[agroal#44] Support for custom log line prefix.

This introduces the configuration parameter `log_line_prefix`
that accepts a strftime(3) valid string that is parsed
and stored at the very first log entry in the configuration
structure (`config->log_line_prefix`).
Logging to a file and to the console is done using such
prefix via strftime.

Documentation updated.

Close agroal#44

doc/CONFIGURATION.md

@@ -29,7 +29,8 @@ See a [sample](./etc/pgagroal/pgagroal.conf) configuration for running `pgagroal
 | management | 0 | Int | No | The remote management port (disable = 0) |
 | log_type | console | String | No | The logging type (console, file, syslog) |
 | log_level | info | String | No | The logging level (fatal, error, warn, info, debug1, ..., debug5) |
-| log_path | pgagroal.log | String | No | The log file location |
+| log_line_prefix | %Y-%m-%d %H:%M:%S | String | No | A prefix to place on every log entry, accepts escape sequences that strftime(3) can parse. No spaces between the string parts are allowed. |
+| log_path | pgagroal.log | String | No | The log file location. Can include escape sequences that strftime(3) accepts, e.g., pgagroal-%Y-%m-%d-%H-%M-%S.log |
 | log_rotation_age | -1 | String | No | The age that will trigger a log file rotation. If expressed as a positive number, is managed as seconds. Supports suffixes: 'S' (seconds, the default), 'M' (minutes), 'H' (hours), 'D' (days), 'W' (weeks) |
 | log_rotation_size | -1 | String | No | The size of the log file that will trigger a log rotation. Supports suffixes: 'B' (bytes), the default if omitted, 'K' (kilobytes), 'M' (megabytes), 'G' (gigabytes). |
 | log_mode | append | String | No | Append to or create the log file (append, create). The create option truncates an already existing file. |

src/include/logging.h

@@ -54,6 +54,7 @@ extern "C" {
 
 #define PGAGROAL_LOGGING_ROTATION_DISABLED -1
 
+#define PGAGROAL_LOGGING_DEFAULT_LOG_LINE_PREFIX "%Y-%m-%d %H:%M:%S"
 
 #define pgagroal_log_trace(...) pgagroal_log_line(PGAGROAL_LOGGING_LEVEL_DEBUG5, __FILE__, __LINE__, __VA_ARGS__)
 #define pgagroal_log_debug(...) pgagroal_log_line(PGAGROAL_LOGGING_LEVEL_DEBUG1, __FILE__, __LINE__, __VA_ARGS__)

src/include/pgagroal.h

@@ -306,7 +306,7 @@ struct configuration
    atomic_schar log_lock;      /**< The logging lock */
    int log_rotation_size;      /**< bytes to force log rotation */
    int log_rotation_age;       /**< minutes for log rotation */
-   bool log_truncate;          /**< Truncate an existing log on rotation */
+   char log_line_prefix[MISC_LENGTH]; /**< The logging prefix */
 
    bool authquery; /**< Is authentication query enabled */
 

src/libpgagroal/configuration.c

@@ -626,6 +626,22 @@ pgagroal_read_configuration(void* shm, char* filename)
                    unknown = true;
                  }
 
+               }
+	       else if (!strcmp(key, "log_line_prefix"))
+               {
+                 if (!strcmp(section, "pgagroal"))
+                 {
+                    max = strlen(value);
+		    if (max > MISC_LENGTH - 1)
+		      max = MISC_LENGTH - 1;
+
+		    memcpy(config->log_line_prefix, value, max);
+                 }
+                 else
+                 {
+                   unknown = true;
+                 }
+
                }
                else if (!strcmp(key, "log_connections"))
                {

src/libpgagroal/logging.c

@@ -86,8 +86,8 @@ log_rotation_enabled(void)
   // logging is not to a file
   if (config->log_type != PGAGROAL_LOGGING_TYPE_FILE)
   {
-    log_rotation_disable();
-    return false;
+     log_rotation_disable();
+     return false;
   }
 
   // log rotation is enabled if either log_rotation_age or
@@ -203,7 +203,7 @@ pgagroal_init_logging(void)
       {
          printf("Failed to open log file %s due to %s\n", strlen(config->log_path) > 0 ? config->log_path : "pgagroal.log", strerror(errno));
          errno = 0;
-	 log_rotation_disable();
+         log_rotation_disable();
          return 1;
       }
    }
@@ -299,15 +299,6 @@ log_file_open(void)
       return 1;
 
     log_rotation_set_next_rotation_age();
-    /*    printf("\n\nLog file %s initialized %d, rotation %sable (every %d bytes or %d seconds or so, next estimated at %ld epoch, now is %d)\n\n",
-	   current_log_path,
-	   config->log_level,
-		       log_rotation_enabled() ? "en" : "dis",
-		       config->log_rotation_size,
-		       config->log_rotation_age,
-	   (long) next_log_rotation_age,
-	   (long) htime);
-    */
     return 0;
   }
 
@@ -400,11 +391,16 @@ pgagroal_log_line(int level, char *file, int line, char *fmt, ...)
             filename = file;
          }
 
+	 if (config->log_line_prefix == NULL || strlen(config->log_line_prefix) == 0)
+	 {
+	    memcpy(config->log_line_prefix,PGAGROAL_LOGGING_DEFAULT_LOG_LINE_PREFIX,strlen(PGAGROAL_LOGGING_DEFAULT_LOG_LINE_PREFIX));
+	 }
+
          va_start(vl, fmt);
 
          if (config->log_type == PGAGROAL_LOGGING_TYPE_CONSOLE)
          {
-            buf[strftime(buf, sizeof(buf), "%Y-%m-%d %H:%M:%S", tm)] = '\0';
+            buf[strftime(buf, sizeof(buf), config->log_line_prefix, tm)] = '\0';
             fprintf(stdout, "%s %s%-5s\x1b[0m \x1b[90m%s:%d\x1b[0m ",
                     buf, colors[level - 1], levels[level - 1],
                     filename, line);
@@ -414,7 +410,7 @@ pgagroal_log_line(int level, char *file, int line, char *fmt, ...)
          }
          else if (config->log_type == PGAGROAL_LOGGING_TYPE_FILE)
          {
-            buf[strftime(buf, sizeof(buf), "%Y-%m-%d %H:%M:%S", tm)] = '\0';
+            buf[strftime(buf, sizeof(buf), config->log_line_prefix, tm)] = '\0';
             fprintf(log_file, "%s %-5s %s:%d ",
                     buf, levels[level - 1], filename, line);
             vfprintf(log_file, fmt, vl);
@@ -423,7 +419,6 @@ pgagroal_log_line(int level, char *file, int line, char *fmt, ...)
 
 	    if (log_rotation_required())
 	    {
-	      printf("\nLOG ROTATION\n\n");
 	       log_file_rotate();
 	    }
          }