Security Considerations of Deployment

Security of computing systems is a complex topic which depends not only on the security of each component, but on how software components interact and on the environment in which they are running. In the subsections here, we will discuss a variety of possible actions which may increase the security of a particular deployment, along with their context.

For more examples and discussion, see the Publications section of the VOLTTRON website where there are a number of Threat Profile reports.

Running as a Managed System Process

It is possible that the running VOLTTRON process could exit undesirably (either due to a bug, or some malicious action). For scenarios where not having the VOLTTRON process running presents a business risk, it is recommended to follow the Setting up VOLTTRON as a System Service to leverage the host system’s process monitoring and management system. Under this configuration, the system will be configured to restart VOLTTRON in the event that it fails.


For this configuration to be effective, it is important that the platfrom is configured such that it automatically starts up in the desired state. In particular, review the installed agents and be sure that agents which should be running are “enabled” and that their priorities are set such that they start in the intended order.

There are scenarios when this configuration may not be desired:

  1. If a system restarts cleanly after an unexpected failure, it is possible that the underlying issue could go unnoticed (and therefore unresolved). This would happen if a user checks the system and sees it is running but does not have a way to realize that there has been one or more restarts. For development systems it may be desirable to not restart, leaving the system in a failed state which is more likely to be noticed as unusual, and with the failure details still present in the recent logs. Consider the relative value of platform up-time and failure this kind of failure discovery. If both are highly valuable, it may be possible to add extra notifications to the process monitoring system (systemd, initd, or other) so that records are retained while service is restored.

  2. For development systems, or systems that are frequently stopped or restarted, it can be more convenient to use the normal start and stop scripts packaged with VOLTTRON. These do not require the user have system-level permissions and are easily used from the terminal.

Run Web Server Behind Proxy

A VOLTTRON deployment may be web-enabled, allowing various interactions over HTTP. There are many reasons why it is often desirable to deploy an external reverse proxy in front of the system, including:

  • Allows regular security patching of the exposed web server independent of the VOLTTRON process’s lifecycle.

  • Prevents DDoS and similar attacks, which may successfuly impact the web server, from impacting the VOLTTRON process itself.

  • Provides a opportunity for institutional cyber security experts to help maintain a secure and compliant web server configuration without needing to gain VOLTTRON-specific experience.

  • Many other traffic management and filtering options which are documented by the various tools (load balancing, http header management, etc.).

The full complexity of configuring a reverse proxy is outside the scope of this documentation. For reference, two common open source options are apache httpd and nginx (relevant portions of their respective documentation pages are linked).

To set up a reverse proxy for VOLTTRON using apache, please refer to this document: Apache Reverse Proxy Setup

Monitor for Data Tampering

One common indication of a potential problem, including tampering, would be the presence of out of bounds values. The Threshold Detection Agent can be used leveraged to create alerts in the event that a topic has a value which is out of reasonable bounds.

This approach has some limitations, including:

  • There can be subtleties in selecting the correct bounds to both ensure issues are seen while minimizing false positives.

  • Including value limits adds a significant amount of configuration to maintain, and which is not necessarily high-visibility because it is in another agent.

  • Currently there is only support for monitoring for values crossing a threshold, more complex conditional logic would require a custom monitor.

  • There could be cases where tampering adjusts values to incorrect but in-bounds values which would not be detected.

Limit Publishing on the Devices Topic to Platform Driver

To further reduce the chances of malicious data disrupting your system, you can limit the ability to publish to the “devices” topic to the platform driver only.

To accomplish this, you will need to modify protected_topics.json, found in your $VOLTTRON_HOME directory. In this specific case, you would need to add the topic “devices” and some capability, for example “can_publish_to_devices”.

   "write-protect": [
      {"topic": "devices", "capabilities": ["can_publish_to_devices"]}

Next, using vctl auth list get the auth index for the platform.driver, and use the command vctl auth update <index of platform.driver>. You will get a prompt to update the auth entry. Skip through the prompts until it prompts for capabilities, and add can_publish_to_devices.

capabilities (delimit multiple entries with comma) []: can_publish_to_devices

For more information, refer to the section on Protecting Pub/Sub Topics.

Limit Access to RPC Methods Using Capabilities

RPC enabled methods provide convenient interfaces between agents. When they are unrestricted however, they open up the potential for malicious agents to cause harm to your system. The best way to prevent this is through the use of capabilities. A capability is a user defined arbitrary string used by an agent to describe its exported RPC method. It is used to limit the access to that RPC method to only those agents who have that capability listed in their authentication record.

To add a capability restriction to an RPC method, the RPC.allow decorator is used. For example, to limit those who can call the RPC enabled method “foo” to those with the capability “can_call_foo”:

def foo:

To give an agent permission to access this method, the auth file must be updated. As in the above example for limiting publishing to the devices topic, vctl can be used to update the auth file and grant the specific agent permission to access the RPC enabled method.

capabilities (delimit multiple entries with comma) []: can_call_foo

For a secure system, only add capabilties to the agents that will need to call a specific RPC enabled method, and apply the allow decorator to all RPC enabled methods.

For more information, refer to the section on VIP Authorization.

Monitoring RabbitMQ Server

Monitoring of RabbitMQ server in deployment setup can be achieved by running RabbitMQ server as a systemd service. RabbitMQ server is configured to run as a systemd service and allow systemd to monitor the status of the service. It can be further configured to detect and restart the RabbitMQ service if it crashes. VOLTTRON agents have the ability to detect when the RabbitMQ server crashes/disconnects and reconnect when it becomes available. In this deployment setup, a VOLTTRON platform will not start/stop the RabbitMQ server.