Install OpenNMS on Rocky Linux 8: Easy And Full Setup

This tutorial will guide you through the process of installing Install OpenNMS on Rocky Linux 8. OpenNMS is a robust, enterprise-grade, integrated, and open-source platform designed for building comprehensive network monitoring solutions. Its primary goals include accelerating the time to production by natively supporting industry-standard network management protocols, agents, and a programmable provisioning system. It also enables the efficient sending of alerts to on-call system engineers through various implemented notification strategies. Furthermore, the platform’s capabilities can be extended using its native Java API or by running scripts directly on the underlying operating system.

The OpenNMS platform provides numerous avenues for forwarding monitoring information, facilitating seamless integration with existing management workflows. To successfully complete the OpenNMS configuration on Rocky Linux 8, meticulously follow the steps detailed below, provided by Orcacore.

Steps To Install and Configure OpenNMS on Rocky Linux 8

Before starting the OpenNMS configuration on Rocky Linux 8, ensure you are logged into your server as a non-root user with sudo privileges and that a basic firewall is set up. You can refer to the guide on Initial Server Setup with Rocky Linux 8 for assistance.

1. Install Java on Rocky Linux 8

Since OpenNMS is written in Java, a Java Development Kit (JDK) is a prerequisite. First, update your system:

sudo dnf update -y

Then, install essential packages using the following command:

sudo dnf install vim curl wget -y

Install Java 11 using the following command:

sudo dnf install java-11-openjdk-devel -y

Verify the Java installation by checking the version:

java -version

**Output**
openjdk version "11.0.18" 2023-01-17 LTS
OpenJDK Runtime Environment (Red_Hat-11.0.18.0.10-2.el8_7) (build 11.0.18+10-LTS)
OpenJDK 64-Bit Server VM (Red_Hat-11.0.18.0.10-2.el8_7) (build 11.0.18+10-LTS, mixed mode, sharing)

2. Set up OpenNMS on Rocky Linux 8

OpenNMS packages aren’t available in the default Rocky Linux repositories. Therefore, you must add the OpenNMS repository manually.

Import OpenNMS GPG Key

Import the OpenNMS GPG key using the following command:

sudo rpm --import https://yum.opennms.org/OPENNMS-GPG-KEY

Add OpenNMS Repository

Add the OpenNMS repository to your server using the command below:

sudo dnf install https://yum.opennms.org/repofiles/opennms-repo-stable-rhel8.noarch.rpm -y

Install OpenNMS on Rocky Linux 8

Now, install OpenNMS with:

sudo dnf install opennms -y

This command installs OpenNMS and all its necessary dependencies.

3. PostgreSQL Setup for OpenNMS Configuration

After installing OpenNMS and its dependencies, configure PostgreSQL, the recommended database for OpenNMS.

First, initialize the PostgreSQL database using:

sudo postgresql-setup --initdb --unit postgresql

**Output**
 * Initializing database in '/var/lib/pgsql/data'
 * Initialized, logs are in /var/lib/pgsql/initdb_postgresql.log

Start and enable the PostgreSQL service:

# sudo systemctl enable postgresql
# sudo systemctl start postgresql

Verify that PostgreSQL is active and running:

sudo systemctl status postgresql

**Output**
● postgresql.service - PostgreSQL database server
   Loaded: loaded (/usr/lib/systemd/system/postgresql.service; enabled; vendor >
   Active: **active** (**running**) since Sat 2023-03-04 05:16:23 EST; 5s ago
  Process: 92932 ExecStartPre=/usr/libexec/postgresql-check-db-dir postgresql (>
 Main PID: 92935 (postmaster)
    Tasks: 8 (limit: 23699)
   Memory: 15.8M
   CGroup: /system.slice/postgresql.service
           └─92935 /usr/bin/postmaster -D /var/lib/pgsql/data
...

Switch to the PostgreSQL user:

sudo -i -u postgres

Create OpenNMS Database and User

Create an OpenNMS user:

createuser -P opennms

Enter password for new role:
Enter it again:

Create the OpenNMS database:

createdb -O opennms opennms

Next, protect the default postgres user with a password:

psql -c "ALTER USER postgres WITH PASSWORD 'StrongPassword';"

**Output**
ALTER ROLE

Exit the PostgreSQL shell:

[postgres@localhost ~]$ exit

Modify PostgreSQL Access Policy

Modify the PostgreSQL access policy by editing the pg_hba.conf file:

sudo vi /var/lib/pgsql/data/pg_hba.conf

Find these lines and replace ident with md5:

# IPv4 local connections:
host    all             all             127.0.0.1/32            **md5**

# IPv6 local connections:
host    all             all             ::1/128                 **md5**

Save the file and restart PostgreSQL:

sudo systemctl restart postgresql

Define database credentials in OpenNMS Configuration File

Define the database credentials in /opt/opennms/etc/opennms-datasources.xml:

sudo vi /opt/opennms/etc/opennms-datasources.xml

Find the following lines and update the credentials:

<jdbc-data-source name="opennms"
                    database-name="opennms"
                    class-name="org.postgresql.Driver"
                    url="jdbc:postgresql://localhost:5432/opennms"
                    user-name="opennms"
                    password="opennms-user-password" />

<jdbc-data-source name="opennms-admin"
                    database-name="template1"
                    class-name="org.postgresql.Driver"
                    url="jdbc:postgresql://localhost:5432/template1"
                    user-name="postgres"
                    password="postgres-password" />

Save and close the file.

