Changed atomic_replace to atomic_move, now ti DOES move atomically in the last

step
Signed-off-by: Brian Coca <briancoca+dev@gmail.com>
This commit is contained in:
Brian Coca 2013-04-23 21:52:23 -04:00 committed by Michael DeHaan
parent f876d51c66
commit caf6bd6ce5
6 changed files with 34 additions and 26 deletions

View file

@ -807,8 +807,9 @@ class AnsibleModule(object):
self.fail_json(msg='Could not make backup of %s to %s: %s' % (fn, backupdest, e)) self.fail_json(msg='Could not make backup of %s to %s: %s' % (fn, backupdest, e))
return backupdest return backupdest
def atomic_replace(self, src, dest): def atomic_move(self, src, dest):
'''atomically replace dest with src, copying attributes from dest''' '''atomically move src to dest, copying attributes from dest, returns true on success'''
rc = False
if os.path.exists(dest): if os.path.exists(dest):
st = os.stat(dest) st = os.stat(dest)
os.chmod(src, st.st_mode & 07777) os.chmod(src, st.st_mode & 07777)
@ -824,7 +825,25 @@ class AnsibleModule(object):
if self.selinux_enabled(): if self.selinux_enabled():
context = self.selinux_default_context(dest) context = self.selinux_default_context(dest)
self.set_context_if_different(src, context, False) self.set_context_if_different(src, context, False)
os.rename(src, dest) # Ensure file is on same partition to make replacement atomic
dest_dir = os.path.dirname(dest)
dest_file = os.path.basename(dest)
tmp_dest = "%s/.%s.%s.%s" % (dest_dir,dest_file,os.getpid(),time.time())
try:
shutil.move(src, tmp_dest)
os.rename(tmp_dest, dest)
rc = True
except (shutil.Error, OSError, IOError), e:
self.fail_json(msg='Could not replace file: %s to %s: %s' % (src, dest, e))
finally:
# Clean up in case of failure (don't leave nasty temps around)
if os.path.exists(tmp_dest):
try:
#TODO: would be nice to respect 'keep_remote_files'
os.unlink(tmp_dest)
except OSError, e:
sys.stderr.write("could not cleanup %s: %s" % (tmp_dest, e))
return rc
def run_command(self, args, check_rc=False, close_fds=False, executable=None, data=None): def run_command(self, args, check_rc=False, close_fds=False, executable=None, data=None):
''' '''

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@ -162,7 +162,7 @@ def writekeys(module, filename, keys):
except IOError, e: except IOError, e:
module.fail_json(msg="Failed to write to file %s: %s" % (tmp_path, str(e))) module.fail_json(msg="Failed to write to file %s: %s" % (tmp_path, str(e)))
f.close() f.close()
module.atomic_replace(tmp_path, filename) module.atomic_move(tmp_path, filename)
def enforce_state(module, params): def enforce_state(module, params):
""" """

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@ -19,7 +19,6 @@
# along with Ansible. If not, see <http://www.gnu.org/licenses/>. # along with Ansible. If not, see <http://www.gnu.org/licenses/>.
import os import os
import shutil
import time import time
DOCUMENTATION = ''' DOCUMENTATION = '''
@ -144,17 +143,15 @@ def main():
if os.path.islink(dest): if os.path.islink(dest):
os.unlink(dest) os.unlink(dest)
open(dest, 'w').close() open(dest, 'w').close()
# TODO:pid + epoch should avoid most collisions, hostname/mac for those using nfs?
# might be an issue with exceeding path length
dest_tmp = "%s.%s.%s.tmp" % (dest,os.getpid(),time.time())
shutil.copyfile(src, dest_tmp)
if validate: if validate:
(rc,out,err) = module.run_command(validate % dest_tmp) (rc,out,err) = module.run_command(validate % src)
if rc != 0: if rc != 0:
module.fail_json(msg="failed to validate: rc:%s error:%s" % (rc,err)) module.fail_json(msg="failed to validate: rc:%s error:%s" % (rc,err))
module.atomic_replace(dest_tmp, dest) if not module.atomic_move(src, dest):
except shutil.Error: try:
module.fail_json(msg="failed to copy: %s and %s are the same" % (src, dest)) os.unlink(src) # cleanup tmp files on failure
except OSError, e:
sys.stderr.write("failed to clean up tmp file %s: %s\n" % (src, e))
except IOError: except IOError:
module.fail_json(msg="failed to copy: %s to %s" % (src, dest)) module.fail_json(msg="failed to copy: %s to %s" % (src, dest))
changed = True changed = True

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@ -145,15 +145,7 @@ def get_jobs_file(module, user, tmpfile, cron_file):
def install_jobs(module, user, tmpfile, cron_file): def install_jobs(module, user, tmpfile, cron_file):
if cron_file: if cron_file:
cron_file = '/etc/cron.d/%s' % cron_file cron_file = '/etc/cron.d/%s' % cron_file
try: module.atomic_move(tmpfile, cron_file)
module.atomic_replace(tmpfile, cron_file)
except (OSError, IOError), e:
return (1, "", str(e))
except:
return (1, "", str(e))
else:
return (0, "", "")
else: else:
cmd = "crontab %s %s" % (user, tmpfile) cmd = "crontab %s %s" % (user, tmpfile)
return module.run_command(cmd) return module.run_command(cmd)

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@ -334,7 +334,7 @@ class Service(object):
os.close(TMP_RCCONF) os.close(TMP_RCCONF)
# Replace previous rc.conf. # Replace previous rc.conf.
self.module.atomic_replace(tmp_rcconf_file, self.rcconf_file) self.module.atomic_move(tmp_rcconf_file, self.rcconf_file)
# =========================================== # ===========================================
# Subclass: Linux # Subclass: Linux

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@ -112,7 +112,7 @@ def write_sysctl(module, lines, **sysctl_args):
f.close() f.close()
# replace the real one # replace the real one
module.atomic_replace(tmp_path, sysctl_args['sysctl_file']) module.atomic_move(tmp_path, sysctl_args['sysctl_file'])
# end # end
return sysctl_args return sysctl_args