checkmk is a snmp tool like LibreNMS, Nagios, Solarwinds, etc that runs on Linux (which means you are already more stable than Solarwinds which will ONLY run on Windows).

Like Nagios Core there is a free version called Raw.  There is also a free Enterprise version that allows up to 25 nodes to be monitored but if you need more than 25, you'll have to pay.

Instructions below are for RedHat/CentOS 8.x

Pre-Req's

sudo yum -y install dialog graphviz graphviz-gd httpd libdbi perl-Locale-Maketext-Simple php uuid freeradius-utils

To install Raw you follow these instructions:

Setting up the package sources, firewall and SELinux

Checkmk requires a number of software packages from your Linux distribution. Third-party software is not required. In order that all necessary packages can be subsequently installed, a correct configuration of the software sources is necessary.

Setting up the package sources

Checkmk requires a number of software packages from your Linux distribution. Third-party software is not required. In order that all necessary packages can be subsequently installed, a correct configuration of the software sources is necessary.

With Red Hat and CentOS the EPEL (Extra Packages for Enterprise Linux) repository must be set up as a package source. You can do this with the help of an RPM package, which can be installed with the yum command.

Download file:

wget --no-check-certificate "https://dl.fedoraproject.org/pub/epel/epel-release-latest-8.noarch.rpm"

Here is an example of an installation on CentOS 8:

sudo yum localinstall epel-release-latest-8.noarch.rpm

In order to be able to use EPEL on RedHat and CentOS, the package sources for optional RPMs are required if these haven’t already been installed during the operating system installation. Without these sources the freeradius-utils, graphviz-gd, and php-mbstring packages will be missing. As of version 8.x it will suffice to activate the so-called PowerTools with the help of Dandified YUM in CentOS or the subscription-manager in RHEL respectively. This can be done, e.g., with the following commands:

CentOS 8.X before 8.3.2011:

dnf config-manager --set-enabled PowerTools

CentOS 8.3.2011 and later:

dnf config-manager --set-enabled powertools

RedHat 8.X:

subscription-manager repos --enable "codeready-builder-for-rhel-8-x86_64-rpms"

Setup SELinux and Firewall

Since Red Hat and thus CentOS also deliver SELinux and a local firewall by default, adjustments may have to be made here. As the first step you will need to allow your web server to access the network interfaces:

setsebool -P httpd_can_network_connect 1

Secondly, you release the web server and activate the change:

firewall-cmd --zone=public --add-service=http --permanent

firewall-cmd --reload

Download the appropriate packages

If you have a subscription, you will find in the customer portal a suitable RPM or DEB package for your distribution for every available Checkmk version. For a free test or small installations of Checkmk you can use our free editions. These don’t need in consequence any subscription. You are still able to do an upgrade any time to one of the  Checkmk Enterprise Editions.

Consider when selecting a package:

Choose one of the editions. If you’re unsure, you can get an overview to the differences of the editions.

Choose the Checkmk version, the distribution and finally the version of the selected distribution.

We recommend the latest stable Checkmk version. If you need an older version anyway, you can find these in the download archive.

The name and version of your distribution must be strictly identical.

After you downloaded the package to your machine, you need to copy the file to the target Linux system where Checkmk needs to be installed. You can do that for example with the programm WinSCP or — if you are able to use SSH connections — with the commandline tool scp, in the following example for the  Checkmk Raw Edition and CentOS 8.x:

scp check-mk-raw-2.1.0p1-el8-38.x86_64.rpm [email protected]:

Signed-package installation

All packages are signed using GnuPG. Through the use of this signature, on the one hand it can be verified whether the package really is from Checkmk, and on the other hand it can be verified that the package is complete.

So that these signed packages can be installed in the usual way, one time only you will need to import our public key so that the signature will be trusted. First, load the key directly from our website:

wget https://download.checkmk.com/checkmk/Check_MK-pubkey.gpg

Then import the key to the list of trusted signatures. On Red Hat and CentOS this is yet another job for rpm:

rpm --import Check_MK-pubkey.gpg

Once the key has been imported, you can verify the package and install it the usual way with yum install afterwards:

rpm -K check-mk-raw-2.1.0p1-el8-38.x86_64.rpm 

check-mk-raw-2.1.0p1-el8-38.x86_64.rpm: digests signatures OK 

yum install check-mk-raw-2.1.0p1-el8-38.x86_64.rpm

Downloading Checkmk for Red Hat or CentOS

Pull in the package using wget

wget https://download.checkmk.com/checkmk/2.1.0p6/check-mk-raw-2.1.0p6-el8-38.x86_64.rpm

SHA-256 file hash:

c718bd7631dc9fe52368d4a9aa86410b263814bd3a1792a1d96e9e835509e461

Install the Checkmk package

Now install the package including all of its dependencies.

sudo rpm --install ./check-mk-raw-2.1.0p6-el8-38.x86_64.rpm

Afterwards we can test if the installation was successful by running the omd version command:

omd version

OMD - Open Monitoring Distribution Version 2.1.0p6.cre

You should see an output similar to this one.

