From 60df591b865831a71e93eb57f4c353c4555b66cf Mon Sep 17 00:00:00 2001
From: Stephen Gallagher <sgallagh@redhat.com>
Date: Feb 19 2014 11:28:27 +0000
Subject: DEBUG: Enable sending structured debug logs to journald


We are now able to send structured debug logs to journald, tagged with
the code file, line number and domain that the log pertains to. To
enable this functionality, SSSD must be configured at build-time with
--with-syslog=journald and must be launched without -f/--debug-to-files

This behavior is nearly identical to how SSSD will function today on a
systemd-based system if --debug-to-files is disabled, since it will
redirect stdout and stderr into journald. This patch merely enhances
the situation to send structured logs instead of simple string messages.

Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>
Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>

---

diff --git a/src/util/debug.c b/src/util/debug.c
index 3643c2b..908fca4 100644
--- a/src/util/debug.c
+++ b/src/util/debug.c
@@ -30,6 +30,10 @@
 #include <sys/stat.h>
 #include <sys/time.h>
 
+#ifdef WITH_JOURNALD
+#include <systemd/sd-journal.h>
+#endif
+
 #include "util/util.h"
 
 const char *debug_prg_name = "sssd";
@@ -129,6 +133,69 @@ static void debug_printf(const char *format, ...)
     va_end(ap);
 }
 
+#ifdef WITH_JOURNALD
+errno_t journal_send(const char *file,
+        long line,
+        const char *function,
+        int level,
+        const char *format,
+        va_list ap)
+{
+    errno_t ret;
+    int res;
+    char *message = NULL;
+    char *code_file = NULL;
+    char *code_line = NULL;
+    const char *domain;
+
+    /* First, evaluate the message to be sent */
+    ret = vasprintf(&message, format, ap);
+    if (ret == -1) {
+        /* ENOMEM, just return */
+        return ENOMEM;
+    }
+
+    res = asprintf(&code_file, "CODE_FILE=%s", file);
+    if (res == -1) {
+        ret = ENOMEM;
+        goto journal_done;
+    }
+
+    res = asprintf(&code_line, "CODE_LINE=%ld", line);
+    if (res == -1) {
+        ret = ENOMEM;
+        goto journal_done;
+    }
+
+    /* If this log message was sent from a provider,
+     * track the domain.
+     */
+    domain = getenv(SSS_DOM_ENV);
+    if (domain == NULL) {
+        domain = "";
+    }
+
+    /* Send the log message to journald, specifying the
+     * source code location and other tracking data.
+     */
+    res = sd_journal_send_with_location(
+            code_file, code_line, function,
+            "MESSAGE=%s", message,
+            "PRIORITY=%i", LOG_DEBUG,
+            "SSSD_DOMAIN=%s", domain,
+            "SSSD_PRG_NAME=%s", debug_prg_name,
+            "SSSD_DEBUG_LEVEL=%x", level,
+            NULL);
+    ret = -res;
+
+journal_done:
+    free(code_line);
+    free(code_file);
+    free(message);
+    return ret;
+}
+#endif /* WiTH_JOURNALD */
+
 void debug_fn(const char *file,
               long line,
               const char *function,
@@ -136,11 +203,34 @@ void debug_fn(const char *file,
               const char *format, ...)
 {
     va_list ap;
+
+#ifdef WITH_JOURNALD
+    errno_t ret;
     struct timeval tv;
     struct tm *tm;
     char datetime[20];
     int year;
 
+    if (!debug_file) {
+        /* If we are not outputting logs to files, we should be sending them
+         * to journald.
+         * NOTE: on modern systems, this is where stdout/stderr will end up
+         * from system services anyway. The only difference here is that we
+         * can also provide extra structuring data to make it more easily
+         * searchable.
+         */
+        va_start(ap, format);
+        ret = journal_send(file, line, function, level, format, ap);
+        if (ret != EOK) {
+            /* Emergency fallback, send to STDERR */
+            debug_vprintf(format, ap);
+            debug_fflush();
+        }
+        va_end(ap);
+        return;
+    }
+#endif
+
     if (debug_timestamps) {
         gettimeofday(&tv, NULL);
         tm = localtime(&tv.tv_sec);