From 9a41fce0c2399f05b2c904948c969623dc04e491 Mon Sep 17 00:00:00 2001
From: Scott Moser <smoser@ubuntu.com>
Date: Fri, 8 Jun 2018 12:11:31 -0400
Subject: subp: support combine_capture argument.
This adds 'combine_capture' argument as was present in curtin's
subp. It is useful to get interleaved output of a command. I noticed
a need for it when looking at user_data_rhevm in DataSourceAltCloud.
That will run a subcommand, logging its stdout but swallowing its stderr.
Another thing to change to use this would be in udevadm_settle which
currently just returns the subp() call.
Also, add the docstring copied from curtin's subp.
---
cloudinit/util.py | 63 +++++++++++++++++++++++++++++++++++++++++++++++++------
1 file changed, 57 insertions(+), 6 deletions(-)
(limited to 'cloudinit')
diff --git a/cloudinit/util.py b/cloudinit/util.py
index d9b61cfe..0017de72 100644
--- a/cloudinit/util.py
+++ b/cloudinit/util.py
@@ -1876,9 +1876,55 @@ def subp_blob_in_tempfile(blob, *args, **kwargs):
return subp(*args, **kwargs)
-def subp(args, data=None, rcs=None, env=None, capture=True, shell=False,
+def subp(args, data=None, rcs=None, env=None, capture=True,
+ combine_capture=False, shell=False,
logstring=False, decode="replace", target=None, update_env=None,
status_cb=None):
+ """Run a subprocess.
+
+ :param args: command to run in a list. [cmd, arg1, arg2...]
+ :param data: input to the command, made available on its stdin.
+ :param rcs:
+ a list of allowed return codes. If subprocess exits with a value not
+ in this list, a ProcessExecutionError will be raised. By default,
+ data is returned as a string. See 'decode' parameter.
+ :param env: a dictionary for the command's environment.
+ :param capture:
+ boolean indicating if output should be captured. If True, then stderr
+ and stdout will be returned. If False, they will not be redirected.
+ :param combine_capture:
+ boolean indicating if stderr should be redirected to stdout. When True,
+ interleaved stderr and stdout will be returned as the first element of
+ a tuple, the second will be empty string or bytes (per decode).
+ if combine_capture is True, then output is captured independent of
+ the value of capture.
+ :param shell: boolean indicating if this should be run with a shell.
+ :param logstring:
+ the command will be logged to DEBUG. If it contains info that should
+ not be logged, then logstring will be logged instead.
+ :param decode:
+ if False, no decoding will be done and returned stdout and stderr will
+ be bytes. Other allowed values are 'strict', 'ignore', and 'replace'.
+ These values are passed through to bytes().decode() as the 'errors'
+ parameter. There is no support for decoding to other than utf-8.
+ :param target:
+ not supported, kwarg present only to make function signature similar
+ to curtin's subp.
+ :param update_env:
+ update the enviornment for this command with this dictionary.
+ this will not affect the current processes os.environ.
+ :param status_cb:
+ call this fuction with a single string argument before starting
+ and after finishing.
+
+ :return
+ if not capturing, return is (None, None)
+ if capturing, stdout and stderr are returned.
+ if decode:
+ entries in tuple will be python2 unicode or python3 string
+ if not decode:
+ entries in tuple will be python2 string or python3 bytes
+ """
# not supported in cloud-init (yet), for now kept in the call signature
# to ease maintaining code shared between cloud-init and curtin
@@ -1904,7 +1950,8 @@ def subp(args, data=None, rcs=None, env=None, capture=True, shell=False,
status_cb('Begin run command: {command}\n'.format(command=command))
if not logstring:
LOG.debug(("Running command %s with allowed return codes %s"
- " (shell=%s, capture=%s)"), args, rcs, shell, capture)
+ " (shell=%s, capture=%s)"),
+ args, rcs, shell, 'combine' if combine_capture else capture)
else:
LOG.debug(("Running hidden command to protect sensitive "
"input/output logstring: %s"), logstring)
@@ -1915,6 +1962,9 @@ def subp(args, data=None, rcs=None, env=None, capture=True, shell=False,
if capture:
stdout = subprocess.PIPE
stderr = subprocess.PIPE
+ if combine_capture:
+ stdout = subprocess.PIPE
+ stderr = subprocess.STDOUT
if data is None:
# using devnull assures any reads get null, rather
# than possibly waiting on input.
@@ -1953,10 +2003,11 @@ def subp(args, data=None, rcs=None, env=None, capture=True, shell=False,
devnull_fp.close()
# Just ensure blank instead of none.
- if not out and capture:
- out = b''
- if not err and capture:
- err = b''
+ if capture or combine_capture:
+ if not out:
+ out = b''
+ if not err:
+ err = b''
if decode:
def ldecode(data, m='utf-8'):
if not isinstance(data, bytes):
--
cgit v1.2.3