hirtectl - implement getting remote unit status

New hirtectl command - status node unit
Add new the new file to the build and include it
main - support status and add to usage
expose create_message_new_method_call to allow internal usage
string-util - add isempty
update the man page

Signed-off-by: Ygal Blum <ygal.blum@gmail.com>

doc/man/hirtectl.1.md

@@ -40,7 +40,7 @@ Creates a monitor on the given agent to observe changes in the specified units.
 
 ### **hirtectl** *monitor* *node-connection*
 
-Creates a monitor to observe connection state changes for all nodes. 
+Creates a monitor to observe connection state changes for all nodes.
 
 
 **Example:**
@@ -54,3 +54,7 @@ hirtectl monitor \\\* dbus.service,apache2.service
 ### **hirtectl** *daemon-reload* [*agent*]
 
 Performs `daemon-reload` for the `hirte-agent`.
+
+### **hirtectl** [*status*] [*agent*] [*unit1*,*...*]
+
+Fetches the status of the systemd units for the `hirte-agent`.

src/client/client.c

@@ -10,6 +10,7 @@
 #include "client.h"
 #include "method_list_units.h"
 #include "method_monitor.h"
+#include "method_status.h"
 
 Client *new_client(char *op, int opargc, char **opargv, char *opt_filter_glob) {
         Client *client = malloc0(sizeof(Client));
@@ -302,7 +303,7 @@ int method_metrics_listen(Client *client) {
         return r;
 }
 
-static int create_message_new_method_call(
+int create_message_new_method_call(
                 Client *client, const char *node_name, const char *member, sd_bus_message **new_message) {
         int r = 0;
         _cleanup_sd_bus_message_ sd_bus_message *outgoing_message = NULL;
@@ -614,6 +615,11 @@ int client_call_manager(Client *client) {
                         return -EINVAL;
                 }
                 r = method_daemon_reload_on(client, client->opargv[0]);
+        } else if (streq(client->op, "status")) {
+                if (client->opargc < 2) {
+                        return -EINVAL;
+                }
+                r = method_status_unit_on(client, client->opargv[0], &client->opargv[1], client->opargc - 1);
         } else {
                 return -EINVAL;
         }
@@ -651,5 +657,7 @@ int print_client_usage(char *argv) {
         printf("    usage: monitor node-connection\n");
         printf("  - daemon-reload: reload systemd daemon on a specific node\n");
         printf("    usage: disable nodename\n");
+        printf("  - status: get the status of systemd units on a specific node\n");
+        printf("    usage: status nodename unitfilename...\n");
         return 0;
 }

src/client/client.h

@@ -31,3 +31,6 @@ int print_client_usage(char *argv);
 
 DEFINE_CLEANUP_FUNC(Client, client_unref)
 #define _cleanup_client_ _cleanup_(client_unrefp)
+
+int create_message_new_method_call(
+                Client *client, const char *node_name, const char *member, sd_bus_message **new_message);

src/client/meson.build

@@ -6,7 +6,8 @@ client_src = [
   'main.c',
   'client.c',
   'method_monitor.c',
-  'method_list_units.c'
+  'method_list_units.c',
+  'method_status.c'
 ]
 
