cluster configuration saving

src/cluster.c

@@ -1,6 +1,8 @@
 #include "redis.h"
 
 #include <arpa/inet.h>
+#include <fcntl.h>
+#include <unistd.h>
 
 void clusterAcceptHandler(aeEventLoop *el, int fd, void *privdata, int mask);
 void clusterReadHandler(aeEventLoop *el, int fd, void *privdata, int mask);
@@ -8,6 +10,7 @@ void clusterSendPing(clusterLink *link, int type);
 void clusterSendFail(char *nodename);
 void clusterUpdateState(void);
 int clusterNodeGetSlotBit(clusterNode *n, int slot);
+sds clusterGenNodesDescription(void);
 
 /* -----------------------------------------------------------------------------
  * Initialization
@@ -32,6 +35,7 @@ void clusterGetRandomName(char *p) {
 int clusterLoadConfig(char *filename) {
     FILE *fp = fopen(filename,"r");
    
+    return REDIS_ERR;
     if (fp == NULL) return REDIS_ERR;
     fclose(fp);
 
@@ -45,6 +49,25 @@ fmterr:
     exit(1);
 }
 
+/* Cluster node configuration is exactly the same as CLUSTER NODES output.
+ *
+ * This function writes the node config and returns 0, on error -1
+ * is returned. */
+int clusterSaveConfig(char *filename) {
+    sds ci = clusterGenNodesDescription();
+    int fd;
+    
+    if ((fd = open(filename,O_WRONLY|O_CREAT,0644)) == -1) goto err;
+    if (write(fd,ci,sdslen(ci)) != (ssize_t)sdslen(ci)) goto err;
+    close(fd);
+    sdsfree(ci);
+    return 0;
+
+err:
+    sdsfree(ci);
+    return -1;
+}
+
 void clusterInit(void) {
     server.cluster.myself = createClusterNode(NULL,REDIS_NODE_MYSELF);
     server.cluster.state = REDIS_CLUSTER_FAIL;
@@ -61,6 +84,10 @@ void clusterInit(void) {
          * by the createClusterNode() function. */
         redisLog(REDIS_NOTICE,"No cluster configuration found, I'm %.40s",
             server.cluster.myself->name);
+        if (clusterSaveConfig("cluster.conf") == -1) {
+            redisLog(REDIS_WARNING,"Fatal: can't update cluster config file.");
+            exit(1);
+        }
     }
     clusterAddNode(server.cluster.myself);
     /* We need a listening TCP port for our cluster messaging needs */
@@ -874,41 +901,10 @@ void clusterUpdateState(void) {
  * CLUSTER command
  * -------------------------------------------------------------------------- */
 
-void clusterCommand(redisClient *c) {
+sds clusterGenNodesDescription(void) {
-    if (server.cluster_enabled == 0) {
-        addReplyError(c,"This instance has cluster support disabled");
-        return;
-    }
-
-    if (!strcasecmp(c->argv[1]->ptr,"meet") && c->argc == 4) {
-        clusterNode *n;
-        struct sockaddr_in sa;
-        long port;
-
-        /* Perform sanity checks on IP/port */
-        if (inet_aton(c->argv[2]->ptr,&sa.sin_addr) == 0) {
-            addReplyError(c,"Invalid IP address in MEET");
-            return;
-        }
-        if (getLongFromObjectOrReply(c, c->argv[3], &port, NULL) != REDIS_OK ||
-                    port < 0 || port > (65535-REDIS_CLUSTER_PORT_INCR))
-        {
-            addReplyError(c,"Invalid TCP port specified");
-            return;
-        }
-
-        /* Finally add the node to the cluster with a random name, this 
-         * will get fixed in the first handshake (ping/pong). */
-        n = createClusterNode(NULL,REDIS_NODE_HANDSHAKE|REDIS_NODE_MEET);
-        strncpy(n->ip,inet_ntoa(sa.sin_addr),sizeof(n->ip));
-        n->port = port;
-        clusterAddNode(n);
-        addReply(c,shared.ok);
-    } else if (!strcasecmp(c->argv[1]->ptr,"nodes") && c->argc == 2) {
     sds ci = sdsempty();
     dictIterator *di;
     dictEntry *de;
-        robj *o;
 
     di = dictGetIterator(server.cluster.nodes);
     while((de = dictNext(di)) != NULL) {
@@ -944,6 +940,43 @@ void clusterCommand(redisClient *c) {
             node->link ? "connected" : "disconnected");
     }
     dictReleaseIterator(di);
+    return ci;
+}
+
+void clusterCommand(redisClient *c) {
+    if (server.cluster_enabled == 0) {
+        addReplyError(c,"This instance has cluster support disabled");
+        return;
+    }
+
+    if (!strcasecmp(c->argv[1]->ptr,"meet") && c->argc == 4) {
+        clusterNode *n;
+        struct sockaddr_in sa;
+        long port;
+
+        /* Perform sanity checks on IP/port */
+        if (inet_aton(c->argv[2]->ptr,&sa.sin_addr) == 0) {
+            addReplyError(c,"Invalid IP address in MEET");
+            return;
+        }
+        if (getLongFromObjectOrReply(c, c->argv[3], &port, NULL) != REDIS_OK ||
+                    port < 0 || port > (65535-REDIS_CLUSTER_PORT_INCR))
+        {
+            addReplyError(c,"Invalid TCP port specified");
+            return;
+        }
+
+        /* Finally add the node to the cluster with a random name, this 
+         * will get fixed in the first handshake (ping/pong). */
+        n = createClusterNode(NULL,REDIS_NODE_HANDSHAKE|REDIS_NODE_MEET);
+        strncpy(n->ip,inet_ntoa(sa.sin_addr),sizeof(n->ip));
+        n->port = port;
+        clusterAddNode(n);
+        addReply(c,shared.ok);
+    } else if (!strcasecmp(c->argv[1]->ptr,"nodes") && c->argc == 2) {
+        robj *o;
+        sds ci = clusterGenNodesDescription();
+
         o = createObject(REDIS_STRING,ci);
         addReplyBulk(c,o);
         decrRefCount(o);