iiab/roles/cups/tasks/install.yml

# ADMINISTER CUPS AT http://box/print -- USERNAME 'Admin' & PASSWORD 'changeme'
# (OR ANY MEMBER OF LINUX GROUP 'lpadmin') AS SET UP BELOW...


- name: Record (initial) disk space used
  shell: df -B1 --output=used / | tail -1
  register: df1


- name: Install 'cups' package
  package:
    name: cups
    state: present

# WARNING: 'apt install cups' AND 'apt install --reinstall cups'
# UNFORTUNATELY DO *NOT* RECREATE /etc/cups/cupsd.conf IF A PRIOR
# INSTALL OF CUPS EXISTED!  SO OPTION #1 OR #2 ARE NEEDED BELOW:

# OPTION #1: OLD WAY (BRITTLE)
#
# - name: Install our own /etc/cups/cupsd.conf from template, to permit local LAN admin
#   template:
#     src: cupsd.conf.j2
#     dest: /etc/cups/cupsd.conf

# OPTION #2: NEW WAY (MORE FUTURE-PROOF, WE HOPE!)

- name: PLEASE RUN 'sudo cupsctl' AND 'sudo cupsd -t' TO VERIFY /etc/cups/cupsd.conf IF YOU MODIFY IT!  The file will now be created -- by ~4 stanzas below.  Also keep an eye on /var/log/cups/error_log
  meta: noop

- name: Copy /usr/share/cups/cupsd.conf.default to /etc/cups/cupsd.conf (root:lp, 0640) -- a timestamped backup of the prior 'cupsd.conf' will be saved in /etc/cups
  copy:
    src: /usr/share/cups/cupsd.conf.default
    dest: /etc/cups/cupsd.conf
    owner: root
    group: lp
    mode: 0640
    backup: yes

# 2021-07-12: lineinfile fails to insert the needed lines, as these same 2 lines
# already appear throughout /etc/cups/cupsd.conf -- so we use blockinfile below.
#
# - name: "CUPS web administration: Insert 2 lines into /etc/cups/cupsd.conf to LOCK DOWN URL'S LIKE http://localhost:631/admin TO LINUX GROUP 'lpadmin' -- to avoid accidental damage to /etc/cups/cupsd.conf and other CUPS settings.  This uses 'SystemGroup lpadmin' in /etc/cups/cups-files.conf -- in coordination with ~14 -> ~15 '@SYSTEM' lines and 'DefaultAuthType Basic' in /etc/cups/cupsd.conf"
#   lineinfile:
#     path: /etc/cups/cupsd.conf
#     #regexp:
#     line: "{{ item }}"
#     insertafter: '^<Location /admin>$'
#   with_items:
#     - "  Require user @SYSTEM"    # Will appear BELOW, in /etc/cups/cupsd.conf
#     - "  AuthType Default"        # Will appear ABOVE, in /etc/cups/cupsd.conf

- name: "CUPS web administration: Insert 2-line block into /etc/cups/cupsd.conf to LOCK DOWN URL'S LIKE http://localhost:631/admin TO LINUX GROUP 'lpadmin' -- to avoid accidental damage to /etc/cups/cupsd.conf and other CUPS settings.  This uses 'SystemGroup lpadmin' in /etc/cups/cups-files.conf -- in coordination with ~14 -> ~15 '@SYSTEM' lines and 'DefaultAuthType Basic' in /etc/cups/cupsd.conf"
  blockinfile:
    path: /etc/cups/cupsd.conf
    insertafter: '^<Location /admin>$'
    block: |2    # |n MEANS: Set the block's left edge n CHARACTERS TO THE RIGHT of *this line's* indentation -- where n is {1..9} -- instead of setting its left edge to the 1st non-blank line's indentation below.  Also surround block with comment lines: "# BEGIN ANSIBLE MANAGED BLOCK", "# END ANSIBLE MANAGED BLOCK"
        AuthType Default
        Require user @SYSTEM

