[cli] fixed hostname mismatch error (#2465)

colossalai/cli/launcher/hostinfo.py

@@ -1,5 +1,5 @@
-from typing import List
 import socket
+from typing import List
 
 
 class HostInfo:
@@ -35,9 +35,14 @@ class HostInfo:
 
         if port is None:
             port = 22    # no port specified, lets just use the ssh port
-        hostname = socket.getfqdn(hostname)
+
+        # socket.getfqdn("127.0.0.1") does not return localhost
+        # on some users' machines
+        # thus, we directly return True if hostname is locahost, 127.0.0.1 or 0.0.0.0
         if hostname in ("localhost", "127.0.0.1", "0.0.0.0"):
             return True
+
+        hostname = socket.getfqdn(hostname)
         localhost = socket.gethostname()
         localaddrs = socket.getaddrinfo(localhost, port)
         targetaddrs = socket.getaddrinfo(hostname, port)