updated utils.check_cmd to accept the same parameters as other commands and be leveraged for node cmds

daemon/core/nodes/base.py

@@ -98,7 +98,7 @@ class NodeBase(object):
         :raises CoreCommandError: when a non-zero exit status occurs
         """
         if self.server is None:
-            return utils.check_cmd(args, env=env, cwd=cwd)
+            return utils.check_cmd(args, env, cwd, wait)
         else:
             args = " ".join(args)
             return distributed.remote_cmd(self.server, args, env, cwd, wait)

daemon/core/nodes/docker.py

@@ -56,7 +56,7 @@ class DockerClient(object):
             cmd=cmd
         ))
 
-    def ns_cmd(self, cmd):
+    def ns_cmd(self, cmd, wait):
         if isinstance(cmd, list):
             cmd = " ".join(cmd)
         args = "nsenter -t {pid} -u -i -p -n {cmd}".format(
@@ -64,7 +64,7 @@ class DockerClient(object):
             cmd=cmd
         )
         logging.info("ns cmd: %s", args)
-        return utils.check_cmd(args)
+        return utils.check_cmd(args, wait=wait)
 
     def get_pid(self):
         args = "docker inspect -f '{{{{.State.Pid}}}}' {name}".format(name=self.name)
@@ -147,7 +147,7 @@ class DockerNode(CoreNode):
             logging.debug("node down, not running network command: %s", args)
             return ""
 
-        return self.client.ns_cmd(args)
+        return self.client.ns_cmd(args, wait)
 
     def termcmdstring(self, sh="/bin/sh"):
         """

daemon/core/nodes/interface.py

@@ -61,7 +61,7 @@ class CoreInterface(object):
         :raises CoreCommandError: when a non-zero exit status occurs
         """
         if self.server is None:
-            return utils.check_cmd(args, env=env, cwd=cwd)
+            return utils.check_cmd(args, env, cwd, wait)
         else:
             args = " ".join(args)
             return distributed.remote_cmd(self.server, args, env, cwd, wait)

daemon/core/nodes/lxd.py

@@ -46,12 +46,12 @@ class LxdClient(object):
     def _cmd_args(self, cmd):
         return "lxc exec -nT {name} -- {cmd}".format(name=self.name, cmd=cmd)
 
-    def check_cmd(self, cmd):
+    def check_cmd(self, cmd, wait):
         if isinstance(cmd, list):
             cmd = " ".join(cmd)
         args = self._cmd_args(cmd)
         logging.info("lxc cmd output: %s", args)
-        return utils.check_cmd(args)
+        return utils.check_cmd(args, wait=wait)
 
     def _ns_args(self, cmd):
         return "nsenter -t {pid} -m -u -i -p -n {cmd}".format(pid=self.pid, cmd=cmd)
@@ -144,7 +144,7 @@ class LxcNode(CoreNode):
         if not self.up:
             logging.debug("node down, not running network command: %s", args)
             return ""
-        return self.client.check_cmd(args)
+        return self.client.check_cmd(args, wait)
 
     def termcmdstring(self, sh="/bin/sh"):
         """

daemon/core/nodes/network.py

@@ -322,7 +322,7 @@ class CoreNetwork(CoreNetworkBase):
         :raises CoreCommandError: when a non-zero exit status occurs
         """
         logging.info("network node(%s) cmd", self.name)
-        output = utils.check_cmd(args, env=env, cwd=cwd)
+        output = utils.check_cmd(args, env, cwd, wait)
 
         args = " ".join(args)
         for server in self.session.servers:

daemon/core/utils.py

@@ -11,8 +11,8 @@ import logging
 import logging.config
 import os
 import shlex
-import subprocess
 import sys
+from subprocess import PIPE, STDOUT, Popen
 
 from past.builtins import basestring
 
@@ -203,33 +203,36 @@ def mute_detach(args, **kwargs):
     args = split_args(args)
     kwargs["preexec_fn"] = _detach_init
     kwargs["stdout"] = DEVNULL
-    kwargs["stderr"] = subprocess.STDOUT
+    kwargs["stderr"] = STDOUT
-    return subprocess.Popen(args, **kwargs).pid
+    return Popen(args, **kwargs).pid
 
 
-def check_cmd(args, **kwargs):
+def check_cmd(args, env=None, cwd=None, wait=True):
     """
     Execute a command on the host and return a tuple containing the exit status and
     result string. stderr output is folded into the stdout result string.
 
     :param list[str]|str args: command arguments
-    :param dict kwargs: keyword arguments to pass to subprocess.Popen
+    :param dict env: environment to run command with
+    :param str cwd: directory to run command in
+    :param bool wait: True to wait for status, False otherwise
     :return: combined stdout and stderr
     :rtype: str
     :raises CoreCommandError: when there is a non-zero exit status or the file to
         execute is not found
     """
-    kwargs["stdout"] = subprocess.PIPE
-    kwargs["stderr"] = subprocess.STDOUT
     args = split_args(args)
     logging.info("command: %s", args)
     try:
-        p = subprocess.Popen(args, **kwargs)
+        p = Popen(args, stdout=PIPE, stderr=PIPE, env=env, cwd=cwd)
-        stdout, _ = p.communicate()
+        if wait:
+            stdout, stderr = p.communicate()
             status = p.wait()
             if status != 0:
-            raise CoreCommandError(status, args, stdout)
+                raise CoreCommandError(status, args, stdout, stderr)
             return stdout.decode("utf-8").strip()
+        else:
+            return ""
     except OSError:
         raise CoreCommandError(-1, args)