Slack Notifications Stopped Working

Slack Notifications Stopped Working

If Slack integration with Nagios XI stopped working for you with an error similar to the one below:

500 Can't connect to (SSL connect attempt failed with unknown errorerror:14077410:SSL routines:SSL23_GET_SERVER_HELLO:sslv3 alert handshake failure)

this means that most likely you are using CentOS/RHEL 6 and older versions of TLS (v1.0 or 1.1).

The Slack announcement was made here:

This issue will impact most CentOS/RHEL 6 users as it doesn't appear that the Perl packages available from official repos are able to use SNI in secure connections.

A quick work around would be to be to install NCPA on another machine(CentOS/RHEL 7 for example that have updated Perl packages) along with a copy of the plugin, and then configure the slack_host_notification_handler and slack_service_notification_handler commands to execute the script via ncpa:

$USER1$/ -H CENTOS7MACHINE -t 'TOKEN' -M 'plugins/' -q 'args=-field slack_channel="#hosts" -field HOSTALIAS="$HOSTNAME$" -field HOSTSTATE="$HOSTSTATE$" -field HOSTOUTPUT="$HOSTOUTPUT$" -field NOTIFICATIONTYPE="$NOTIFICATIONTYPE$"'

Configuring the Slack plugin:

NCPA install and documentation:

How to run third party scripts with NCPA:

Article ID: 868
Created On: Wed, Mar 18, 2020 at 10:20 AM
Last Updated On: Wed, Mar 18, 2020 at 10:21 AM
Authored by: lmiltchev

Online URL: