From c142ae3f1530067f35b8a1e1bac9ddeea4d81c09 Mon Sep 17 00:00:00 2001
From: Sage Weil <sage@redhat.com>
Date: Thu, 7 Dec 2017 16:39:30 -0600
Subject: [PATCH] log: add log_stderr_prefix option

Allows you to set a prefix for debug log messages send to stderr (e.g.,
"debug ").

Signed-off-by: Sage Weil <sage@redhat.com>
---
 src/common/ceph_context.cc | 5 +++++
 src/common/options.cc      | 3 +++
 src/log/Log.cc             | 7 ++++++-
 src/log/Log.h              | 3 +++
 4 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/src/common/ceph_context.cc b/src/common/ceph_context.cc
index b2b3957fcb6..401dbf53fc0 100644
--- a/src/common/ceph_context.cc
+++ b/src/common/ceph_context.cc
@@ -202,6 +202,7 @@ public:
       "log_max_recent",
       "log_to_syslog",
       "err_to_syslog",
+      "log_stderr_prefix",
       "log_to_stderr",
       "err_to_stderr",
       "log_to_graylog",
@@ -236,6 +237,10 @@ public:
       log->reopen_log_file();
     }
 
+    if (changed.count("log_stderr_prefix")) {
+      log->set_log_stderr_prefix(conf->get_val<string>("log_stderr_prefix"));
+    }
+
     if (changed.count("log_max_new")) {
 
       log->set_max_new(conf->log_max_new);
diff --git a/src/common/options.cc b/src/common/options.cc
index ec5d10a86fb..91f48dcee2b 100644
--- a/src/common/options.cc
+++ b/src/common/options.cc
@@ -345,6 +345,9 @@ std::vector<Option> get_global_options() {
     .set_daemon_default(true)
     .set_description("send critical error log lines to stderr"),
 
+    Option("log_stderr_prefix", Option::TYPE_STR, Option::LEVEL_ADVANCED)
+    .set_description("String to prefix log messages with when sent to stderr"),
+
     Option("log_to_syslog", Option::TYPE_BOOL, Option::LEVEL_BASIC)
     .set_default(false)
     .set_description("send log lines to syslog facility"),
diff --git a/src/log/Log.cc b/src/log/Log.cc
index dea7c6efa5d..10b76c32a54 100644
--- a/src/log/Log.cc
+++ b/src/log/Log.cc
@@ -133,6 +133,11 @@ void Log::set_log_file(string fn)
   m_log_file = fn;
 }
 
+void Log::set_log_stderr_prefix(const std::string& p)
+{
+  m_log_stderr_prefix = p;
+}
+
 void Log::reopen_log_file()
 {
   pthread_mutex_lock(&m_flush_mutex);
@@ -336,7 +341,7 @@ void Log::_flush(EntryQueue *t, EntryQueue *requeue, bool crash)
       }
 
       if (do_stderr) {
-        cerr << buf << std::endl;
+        cerr << m_log_stderr_prefix << buf << std::endl;
       }
       if (do_fd) {
         buf[buflen] = '\n';
diff --git a/src/log/Log.h b/src/log/Log.h
index 9d3c6b31baf..acb8f38edda 100644
--- a/src/log/Log.h
+++ b/src/log/Log.h
@@ -44,6 +44,8 @@ class Log : private Thread
   int m_stderr_log, m_stderr_crash;
   int m_graylog_log, m_graylog_crash;
 
+  std::string m_log_stderr_prefix;
+
   shared_ptr<Graylog> m_graylog;
 
   bool m_stop;
@@ -70,6 +72,7 @@ public:
   void set_log_file(std::string fn);
   void reopen_log_file();
   void chown_log_file(uid_t uid, gid_t gid);
+  void set_log_stderr_prefix(const std::string& p);
 
   void flush();
 
-- 
2.39.5