x/cloud-init
Code Issues Proposed changes

improve debug via _CLOUD_INIT_SAVE_STDIN and _CLOUD_INIT_SAVE_STDOUT

Browse Source 
This does 2 things:
 a.) fixes broken logic in 'close_stdin'
     previously _CLOUD_INIT_SAVE_STDIN had to be set to false to
     preserve stdin.  "save_stdin" should be true to indicate it
     should be saved.

The net result is that you can stuff just add
 import pdb; pdb.set_trace()
to code, and then run something like:
 sudo _CLOUD_INIT_SAVE_STDIN=1 _CLOUD_INIT_SAVE_STDOUT=1 \
   cloud-init single --name=mounts --frequency=always

And enter the debugger even if you had a 'output' that would redirect
stdin/out by default, like:
   output: {all: '| tee -a /var/log/cloud-init-output.log'}
This commit is contained in:
Scott Moser 2012-07-16 16:46:22 -04:00
parent c1b947c735
commit aef06d4f60
1 changed files with 12 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
cloudinit/util.py
View File

@ -406,7 +406,16 @@ def fixup_output(cfg, mode):
# #
# with a '|', arguments are passed to shell, so one level of # with a '|', arguments are passed to shell, so one level of
# shell escape is required. # shell escape is required.
#
# if _CLOUD_INIT_SAVE_STDOUT is set in environment to a non empty and true
# value then output input will not be closed (useful for debugging).
#
def redirect_output(outfmt, errfmt, o_out=None, o_err=None): def redirect_output(outfmt, errfmt, o_out=None, o_err=None):
if is_true(os.environ.get("_CLOUD_INIT_SAVE_STDOUT")):
LOG.debug("Not redirecting output due to _CLOUD_INIT_SAVE_STDOUT")
return
if not o_out: if not o_out:
o_out = sys.stdout o_out = sys.stdout
if not o_err: if not o_err:
@ -853,10 +862,10 @@ def close_stdin():
reopen stdin as /dev/null so even subprocesses or other os level things get reopen stdin as /dev/null so even subprocesses or other os level things get
/dev/null as input. /dev/null as input.
if _CLOUD_INIT_SAVE_STDIN is set in environment to a non empty or '0' value if _CLOUD_INIT_SAVE_STDIN is set in environment to a non empty and true
then input will not be closed (only useful potentially for debugging). value then input will not be closed (useful for debugging).
""" """
if is_false(os.environ.get("_CLOUD_INIT_SAVE_STDIN")): if is_true(os.environ.get("_CLOUD_INIT_SAVE_STDIN")):
return return
with open(os.devnull) as fp: with open(os.devnull) as fp:
os.dup2(fp.fileno(), sys.stdin.fileno()) os.dup2(fp.fileno(), sys.stdin.fileno())