[CLI] refactored the launch CLI and fixed bugs in multi-node launching (#844)

* [cli] fixed multi-node job launching

* [cli] fixed a bug in version comparison

* [cli] support launching with env var

* [cli] fixed multi-node job launching

* [cli] fixed a bug in version comparison

* [cli] support launching with env var

* added docstring

* [cli] added extra launch arguments

* [cli] added default launch rdzv args

* [cli] fixed version comparison

* [cli] added docstring examples and requierment

* polish docstring

* polish code

* polish code

colossalai/cli/launcher/hostinfo.py

@@ -0,0 +1,122 @@
+from typing import List
+import socket
+
+
+class HostInfo:
+    """
+    A data class to store host connection-related data.
+
+    Args:
+        hostname (str): name or IP address of the host
+        port (str): the port for ssh connection
+    """
+
+    def __init__(
+        self,
+        hostname: str,
+        port: str = None,
+    ):
+        self.hostname = hostname
+        self.port = port
+        self.is_local_host = HostInfo.is_host_localhost(hostname, port)
+
+    @staticmethod
+    def is_host_localhost(hostname: str, port: str = None) -> None:
+        """
+        Check if the host refers to the local machine.
+
+        Args:
+            hostname (str): name or IP address of the host
+            port (str): the port for ssh connection
+
+        Returns:
+            bool: True if it is local, False otherwise
+        """
+
+        if port is None:
+            port = 22    # no port specified, lets just use the ssh port
+        hostname = socket.getfqdn(hostname)
+        if hostname in ("localhost", "127.0.0.1", "0.0.0.0"):
+            return True
+        localhost = socket.gethostname()
+        localaddrs = socket.getaddrinfo(localhost, port)
+        targetaddrs = socket.getaddrinfo(hostname, port)
+        for (family, socktype, proto, canonname, sockaddr) in localaddrs:
+            for (rfamily, rsocktype, rproto, rcanonname, rsockaddr) in targetaddrs:
+                if rsockaddr[0] == sockaddr[0]:
+                    return True
+        return False
+
+    def __str__(self):
+        return f'hostname: {self.hostname}, port: {self.port}'
+
+    def __repr__(self):
+        return self.__str__()
+
+
+class HostInfoList:
+    """
+    A data class to store a list of HostInfo objects.
+    """
+
+    def __init__(self):
+        self.hostinfo_list = []
+
+    def append(self, hostinfo: HostInfo) -> None:
+        """
+        Add an HostInfo object to the list.
+
+        Args:
+            hostinfo (HostInfo): host information
+        """
+
+        self.hostinfo_list.append(hostinfo)
+
+    def remove(self, hostname: str) -> None:
+        """
+        Add an HostInfo object to the list.
+
+        Args:
+            hostname (str): the name of the host
+        """
+
+        hostinfo = self.get_hostinfo(hostname)
+        self.hostinfo_list.remove(hostinfo)
+
+    def get_hostinfo(self, hostname: str) -> HostInfo:
+        """
+        Return the HostInfo object which matches with the hostname.
+
+        Args:
+            hostname (str): the name of the host
+
+        Returns:
+            hostinfo (HostInfo): the HostInfo object which matches with the hostname
+        """
+
+        for hostinfo in self.hostinfo_list:
+            if hostinfo.hostname == hostname:
+                return hostinfo
+
+        raise Exception(f"Hostname {hostname} is not found")
+
+    def has(self, hostname: str) -> bool:
+        """
+        Check if the hostname has been added.
+
+        Args:
+            hostname (str): the name of the host
+
+        Returns:
+            bool: True if added, False otherwise
+        """
+        for hostinfo in self.hostinfo_list:
+            if hostinfo.hostname == hostname:
+                return True
+        return False
+
+    def __iter__(self):
+        return iter(self.hostinfo_list)
+
+    def __len__(self):
+        return len(self.hostinfo_list)