4. Manage OpenNMS Service on Rocky Linux 8

First, initialize OpenNMS by adding the Java settings:

sudo /opt/opennms/bin/runjava -s

**Output**
runjava: Looking for an appropriate JVM...
runjava: Checking for an appropriate JVM in JAVA_HOME...
runjava: Skipping... JAVA_HOME not set.
runjava: Checking JVM in the PATH: "/usr/lib/jvm/java-11-openjdk-11.0.18.0.10-2.el8_7.x86_64/bin/java"...
runjava: Found an appropriate JVM in the PATH: "/usr/lib/jvm/java-11-openjdk-11.0.18.0.10-2.el8_7.x86_64/bin/java"
runjava: Value of "/usr/lib/jvm/java-11-openjdk-11.0.18.0.10-2.el8_7.x86_64/bin/java" stored in configuration file.

Next, initialize the database and detect system libraries:

sudo /opt/opennms/bin/install -dis

Start and enable the OpenNMS service:

# sudo dnf install chkconfig -y
# sudo systemctl enable --now opennms

Verify that OpenNMS is active and running:

sudo systemctl status opennms

**Output**
   Loaded: loaded (/usr/lib/systemd/system/opennms.service; enabled; vendor pre>
   Active: **active** (**running**) since Sat 2023-03-04 05:21:06 EST; 4s ago
  Process: 94430 ExecStartPost=/bin/sleep 3 (code=exited, status=0/SUCCESS)
  Process: 93439 ExecStart=/opt/opennms/bin/opennms -s start (code=exited, stat>
 Main PID: 94429 (java)
    Tasks: 44 (limit: 23699)
   Memory: 324.8M
...

5. Configure Firewall For OpenNMS

Assuming firewalld is enabled, allow port 8980 through the firewall:

sudo firewall-cmd --permanent --add-port=8980/tcp

Reload the firewall:

sudo firewall-cmd --reload

If SELinux is enabled, allow the port:

sudo semanage port -a -t http_port_t -p tcp 8980

6. Access OpenNMS Web Interface

Access the OpenNMS Horizon web interface by navigating to your server’s IP address followed by :8980/opennms:

http://<server-ip>:8980/opennms

You should now see the OpenNMS dashboard.

Change the default password by navigating to admin -> Change Password.

OpenNMS Configuration: Add New Admin Password

7. How To Monitor Systems with OpenNMS?

Add systems to OpenNMS for monitoring by clicking the "+" icon.

Enter the required details (requisition, IP address, node label) and click "Provision".

After adding the node, it will appear under Info -> Nodes.

You can now view graphs and create alerts for the device.

For more detailed information, consult the OpenNMS Documentation.

Conclusion

You have now successfully learned how to Install OpenNMS on Rocky Linux 8. OpenNMS is a powerful tool for collecting and analyzing data from network devices, providing valuable insights into network performance and health. With Install OpenNMS on Rocky Linux 8, you can proactively manage your network and address potential issues before they impact your users. The detailed guide to Install OpenNMS on Rocky Linux 8 above provides a solid foundation for setting up your network monitoring solution.

Install OpenNMS on Rocky Linux 8 is a great solution! Here are some other articles you might find interesting:

Alternative Solutions for Network Monitoring on Rocky Linux 8

While OpenNMS is a solid choice for network monitoring, other solutions can be implemented on Rocky Linux 8, each with its strengths and weaknesses. Here are two alternatives:

1. Using Zabbix

Zabbix is another popular open-source monitoring solution offering similar functionalities to OpenNMS. However, it has a different architecture and configuration approach.

Explanation:

Zabbix uses agents installed on monitored hosts to collect data, or it can monitor network devices directly via SNMP, SSH, or other protocols. It offers a web-based interface for configuration, data visualization, and alert management. Zabbix is known for its ease of use, scalability, and comprehensive feature set.

