[CORE] logger: add option to disable timestamps

Add an option to disable printing the timestamp. This is useful to not
have duplicate timestamps, when stderr is piped into a logging system
that adds timestamps on its own. For example with systemd's journald:

$ journalctl -u open5gs-smfd
Apr 10 13:25:18 hostname open5gs-smfd[1582]: 04/10 13:25:18.274: [app] INFO: Configuration: '/etc/open5gs/smf.yaml' (../lib/app/ogs-init.c:130)

Configuration change:
```
<OLD Format>
logger:
  file: /var/log/open5gs/smf.log

<NEW Format>
logger:
  file:
    path: /var/log/open5gs/smf.log
```

Example config, to have no timestamps on stderr:
```
logger:
  default:
    timestamp: false
  file:
    path: /var/log/open5gs/smf.log
    timestamp: true
```

lib/app/ogs-context.h

@@ -36,10 +36,15 @@ typedef struct ogs_app_context_s {
 
     const char *db_uri;
 
+    struct {
+        ogs_log_ts_e timestamp;
+    } logger_default;
+
     struct {
         const char *file;
         const char *level;
         const char *domain;
+        ogs_log_ts_e timestamp;
     } logger;
 
     ogs_queue_t *queue;

lib/app/ogs-init.c

@@ -114,6 +114,9 @@ int ogs_app_initialize(
             ogs_app()->logger.domain, ogs_app()->logger.level);
     if (rv != OGS_OK) return rv;
 
+    ogs_log_set_timestamp(ogs_app()->logger_default.timestamp,
+                          ogs_app()->logger.timestamp);
+
     /**************************************************************************
      * Stage 5 : Setup Database Module
      */
@@ -254,6 +257,57 @@ static int context_validation(void)
     return OGS_OK;
 }
 
+static void parse_config_logger_file(ogs_yaml_iter_t *logger_iter,
+                                     const char *logger_key)
+{
+    ogs_yaml_iter_t iter;
+
+    /* Legacy format:
+     *   logger:
+     *     file: /var/log/open5gs/mme.log */
+    if (!strcmp(logger_key, "file") && ogs_yaml_iter_has_value(logger_iter)) {
+        ogs_app()->logger.file = ogs_yaml_iter_value(logger_iter);
+
+        ogs_warn("Please change the configuration file as below.");
+        ogs_log_print(OGS_LOG_WARN, "\n<OLD Format>\n");
+        ogs_log_print(OGS_LOG_WARN, "logger:\n");
+        ogs_log_print(OGS_LOG_WARN, "  file: %s\n", ogs_app()->logger.file);
+        ogs_log_print(OGS_LOG_WARN, "\n<NEW Format>\n");
+        ogs_log_print(OGS_LOG_WARN, "logger:\n");
+        ogs_log_print(OGS_LOG_WARN, "  file:\n");
+        ogs_log_print(OGS_LOG_WARN, "    path: %s\n", ogs_app()->logger.file);
+        ogs_log_print(OGS_LOG_WARN, "\n\n\n");
+        return;
+    }
+
+    /* Current format:
+     *   logger:
+     *     default:
+     *       timestamp: false
+     *     file:
+     *       path: /var/log/open5gs/mme.log
+     *       timestamp: true */
+    ogs_yaml_iter_recurse(logger_iter, &iter);
+    while (ogs_yaml_iter_next(&iter)) {
+        const char *key = ogs_yaml_iter_key(&iter);
+        ogs_assert(key);
+        if (!strcmp(key, "timestamp")) {
+            ogs_log_ts_e ts = ogs_yaml_iter_bool(&iter)
+                              ? OGS_LOG_TS_ENABLED
+                              : OGS_LOG_TS_DISABLED;
+            if (!strcmp(logger_key, "default")) {
+                ogs_app()->logger_default.timestamp = ts;
+            } else if (!strcmp(logger_key, "file")) {
+                ogs_app()->logger.timestamp = ts;
+            }
+        } else if (!strcmp(key, "path")) {
+            if (!strcmp(logger_key, "file")) {
+                ogs_app()->logger.file = ogs_yaml_iter_value(&iter);
+            }
+        }
+    }
+}
+
 static int parse_config(void)
 {
     int rv;
@@ -278,9 +332,8 @@ static int parse_config(void)
             while (ogs_yaml_iter_next(&logger_iter)) {
                 const char *logger_key = ogs_yaml_iter_key(&logger_iter);
                 ogs_assert(logger_key);
-                if (!strcmp(logger_key, "file")) {
-                    ogs_app()->logger.file = ogs_yaml_iter_value(&logger_iter);
-                } else if (!strcmp(logger_key, "level")) {
+                parse_config_logger_file(&logger_iter, logger_key);
+                if (!strcmp(logger_key, "level")) {
                     ogs_app()->logger.level =
                         ogs_yaml_iter_value(&logger_iter);
                 } else if (!strcmp(logger_key, "domain")) {

lib/app/ogs-yaml.c

@@ -178,6 +178,34 @@ const char *ogs_yaml_iter_value(ogs_yaml_iter_t *iter)
     return NULL;
 }
 
+int ogs_yaml_iter_has_value(ogs_yaml_iter_t *iter)
+{
+    ogs_assert(iter);
+    ogs_assert(iter->document);
+    ogs_assert(iter->node);
+
+    if (iter->node->type == YAML_SCALAR_NODE) {
+        return 1;
+    } else if (iter->node->type == YAML_MAPPING_NODE) {
+        yaml_node_t *node = NULL;
+
+        ogs_assert(iter->pair);
+        node = yaml_document_get_node(iter->document, iter->pair->value);
+        ogs_assert(node);
+        return node->type == YAML_SCALAR_NODE;
+    } else if (iter->node->type == YAML_SEQUENCE_NODE) {
+        yaml_node_t *node = NULL;
+
+        ogs_assert(iter->item);
+        node = yaml_document_get_node(iter->document, *iter->item);
+        ogs_assert(node);
+        return node->type == YAML_SCALAR_NODE;
+    }
+
+    ogs_assert_if_reached();
+    return 0;
+}
+
 int ogs_yaml_iter_bool(ogs_yaml_iter_t *iter)
 {
     const char *v = ogs_yaml_iter_value(iter);

lib/app/ogs-yaml.h

@@ -59,6 +59,7 @@ void ogs_yaml_iter_recurse(ogs_yaml_iter_t *parent, ogs_yaml_iter_t *iter);
 int ogs_yaml_iter_type(ogs_yaml_iter_t *iter);
 const char *ogs_yaml_iter_key(ogs_yaml_iter_t *iter);
 const char *ogs_yaml_iter_value(ogs_yaml_iter_t *iter);
+int ogs_yaml_iter_has_value(ogs_yaml_iter_t *iter);
 int ogs_yaml_iter_bool(ogs_yaml_iter_t *iter);
 
 #ifdef __cplusplus

lib/core/ogs-log.c

@@ -340,6 +340,28 @@ void ogs_log_set_mask_level(const char *_mask, ogs_log_level_e level)
     }
 }
 
+void ogs_log_set_timestamp(ogs_log_ts_e ts_default, ogs_log_ts_e ts_file)
+{
+    ogs_log_t *log;
+
+    if (ts_default == OGS_LOG_TS_UNSET)
+        ts_default = OGS_LOG_TS_ENABLED;
+
+    if (ts_file == OGS_LOG_TS_UNSET)
+        ts_file = ts_default;
+
+    ogs_list_for_each(&log_list, log) {
+        switch (log->type) {
+            case OGS_LOG_FILE_TYPE:
+                log->print.timestamp = (ts_file == OGS_LOG_TS_ENABLED);
+                break;
+            default:
+                log->print.timestamp = (ts_default == OGS_LOG_TS_ENABLED);
+                break;
+        }
+    }
+}
+
 static ogs_log_level_e ogs_log_level_from_string(const char *string)
 {
     ogs_log_level_e level = OGS_ERROR;

lib/core/ogs-log.h

@@ -64,6 +64,12 @@ typedef enum {
     OGS_LOG_FULL = OGS_LOG_TRACE,
 } ogs_log_level_e;
 
+typedef enum {
+    OGS_LOG_TS_UNSET,
+    OGS_LOG_TS_ENABLED,
+    OGS_LOG_TS_DISABLED,
+} ogs_log_ts_e;
+
 typedef struct ogs_log_s ogs_log_t;
 typedef struct ogs_log_domain_s ogs_log_domain_t;
 
@@ -90,6 +96,7 @@ void ogs_log_install_domain(int *domain_id,
 int ogs_log_config_domain(const char *domain, const char *level);
 
 void ogs_log_set_mask_level(const char *mask, ogs_log_level_e level);
+void ogs_log_set_timestamp(ogs_log_ts_e ts_default, ogs_log_ts_e ts_file);
 
 void ogs_log_vprintf(ogs_log_level_e level, int id,
     ogs_err_t err, const char *file, int line, const char *func,