variables cilium_enable_host_firewall and cilium_policy_audit_mode for configmap/cilium-config

[ledroide]

What type of PR is this?

/kind feature

Special notes for your reviewer:

In order to enable (Cilium Host Firewall](https://docs.cilium.io/en/v1.15/security/host-firewall/) and the recommended PolicyAuditMode that prevents unwanted side effects during testing, we have added 2 variables to cilium role and to inventory (features are disabled by default) :

cilium_enable_host_firewall: false
cilium_policy_audit_mode: false

These features are then added in ConfigMap/cilium-config by cilium role

enable-host-firewall: "true"
policy-audit-mode: "true"

We have added related documentation in docs/cilium.md

Does this PR introduce a user-facing change?:

Add optional support for _Host Firewall_ and _PolicyAuditMode_ features in Cilium

[k8s-ci-robot]

Hi @ledroide. Thanks for your PR.

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[yankay]

/ok-to-test

[ledroide]

I have a doubt about the right choice for conditionals in the cilium-config template at path roles/network_plugin/cilium/templates/cilium/config.yml.j2.

Here is what I wrote, just because many options are implemented this way.

{% if cilium_enable_host_firewall %}
  enable-host-firewall: "true"
{% endif %}
{% if cilium_policy_audit_mode %}
  policy-audit-mode: "true"
{% endif %}

Let's say I want to enable policy-audit-mode temporarily in order to set my rules. Si I set the variable cilium_policy_audit_mode: true and run my playbook. Because cilium_policy_audit_mode is true the the configmap contains policy-audit-mode: "true".

But what if, after my whole setting, I want to explicitly set policy-audit-mode: "false" in the configmap/cilium-config - changing to cilium_policy_audit_mode: false ?

Maybe we had better always rely on default values for the role - that are already set in roles/network_plugin/cilium/defaults/main.yml - and always set a value for policy-audit-mode in the configmap/cilium-config ?

This would simply be written this way, instead of conditionals :

  enable-host-firewall: {{ cilium_enable_host_firewall | quote }}
  policy-audit-mode: {{ cilium_policy_audit_mode | quote }}

What do you think ?

[k8s-ci-robot]

PR needs rebase.

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[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: ledroide

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