How to install Monit on NetBSD

Introduction

Monit is an open source tool for monitoring Linux and UNIX systems. It can be used for monitoring system resources, such as CPU usage, memory usage, and disk I/O, as well as monitoring network connections and services. In this tutorial, we will learn how to install Monit on NetBSD.

Prerequisites

To follow this tutorial, you will need:

A NetBSD server (tested on NetBSD 9.1)
Access to a terminal window or console with root privileges
Internet connectivity

Step 1: Download and extract Monit

First, we will need to download the latest version of Monit from the official website at http://mmonit.com/monit/#download. We will download the source code and compile it ourselves.

To download and extract the code, run the following commands:

# cd /usr/local/src
# curl -O https://mmonit.com/monit/dist/monit-5.28.0.tar.gz
# tar xzf monit-5.28.0.tar.gz

Replace 5.28.0 with the latest version available.

Step 2: Install dependencies

Monit depends on several libraries, including OpenSSL, GnuTLS, Net-SNMP, and zlib. We can install these libraries using the pkgsrc package manager.

To install the dependencies, run the following command:

# cd /usr/pkgsrc/security/openssl && make install clean
# cd /usr/pkgsrc/security/gnutls && make install clean
# cd /usr/pkgsrc/net/net-snmp && make install clean
# cd /usr/pkgsrc/archivers/zlib && make install clean

Step 3: Compile and install Monit

Once the dependencies are installed, we can compile and install Monit.

To do this, run the following commands:

# cd /usr/local/src/monit-5.28.0
# ./configure --with-ssl-incl=/usr/include/openssl --with-ssl-lib=/usr/lib --with-libiconv-prefix=/usr/local --with-libintl-prefix=/usr/local
# make && make install

Step 4: Configure Monit

Now that Monit is installed, we can configure it to monitor our system. By default, Monit is configured to monitor system resources such as CPU, memory, load average, and disk usage.

To configure Monit, we need to create a configuration file in /usr/local/etc/monitrc. We can use the sample configuration file that comes with Monit as a starting point. Run the following command to create the configuration file:

# cp /usr/local/src/monit-5.28.0/monitrc /usr/local/etc/monitrc

Next, we need to edit the configuration file to suit our needs. The configuration file is well commented and should be self-explanatory. For example, to monitor a service, we can add the following lines to the configuration file:

check process apache with pidfile /var/run/httpd.pid
  start program = "/usr/local/etc/rc.d/httpd start"
  stop program = "/usr/local/etc/rc.d/httpd stop"
  if failed host example.com port 80 protocol http then restart

This will monitor the Apache web server and restart it if it fails to respond to an HTTP request to example.com on port 80.

Step 5: Start Monit

Once we have configured Monit, we can start it by running the following command:

# /usr/local/bin/monit -Ic /usr/local/etc/monitrc

The -I flag tells Monit to run in interactive mode, which will display any alerts or messages on the console. The -c flag specifies the location of the configuration file. You can add this command to /etc/rc.local to start Monit automatically at boot time.

Conclusion

Congratulations! You have successfully installed and configured Monit on NetBSD. Monit is an essential tool for monitoring system resources, services, and network connections. With Monit, you can receive alerts when problems occur and take action to ensure the availability and reliability of your system.