security: always restore sudoers after makepkg, drop dead paru block

The archlinux and zfs roles temporarily write `%wheel ALL=(ALL) NOPASSWD: ALL`
to /etc/sudoers so makepkg/paru can run unattended, then restore it in a
following task. Since the restore was a plain sibling task, any failure in
between aborted the play and left the host with passwordless root for the
whole wheel group. Move the restore into `always:` so it runs on failure too,
and narrow the window in yay.yml to just the makepkg call (dependency install,
directory setup and git clone no longer run inside it).

This is not hypothetical: a provisioning run of omega failed on paru's git
clone and left the sudoers hack in place.

The clone failed because the deprecated compile-from-source paru block, which
was commented out in tree, had been re-enabled. It fed paru_git_repo into the
git module, but that variable now holds a GitHub owner/repo slug for the
releases API rather than a clone URL. Remove the block outright, along with
the orphaned paru_src_path default; paru is installed from the release binary.

Also fix the ansible-lint violations this surfaced so roles/archlinux passes
the production profile: explicit `become` next to `become_user`, a pinned
branch on the yay clone, and `changed_when` on the command/shell tasks.

roles/archlinux/defaults/main.yml

@@ -2,6 +2,5 @@
 arch_locale: en_US.UTF-8
 yay_src_path: /opt/yay
 yay_git_repo: https://aur.archlinux.org/yay.git
-paru_git_repo: Morganamilo/paru
+paru_git_repo: Morganamilo/paru # GitHub owner/repo slug, used for the releases API
-paru_src_path: /opt/paru
 os_arch: x86_64 # or aarch64

roles/archlinux/tasks/pacman.yml

@@ -34,6 +34,7 @@
     reflector --latest 20 --protocol https --sort rate
     --save /etc/pacman.d/mirrorlist
   when: mirrorlist_bak.stat.exists is false or (mirrorlist.stat.exists and (ansible_date_time.epoch | int - mirrorlist.stat.mtime) > 604800)
+  changed_when: true
 
 - name: Configure pacman to output colors
   ansible.builtin.lineinfile:

roles/archlinux/tasks/paru.yml

@@ -6,53 +6,6 @@
 
 - name: Install paru
   when: not paru.stat.exists
-  ##
-  ## Deprecated version with compilation
-  ##
-  # - name: Install paru
-  #   block:
-  #     - name: Install build dependencies
-  #       package:
-  #         name:
-  #           - base-devel
-  #           - git
-  #         state: present
-
-  #     - name: Disable sudo password prompt (makepkg sudoers hack)
-  #       lineinfile:
-  #         dest: /etc/sudoers
-  #         state: present
-  #         regexp: "^#?%wheel"
-  #         line: "%wheel ALL=(ALL) NOPASSWD: ALL"
-  #         validate: /usr/sbin/visudo -cf %s
-
-  #     - name: Create paru sources dir
-  #       file:
-  #         path: "{{ paru_src_path }}"
-  #         state: directory
-  #         owner: "{{ ansible_user }}"
-
-  #     - name: Clone git sources
-  #       become: false
-  #       git:
-  #         repo: "{{ paru_git_repo }}"
-  #         dest: "{{ paru_src_path }}"
-
-  #     # note: this only works because SUDOERS password prompt is disabled
-  #     - name: Build and install
-  #       become: false
-  #       command:
-  #         chdir: "{{ paru_src_path }}"
-  #         cmd: "makepkg -si -f --noconfirm"
-
-  #     - name: Restore sudo with password prompt
-  #       lineinfile:
-  #         dest: /etc/sudoers
-  #         state: present
-  #         regexp: "^#?%wheel"
-  #         line: "%wheel ALL=(ALL:ALL) ALL"
-  #         validate: /usr/sbin/visudo -cf %s
-  #   when: not paru.stat.exists
   block:
     - name: Get the last github release
       ansible.builtin.uri:
@@ -60,10 +13,6 @@
         return_content: true
       register: paru_release
 
