fix: pass stdin=DEVNULL to Popen to avoid eating stdin from pipes (#4189

)

- For the first cmd to run in subprocess.call, specified
  "stdin=subprocess.DEVNULL" to avoid it from eating
  the stdin behind it
- also fix: #4187 in the base call

Signed-off-by: Xiangce Liu <[email protected]>

* undo the wrapped lines which is unnecessary

Signed-off-by: Xiangce Liu <[email protected]>

insights/util/subproc.py

@@ -10,6 +10,11 @@
 from insights.core.exceptions import CalledProcessError
 from insights.util import which
 
+try:
+    from subprocess import DEVNULL
+except:
+    DEVNULL = open(os.devnull, 'w')
+
 log = logging.getLogger(__name__)
 
 
@@ -57,9 +62,9 @@ def __init__(self, *cmds, **kwargs):
     def _build_pipes(self, out_stream=PIPE):
         log.debug("Executing: %s" % str(self.cmds))
         if len(self.cmds) == 1:
-            return Popen(self.cmds[0], bufsize=self.bufsize, stderr=STDOUT, stdout=out_stream, env=self.env)
+            return Popen(self.cmds[0], bufsize=self.bufsize, stdin=DEVNULL, stderr=STDOUT, stdout=out_stream, env=self.env)
 
-        stdout = Popen(self.cmds[0], bufsize=self.bufsize, stderr=STDOUT, stdout=PIPE, env=self.env).stdout
+        stdout = Popen(self.cmds[0], bufsize=self.bufsize, stdin=DEVNULL, stderr=STDOUT, stdout=PIPE, env=self.env).stdout
         last = len(self.cmds) - 2
         for i, arg in enumerate(self.cmds[1:]):
             if i < last: