[checkmk-commits] 7068 FIX Truncate values of the notification context which are too long

Module: check_mk Branch: master Commit: 36c1927d2a1e2c8365f9eedae502ea3c0445f15e URL: http://git.mathias-kettner.de/git/?p=check_mk.git;a=commit;h=36c1927d2a1e2c… Author: Tom Baerwinkel <tb(a)mathias-kettner.de> Date: Thu Mar 21 16:14:09 2019 +0100 7068 FIX Truncate values of the notification context which are too long If the the value stored in the notification context was larger than the OS limit MAX_ARG_STRLEN a failed notification was produced and the error 'OSError: [Errno 7] Argument list too long' appeared in the notify.log. This was usually the case for very long values in the long outputs of a service like e.g. fileinfo.groups. Now the values are truncated and the text 'Attention: Removed remaining content because it was too long.' is shown at the end. Change-Id: I726dc536378f54da5dccf624d551b1565ecf0d47 --- .werks/7068 | 16 ++++++++++++++++ cmk_base/notify.py | 35 +++++++++++++++++++++-------------- 2 files changed, 37 insertions(+), 14 deletions(-) diff --git a/.werks/7068 b/.werks/7068 new file mode 100644 index 0000000..3bfc58b --- /dev/null +++ b/.werks/7068 @@ -0,0 +1,16 @@ +Title: Truncate values of the notification context which are too long +Level: 1 +Component: notifications +Compatible: compat +Edition: cre +Version: 1.6.0i1 +Date: 1553180240 +Class: fix + +If the the value stored in the notification context was larger than +the OS limit MAX_ARG_STRLEN a failed notification was produced and +the error 'OSError: [Errno 7] Argument list too long' appeared in +the notify.log. This was usually the case for very long values in +the long outputs of a service like e.g. fileinfo.groups. Now the +values are truncated and the text 'Attention: Removed remaining +content because it was too long.' is shown at the end. diff --git a/cmk_base/notify.py b/cmk_base/notify.py index f669089..94f90ea 100755 --- a/cmk_base/notify.py +++ b/cmk_base/notify.py @@ -1310,18 +1310,6 @@ def path_to_notification_script(plugin): # # Note: this function is *not* being called for bulk notification. def call_notification_script(plugin, plugin_context): - # FIXME: This is a temporary workaround to avoid a possible crash of - # subprocess.Popen when a crash dump occurs. Since in this case the - # LONGSERVICEOUTPUT and LONGSERVICEOUTPUT_HTML contain very long base64 - # encoded strings an 'OSError: [Errno 7] Argument list too long' may - # occur. To avoid this we replace the base64 encoded strings here. - if plugin_context.get('LONGSERVICEOUTPUT', '').startswith('Crash dump:\\n'): - plugin_context[ - 'LONGSERVICEOUTPUT'] = u'Check failed:\\nA crash report can be submitted via the user interface.' - if plugin_context.get('LONGSERVICEOUTPUT_HTML', '').startswith('Crash dump:\\n'): - plugin_context[ - 'LONGSERVICEOUTPUT_HTML'] = u'Check failed:\\nA crash report can be submitted via the user interface.' - core_notification_log(plugin, plugin_context) def plugin_log(s): @@ -1374,8 +1362,27 @@ def call_notification_script(plugin, plugin_context): # Construct the environment for the notification script def notification_script_env(plugin_context): - return dict(os.environ.items() + - [("NOTIFY_" + k, v.encode("utf-8")) for k, v in plugin_context.items()]) + # Use half of the maximum allowed string length MAX_ARG_STRLEN + # which is usually 32 pages on Linux (see "man execve"). + # + # Assumption: We don't have to consider ARG_MAX, i.e. the maximum + # size of argv + envp, because it is derived from RLIMIT_STACK + # and large enough. + try: + max_length = 32 * os.sysconf("SC_PAGESIZE") // 2 + except ValueError: + max_length = 32 * 4046 // 2 + + def format_(value): + if len(value) > max_length: + value = value[:max_length] + "...\nAttention: Removed remaining content because it was too long." + return value.encode("utf-8") + + notify_env = { + "NOTIFY_" + variable: format_(value) for variable, value in plugin_context.iteritems() + } + notify_env.update(os.environ) + return notify_env class NotificationTimeout(Exception):