-    - name: Extract tag_name
-      ansible.builtin.set_fact:
-        paru_version: "{{ (paru_release.json.tag_name | regex_replace('^v', '')) }}"
-
     - name: Get the binary URL ({{ os_arch }})
       ansible.builtin.set_fact:
         paru_url: "{{ item.browser_download_url }}"
@@ -91,12 +40,10 @@
         remote_src: true
         mode: "0755"
 
-    - name: Ensure permissions
-      ansible.builtin.file:
-        path: /usr/bin/paru
-        mode: "0755"
-
     - name: Cleanup
       ansible.builtin.file:
-        path: "/tmp/paru-{{ os_arch }}.tar.zst"
+        path: "{{ item }}"
         state: absent
+      loop:
+        - "/tmp/paru-{{ os_arch }}.tar.zst"
+        - /tmp/paru

roles/archlinux/tasks/yay.yml

@@ -14,14 +14,6 @@
           - git
         state: present
 
-    - name: Disable sudo password prompt (makepkg sudoers hack)
-      ansible.builtin.lineinfile:
-        dest: /etc/sudoers
-        state: present
-        regexp: "^#?%wheel"
-        line: "%wheel ALL=(ALL) NOPASSWD: ALL"
-        validate: /usr/sbin/visudo -cf %s
-
     - name: Clean up stale yay sources dir
       ansible.builtin.file:
         path: "{{ yay_src_path }}"
@@ -35,18 +27,36 @@
         mode: "0755"
 
     - name: Clone git sources
+      become: true
       become_user: "{{ ansible_user }}"
       ansible.builtin.git:
         repo: "{{ yay_git_repo }}"
         dest: "{{ yay_src_path }}"
+        version: master
+
+    # makepkg refuses to run as root and shells out to sudo to install the
+    # built package, so `--noconfirm` needs a passwordless sudo window.
+    # Keep that window as small as possible and always close it: the restore
+    # lives in `always` so it runs even when the build fails, which otherwise
+    # leaves the host with passwordless root for the whole wheel group.
+    - name: Build and install yay
+      block:
+        - name: Disable sudo password prompt (makepkg sudoers hack)
+          ansible.builtin.lineinfile:
+            dest: /etc/sudoers
+            state: present
+            regexp: "^#?%wheel"
+            line: "%wheel ALL=(ALL) NOPASSWD: ALL"
+            validate: /usr/sbin/visudo -cf %s
 
-    # note: this only works because SUDOERS password prompt is disabled
         - name: Build and install
+          become: true
           become_user: "{{ ansible_user }}"
           ansible.builtin.command:
             chdir: "{{ yay_src_path }}"
             cmd: "makepkg -si -f --noconfirm"
-
+          changed_when: true
+      always:
         - name: Restore sudo with password prompt
           ansible.builtin.lineinfile:
             dest: /etc/sudoers

roles/zfs/tasks/install.yml

@@ -5,6 +5,8 @@
   changed_when: false
   failed_when: false
 
+# The restore lives in `always` so it runs even when paru fails. Otherwise a
+# failed build leaves the host with passwordless root for the whole wheel group.
 - name: Install zfs
   when: zfs_dkms_installed.stderr | length > 0
   block:
@@ -24,7 +26,8 @@
       become: false
       ansible.builtin.command:
         cmd: "paru -S --noconfirm zfs-dkms zfs-utils"
-
+      changed_when: true
+  always:
     - name: Restore SUDOERS password prompt after paru
       no_log: true
       ansible.builtin.lineinfile:
@@ -65,7 +68,8 @@
       become: false
       ansible.builtin.command:
         cmd: "paru -S --noconfirm zrepl"
-
+      changed_when: true
+  always:
     - name: Restore SUDOERS password prompt after paru
       no_log: true
       ansible.builtin.lineinfile: