feat(ansible): Add role for managing ingress restrictions

Introduces a new Ansible role `ingress-restrictions` with tasks to manage
ingress restrictions between edge and middle hosts. Also includes necessary
files such as handlers, vars, defaults, and README.

external/sketch/ansible/roles/ingress-restrictions/README.md

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+ingress-restrictions
+=========
+
+This role is used to help reduce the chances for backflip correlation from public ssh keys from tools like Censys.
+
+This will automatically tell middle hosts to only allow connections on port 2222 from edge hosts.
+
+This role only handles the sketch infrastructure as of now.
+
+Requirements
+------------
+
+Once you've ran this in your Sketch infrastructure, you will need to grab the IP Addresses or IP Address range from your middles and add them to your OCI/AWS infrastructure manually.
+
+Whenever we do the grand restructure, this should be done automatically for you everywhere.
+
+Example Playbook
+----------------
+
+```yml
+- hosts: all
+  roles:
+    - ingress-restrictions
+```

external/sketch/ansible/roles/ingress-restrictions/defaults/main.yml

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+---
+# defaults file for ingress-restrictions

external/sketch/ansible/roles/ingress-restrictions/handlers/main.yml

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+---
+# handlers file for ingress-restrictions

external/sketch/ansible/roles/ingress-restrictions/meta/main.yml

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+galaxy_info:
+  author: your name
+  description: your role description
+  company: your company (optional)
+
+  # If the issue tracker for your role is not on github, uncomment the
+  # next line and provide a value
+  # issue_tracker_url: http://example.com/issue/tracker
+
+  # Choose a valid license ID from https://spdx.org - some suggested licenses:
+  # - BSD-3-Clause (default)
+  # - MIT
+  # - GPL-2.0-or-later
+  # - GPL-3.0-only
+  # - Apache-2.0
+  # - CC-BY-4.0
+  license: license (GPL-2.0-or-later, MIT, etc)
+
+  min_ansible_version: 2.1
+
+  # If this a Container Enabled role, provide the minimum Ansible Container version.
+  # min_ansible_container_version:
+
+  #
+  # Provide a list of supported platforms, and for each platform a list of versions.
+  # If you don't wish to enumerate all versions for a particular platform, use 'all'.
+  # To view available platforms and versions (or releases), visit:
+  # https://galaxy.ansible.com/api/v1/platforms/
+  #
+  # platforms:
+  # - name: Fedora
+  #   versions:
+  #   - all
+  #   - 25
+  # - name: SomePlatform
+  #   versions:
+  #   - all
+  #   - 1.0
+  #   - 7
+  #   - 99.99
+
+  galaxy_tags: []
+    # List tags for your role here, one per line. A tag is a keyword that describes
+    # and categorizes the role. Users find roles by searching for tags. Be sure to
+    # remove the '[]' above, if you add tags to this list.
+    #
+    # NOTE: A tag is limited to a single word comprised of alphanumeric characters.
+    #       Maximum 20 tags per role.
+
+dependencies: []
+  # List your role dependencies here, one per line. Be sure to remove the '[]' above,
+  # if you add dependencies to this list.

external/sketch/ansible/roles/ingress-restrictions/tasks/main.yml

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+---
+# tasks file for ingress-restrictions
+
+- name: Set fact for 'edge' hosts
+  set_fact:
+    is_edge_host: true
+  when: "'edge' in inventory_hostname"
+
+- name: Gather Edge IPs into a dictionary
+  set_fact:
+    edge_ips_dict: >-
+      {{
+        edge_ips_dict | default({}) | combine(
+          { item: hostvars[item]['host_ip_address'] }
+        )
+      }}
+  loop: "{{ groups['all'] }}"
+  when: hostvars[item]['is_edge_host'] is defined and hostvars[item]['is_edge_host']
+  delegate_to: localhost
+
+- name: Allow port 2222 from Edges to Middles
+  ufw:
+    rule: allow
+    port: 2222
+    from_ip: "{{ item.value }}"
+  with_items: "{{ edge_ips_dict | dict2items }}"
+  when: "'middle' in inventory_hostname"
+
+- name: Deny port 2222
+  ufw:
+    rule: deny
+    port: 2222
+  when: "'middle' in inventory_hostname"

external/sketch/ansible/roles/ingress-restrictions/tests/inventory

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+localhost
+

external/sketch/ansible/roles/ingress-restrictions/tests/test.yml

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+---
+- hosts: localhost
+  remote_user: root
+  roles:
+    - ingress-restrictions

external/sketch/ansible/roles/ingress-restrictions/vars/main.yml

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+---
+# vars file for ingress-restrictions