Merge pull request #775 from JoshuaWatt/console-settle

shelldriver: Handle intermingled output on login

Author: jluebbe

doc/configuration.rst

@@ -1185,6 +1185,9 @@ Arguments:
     to pass before sending a newline to device.
   - console_ready (regex): optional, pattern used by the kernel to inform
     the user that a console can be activated by pressing enter.
+  - post_login_settle_time (int): optional, seconds of silence after logging in
+    before check for a prompt. Useful when the console is interleaved with boot
+    output which may interrupt prompt detection
 
 .. _conf-sshdriver:
 

labgrid/driver/consoleexpectmixin.py

@@ -1,6 +1,7 @@
-from time import sleep
+import time
+import pexpect
 
-from ..util import PtxExpect
+from ..util import PtxExpect, Timeout
 from ..step import step
 from .common import Driver
 
@@ -33,7 +34,7 @@ def write(self, data):
                               len(data), data, self.txdelay)
             count = 0
             for i in range(len(data)):
-                sleep(self.txdelay)
+                time.sleep(self.txdelay)
                 count += self._write(data[i:i+1])
             return count
 
@@ -54,6 +55,16 @@ def expect(self, pattern, timeout=-1):
         index = self._expect.expect(pattern, timeout=timeout)
         return index, self._expect.before, self._expect.match, self._expect.after
 
+    @Driver.check_active
+    @step(args=['quiet_time'])
+    def settle(self, quiet_time, timeout=120.0):
+        t = Timeout(timeout)
+        while not t.expired:
+            try:
+                self.read(timeout=quiet_time)
+            except pexpect.TIMEOUT:
+                break
+
     def resolve_conflicts(self, client):
         for other in self.clients:
             if other is client:

labgrid/driver/shelldriver.py

@@ -15,7 +15,7 @@
 from ..factory import target_factory
 from ..protocol import CommandProtocol, ConsoleProtocol, FileTransferProtocol
 from ..step import step
-from ..util import gen_marker
+from ..util import gen_marker, Timeout
 from .commandmixin import CommandMixin
 from .common import Driver
 from .exception import ExecutionError
@@ -37,6 +37,9 @@ class ShellDriver(CommandMixin, Driver, CommandProtocol, FileTransferProtocol):
         password (str): password to login with
         keyfile (str): keyfile to bind mount over users authorized keys
         login_timeout (int): optional, timeout for login prompt detection
+        post_login_settle_time (int): optional, seconds of silence after logging in
+            before check for a prompt. Useful when the console is interleaved with boot
+            output which may interrupt prompt detection
     """
     bindings = {"console": ConsoleProtocol, }
     prompt = attr.ib(validator=attr.validators.instance_of(str))
@@ -47,6 +50,7 @@ class ShellDriver(CommandMixin, Driver, CommandProtocol, FileTransferProtocol):
     login_timeout = attr.ib(default=60, validator=attr.validators.instance_of(int))
     console_ready = attr.ib(default="", validator=attr.validators.instance_of(str))
     await_login_timeout = attr.ib(default=2, validator=attr.validators.instance_of(int))
+    post_login_settle_time = attr.ib(default=0, validator=attr.validators.instance_of(int))
 
 
     def __attrs_post_init__(self):
@@ -114,9 +118,9 @@ def run(self, cmd, timeout=30.0, codec="utf-8", decodeerrors="strict"):
     def _await_login(self):
         """Awaits the login prompt and logs the user in"""
 
-        start = time.time()
+        timeout = Timeout(float(self.login_timeout))
 
-        expectations = [self.prompt, self.login_prompt, TIMEOUT]
+        expectations = [self.prompt, self.login_prompt, "Password: ", TIMEOUT]
         if self.console_ready != "":
             expectations.append(self.console_ready)
 
@@ -126,6 +130,7 @@ def _await_login(self):
         # Because pexpect keeps any read data in it's buffer when a timeout
         # occours, we can't lose any data this way.
         last_before = b''
+        did_login = False
 
         while True:
             index, before, _, _ = self.console.expect(
@@ -142,18 +147,15 @@ def _await_login(self):
             elif index == 1:
                 # we need to login
                 self.console.sendline(self.username)
-                index, _, _, _ = self.console.expect([self.prompt, "Password: "], timeout=10)
-                if index == 1:
-                    if self.password:
-                        self.console.sendline(self.password)
-                        remaining_time = (start + self.login_timeout) - time.time()
-                        self.console.expect(self.prompt, timeout=remaining_time)
-                    else:
-                        raise Exception("Password entry needed but no password set")
-                self._check_prompt()
-                break
+                did_login = True
 
             elif index == 2:
+                if self.password:
+                    self.console.sendline(self.password)
+                else:
+                    raise Exception("Password entry needed but no password set")
+
+            elif index == 3:
                 # expect hit a timeout while waiting for a match
                 if before == last_before:
                     # we did not receive anything during
@@ -162,17 +164,22 @@ def _await_login(self):
                     # newline to check the state
                     self.console.sendline("")
 
-            elif index == 3:
+            elif index == 4:
                 # we have just activated a console here
                 # lets start over again and see if login or prompt will appear
                 # now.
                 self.console.sendline("")
 
             last_before = before
 
-            if time.time() > start + self.login_timeout:
+            if timeout.expired:
                 raise TIMEOUT("Timeout of {} seconds exceeded during waiting for login".format(self.login_timeout))  # pylint: disable=line-too-long
 
+        if did_login:
+            if self.post_login_settle_time > 0:
+                self.console.settle(self.post_login_settle_time, timeout=timeout.remaining)
+            self._check_prompt()
+
     @step()
     def get_status(self):
         """Returns the status of the shell-driver.