Create a Checkmk monitoring site

Use the omd command to create a new Checkmk site. You can choose your own name, in this example we named the site 'monitoring'

omd create monitoring

After the site has been created you will see an output similar to the one below.

Adding /opt/omd/sites/monitoring/tmp to /etc/fstab. 
Creating temporary filesystem /omd/sites/monitoring/tmp...OK 
Restarting Apache...OK 
Created new site monitoring with version 2.1.0p6.cre. 

     The site can be started with omd start monitoring. 
     The default web UI is available at http://your_server/monitoring/ 

     The admin user for the web applications is cmkadmin with password: generated-password 
     (It can be changed with 'htpasswd -m ~/etc/htpasswd cmkadmin' as site user.) 
     Please do a su - monitoring for administration of this site.

Here you can see the URL on which your site is accessible, default username, and an automatically generated password for accessing the site. The site is now created, but it still needs to be started. To start the site, type:

omd start monitoring

When everything has been started successfully you will see an output similar to the one below.

Starting mkeventd...OK 
Starting liveproxyd...OK 
Starting mknotifyd...OK 
Starting rrdcached...OK 
Starting cmc...OK 
Starting apache...OK 
Starting dcd...OK 
Starting redis...OK 
Initializing Crontab...OK

Your Checkmk site is now up and running. You can visit the user interface in the browser by using the aforementioned URL.

Final test

After the successful installation of Checkmk, and all dependencies, you will have access to the omd command. With this command you are able to create and manage monitoring sites. You can request the installed version to verify your installation:

omd version 

OMD - Open Monitoring Distribution Version 2.1.0p1.cre

 

To install Free / Enterprise Trial you follow these instructions

Setting up the package sources, firewall and SELinux

Checkmk requires a number of software packages from your Linux distribution. Third-party software is not required. In order that all necessary packages can be subsequently installed, a correct configuration of the software sources is necessary. Follow the steps described here for setting up the package sources, SELinux and the firewall..

Downloading Checkmk for Red Hat or CentOS

Pull in the package using wget

wget https://download.checkmk.com/checkmk/2.1.0p6/check-mk-free-2.1.0p6-el8-38.x86_64.rpm

 

SHA-256 file hash:

69c8bd70b4eaf002d200ff91579e5c297de5d5920a72bf9fcfe6c1b2a310b982

Signed-package installation

All packages are signed using GnuPG. Through the use of this signature, on the one hand it can be verified whether the package really is from Checkmk, and on the other hand it can be verified that the package is complete.

So that these signed packages can be installed in the usual way, one time only you will need to import our public key so that the signature will be trusted. First, load the key directly from our website:

wget https://download.checkmk.com/checkmk/Check_MK-pubkey.gpg

 

Then import the key to the list of trusted signatures. On Red Hat and CentOS this is yet another job for rpm:

rpm --import Check_MK-pubkey.gpg

Once the key has been imported, you can verify the package and install it the usual way with yum install afterwards:

rpm -K check-mk-raw-2.1.0p1-el8-38.x86_64.rpm

yum install check-mk-raw-2.1.0p1-el8-38.x86_64.rpm

Final test

After the successful installation of Checkmk, and all dependencies, you will have access to the omd command. With this command you are able to create and manage monitoring sites. You can request the installed version to verify your installation:

omd version

Install the Checkmk package

Now install the package including all of its dependencies.

sudo rpm --install ./check-mk-free-2.1.0p6-el8-38.x86_64.rpm

Afterwards we can test if the installation was successful by running the omd version command:

omd version

OMD - Open Monitoring Distribution Version 2.1.0p6.cfe

You should see an output similar to the one shown above.

Create a Checkmk monitoring site

Use the omd command to create a new Checkmk site. You can choose your own name, in this example we named the site 'monitoring'

omd create monitoring

After the site has been created you will see an output similar to the one below.

Adding /opt/omd/sites/monitoring/tmp to /etc/fstab. 
Creating temporary filesystem /omd/sites/monitoring/tmp...OK 
Restarting Apache...OK 
Created new site monitoring with version 2.1.0p6.cfe.

     The site can be started with omd start monitoring.
     The default web UI is available at http://your_server/monitoring/ 

     The admin user for the web applications is cmkadmin with password: generated-password 
     (It can be changed with 'htpasswd -m ~/etc/htpasswd cmkadmin' as site user.) 
     Please do a su - monitoring for administration of this site.

Here you can see the URL on which your site is accessible, default username, and an automatically generated password for accessing the site. The site is now created, but it still needs to be started. To start the site, type:

omd start monitoring

When everything has been started successfully you will see an output similar to the one below.

Starting mkeventd...OK 
Starting liveproxyd...OK 
Starting mknotifyd...OK 
Starting rrdcached...OK 
Starting cmc...OK 
Starting apache...OK 
Starting dcd...OK 
Starting redis...OK 
Initializing Crontab...OK

Your Checkmk site is now up and running. You can visit the user interface in the browser by using the aforementioned URL.

Getting started with Checkmk

If you are new to Checkmk then the beginners guide might help you to get started.
We recommend watching the video tutorial series, which covers all important aspects around your first steps with Checkmk.

 

 

 

Hope you enjoy