no42

... search for answer?

Send notifications with Signal

2018-11-01 Ronny Trommer
In some cases it is nice to have notifications from OpenNMS in a separate channel on a smartphone and you don’t want to pay for SMS. Here is a tutorial where I use Signal using the signal-cli. This Howto will describe how to download the latest signal-cli tool, link it to your existing Signal account and how to configure OpenNMS to use it as a notification target. You should have already an OpenNMS Horizon or Meridian running and you need a Signal account with the Signal app installed and configured on your smartphone. Continue reading

Monitoring Websites with OpenNMS

2018-07-27 Ronny Trommer
Monitoring websites is a common requirement. Using OpenNMS to monitor websites can be done by using the built in HTTP/HTTPS based monitors. While a “Node” can be pretty much everything in a network, the internal model to monitor something is pretty old-fashioned and static. Monitoring a service requires to assign a service to an IP address. This article describes a pattern how you can monitor web sites with low maintenance and without the need to maintain for each website a monitor which is cumbersome in maintenance. Continue reading

Authenticate OpenNMS Horizon with FreeRADIUS

2018-07-22 Ronny Trommer
Centralized authentication is a core service as soon you have a network with more than 3 computers. This article is about how to authenticate a OpenNMS Horizon 22.0.2 using RADIUS provided by a FreeRADIUS service. In this example the FreeRADIUS server is configured to provide 3 users. A dictionary is configured which returns 2 roles, ROLE_USER and ROLE_ADMIN which can be used to decide which security role is assigned in the OpenNMS Horizon Web UI. Continue reading

Authenticate OpenNMS Horizon with Active Directory on Windows Server 2016

2018-07-16 Ronny Trommer
Centralized authentication is a core service as soon you have a network with more than 3 computers. This article is about how to authenticate a OpenNMS Horizon 22.0.1 against an Active Directory provided on a Microsoft Windows Server 2016. I’ll focus here on the Active Directory and Spring configuration parts, securing the connection with LDAPS and using self-signed certificates in Java is another topic and not covered here. In this example the domain is called labmonkeys. Continue reading

Build OpenNMS with Docker

2018-07-14 Ronny Trommer
Being able to compiling an Open Source project is important. You can change the code, so you should also able to build it. Why is there a dedicated Docker image for the build environment? The dependencies running a pre-build OpenNMS Horizon distribution and compiling from source are different. To build OpenNMS Horizon you need Apache Maven and to compile JICMP, JRRD you need a C compiler environment. This is nothing you want to carry when you just want to run OpenNMS Horizon. Continue reading

Centralized Logging with Graylog2

2017-11-17 Ronny Trommer
How many times do you connect with SSH to your remote server and cat, grep, tail and awk through your logs? It probably works for 3 servers and running a handful services, but if you have more, you should definitely spend some time to centralize your logs. I personally prefer Graylog2 which can deal very well with different log formats like GELF, Syslog RFC’s. Just start some listener with the format and forward them to your Graylog2 instance. Continue reading

Net-SNMP version 3 and OpenNMS

2017-09-22 Ronny Trommer
To monitor your systems you rely heavily on SNMP, it gives out of the box a lot of possibilities getting important performance and status information. The main topic security is often not considered. SNMP version 1 and 2c transmit everything in plain text over the wire. There is also no user, password authentication method, just a shared community string which gives access to the information. To address these problems SNMP v3 was introduced. Continue reading

Pimp my Mail Notifications

2016-03-07 Ronny Trommer
Notifications are important if you do monitoring. I never liked mail notifications from monitoring systems where all the information is hidden in non-sense text. Otherwise notifications never look the same, so I’m always forced to read all that useless crap again and again. This is an approach to improve the usability of monitoring notifications using more a table pattern which helps me to recognize useful information much quicker. Probably a lot of E-Mail guys will hate me for the reason I’m using HTML in mails. Continue reading
Older posts