Nagios Support Forum

Hi All, Over the weekend our slack integration with Nagios stopped working with the following error.

500 Can't connect to iaitdepartment.slack.com:443 (SSL connect attempt failed with unknown errorerror:14077410:SSL routines:SSL23_GET_SERVER_HELLO:sslv3 alert handshake failure)

It would appear that SSLv3 and possibly earlier versions of TLS has been disabled at slacks end which makes sense as per security guidelines but we are at a loss as to how we get this going again. We use the standard slack_nagios.pl and the below command yields the above error.


slack_nagios.pl -field slack_channel=#hosts -field HOSTALIAS="Test host" -field HOSTSTATE="UP" -field HOSTOUTPUT="Host is Up" -field NOTIFICTATIONTYPE="RECOVERY"
Request: POST https://ourinstance.slack.com/services/ ... iBSKbnFtAP

I'm keen to get this up and going any assistance in how we get this happening would be much appreciated.
scrantic

The Slack announcement was made here:

https://api.slack.com/changelog/2019-07 ... s-versions

This will impact most Cent/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(Cent/RHEL 7 for example that have updated Perl packages) along with a copy of the slack_nagios.pl plugin, and then configure the slack_host_notification_handler and slack_service_notification_handler commands to execute the slack_nagios.pl script via ncpa:
Configuring the Slack plugin: https://assets.nagios.com/downloads/nag ... ios-XI.pdf
NCPA install and documentation: https://www.nagios.org/ncpa/
How to run third party scripts with NCPA: https://support.nagios.com/kb/article/n ... a-722.html

Was quicker to backup/restore and repair our Nagios install the CentOS Hyper-V image

scrantic wrote:Was quicker to backup/restore and repair our Nagios install the CentOS Hyper-V image

Are you back to a working setup?