[checkmk-commits] Check_MK Git: check_mk: FIX: fix user database corruption in case of a race condition

Module: check_mk Branch: master Commit: d65c0a577722552019482271dbc1cdacc94b16f7 URL: http://git.mathias-kettner.de/git/?p=check_mk.git;a=commit;h=d65c0a57772255… Author: Mathias Kettner <mk(a)mathias-kettner.de> Date: Tue Feb 26 15:53:44 2013 +0100 FIX: fix user database corruption in case of a race condition Conflicts: ChangeLog --- ChangeLog | 1 + web/htdocs/userdb.py | 46 +++++++++++++++++++++------------------------- 2 files changed, 22 insertions(+), 25 deletions(-) diff --git a/ChangeLog b/ChangeLog index 5f4185e..d0e730d 100644 --- a/ChangeLog +++ b/ChangeLog @@ -70,6 +70,7 @@ * FIX: fixed focus bug in transform valuespec class * FIX: stop doing snapin refreshes after they have been removed * FIX: sidebar snapins which refresh do not register for restart detection anymore + * FIX: fix user database corruption in case of a race condition * Changed sidebar snapin reload to a global interval (option: sidebar_update_interval), defaults to 30 seconds * Sidebar snapins are now bulk updated with one HTTP request each interval diff --git a/web/htdocs/userdb.py b/web/htdocs/userdb.py index 8c3096c..075a467 100644 --- a/web/htdocs/userdb.py +++ b/web/htdocs/userdb.py @@ -140,22 +140,27 @@ def reset_user_attributes(): user_attributes = {} def load_users(): - # First load monitoring contacts from Check_MK's world filename = root_dir + "contacts.mk" - if os.path.exists(filename): - try: - vars = { "contacts" : {} } - execfile(filename, vars, vars) - contacts = vars["contacts"] - except Exception, e: - if config.debug: - raise MKGeneralException(_("Cannot read configuration file %s: %s" % - (filename, e))) - else: - html.log('load_users: Problem while loading contacts (%s - %s). ' - 'Initializing structure...' % (filename, e)) - contacts = {} - else: + + # Make sure that the file exists without modifying it, *if* it exists. + # Note the lock will be released at end of page request automatically. + file(filename, "a") + aquire_lock(filename) + + # First load monitoring contacts from Check_MK's world. If this is + # the first time, then the file will be empty, which is no problem. + # Execfile will the simply leave contacts = {} unchanged. + try: + vars = { "contacts" : {} } + execfile(filename, vars, vars) + contacts = vars["contacts"] + except Exception, e: + if config.debug: + raise MKGeneralException(_("Cannot read configuration file %s: %s" % + (filename, e))) + else: + html.log('load_users: Problem while loading contacts (%s - %s). ' + 'Initializing structure...' % (filename, e)) contacts = {} # Now add information about users from the Web world @@ -261,6 +266,7 @@ def load_users(): def split_dict(d, keylist, positive): return dict([(k,v) for (k,v) in d.items() if (k in keylist) == positive]) + def save_users(profiles): custom_values = user_attributes.keys() @@ -300,19 +306,9 @@ def save_users(profiles): if p in multisite_keys + multisite_attributes(profile.get('connector'))]) filename = root_dir + "contacts.mk" - locked = False - if os.path.exists(filename): - # When the file exists, lock the file before opening (and truncating) it - aquire_lock(filename) - locked = True # Check_MK's monitoring contacts out = create_user_file(filename, "w") - - # In create mode lock the file after creation - if not locked: - aquire_lock(filename) - out.write("# Written by Multisite UserDB\n# encoding: utf-8\n\n") out.write("contacts.update(\n%s\n)\n" % pprint.pformat(contacts)) out.close()