Overview

The Opsview Infrastructure Agent is designed to be a replacement for the existing (NRPE and NSClient) Agents and operates on servers running on either Windows or Linux systems.

The Infrastructure Agent enables communication between systems by running a daemon that Opsview Monitor Collectors can use to interrogate the status of the system. It provides some default plugins (for checking on RAM, CPU, and DISK, amongst others) that Host Templates within Opsview Monitor can make use of straight away, but can be extended with additional plugins.

Support versions

Packages such as .msi, .deb, and .rpm are available for both Linux and Windows installation. The following is a list of all operating systems that are directly supported:

• All Opsview supported Linux OSs (Centos7, OL7, RHEL7, RHEL8, Debian10, Ubuntu18, Ubuntu20).
• Windows 10, 11, and Windows Server 2012, 2012-R2, 2016, 2019, 2022.

Contact Opsview Customer Success for support with any Operating Systems not listed above.

Installation

The Agent packages are available from the Opsview Downloads website.

On Debian and Ubuntu:

sudo apt install /path/to/downloaded/infrastructure-agent*.deb

On RHEL, OL, and CentOS:

sudo yum install /path/to/downloaded/infrastructure-agent*.rpm

On Windows:

Download and run the Windows Infrastructure Agent installer.

Import existing configuration

When the Agent is started, it will attempt to automatically import the following settings from previously installed Opsview Agents:

• allowed hosts
• server port
• commands

The imported settings are stored inside the Agent file: cfg/custom/imported.yml. If this file already exists, the Agent will skip the import process.

Initial configuration

The Agent requires some initial configuration prior to operation which should be added to the custom configuration files in these locations:

Linux:

/opt/itrs/infrastructure-agent/cfg/custom/agent.yml

Windows:

C:/Program Files/Infrastructure Agent/cfg/custom/agent.yml

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Note: The configuration file is written in YAML which uses a whitespace sensitive syntax.

Allowed hosts

The Agent will reject requests from any hosts by default, so it must be configured to accept requests from known hosts. Typically, this will be the executors in the collector cluster of the Opsview system monitoring this device. This list should be configured in the custom configuration file, for example:

server:
  allowed_hosts:
    - collector1.myopsview.local
    - collector2.myopsview.local
    - 168.10.1.2

If the Agent has successfully imported existing configuration, allowed_hosts may already be defined in cfg/custom/imported.yml.

To allow any host to submit requests, an empty list can be used:

server:
  allowed_hosts: []

❗️

It is not recommended to have the allowed_hosts as an empty list. This would allow anyone to launch plugins against the server.

Transport Layer Security

It is recommended that TLS be enabled at all times to ensure the security of communications. A valid CA, certificate and key file will need to be used in the custom configuration file to use TLS:

server:
  tls:
    cert_file: /opt/itrs/infrastructure-agent/cfg/custom/<FQDN>.pem
    key_file: /opt/itrs/infrastructure-agent/cfg/custom/<FQDN>.key
    ca_cert: /opt/itrs/infrastructure-agent/cfg/custom/ca.pem
    check_client_cert: true
  tls_enabled: true

Generate certificates

Certificates can be generated using any valid method; however, the simplest way to get started is by using the Opsview Public Key Infrastructure. You can follow these steps in PKI to generate both client and server certificates. The CA certificate, server certificate and server key should be added to the TLS configuration while client certificates should be added to the hosts listed under allowed_hosts.

❗️

Setting tls_enabled to false is not recommended as communications will not be secure.

Restart the Agent

Once the configuration file has been updated the Agent will need to be restarted to apply the new configuration. The old Agent (NRPE or NSClient) should be stopped (and disabled) before starting the Opsview Infrastructure Agent to avoid any interference.

Linux

sudo systemctl restart infrastructure-agent

Windows Control Panel

• Open Services.
• Click Start > Run, and then type services.msc.
• Right-click the InfrastructureAgent service and then click Restart.

Windows command prompt

From the start menu, right-click Command Prompt, select More, and click Run as Administrator. Then type

net stop InfrastructureAgent
net start InfrastructureAgent

The Agent will automatically attempt to restart itself in an error state, such as an invalid configuration. The restart behaviour differs slightly across operating systems:

Ubuntu 18, Ubuntu 20, Debian 10, RHEL 8:

• The Agent will try to restart twice with a 10-second pause between restarts.
• After updating the configuration, the Agent will need to be restarted manually.

On OL7, CentOS 7, RHEL 7, and Windows:

• The Agent will continually restart every 10 seconds.
• After updating the configuration, the Agent will restart automatically.

Poller

The poller provides a mechanism for the Agent to poll specified plugins in the background on a schedule to allow for capturing and aggregating data at a higher frequency than that normally supported by plugin execution.

Poller operation

The Poller will read the poller_schedule and ensure that plugins are executed at the specified interval.

poller_schedule:
  nsc_checkcpu: 10

Agent version

The version of the Agent is stored in the version file inside the Agent’s var directory. This can either be read directly from the file or retrieved remotely by sending an empty check_nrpe command to the Agent. The version number follows its own release cycle and has the format <major>.<minor>.<build>.