[dts] [PATCH 08/16] framework/ssh_pexpect: support multiple VMs module

[Marvin Liu]

1. Protect ssh connection action by parallel lock, number is limited to
DUT SSH service.
2. Enlarge terminal column for serial output.
3. Enhance error handling when exception happened.
4. Add DUT index argument when connection CRB which can separate locks.

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

diff --git a/framework/ssh_pexpect.py b/framework/ssh_pexpect.py
index 8d6c3dd..3c988b7 100644
--- a/framework/ssh_pexpect.py
+++ b/framework/ssh_pexpect.py
@@ -3,7 +3,7 @@ import pexpect
 from pexpect import pxssh
 from debugger import ignore_keyintr, aware_keyintr
 from exception import TimeoutException, SSHConnectionException, SSHSessionDeadException
-from utils import RED, GREEN
+from utils import RED, GREEN, parallel_lock
 
 """
 Module handle ssh sessions between tester and DUT.
@@ -14,31 +14,47 @@ Aslo support transfer files to tester or DUT.
 
 class SSHPexpect(object):
 
-    def __init__(self, host, username, password):
+    def __init__(self, host, username, password, dut_id):
         self.magic_prompt = "MAGIC PROMPT"
+        self.logger = None
+
+        self.host = host
+        self.username = username
+        self.password = password
+
+        self._connect_host(dut_id=dut_id)
+
+    @parallel_lock(num=8)
+    def _connect_host(self, dut_id=0):
+        """
+        Create connection to assigned crb, parameter dut_id will be used in
+        parallel_lock thus can assure isolated locks for each crb.
+        Parallel ssh connections are limited to MaxStartups option in SSHD
+        configuration file. By default concurrent number is 10, so default
+        threads number is limited to 8 which less than 10. Lock number can
+        be modified along with MaxStartups value.
+        """
         try:
             self.session = pxssh.pxssh()
-            self.host = host
-            self.username = username
-            self.password = password
-            if ':' in host:
-                self.ip = host.split(':')[0]
-                self.port = int(host.split(':')[1])
+            if ':' in self.host:
+                self.ip = self.host.split(':')[0]
+                self.port = int(self.host.split(':')[1])
                 self.session.login(self.ip, self.username,
                                    self.password, original_prompt='[$#>]',
                                    port=self.port, login_timeout=20)
             else:
                 self.session.login(self.host, self.username,
                                    self.password, original_prompt='[$#>]')
-            self.send_expect('stty -echo', '# ', timeout=2)
-        except Exception, e:
+            self.send_expect('stty -echo', '#')
+            self.send_expect('stty columns 1000', "#")
+        except Exception as e:
             print RED(e)
             if getattr(self, 'port', None):
                 suggestion = "\nSuggession: Check if the fireware on [ %s ] " % \
                     self.ip + "is stoped\n"
                 print GREEN(suggestion)
 
-            raise SSHConnectionException(host)
+            raise SSHConnectionException(self.host)
 
     def init_log(self, logger, name):
         self.logger = logger
@@ -56,24 +72,33 @@ class SSHPexpect(object):
         return before
 
     def send_expect(self, command, expected, timeout=15, verify=False):
-        ret = self.send_expect_base(command, expected, timeout)
-        if verify:
-            ret_status = self.send_expect_base("echo $?", expected, timeout)
-            if not int(ret_status):
-                return ret
+
+        try:
+            ret = self.send_expect_base(command, expected, timeout)
+            if verify:
+                ret_status = self.send_expect_base("echo $?", expected, timeout)
+                if not int(ret_status):
+                    return ret
+                else:
+                    self.logger.error("Command: %s failure!" % command)
+                    self.logger.error(ret)
+                    return int(ret_status)
             else:
-                self.logger.error("Command: %s failure!" % command)
-                self.logger.error(ret)
-                return int(ret_status)
-        else:
-            return ret
+                return ret
+        except Exception as e:
+            print RED("Exception happened in [%s] and output is [%s]" % (command, self.get_output_before()))
+            raise(e)
 
     def send_command(self, command, timeout=1):
-        ignore_keyintr()
-        self.clean_session()
-        self.__sendline(command)
-        aware_keyintr()
-        return self.get_session_before(timeout)
+        try:
+            ignore_keyintr()
+            self.clean_session()
+            self.__sendline(command)
+            aware_keyintr()
+        except Exception as e:
+            raise(e)
+
+        return self.get_session_before(timeout=timeout)
 
     def clean_session(self):
         self.get_session_before(timeout=0.01)
@@ -90,8 +115,9 @@ class SSHPexpect(object):
             pass
 
         aware_keyintr()
-        before = self.get_output_before()
+        before = self.get_output_all()
         self.__flush()
+
         return before
 
     def __flush(self):
@@ -116,7 +142,6 @@ class SSHPexpect(object):
     def get_output_before(self):
         if not self.isalive():
             raise SSHSessionDeadException(self.host)
-        self.session.flush()
         before = self.session.before.rsplit('\r\n', 1)
         if before[0] == "[PEXPECT]":
             before[0] = ""
@@ -124,7 +149,6 @@ class SSHPexpect(object):
         return before[0]
 
     def get_output_all(self):
-        self.session.flush()
         output = self.session.before
         output.replace("[PEXPECT]", "")
         return output
-- 
1.9.3