Hi,

The "when" statement is used to prevent execution of certain Ansible tasks on Docker containers. It's unrelated to virtual machines. I admit the variable name is confusing, but they're embedded in Ansible. I think we need a comment or document this somewhere.

Regards

On Tue, Feb 11, 2020 at 6:56 PM Link, Henry L II CTR USN NIWC ATLANTIC SC (USA) henry.l.link1.ctr@navy.mil wrote:

Good afternoon! I am new to this list, and would normally lurk a bit more first, but I have a question I am hoping the community might be able to help me with.

I have been reviewing the ansible playbook content for the NIAP OSPP for RHEL 8 on the following site:

https://static.open-scap.org/ssg-guides/ssg-rhel8-guide-index.html

And I came across what has been labeled the “[DRAFT] DISA STIG for Red Hat Enterprise Linux 8”

It just so happens to mirror the NIAP OSPP guidance, no surprise there for a first draft. However, a large number of the tasks in the playbook are restricted with the WHEN statement:

• when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker"

These filters are from the original NIAP OSPP ansible guidance as well.

Does anyone have an understanding why these tasks are filtered out for virtual machines? The text guidance makes no mention why these would be excluded, and in fact other code snippets (e.g. the bash scripts) don’t include an exclusion like this. Even in cases like CCE-81024-2, I’ve never had issues with enabling this on virtual guests in the past (in VMWare, mind you), but items like CCE-82297-3 (tipc disable) or CCE-80834-5 (sctp disable) they don’t cause any significant issues for a virtual guest where these are disabled. (My interest is in use in a DoD implementation, and though there is no STIG yet, I am negotiating with our accrediting body on appropriate controls until the STIG is available.)

If anyone has any further insight why these were restricted with “when” directives in the ansible role/playbook for Draft STIG and NIAP, thank you in advance. For my part, I’m removing the clause for my implementation, but wanted to see what the original reason was and if it was something I should be aware of to avoid any future unforeseen issues.

v/r

Henry Link

---

scap-security-guide mailing list -- scap-security-guide@lists.fedorahosted.org To unsubscribe send an email to scap-security-guide-leave@lists.fedorahosted.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedorahosted.org/archives/list/scap-security-guide@lists.fedor...

when: ansible_virtualization_role != "guest" or ansible_virtualization_type != "docker" is the same as

when: not (ansible_virtualization_role == "guest" and ansible_virtualization_type == "docker"),

i.e. it means that the task is not executed only and only on Docker containers. It is executed on Docker hosts and on VMs though.

Rules that are about kernel parameters, services enabled etc. are not applicable to containers the same way as they are applicable to bare-metal machines and VMs, so we disable the respective Ansible remediation.

If your use case is about remediating VMs, you can keep the when: clause there, as it doesn't make any difference. Check out output of the

ansible all -m gather_facts -i <VM hostname/IP>, | grep virtualization

command - I get

"ansible_virtualization_role": "guest",         "ansible_virtualization_type": "kvm",

and therefore in my case, the result of the when condition would evaluate to true - it is either (false or true) = true for the first form, or (not (true and false)) = true for the second form.

In other words, if a task gets skipped on VMs, this when: can't be the cause unless there is a problem with Ansible.

Hope it helps, Matej

On 11. 02. 20 18:46, Link, Henry L II CTR USN NIWC ATLANTIC SC (USA) wrote:

Good afternoon! I am new to this list, and would normally lurk a bit more first, but I have a question I am hoping the community might be able to help me with.

I have been reviewing the ansible playbook content for the NIAP OSPP for RHEL 8 on the following site:

https://static.open-scap.org/ssg-guides/ssg-rhel8-guide-index.html

And I came across what has been labeled the “[DRAFT] DISA STIG for Red Hat Enterprise Linux 8”

It just so happens to mirror the NIAP OSPP guidance, no surprise there for a first draft. However, a large number of the tasks in the playbook are restricted with the WHEN statement:

• when: ansible_virtualization_role != "guest" or

ansible_virtualization_type != "docker"

These filters are from the original NIAP OSPP ansible guidance as well.

Does anyone have an understanding why these tasks are filtered out for virtual machines? The text guidance makes no mention why these would be excluded, and in fact other code snippets (e.g. the bash scripts) don’t include an exclusion like this. Even in cases like CCE-81024-2, I’ve never had issues with enabling this on virtual guests in the past (in VMWare, mind you), but items like CCE-82297-3 (tipc disable) or CCE-80834-5 (sctp disable) they don’t cause any significant issues for a virtual guest where these are disabled. (My interest is in use in a DoD implementation, and though there is no STIG yet, I am negotiating with our accrediting body on appropriate controls until the STIG is available.)

If anyone has any further insight why these were restricted with “when” directives in the ansible role/playbook for Draft STIG and NIAP, thank you in advance. For my part, I’m removing the clause for my implementation, but wanted to see what the original reason was and if it was something I should be aware of to avoid any future unforeseen issues.

v/r

Henry Link

---

scap-security-guide mailing list -- scap-security-guide@lists.fedorahosted.org To unsubscribe send an email to scap-security-guide-leave@lists.fedorahosted.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedorahosted.org/archives/list/scap-security-guide@lists.fedor...