From 297de1ab26789f8a30a5d4c8a188636a5b9ea821 Mon Sep 17 00:00:00 2001
From: antirez <antirez@gmail.com>
Date: Thu, 21 Nov 2013 12:27:14 +0100
Subject: [PATCH] Sentinel: test for writable config file.

This commit introduces a funciton called when Sentinel is ready for
normal operations to avoid putting Sentinel specific stuff in redis.c.
---
 src/redis.c    |  2 +-
 src/redis.h    |  1 +
 src/sentinel.c | 13 ++++++++++++-
 3 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/src/redis.c b/src/redis.c
index af24505b..76ca2a21 100644
--- a/src/redis.c
+++ b/src/redis.c
@@ -3109,7 +3109,7 @@ int main(int argc, char **argv) {
         if (server.sofd > 0)
             redisLog(REDIS_NOTICE,"The server is now ready to accept connections at %s", server.unixsocket);
     } else {
-        redisLog(REDIS_WARNING,"Sentinel runid is %s", server.runid);
+        sentinelIsRunning();
     }
 
     /* Warning the user about suspicious maxmemory setting. */
diff --git a/src/redis.h b/src/redis.h
index bdc69522..76f7dd3b 100644
--- a/src/redis.h
+++ b/src/redis.h
@@ -1223,6 +1223,7 @@ void initSentinelConfig(void);
 void initSentinel(void);
 void sentinelTimer(void);
 char *sentinelHandleConfiguration(char **argv, int argc);
+void sentinelIsRunning(void);
 
 /* Scripting */
 void scriptingInit(void);
diff --git a/src/sentinel.c b/src/sentinel.c
index b963da10..ca6d0eb5 100644
--- a/src/sentinel.c
+++ b/src/sentinel.c
@@ -413,6 +413,17 @@ void initSentinel(void) {
     sentinel.scripts_queue = listCreate();
 }
 
+/* This function gets called when the server is in Sentinel mode, started,
+ * loaded the configuration, and is ready for normal operations. */
+void sentinelIsRunning(void) {
+    redisLog(REDIS_WARNING,"Sentinel runid is %s", server.runid);
+
+    if (server.configfile == NULL || access(server.configfile,W_OK) == -1) {
+        redisLog(REDIS_WARNING,"Sentinel started without a config file, or config file not writable. Exiting...");
+        exit(1);
+    }
+}
+
 /* ============================== sentinelAddr ============================== */
 
 /* Create a sentinelAddr object and return it on success.
@@ -2069,7 +2080,7 @@ int sentinelSendHello(sentinelRedisInstance *ri) {
 
     /* Try to obtain our own IP address. */
     if (anetSockName(ri->cc->c.fd,ip,sizeof(ip),NULL) == -1) return REDIS_ERR;
-    if (ri->flags & SRI_DISCONNECTED) return;
+    if (ri->flags & SRI_DISCONNECTED) return REDIS_ERR;
 
     /* Format and send the Hello message. */
     snprintf(payload,sizeof(payload),