Use utils.shell instead of subprocess.Popen

This commit is contained in:
mike 2016-01-14 10:24:04 -05:00
parent 8932aaf4ef
commit 6b408ef824
1 changed files with 16 additions and 9 deletions

View File

@ -530,24 +530,31 @@ def munin_cgi(filename=""):
support infrastructure like spawn-fcgi.
"""
COMMAND = 'su - munin --preserve-environment --shell=/bin/bash -c "/usr/lib/munin/cgi/munin-cgi-graph \'%s\'"'
COMMAND = 'su - munin --preserve-environment --shell=/bin/bash -c /usr/lib/munin/cgi/munin-cgi-graph "%s"'
# su changes user, we use the munin user here
# --preserve-environment retains the environment, which is where Popen's `env` data is
# --shell=/bin/bash ensures the shell used is bash
# -c "/usr/lib/munin/cgi/munin-cgi-graph" passes the command to run as munin
# \'%s\' is a placeholder for where the request's querystring will be added
# "%s" is a placeholder for where the request's querystring will be added
if filename == "":
return ("a path must be specified", 404)
query_str = request.query_string.decode("utf-8", 'ignore')
query_str = query_str[1:] if query_str.startswith('&') else query_str[1:]
# I don't know if this is strictly necessary
env = {'PATH_INFO': '/%s/' % filename, 'QUERY_STRING': query_str}
cmd = COMMAND % (query_str if not query_str.startswith('&') else query_str[1:])
process = subprocess.Popen(cmd, env=env, shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE, close_fds=True)
stdout, stderr = process.communicate()
cmd = COMMAND % query_str
code, binout = utils.shell('check_output',
cmd.split(' ', 5),
# Using a maxsplit of 5 keeps the last 2 arguments together
input=query_str.encode('UTF-8'),
env=env,
return_bytes=True,
trap=True)
if process.returncode != 0:
if code != 0:
# nonzero returncode indicates error
app.logger.error("munin_cgi: munin-cgi-graph returned nonzero exit code, %s", process.returncode)
return ("error processing graph image", 500)
@ -556,10 +563,10 @@ def munin_cgi(filename=""):
# Per http://www.libpng.org/pub/png/spec/1.2/PNG-Structure.html PNG files always start
# with the same 8 bytes (137 80 78 71 13 10 26 10) or b'\x89PNG\r\n\x1a\n' So we split
# the output of munin-cgi-graph where the PNG begins
bin_start = stdout.find(b'\x89PNG\r\n\x1a\n')
str_headers = stdout[:bin_start].decode("utf-8")
bin_start = binout.find(b'\x89PNG\r\n\x1a\n')
str_headers = binout[:bin_start].decode("utf-8")
# decode the byte str containing response headers
bin_image = stdout[bin_start:]
bin_image = binout[bin_start:]
response = make_response(bin_image)
for line in str_headers.splitlines():
if line: