Configuration option to output logs in logfmt

src/config.c

@@ -164,6 +164,19 @@ configEnum propagation_error_behavior_enum[] = {
     {NULL, 0}
 };
 
+configEnum log_format_enum[] = {
+    {"default", LOG_FORMAT_DEFAULT},
+    {"logfmt", LOG_FORMAT_LOGFMT},
+    {NULL, 0}
+};
+
+configEnum log_timestamp_format_enum[] = {
+    {"default", LOG_TIMESTAMP_DEFAULT},
+    {"iso8601", LOG_TIMESTAMP_ISO8601},
+    {"unix",LOG_TIMESTAMP_UNIX},
+    {NULL, 0}
+};
+
 /* Output buffer limits presets. */
 clientBufferLimitsConfig clientBufferLimitsDefaults[CLIENT_TYPE_OBUF_COUNT] = {
     {0, 0, 0}, /* normal */
@@ -3154,6 +3167,8 @@ standardConfig static_configs[] = {
     createEnumConfig("propagation-error-behavior", NULL, MODIFIABLE_CONFIG, propagation_error_behavior_enum, server.propagation_error_behavior, PROPAGATION_ERR_BEHAVIOR_IGNORE, NULL, NULL),
     createEnumConfig("shutdown-on-sigint", NULL, MODIFIABLE_CONFIG | MULTI_ARG_CONFIG, shutdown_on_sig_enum, server.shutdown_on_sigint, 0, isValidShutdownOnSigFlags, NULL),
     createEnumConfig("shutdown-on-sigterm", NULL, MODIFIABLE_CONFIG | MULTI_ARG_CONFIG, shutdown_on_sig_enum, server.shutdown_on_sigterm, 0, isValidShutdownOnSigFlags, NULL),
+    createEnumConfig("log-format", NULL, MODIFIABLE_CONFIG, log_format_enum, server.log_format, LOG_FORMAT_DEFAULT, NULL, NULL),
+    createEnumConfig("log-timestamp-format", NULL, MODIFIABLE_CONFIG, log_timestamp_format_enum, server.log_timestamp_format, LOG_TIMESTAMP_DEFAULT, NULL, NULL),
 
     /* Integer configs */
     createIntConfig("databases", NULL, IMMUTABLE_CONFIG, 1, INT_MAX, server.dbnum, 16, INTEGER_CONFIG, NULL, NULL),

src/server.c

@@ -108,11 +108,35 @@ const char *replstateToString(int replstate);
  * function of Redis may be called from other threads. */
 void nolocks_localtime(struct tm *tmp, time_t t, time_t tz, int dst);
 
+/* Formats the timezone offset into a string.
+ * 
+ * Assumes:
+ * - size of `buf` is 7 or larger
+ * - `timezone` is valid, within the range of [-50400, +43200].
+ * - `daylight_active` indicates whether dst is active (1) or not (0). */
+
+void format_timezone(char *buf, int timezone, int daylight_active) {
+    // Adjust the timezone for daylight saving, if active
+    int total_offset = (-1)*timezone + 3600*daylight_active;
+    int hours = abs(total_offset / 3600);
+    int minutes = abs(total_offset % 3600) / 60;
+    buf[0] = total_offset >= 0 ? '+' : '-';
+    buf[1] = '0' + hours / 10;
+    buf[2] = '0' + hours % 10;
+    buf[3] = ':';
+    buf[4] = '0' + minutes / 10;
+    buf[5] = '0' + minutes % 10;
+    buf[6] = '\0';
+}
+
 /* Low level logging. To use only for very big messages, otherwise
  * serverLog() is to prefer. */
 void serverLogRaw(int level, const char *msg) {
     const int syslogLevelMap[] = { LOG_DEBUG, LOG_INFO, LOG_NOTICE, LOG_WARNING };
     const char *c = ".-*#";
+    const char* verbose_level[] = {"debug", "info", "notice", "warning"};
+    const char* roles[] = {"sentinel", "RDB/AOF", "replica", "master"};
+    const char* role_chars = "XCSM";
     FILE *fp;
     char buf[64];
     int rawmode = (level & LL_RAW);
@@ -129,23 +153,52 @@ void serverLogRaw(int level, const char *msg) {
     } else {
         int off;
         struct timeval tv;
-        int role_char;
         pid_t pid = getpid();
 
