Add optionally-include configuration directive.

README.Garantia

@@ -45,6 +45,8 @@ load-on-startup
     even if they exist.  This is useful on slaves that would immediately need
     to replicate from masters anyway.
 
+optionally-include
+    Works like 'include' but silently ignores non-existing files.
 
 Additional Statistics
 ---------------------

redis.conf

@@ -549,3 +549,5 @@ client-output-buffer-limit pubsub 32mb 8mb 60
 #
 # include /path/to/local.conf
 # include /path/to/other.conf
+# optionally-include /path/to/optional-file.conf
+

src/config.c

@@ -184,6 +184,12 @@ void loadServerConfigFromString(char *config) {
             }
         } else if (!strcasecmp(argv[0],"include") && argc == 2) {
             loadServerConfig(argv[1],NULL);
+        } else if (!strcasecmp(argv[0],"optionally-include") && argc == 2) {
+            FILE *tmp = fopen(argv[1], "r");
+            if (tmp != NULL) {
+                fclose(tmp);
+                loadServerConfig(argv[1],NULL);
+            }
         } else if (!strcasecmp(argv[0],"maxclients") && argc == 2) {
             server.maxclients = atoi(argv[1]);
             if (server.maxclients < 1) {