 executable(

src/client/method_status.c

@@ -0,0 +1,281 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#include "libhirte/bus/utils.h"
+#include "libhirte/common/common.h"
+
+#include "client.h"
+#include "method_status.h"
+
+typedef struct unit_info_t {
+        const char *id;
+        const char *load_state;
+        const char *active_state;
+        const char *sub_state;
+        const char *unit_file_state;
+} unit_info_t;
+
+struct bus_properties_map {
+        const char *member;
+        size_t offset;
+};
+
+static const struct bus_properties_map property_map[] = {
+        { "Id", offsetof(unit_info_t, id) },
+        { "LoadState", offsetof(unit_info_t, load_state) },
+        { "ActiveState", offsetof(unit_info_t, active_state) },
+        { "SubState", offsetof(unit_info_t, sub_state) },
+        { "UnitFileState", offsetof(unit_info_t, unit_file_state) },
+        {}
+};
+
+static int get_property_map(sd_bus_message *m, const struct bus_properties_map **prop) {
+        int r = 0;
+        const char *member = NULL;
+        int i = 0;
+
+        r = sd_bus_message_read_basic(m, SD_BUS_TYPE_STRING, &member);
+        if (r < 0) {
+                fprintf(stderr, "Failed to read the name of the property: %s\n", strerror(-r));
+                return r;
+        }
+
+        for (i = 0; property_map[i].member; i++) {
+                if (streq(property_map[i].member, member)) {
+                        *prop = &property_map[i];
+                        break;
+                }
+        }
+
+        return 0;
+}
+
+static int read_property_value(sd_bus_message *m, const struct bus_properties_map *prop, unit_info_t *unit_info) {
+        int r = 0;
+        char type = 0;
+        const char *contents = NULL;
+        const char *s = NULL;
+        const char **v = (const char **) ((uint8_t *) unit_info + prop->offset);
+
+        r = sd_bus_message_peek_type(m, NULL, &contents);
+        if (r < 0) {
+                fprintf(stderr, "Failed to peek into the type of the property: %s\n", strerror(-r));
+                return r;
+        }
+
+        r = sd_bus_message_enter_container(m, SD_BUS_TYPE_VARIANT, contents);
+        if (r < 0) {
+                fprintf(stderr, "Failed to enter into the container of the property: %s\n", strerror(-r));
+                return r;
+        }
+
+        r = sd_bus_message_peek_type(m, &type, NULL);
+        if (r < 0) {
+                fprintf(stderr, "Failed to get the type of the property: %s\n", strerror(-r));
+                return r;
+        }
+
+        if (type != SD_BUS_TYPE_STRING) {
+                fprintf(stderr, "Currently only string types are expected\n");
+                return -EINVAL;
+        }
+
+        r = sd_bus_message_read_basic(m, type, &s);
+        if (r < 0) {
+                fprintf(stderr, "Failed to get the value of the property: %s\n", strerror(-r));
+                return r;
+        }
+
+        if (isempty(s)) {
+                s = NULL;
+        }
+
+        *v = s;
+
+        r = sd_bus_message_exit_container(m);
+        if (r < 0) {
+                fprintf(stderr, "Failed to exit from the container of the property: %s\n", strerror(-r));
+        }
+
+        return r;
+}
+
+static int process_dict_entry(sd_bus_message *m, unit_info_t *unit_info) {
+        int r = 0;
+        const struct bus_properties_map *prop = NULL;
+
+        r = get_property_map(m, &prop);
+        if (r < 0) {
+                return r;
+        }
+
+        if (prop) {
+                r = read_property_value(m, prop, unit_info);
+                if (r < 0) {
+                        fprintf(stderr,
+                                "Failed to get the value for member %s - %s\n",
+                                prop->member,
+                                strerror(-r));
+                }
+        } else {
+                r = sd_bus_message_skip(m, "v");
+                if (r < 0) {
+                        fprintf(stderr, "Failed to skip the property container: %s\n", strerror(-r));
+                }
+        }
+
+        return r;
+}
+
+static int parse_unit_status_response_from_message(sd_bus_message *m, unit_info_t *unit_info) {
+        int r = 0;
+
+        r = sd_bus_message_enter_container(m, SD_BUS_TYPE_ARRAY, "{sv}");
+        if (r < 0) {
+                fprintf(stderr, "Failed to open the strings array container: %s\n", strerror(-r));
+                return r;
+        }
+
+        for (;;) {
+                r = sd_bus_message_enter_container(m, SD_BUS_TYPE_DICT_ENTRY, "sv");
+                if (r < 0) {
+                        fprintf(stderr, "Failed to enter the property container: %s\n", strerror(-r));
+                        return r;
+                }
+
+                if (r == 0) {
+                        break;
+                }
+
+                r = process_dict_entry(m, unit_info);
+                if (r < 0) {
+                        break;
+                }
+
+                r = sd_bus_message_exit_container(m);
+                if (r < 0) {
+                        fprintf(stderr, "Failed to exit the property container: %s\n", strerror(-r));
