Adds connection timeout option to redis-cli (#10609)

This allows specifying the timeout value for opening the TCP
connection to a server. The timeout, default 0 means no limit,
depending on the OS. It can be specified using the new `-t` switch.

revive #3764, fixes #3763

---------

Co-authored-by: Itamar Haber <itamar@redislabs.com>
Co-authored-by: yoav-steinberg <yoav@redislabs.com>

src/cli_common.c

@@ -424,3 +424,21 @@ sds cliVersion(void) {
     }
     return version;
 }
+
+/* This is a wrapper to call redisConnect or redisConnectWithTimeout. */
+redisContext *redisConnectWrapper(const char *ip, int port, const struct timeval tv) {
+    if (tv.tv_sec == 0 && tv.tv_usec == 0) {
+        return redisConnect(ip, port);
+    } else {
+        return redisConnectWithTimeout(ip, port, tv);
+    }
+}
+
+/* This is a wrapper to call redisConnectUnix or redisConnectUnixWithTimeout. */
+redisContext *redisConnectUnixWrapper(const char *path, const struct timeval tv) {
+    if (tv.tv_sec == 0 && tv.tv_usec == 0) {
+        return redisConnectUnix(path);
+    } else {
+        return redisConnectUnixWithTimeout(path, tv);
+    }
+}

src/cli_common.h

@@ -53,4 +53,7 @@ sds escapeJsonString(sds s, const char *p, size_t len);
 
 sds cliVersion(void);
 
+redisContext *redisConnectWrapper(const char *ip, int port, const struct timeval tv);
+redisContext *redisConnectUnixWrapper(const char *path, const struct timeval tv);
+
 #endif /* __CLICOMMON_H */

src/redis-cli.c

@@ -211,6 +211,7 @@ static int createClusterManagerCommand(char *cmdname, int argc, char **argv);
 static redisContext *context;
 static struct config {
     cliConnInfo conn_info;
+    struct timeval connect_timeout;
     char *hostsocket;
     int tls;
     cliSSLconfig sslconfig;
@@ -1648,9 +1649,10 @@ static int cliConnect(int flags) {
         /* Do not use hostsocket when we got redirected in cluster mode */
         if (config.hostsocket == NULL ||
             (config.cluster_mode && config.cluster_reissue_command)) {
-            context = redisConnect(config.conn_info.hostip,config.conn_info.hostport);
+            context = redisConnectWrapper(config.conn_info.hostip, config.conn_info.hostport,
+                                          config.connect_timeout);
         } else {
-            context = redisConnectUnix(config.hostsocket);
+            context = redisConnectUnixWrapper(config.hostsocket, config.connect_timeout);
         }
 
         if (!context->err && config.tls) {
@@ -2593,7 +2595,8 @@ static redisReply *reconnectingRedisCommand(redisContext *c, const char *fmt, ..
             fflush(stdout);
 
             redisFree(c);
-            c = redisConnect(config.conn_info.hostip,config.conn_info.hostport);
+            c = redisConnectWrapper(config.conn_info.hostip, config.conn_info.hostport,
+                                    config.connect_timeout);
             if (!c->err && config.tls) {
                 const char *err = NULL;
                 if (cliSecureConnection(c, config.sslconfig, &err) == REDIS_ERR && err) {
@@ -2648,6 +2651,15 @@ static int parseOptions(int argc, char **argv) {
                 fprintf(stderr, "Invalid server port.\n");
                 exit(1);
             }
+        } else if (!strcmp(argv[i],"-t") && !lastarg) {
+            char *eptr;
+            double seconds = strtod(argv[++i], &eptr);
+            if (eptr[0] != '\0' || isnan(seconds) || seconds < 0.0) {
+                fprintf(stderr, "Invalid connection timeout for -t.\n");
+                exit(1);
+            }
+            config.connect_timeout.tv_sec = (long long)seconds;
+            config.connect_timeout.tv_usec = ((long long)(seconds * 1000000)) % 1000000;
         } else if (!strcmp(argv[i],"-s") && !lastarg) {
             config.hostsocket = argv[++i];
         } else if (!strcmp(argv[i],"-r") && !lastarg) {
@@ -3011,6 +3023,8 @@ static void usage(int err) {
 "Usage: redis-cli [OPTIONS] [cmd [arg [arg ...]]]\n"
 "  -h <hostname>      Server hostname (default: 127.0.0.1).\n"
 "  -p <port>          Server port (default: 6379).\n"
+"  -t <timeout>       Server connection timeout in seconds (decimals allowed).\n"
+"                     Default timeout is 0, meaning no limit, depending on the OS.\n"
 "  -s <socket>        Server socket (overrides hostname and port).\n"
 "  -a <password>      Password to use when connecting to the server.\n"
 "                     You can also use the " REDIS_CLI_AUTH_ENV " environment\n"
@@ -4072,7 +4086,7 @@ cleanup:
 
 static int clusterManagerNodeConnect(clusterManagerNode *node) {
     if (node->context) redisFree(node->context);
-    node->context = redisConnect(node->ip, node->port);
+    node->context = redisConnectWrapper(node->ip, node->port, config.connect_timeout);
     if (!node->context->err && config.tls) {
         const char *err = NULL;
         if (cliSecureConnection(node->context, config.sslconfig, &err) == REDIS_ERR && err) {
@@ -7897,7 +7911,7 @@ static int clusterManagerCommandImport(int argc, char **argv) {
     char *reply_err = NULL;
     redisReply *src_reply = NULL;
     // Connect to the source node.
-    redisContext *src_ctx = redisConnect(src_ip, src_port);
+    redisContext *src_ctx = redisConnectWrapper(src_ip, src_port, config.connect_timeout);
     if (src_ctx->err) {
         success = 0;
         fprintf(stderr,"Could not connect to Redis at %s:%d: %s.\n", src_ip,
@@ -9832,6 +9846,8 @@ int main(int argc, char **argv) {
     memset(&config.sslconfig, 0, sizeof(config.sslconfig));
     config.conn_info.hostip = sdsnew("127.0.0.1");
     config.conn_info.hostport = 6379;
+    config.connect_timeout.tv_sec = 0;
+    config.connect_timeout.tv_usec = 0;
     config.hostsocket = NULL;
     config.repeat = 1;
     config.interval = 0;