         gettimeofday(&tv,NULL);
         struct tm tm;
         nolocks_localtime(&tm,tv.tv_sec,server.timezone,server.daylight_active);
-        off = strftime(buf,sizeof(buf),"%d %b %Y %H:%M:%S.",&tm);
-        snprintf(buf+off,sizeof(buf)-off,"%03d",(int)tv.tv_usec/1000);
+        switch(server.log_timestamp_format) {
+            case LOG_TIMESTAMP_DEFAULT:
+                off = strftime(buf,sizeof(buf),"%d %b %Y %H:%M:%S.",&tm);
+                snprintf(buf+off,sizeof(buf)-off,"%03d",(int)tv.tv_usec/1000);
+                break;
+
+            case LOG_TIMESTAMP_ISO8601:
+                off = strftime(buf,sizeof(buf),"%Y-%m-%dT%H:%M:%S.",&tm);
+                char tzbuf[7];
+                format_timezone(tzbuf, server.timezone, server.daylight_active);
+                snprintf(buf + off, sizeof(buf) - off, "%03d%s",
+                         (int)tv.tv_usec/1000, tzbuf);
+                break;
+
+            case LOG_TIMESTAMP_UNIX:
+                snprintf(buf,sizeof(buf),"%ld",tv.tv_sec);
+                break;
+            default:
+                break;
+        }
+        int role_index;
         if (server.sentinel_mode) {
-            role_char = 'X'; /* Sentinel. */
+            role_index = 0; /* Sentinel. */
         } else if (pid != server.pid) {
-            role_char = 'C'; /* RDB / AOF writing child. */
+            role_index = 1; /* RDB / AOF writing child. */
         } else {
-            role_char = (server.masterhost ? 'S':'M'); /* Slave or Master. */
+            role_index = (server.masterhost ? 2 : 3); /* Slave or Master. */
+        }
+        switch (server.log_format) {
+            case LOG_FORMAT_LOGFMT: {
+                fprintf(fp, "pid=%d role=%s timestamp=\"%s\" level=%s message=\"%s\"\n",
+                        (int)getpid(),roles[role_index],buf,verbose_level[level],msg);
+                break;
+            }
+
+            default: {
+                fprintf(fp,"%d:%c %s %c %s\n",
+                        (int)getpid(),role_chars[role_index], buf,c[level],msg);
+                break;
+            }
         }
-        fprintf(fp,"%d:%c %s %c %s\n",
-            (int)getpid(),role_char, buf,c[level],msg);
     }
     fflush(fp);
 

src/server.h

@@ -608,6 +608,18 @@ typedef enum {
 #define PAUSE_ACTION_EVICT            (1<<3)
 #define PAUSE_ACTION_REPLICA          (1<<4) /* pause replica traffic */
 
+/* Sets log format */
+typedef enum {
+    LOG_FORMAT_DEFAULT = 0,
+    LOG_FORMAT_LOGFMT
+} log_format_type;
+
+/* Sets log timestamp format */
+/* Also update LOG_TIMESTAMP_FORMATS */
+#define LOG_TIMESTAMP_DEFAULT 0
+#define LOG_TIMESTAMP_ISO8601 1
+#define LOG_TIMESTAMP_UNIX 2
+
 /* common sets of actions to pause/unpause */
 #define PAUSE_ACTIONS_CLIENT_WRITE_SET (PAUSE_ACTION_CLIENT_WRITE|\
                                         PAUSE_ACTION_EXPIRE|\
@@ -1865,6 +1877,8 @@ struct redisServer {
     int memcheck_enabled;           /* Enable memory check on crash. */
     int use_exit_on_panic;          /* Use exit() on panic and assert rather than
                                      * abort(). useful for Valgrind. */
+    int log_format;                 /* Print log in specific format */
+    int log_timestamp_format;       /* Timestamp format in log */
     /* Shutdown */
     int shutdown_timeout;           /* Graceful shutdown time limit in seconds. */
     int shutdown_on_sigint;         /* Shutdown flags configured for SIGINT. */