Steps for Installing Zabbix on Rocky Linux 8:

Install the Zabbix Repository:

rpm -Uvh https://repo.zabbix.com/zabbix/5.0/rhel/8/x86_64/zabbix-release-5.0-1.el8.noarch.rpm
dnf clean all

Install Zabbix Server, Frontend, and Agent:

dnf install zabbix-server-pgsql zabbix-web-pgsql zabbix-agent

Install PHP Modules (required by the Zabbix web frontend):

dnf install php php-fpm php-mysqlnd php-gd php-ldap php-mbstring php-xml

Create a Database for Zabbix:

sudo -i -u postgres
createuser -P zabbix
createdb -O zabbix zabbix
exit

Import Initial Schema and Data:

zcat /usr/share/doc/zabbix-server-pgsql*/create.sql.gz | sudo -u zabbix psql zabbix

Configure Zabbix Server: Edit /etc/zabbix/zabbix_server.conf and set the database details:
```
DBHost=localhost
DBName=zabbix
DBUser=zabbix
DBPassword=your_zabbix_password
```

Configure PHP: Edit /etc/php-fpm.d/zabbix.conf and uncomment/modify the php_value directives to match Zabbix’s requirements:

php_value[post_max_size] = 16M
php_value[upload_max_filesize] = 2M
php_value[max_execution_time] = 300
php_value[max_input_time] = 300
php_value[date.timezone] = America/Los_Angeles #Replace with your timezone

Start and Enable Zabbix Server, Agent, and PHP-FPM:

systemctl enable zabbix-server zabbix-agent php-fpm
systemctl start zabbix-server zabbix-agent php-fpm

Configure Firewall:

firewall-cmd --permanent --add-port={80/tcp,10051/tcp}
firewall-cmd --reload

Access the Zabbix Web Interface: Open your web browser and navigate to http://<server-ip>/zabbix. The default username is Admin and the password is zabbix.

2. Using Prometheus and Grafana

Prometheus is an open-source systems monitoring and alerting toolkit initially built at SoundCloud. Grafana is an open-source data visualization and monitoring suite. They often work together.

Explanation:

Prometheus excels at collecting and storing time-series data. It uses a pull model, where it scrapes metrics from exposed endpoints on monitored systems. Grafana then connects to Prometheus as a data source and provides rich dashboards and visualizations of the collected metrics. This combination is highly flexible and scalable, especially suitable for dynamic environments and containerized applications.

Steps for Installing Prometheus and Grafana on Rocky Linux 8:

Create User and Directories for Prometheus:

sudo groupadd prometheus
sudo useradd -g prometheus --no-create-home --shell /bin/false prometheus
sudo mkdir /etc/prometheus
sudo mkdir /var/lib/prometheus
sudo chown prometheus:prometheus /etc/prometheus
sudo chown prometheus:prometheus /var/lib/prometheus

Download and Extract Prometheus:

wget https://github.com/prometheus/prometheus/releases/download/v2.45.0/prometheus-2.45.0.linux-amd64.tar.gz
tar xvf prometheus-2.45.0.linux-amd64.tar.gz
sudo mv prometheus-2.45.0.linux-amd64/prometheus /usr/local/bin/
sudo mv prometheus-2.45.0.linux-amd64/promtool /usr/local/bin/
sudo chown prometheus:prometheus /usr/local/bin/prometheus /usr/local/bin/promtool
sudo mv prometheus-2.45.0.linux-amd64/consoles /etc/prometheus
sudo mv prometheus-2.45.0.linux-amd64/console_libraries /etc/prometheus
sudo chown -R prometheus:prometheus /etc/prometheus/consoles
sudo chown -R prometheus:prometheus /etc/prometheus/console_libraries

Configure Prometheus: Create a prometheus.yml file in /etc/prometheus:

sudo vi /etc/prometheus/prometheus.yml

Example prometheus.yml:

global:
  scrape_interval:     15s
  evaluation_interval: 15s

scrape_configs:
  - job_name: 'prometheus'
    static_configs:
      - targets: ['localhost:9090']

Ensure the file is owned by the prometheus user:

sudo chown prometheus:prometheus /etc/prometheus/prometheus.yml

Create Systemd Service File for Prometheus:

cat <<EOF | sudo tee /etc/systemd/system/prometheus.service
[Unit]
Description=Prometheus
Wants=network-online.target
After=network-online.target

[Service]
User=prometheus
Group=prometheus
Type=simple
ExecStart=/usr/local/bin/prometheus 
    --config.file=/etc/prometheus/prometheus.yml 
    --storage.tsdb.path=/var/lib/prometheus/ 
    --web.console.templates=/etc/prometheus/consoles 
    --web.console.libraries=/etc/prometheus/console_libraries

[Install]
WantedBy=multi-user.target
EOF

Start and Enable Prometheus:

sudo systemctl daemon-reload
sudo systemctl enable prometheus
sudo systemctl start prometheus
sudo systemctl status prometheus

Install Grafana:

cat <<EOF | sudo tee /etc/yum.repos.d/grafana.repo
[grafana]
name=grafana
baseurl=https://rpm.grafana.com
repo_gpgcheck=1
enabled=1
gpgcheck=1
gpgkey=https://rpm.grafana.com/gpg.key
sslverify=1
sslcacert=/etc/pki/tls/certs/ca-bundle.crt
EOF

sudo dnf install grafana

Start and Enable Grafana:

sudo systemctl enable grafana-server
sudo systemctl start grafana-server
sudo systemctl status grafana-server