c

@@ -27,7 +27,6 @@
 #include <locale.h>
 
 #include "sd-bus.h"
-
 #include "log.h"
 #include "util.h"
 #include "macro.h"
@@ -46,12 +45,8 @@ static bool arg_full = false;
 static bool arg_no_pager = false;
 static const char *arg_kill_who = NULL;
 static int arg_signal = SIGTERM;
-static enum transport {
-        TRANSPORT_LOCAL,
-        TRANSPORT_REMOTE,
-        TRANSPORT_CONTAINER
-} arg_transport = TRANSPORT_LOCAL;
 static bool arg_ask_password = true;
+static BusTransport arg_transport = BUS_TRANSPORT_LOCAL;
 static char *arg_host = NULL;
 
 static void pager_open_if_enabled(void) {
@@ -126,7 +121,7 @@ static int show_scope_cgroup(sd_bus *bus, const char *unit, pid_t leader) {
         assert(bus);
         assert(unit);
 
-        if (arg_transport == TRANSPORT_REMOTE)
+        if (arg_transport == BUS_TRANSPORT_REMOTE)
                 return 0;
 
         path = unit_dbus_path_from_name(unit);
@@ -628,12 +623,12 @@ static int parse_argv(int argc, char *argv[]) {
                         break;
 
                 case 'H':
-                        arg_transport = TRANSPORT_REMOTE;
+                        arg_transport = BUS_TRANSPORT_REMOTE;
                         arg_host = optarg;
                         break;
 
                 case 'M':
-                        arg_transport = TRANSPORT_CONTAINER;
+                        arg_transport = BUS_TRANSPORT_CONTAINER;
                         arg_host = optarg;
                         break;
 
@@ -749,16 +744,9 @@ int main(int argc, char*argv[]) {
                 goto finish;
         }
 
-        if (arg_transport == TRANSPORT_LOCAL)
+        r = bus_open_transport(arg_transport, arg_host, false, &bus);
-                r = sd_bus_open_system(&bus);
-        else if (arg_transport == TRANSPORT_REMOTE)
-                r = sd_bus_open_system_remote(arg_host, &bus);
-        else if (arg_transport == TRANSPORT_CONTAINER)
-                r = sd_bus_open_system_container(arg_host, &bus);
-        else
-                assert_not_reached("Uh, invalid transport...");
         if (r < 0) {
-                log_error("Failed to connect to machined: %s", strerror(-r));
+                log_error("Failed to create bus connection: %s", strerror(-r));
                 ret = EXIT_FAILURE;
                 goto finish;
         }

src/run/run.c

@@ -30,12 +30,14 @@
 #include "path-util.h"
 
 static bool arg_scope = false;
-static bool arg_user = false;
 static bool arg_remain_after_exit = false;
 static const char *arg_unit = NULL;
 static const char *arg_description = NULL;
 static const char *arg_slice = NULL;
 static bool arg_send_sighup = false;
+static BusTransport arg_transport = BUS_TRANSPORT_LOCAL;
+static char *arg_host = NULL;
+static bool arg_user = false;
 
 static int help(void) {
 
@@ -44,6 +46,8 @@ static int help(void) {
                "  -h --help               Show this help\n"
                "     --version            Show package version\n"
                "     --user               Run as user unit\n"
+               "  -H --host=[USER@]HOST  Operate on remote host\n"
+               "  -M --machine=CONTAINER Operate on local container\n"
                "     --scope              Run this as scope rather than service\n"
                "     --unit=UNIT          Run under the specified unit name\n"
                "     --description=TEXT   Description for unit\n"
@@ -77,6 +81,8 @@ static int parse_argv(int argc, char *argv[]) {
                 { "slice",             required_argument, NULL, ARG_SLICE       },
                 { "remain-after-exit", no_argument,       NULL, 'r'             },
                 { "send-sighup",       no_argument,       NULL, ARG_SEND_SIGHUP },
+                { "host",              required_argument, NULL, 'H'             },
+                { "machine",           required_argument, NULL, 'M'             },
                 { NULL,                0,                 NULL, 0               },
         };
 
@@ -85,7 +91,7 @@ static int parse_argv(int argc, char *argv[]) {
         assert(argc >= 0);
         assert(argv);
 
-        while ((c = getopt_long(argc, argv, "+hr", options, NULL)) >= 0) {
+        while ((c = getopt_long(argc, argv, "+hrH:M:", options, NULL)) >= 0) {
 
                 switch (c) {
 
@@ -126,6 +132,16 @@ static int parse_argv(int argc, char *argv[]) {
                         arg_remain_after_exit = true;
                         break;
 
+                case 'H':
+                        arg_transport = BUS_TRANSPORT_REMOTE;
+                        arg_host = optarg;
+                        break;
+
+                case 'M':
+                        arg_transport = BUS_TRANSPORT_CONTAINER;
+                        arg_host = optarg;
+                        break;
+
                 case '?':
                         return -EINVAL;
 
@@ -140,6 +156,16 @@ static int parse_argv(int argc, char *argv[]) {
                 return -EINVAL;
         }
 
+        if (arg_user && arg_transport != BUS_TRANSPORT_LOCAL) {
+                log_error("Execution in user context is not supported on non-local systems.");
+                return -EINVAL;
+        }
+
+        if (arg_scope && arg_transport != BUS_TRANSPORT_LOCAL) {
+                log_error("Scope execution is not supported on non-local systems.");
+                return -EINVAL;
+        }
+
         return 1;
 }
 
@@ -351,12 +377,9 @@ int main(int argc, char* argv[]) {
                 arg_description = description;
         }
 
-        if (arg_user)
+        r = bus_open_transport(arg_transport, arg_host, arg_user, &bus);
-                r = sd_bus_open_user(&bus);
-        else
-                r = sd_bus_open_system(&bus);
         if (r < 0) {
-                log_error("Failed to create new bus connection: %s", strerror(-r));
+                log_error("Failed to create bus connection: %s", strerror(-r));
                 goto fail;
         }