+                        break;
+                }
+        }
+
+        return r;
+}
+
+#define PRINT_TAB_SIZE 8
+static void print_info_header(unsigned long name_col_width) {
+        unsigned long i = 0;
+
+        fprintf(stderr, "UNIT");
+        for (i = name_col_width; i > 0; i -= PRINT_TAB_SIZE) {
+                fprintf(stderr, "\t");
+        }
+
+        fprintf(stderr, "| LOADED\t| ACTIVE\t| SUBSTATE\t| ENABLED\t|\n");
+        for (i = name_col_width; i > 0; i -= PRINT_TAB_SIZE) {
+                fprintf(stderr, "--------");
+        }
+        fprintf(stderr, "----------------");
+        fprintf(stderr, "----------------");
+        fprintf(stderr, "----------------");
+        fprintf(stderr, "----------------\n");
+}
+
+#define PRINT_AND_ALIGN(x)                                       \
+        do {                                                     \
+                fprintf(stderr, "| %s\t", unit_info->x);         \
+                if (!unit_info->x || strlen(unit_info->x) < 6) { \
+                        fprintf(stderr, "\t");                   \
+                }                                                \
+        } while (0)
+
+
+static void print_unit_info(unit_info_t *unit_info, unsigned long name_col_width) {
+        unsigned long i = 0;
+
+        if (unit_info->load_state && streq(unit_info->load_state, "not-found")) {
+                fprintf(stderr, "Unit %s could not be found.\n", unit_info->id);
+                return;
+        }
+
+        fprintf(stderr, "%s", unit_info->id);
+        name_col_width -= unit_info->id ? strlen(unit_info->id) : 0;
+        name_col_width += PRINT_TAB_SIZE;
+        for (i = name_col_width; i > 0; i -= PRINT_TAB_SIZE) {
+                fprintf(stderr, "\t");
+        }
+
+        PRINT_AND_ALIGN(load_state);
+        PRINT_AND_ALIGN(active_state);
+        PRINT_AND_ALIGN(sub_state);
+        PRINT_AND_ALIGN(unit_file_state);
+
+        fprintf(stderr, "|\n");
+}
+
+static unsigned long get_max_name_len(char **units, size_t units_count) {
+        size_t i = 0;
+        unsigned long max_unit_name_len = 0;
+
+        for (i = 0; i < units_count; i++) {
+                unsigned long unit_name_len = strlen(units[i]);
+                max_unit_name_len = max_unit_name_len > unit_name_len ? max_unit_name_len : unit_name_len;
+        }
+
+        return max_unit_name_len;
+}
+
+static int get_status_unit_on(Client *client, char *node_name, char *unit_name, unsigned long name_col_width) {
+        int r = 0;
+        _cleanup_sd_bus_error_ sd_bus_error error = SD_BUS_ERROR_NULL;
+        _cleanup_sd_bus_message_ sd_bus_message *result = NULL;
+        _cleanup_sd_bus_message_ sd_bus_message *outgoing_message = NULL;
+        unit_info_t unit_info = { 0 };
+
+        r = create_message_new_method_call(client, node_name, "GetUnitProperties", &outgoing_message);
+        if (r < 0) {
+                fprintf(stderr, "Failed to create a new message: %s\n", strerror(-r));
+                return r;
+        }
+
+        r = sd_bus_message_append(outgoing_message, "ss", unit_name, "");
+        if (r < 0) {
+                fprintf(stderr, "Failed to append runtime to the message: %s\n", strerror(-r));
+                return r;
+        }
+
+        r = sd_bus_call(client->api_bus, outgoing_message, HIRTE_DEFAULT_DBUS_TIMEOUT, &error, &result);
+        if (r < 0) {
+                fprintf(stderr, "Failed to issue call: %s\n", error.message);
+                return r;
+        }
+
+        r = parse_unit_status_response_from_message(result, &unit_info);
+        if (r < 0) {
+                fprintf(stderr, "Failed to parse the response strings array: %s\n", error.message);
+                return r;
+        }
+
+        print_unit_info(&unit_info, name_col_width);
+
+        return 0;
+}
+
+int method_status_unit_on(Client *client, char *node_name, char **units, size_t units_count) {
+        unsigned i = 0;
+
+        unsigned long max_name_len = get_max_name_len(units, units_count);
+
+        print_info_header(max_name_len);
+        for (i = 0; i < units_count; i++) {
+                int r = get_status_unit_on(client, node_name, units[i], max_name_len);
+                if (r < 0) {
+                        fprintf(stderr,
+                                "Failed to get status of unit %s on node %s - %s",
+                                units[i],
+                                node_name,
+                                strerror(-r));
+                        return r;
+                }
+        }
+
+        return 0;
+}

src/client/method_status.h

@@ -0,0 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#include <stddef.h>
+
+#include "types.h"
+
+int method_status_unit_on(Client *client, char *node_name, char **units, size_t units_count);

src/libhirte/common/string-util.h

@@ -70,3 +70,7 @@ static inline bool match_glob(const char *str, const char *glob) {
         return !*glob;
 }
 // NOLINTEND(misc-no-recursion)
+
+static inline bool isempty(const char *a) {
+        return !a || a[0] == '\0';
+}