Docker cleanup and improvements

gns3server/utils/asyncio/__init__.py

@@ -0,0 +1,127 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright (C) 2015 GNS3 Technologies Inc.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+
+import asyncio
+import sys
+import os
+
+
+@asyncio.coroutine
+def wait_run_in_executor(func, *args):
+    """
+    Run blocking code in a different thread and wait
+    for the result.
+
+    :param func: Run this function in a different thread
+    :param args: Parameters of the function
+    :returns: Return the result of the function
+    """
+
+    loop = asyncio.get_event_loop()
+    future = loop.run_in_executor(None, func, *args)
+    yield from asyncio.wait([future])
+    return future.result()
+
+
+@asyncio.coroutine
+def subprocess_check_output(*args, cwd=None, env=None):
+    """
+    Run a command and capture output
+
+    :param *args: List of command arguments
+    :param cwd: Current working directory
+    :param env: Command environment
+    :returns: Command output
+    """
+
+    proc = yield from asyncio.create_subprocess_exec(*args, stdout=asyncio.subprocess.PIPE, cwd=cwd, env=env)
+    output = yield from proc.stdout.read()
+    if output is None:
+        return ""
+    # If we received garbage we ignore invalid characters
+    # it should happend only when user try to use another binary
+    # and the code of VPCS, dynamips... Will detect it's not the correct binary
+    return output.decode("utf-8", errors="ignore")
+
+
+@asyncio.coroutine
+def wait_for_process_termination(process, timeout=10):
+    """
+    Wait for a process terminate, and raise asyncio.TimeoutError in case of
+    timeout.
+
+    In theory this can be implemented by just:
+    yield from asyncio.wait_for(self._iou_process.wait(), timeout=100)
+
+    But it's broken before Python 3.4:
+    http://bugs.python.org/issue23140
+
+    :param process: An asyncio subprocess
+    :param timeout: Timeout in seconds
+    """
+
+    while timeout > 0:
+        if process.returncode is not None:
+            return
+        yield from asyncio.sleep(0.1)
+        timeout -= 0.1
+    raise asyncio.TimeoutError()
+
+
+@asyncio.coroutine
+def _check_process(process, termination_callback):
+    if not hasattr(sys, "_called_from_test") or not sys._called_from_test:
+        returncode = yield from process.wait()
+        if asyncio.iscoroutinefunction(termination_callback):
+            yield from termination_callback(returncode)
+        else:
+            termination_callback(returncode)
+
+
+def monitor_process(process, termination_callback):
+    """Call termination_callback when a process dies"""
+
+    asyncio.async(_check_process(process, termination_callback))
+
+
+@asyncio.coroutine
+def wait_for_file_creation(path, timeout=10):
+
+    while timeout > 0:
+        if os.path.exists(path):
+            return
+        yield from asyncio.sleep(0.5)
+        timeout -= 0.5
+    raise asyncio.TimeoutError()
+
+
+@asyncio.coroutine
+def wait_for_named_pipe_creation(pipe_path, timeout=60):
+
+    import win32pipe
+    import pywintypes
+
+    while timeout > 0:
+        try:
+            win32pipe.WaitNamedPipe(pipe_path, 1)
+        except pywintypes.error:
+            yield from asyncio.sleep(0.5)
+            timeout -= 0.5
+        else:
+            return
+    raise asyncio.TimeoutError()