From 1524493c33f019c6719165f6d89c594cca5ea492 Mon Sep 17 00:00:00 2001
From: grossmj <grossmj@gns3.net>
Date: Thu, 12 Oct 2017 23:32:45 +0800
Subject: [PATCH] Fix IOU detection of layer 1 keepalive support. Fixes #1183.

---
 gns3server/compute/iou/iou_vm.py     |  4 ++--
 gns3server/utils/asyncio/__init__.py | 12 ++++++++----
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/gns3server/compute/iou/iou_vm.py b/gns3server/compute/iou/iou_vm.py
index 890bbc63..542a850d 100644
--- a/gns3server/compute/iou/iou_vm.py
+++ b/gns3server/compute/iou/iou_vm.py
@@ -945,13 +945,13 @@ class IOUVM(BaseNode):
         if "IOURC" not in os.environ:
             env["IOURC"] = self.iourc_path
         try:
-            output = yield from gns3server.utils.asyncio.subprocess_check_output(self._path, "-h", cwd=self.working_dir, env=env)
+            output = yield from gns3server.utils.asyncio.subprocess_check_output(self._path, "-h", cwd=self.working_dir, env=env, stderr=True)
             if re.search("-l\s+Enable Layer 1 keepalive messages", output):
                 command.extend(["-l"])
             else:
                 raise IOUError("layer 1 keepalive messages are not supported by {}".format(os.path.basename(self._path)))
         except (OSError, subprocess.SubprocessError) as e:
-            log.warn("could not determine if layer 1 keepalive messages are supported by {}: {}".format(os.path.basename(self._path), e))
+            log.warning("could not determine if layer 1 keepalive messages are supported by {}: {}".format(os.path.basename(self._path), e))
 
     @property
     def startup_config_content(self):
diff --git a/gns3server/utils/asyncio/__init__.py b/gns3server/utils/asyncio/__init__.py
index 2046f6a6..34e7571c 100644
--- a/gns3server/utils/asyncio/__init__.py
+++ b/gns3server/utils/asyncio/__init__.py
@@ -41,18 +41,23 @@ def wait_run_in_executor(func, *args, **kwargs):
 
 
 @asyncio.coroutine
-def subprocess_check_output(*args, cwd=None, env=None):
+def subprocess_check_output(*args, cwd=None, env=None, stderr=False):
     """
     Run a command and capture output
 
     :param *args: List of command arguments
     :param cwd: Current working directory
     :param env: Command environment
+    :param stderr: Read on stderr
     :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 stderr:
+        proc = yield from asyncio.create_subprocess_exec(*args, stderr=asyncio.subprocess.PIPE, cwd=cwd, env=env)
+        output = yield from proc.stderr.read()
+    else:
+        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
@@ -60,7 +65,6 @@ def subprocess_check_output(*args, cwd=None, env=None):
     # 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):
     """