It helps you, monitor, search and analyze the vast amount of data, (especially in larger environments) into a simple format that you can easily read and digest. OpenNMS automatically discover your entire network using CDP, FDP, LLDP, OSPF, BGP, SNMP, and ARP and provide you alerts via email, slack, support for Microblog notifications via Identica / StatusNet / Twitter, and more. The majority of the network devices in use today support protocols that work with OpenNMS — from many major manufacturers… including the vast majority of the networking devices deployed… For more about OpenNMS, please check its homepage. Since OpenNMS is based on Java and requires Java to function, you’ll want to install Java JDK. The open-source version of JavaJDK works great, so use the steps below to install and configure it on Ubuntu.

Install OpenJDK on Ubuntu

Run the commands below to install OpenJDK on the Ubuntu desktop. That should install the latest OpenJDK on Ubuntu. At the time of this writing, the latest OpenJDK version was 11. After installing OpenJDK, run the commands below to configure it as the default JDK runtime for Ubuntu. To find out which version of JDK to run, type the commands below: If you have multiple versions, you’ll see OpenJDK on the list. If only OpenJDK is installed, you should see a message that there is only one alternative for Java. Take notes of where JAVA is located. Next, copy the installation path of your preferred JDK home. Next, open the /etc/environment file: Add the following line, at the end of the file: Closeout and save. Then run the commands below to apply. When you’re done, OpenJDK should be installed and ready to use.

Downloading OpenNMS

After installing OpenJDK to your system, run the commands below to Add the apt repository in /etc/apt/sources.list.d/opennms.list and add the GPG key. To do that, run the commands below to create new opennms.list file. Then copy and paste the lines below into the file and save. After that, run the commands below to add the repository PGP key. Finally, run the commands below to install OpenNMS packages including all dependencies. The above commands will install the OpenNMS meta package together with all built-in dependencies such as jicmp6 and jicmp, opennms-core, opennms-webapp-jetty, PostgreSQL, and postgresql-libs. With the successfully installed packages the OpenNMS Horizon is installed in the following directory structure: With the successfully installed packages the OpenNMS Horizon is installed in the following directory structure: The Debian package installs the PostgreSQL database and is already initialized. The PostgreSQL service is already added in the runlevel configuration for system startup. Startup the PostgreSQL database by running the commands below: After installing PostgreSQL, it’s a good idea to create/change the default PostgreSQL user password. Run the commands below to create/change the user password in the bash shell and not PostgreSQL interactive shell. Set password for Linux user (Postgres) You should be prompted to create a new Linux password for Postgres users. After setting a new password, every time you want to access PostgreSQL interactive shell, you’ll be prompted to confirm the password you created after running the commands above. Next, create an opennms database user with a password and create an opennms database which is owned by the user opennms Set a password for Postgres super user Next, configure database access in OpenNMS Horizon Make the highlighted changes below, then save.

Set credentials to access the PostgreSQL database Set the database name OpenNMS Horizon should use Set the user name to access the opennms database table Set the password to access the opennms database table Set the postgres user for administrative access to PostgreSQL Set the password for administrative access to PostgreSQL

Save and exit. Detect of Java environment and persist in /usr/share/opennms/etc/java.conf You should see the output below: If you getting an error starting OpenNMS, manually add the JAVA_HOME settings using the commands below: Then add the highlighted line in the file and save Initialize the database and detect system libraries persisted in /opt/opennms/etc/libraries.properties You should see an output similar to below: Configure systemd to start OpenNMS Horizon on the system boot Finally, the OpenNMS web application at http://localhost:8980/opennms. The default login user is admin and the password is initialized to admin. Username: admin Password: admin Log in and start configuring your settings. Enjoy! You may also like the post below: