ansible-role-cdm-nessus-agent

This is an Ansible role for installing Nessus Agent, specifically for the CISA Continuous Diagnostics and Mitigation (CDM) environment.

Note that the command to link the Nessus Agent to the Tenable/Nessus server (nessuscli agent link) is not run by this Ansible role. It must be run at instance startup via cloud-init or a separate Ansible playbook. The reason for this is that this Ansible role is used to build AWS AMIs, and the linking command generates the Tenable tag even if run with the --offline-install option. This causes all instances generates from that AMI to have the same Tenable tag, and the Tenable server cannot handle such duplicate agents.

I would prefer to perform all configuration at AMI build time; but, unless Nessus modifies their code to, for example, allow one to specify the linking parameters ahead of time we are stuck with this substandard solution.

Pre-requisites

In order to execute the Molecule tests for this Ansible role in GitHub Actions, a build user must exist in AWS. The accompanying Terraform code will create the user with the appropriate name and permissions. This only needs to be run once per project, per AWS account. This user can also be used to run the Molecule tests on your local machine.

Before the build user can be created, you will need a profile in your AWS credentials file that allows you to read and write your remote Terraform state. (You almost certainly do not want to use local Terraform state for this long-lived build user.) If the build user is to be created in the CISA COOL environment, for example, then you will need the cool-terraform-backend profile.

The easiest way to set up the Terraform remote state profile is to make use of our aws-profile-sync utility. Follow the usage instructions in that repository before continuing with the next steps, and note that you will need to know where your team stores their remote profile data in order to use aws-profile-sync.

To create the build user, follow these instructions:

cd terraform
terraform init --upgrade=true
terraform apply

Once the user is created you will need to update the repository's secrets with the new encrypted environment variables. This should be done using the terraform-to-secrets tool available in the development guide. Instructions for how to use this tool can be found in the "Terraform IAM Credentials to GitHub Secrets" section. of the Project Setup README.

If you have appropriate permissions for the repository you can view existing secrets on the appropriate page in the repository's settings.

Requirements

None.

Role Variables

Variable	Description	Default	Required
cdm_nessus_agent_install_directory	The directory where Nessus Agent is installed.	/opt/nessus_agent	No
cdm_nessus_agent_third_party_bucket_name	The name of the AWS S3 bucket where third-party software is located.	cisa-cool-third-party-production	No

Dependencies

• cisagov/ansible-role-dhs-certificates
• cisagov/ansible-role-cdm-certificates

Installation

This role can be installed via the command:

ansible-galaxy install --role-file path/to/requirements.yml

where requirements.yml looks like:

---
- name: cdm_nessus_agent
  src: https://github.com/cisagov/ansible-role-cdm-nessus-agent

and may contain other roles as well.

For more information about installing Ansible roles via a YAML file, please see the ansible-galaxy documentation.

Example Playbook

Here's how to use it in a playbook:

- hosts: all
  become: true
  become_method: sudo
  tasks:
    - name: Install Nessus Agent for CDM
      ansible.builtin.include_role:
        name: cdm_nessus_agent

Contributing

We welcome contributions! Please see CONTRIBUTING.md for details.

License

This project is in the worldwide public domain.

This project is in the public domain within the United States, and copyright and related rights in the work worldwide are waived through the CC0 1.0 Universal public domain dedication.

All contributions to this project will be released under the CC0 dedication. By submitting a pull request, you are agreeing to comply with this waiver of copyright interest.

Author Information

Shane Frasier - jeremy.frasier@gwe.cisa.dhs.gov