[dts] [PATCH v2] framework: support create addtional sessions on crb

[Yong Liu <yong.liu@intel.com>]

Add session create/destroy functions in crb module.
Suite can create addtional session in dut by this function.
When session useless, suite should close the session definitely.
Suite should appoint out which logfile used to save output message.
By default output message will be saved in dts.log.
Below is sample code for addtional session:

    session = self.dut.new_session(suite="TestVlan")
    session.send_expect("ls -al", "# ")
    self.dut.close_session(session=session)

Signed-off-by: Marvin Liu <yong.liu@intel.com>

diff --git a/framework/crb.py b/framework/crb.py
index 3c158ec..5ea0d63 100644
--- a/framework/crb.py
+++ b/framework/crb.py
@@ -56,6 +56,7 @@ class Crb(object):
         self.skip_setup = False
         self.serializer = serializer
         self.ports_info = None
+        self.sessions = []
 
         self.logger = getLogger(name)
         self.session = SSHConnection(self.get_ip_address(), name,
@@ -81,6 +82,28 @@ class Crb(object):
 
         return self.session.send_expect(cmds, expected, timeout, verify)
 
+    def create_session(self, name=""):
+        """
+        Create new session for addtional useage. This session will not enable log.
+        """
+        logger = getLogger(name)
+        session = SSHConnection(self.get_ip_address(), name,
+                                     self.get_password())
+        session.init_log(logger)
+        self.sessions.append(session)
+        return session
+
+    def destroy_session(self, session=None):
+        """
+        Destroy addtional session.
+        """
+        for save_session in self.sessions:
+            if save_session == session:
+                save_session.close()
+                logger = getLogger(save_session.name)
+                logger.logger_exit()
+            self.sessions.remove(save_session)
+
     def send_command(self, cmds, timeout=TIMEOUT, alt_session=False):
         """
         Send commands to crb and return string before timeout.
diff --git a/framework/dut.py b/framework/dut.py
index c75f325..2101fc8 100644
--- a/framework/dut.py
+++ b/framework/dut.py
@@ -41,6 +41,7 @@ from crb import Crb
 from net_device import NetDevice
 from virt_resource import VirtResource
 from utils import RED
+from uuid import uuid4
 
 
 class Dut(Crb):
@@ -85,6 +86,25 @@ class Dut(Crb):
             self.host_session.init_log(self.logger)
             self.host_init_flag = True
 
+    def new_session(self, suite=""):
+        """
+        Create new session for dut instance. Session name will be unique.
+        """
+        session_name = self.NAME + '_' + str(uuid4())
+        session = self.create_session(name=session_name)
+        if suite != "":
+            session.logger.config_suite(suite, self.NAME)
+        else:
+            session.logger.config_execution(self.NAME)
+        session.send_expect("cd %s" % self.base_dir, "# ")
+        return session
+
+    def close_session(self, session):
+        """
+        close new session in dut instance
+        """
+        self.destroy_session(session)
+
     def change_config_option(self, target, parameter, value):
         """
         This function change option in the config file
-- 
1.9.3