knotc: add 'conf-snapshot' command

src/knot/ctl/commands.c

@@ -2271,6 +2271,42 @@ static int ctl_conf_modify(ctl_args_t *args, ctl_cmd_t cmd)
 	return ret;
 }
 
+static int ctl_conf_snapshot(ctl_args_t *args, ctl_cmd_t cmd)
+{
+	assert(conf() != NULL);
+
+	int ret = KNOT_EOK;
+	const char *output_path = args->data[KNOT_CTL_IDX_DATA];
+	if (output_path == NULL || output_path[0] == '\0') {
+		ret = KNOT_EINVAL;
+		log_ctl_error("control, conf-snapshot (missing destination)");
+		send_error(args, knot_strerror(ret));
+		return ret;
+	}
+
+	// Create confdb directory
+	ret = make_dir(output_path, LMDB_DIR_MODE, true);
+	if (ret != KNOT_EOK) {
+		const char *err_str = knot_strerror(ret);
+		log_ctl_error("control, conf-snapshot failed to create destination directory (%s)", err_str);
+		send_error(args, err_str);
+		return ret;
+	}
+
+	// Snapshot configuration database
+	ret = knot_db_lmdb_clone(conf()->db, output_path);
+	if (ret != KNOT_EOK) {
+		const char *err_str = knot_strerror(ret);
+		log_ctl_error("control, unable to store confdb (%s)", err_str);
+		send_error(args, err_str);
+		return ret;
+	}
+
+	log_ctl_info("control, current confdb snapshot were saved at '%s'", output_path);
+
+	return ret;
+}
+
 typedef struct {
 	const char *name;
 	int (*fcn)(ctl_args_t *, ctl_cmd_t);
@@ -2322,6 +2358,7 @@ static const desc_t cmd_table[] = {
 	[CTL_CONF_GET]        = { "conf-get",        ctl_conf_read },
 	[CTL_CONF_SET]        = { "conf-set",        ctl_conf_modify },
 	[CTL_CONF_UNSET]      = { "conf-unset",      ctl_conf_modify },
+	[CTL_CONF_SNAPSHOT]   = { "conf-snapshot",   ctl_conf_snapshot },
 };
 
 #define MAX_CTL_CODE (sizeof(cmd_table) / sizeof(desc_t) - 1)

src/knot/ctl/commands.h

@@ -116,6 +116,7 @@ typedef enum {
 	CTL_CONF_GET,
 	CTL_CONF_SET,
 	CTL_CONF_UNSET,
+	CTL_CONF_SNAPSHOT,
 } ctl_cmd_t;
 
 /*! Control command parameters. */

src/libknot/db/db_lmdb.c

@@ -559,6 +559,28 @@ const char *knot_db_lmdb_get_path(knot_db_t *db)
 	}
 }
 
+_public_
+int knot_db_lmdb_clone(knot_db_t *db, const char *path)
+{
+	struct lmdb_env *env = db;
+	// NOTE: Must be opened for copy
+	if (env == NULL || env->env == NULL) {
+		return KNOT_EACCES;
+	}
+
+	int ret = make_dir(path, LMDB_DIR_MODE, true);
+	if (ret != KNOT_EOK) {
+		return ret;
+	}
+
+	ret = mdb_env_copy(env->env, path);
+	if (ret != KNOT_EOK) {
+		return knot_map_errno_code(ret);
+	}
+	return KNOT_EOK;
+
+}
+
 _public_
 const knot_db_api_t *knot_db_lmdb_api(void)
 {

src/libknot/db/db_lmdb.h

@@ -69,5 +69,6 @@ int knot_db_lmdb_iter_del(knot_db_iter_t *iter);
 size_t knot_db_lmdb_get_mapsize(knot_db_t *db);
 size_t knot_db_lmdb_get_usage(knot_db_t *db);
 const char *knot_db_lmdb_get_path(knot_db_t *db);
+int knot_db_lmdb_clone(knot_db_t *db, const char *path);
 
 /*! @} */

src/utils/knotc/commands.c

@@ -84,6 +84,7 @@
 #define CMD_CONF_GET		"conf-get"
 #define CMD_CONF_SET		"conf-set"
 #define CMD_CONF_UNSET		"conf-unset"
+#define CMD_CONF_SNAPSHOT	"conf-snapshot"
 
 #define CTL_LOG_STR		"failed to control"
 
@@ -244,6 +245,7 @@ static void format_data(cmd_args_t *args, knot_ctl_type_t data_type,
 	case CTL_RELOAD:
 	case CTL_CONF_BEGIN:
 	case CTL_CONF_ABORT:
+	case CTL_CONF_SNAPSHOT:
 		// Only error message is expected here.
 		if (error != NULL) {
 			printf("error: (%s)", error);
@@ -404,6 +406,7 @@ static void format_block(ctl_cmd_t cmd, bool failed, bool empty)
 	case CTL_CONF_COMMIT:
 	case CTL_CONF_ABORT:
 	case CTL_CONF_SET:
+	case CTL_CONF_SNAPSHOT:
 	case CTL_CONF_UNSET:
 	case CTL_ZONE_RELOAD:
 	case CTL_ZONE_REFRESH:
@@ -1225,6 +1228,27 @@ static int cmd_conf_export(cmd_args_t *args)
 	return ret;
 }
 
+static int cmd_conf_snapshot(cmd_args_t *args)
+{
+	int ret = check_args(args, 1, 1);
+	if (ret != KNOT_EOK) {
+		if (args->argv == 0) {
+			log_error("conf-snapshot (missing argument)");
+		}
+		return ret;
+	}
+
+	knot_ctl_data_t data = {
+		[KNOT_CTL_IDX_CMD] = ctl_cmd_to_str(args->desc->cmd),
+		[KNOT_CTL_IDX_FLAGS] = args->flags,
+		[KNOT_CTL_IDX_DATA] = args->argv[0],
+	};
+	CTL_SEND_DATA
+	CTL_SEND_BLOCK
+
+	return ctl_receive(args);
+}
+
 static int cmd_conf_ctl(cmd_args_t *args)
 {
 	// Check the number of arguments.
@@ -1321,6 +1345,7 @@ const cmd_desc_t cmd_table[] = {
 	{ CMD_CONF_CHECK,      cmd_conf_check,    CTL_NONE,            CMD_FREAD  | CMD_FREQ_MOD },
 	{ CMD_CONF_IMPORT,     cmd_conf_import,   CTL_NONE,            CMD_FWRITE | CMD_FOPT_MOD },
 	{ CMD_CONF_EXPORT,     cmd_conf_export,   CTL_NONE,            CMD_FREAD  | CMD_FOPT_MOD },
+	{ CMD_CONF_SNAPSHOT,   cmd_conf_snapshot, CTL_CONF_SNAPSHOT,   CMD_FOPT_DATA },
 	{ CMD_CONF_LIST,       cmd_conf_ctl,      CTL_CONF_LIST,       CMD_FOPT_ITEM | CMD_FLIST_SCHEMA },
 	{ CMD_CONF_READ,       cmd_conf_ctl,      CTL_CONF_READ,       CMD_FOPT_ITEM },
 	{ CMD_CONF_BEGIN,      cmd_conf_ctl,      CTL_CONF_BEGIN },