- name: "CUPS web administration: Create Linux username 'Admin' with password 'changeme' in Linux group 'lpadmin' (shell: /usr/sbin/nologin, create_home: no)"
  user:
    name: Admin
    append: yes    # Don't clobber other groups, that other IIAB Apps might need.
    groups: lpadmin
    password: "{{ 'changeme' | password_hash('sha512') }}"    # Random salt.  Presumably runs 5000 rounds of SHA-512 per /etc/login.defs & /etc/pam.d/common-password -- https://docs.ansible.com/ansible/latest/user_guide/playbooks_filters.html#encrypting-and-checksumming-strings-and-passwords
    create_home: no
    shell: /usr/sbin/nologin    # Debian/Ubuntu norm -- instead of /sbin/nologin, /bin/false

# - name: Add user '{{ iiab_admin_user }}' to Linux group 'lpadmin' -- for CUPS web administration (or modify default 'SystemGroup lpadmin' in /etc/cups/cups-files.conf -- in coordination with ~14 -> ~15 '@SYSTEM' lines in /etc/cups/cupsd.conf)
#   #command: "gpasswd -a {{ iiab_admin_user | quote }} lpadmin"
#   #command: "gpasswd -d {{ iiab_admin_user | quote }} lpadmin"
#   user:
#     name: "{{ iiab_admin_user }}"    # iiab-admin
#     append: yes
#     groups: lpadmin

- name: Start 'cups' systemd service as nec -- CUPS DAEMON MUST BE RUNNING FOR 'cupsctl' COMMAND JUST BELOW
  systemd:
    #daemon_reload: yes
    name: cups
    state: started

# - name: "Authorize Nearby IP Addresses: Run 'cupsctl --remote-admin --share-printers --user-cancel-any' to enable http://192.168.0.x:631 AND http://{{ lan_ip }}:631 (if cups_enabled) -- REPEATED USE OF 'cupsctl' COMMANDS CAN *DAMAGE* /etc/cups/cupsd.conf BY ADDING DUPLICATE LINES (AND WORSE!) -- SO PLEASE ALSO MANUALLY RUN 'sudo cupsctl' AND 'sudo cupsd -t' TO VERIFY /etc/cups/cupsd.conf"
#   command: cupsctl --remote-admin --share-printers --user-cancel-any

# 2021-07-11: BOTH FLAGS *CANNOT* BE USED TOGETHER -- CHOOSE ONE OR THE OTHER:
# (1) '--remote-admin' AS ABOVE, OR (2) '--remote-any' AS BELOW.
# (RUN 'cupsctl' WITHOUT PARAMETERS TO CONFIRM THIS!)

- name: "Authorize All IP Addresses: Run 'cupsctl --remote-any --share-printers --user-cancel-any' to enable http://192.168.0.x:631 AND http://{{ lan_ip }}:631 AND http://10.8.0.y:631 (if cups_enabled) -- REPEATED USE OF 'cupsctl' COMMANDS CAN *DAMAGE* /etc/cups/cupsd.conf BY ADDING DUPLICATE LINES (AND WORSE!) -- SO PLEASE ALSO MANUALLY RUN 'sudo cupsctl' AND 'sudo cupsd -t' TO VERIFY /etc/cups/cupsd.conf"
  command: cupsctl --remote-any --share-printers --user-cancel-any

# 2021-07-11: In theory 'cupsctl' stanzas could be put in enable-or-disable.yml
# BUT LET'S AVOID THAT -- AS REPEATED USE OF 'cupsctl' COMMANDS CAN *DAMAGE*
# /etc/cups/cupsd.conf BY ADDING DUPLICATE LINES (AND WORSE!)
#
# FYI repeated use of 'cupsctl' commands also removes comments and blank lines.
#
# - name: Run 'cupsctl --no-remote-admin --no-remote-any --no-share-printers --no-user-cancel-any --no-debug-logging' (if not cups_enabled) -- REPEATED USE OF 'cupsctl' COMMANDS CAN *DAMAGE* /etc/cups/cupsd.conf BY ADDING DUPLICATE LINES (AND WORSE!) -- SO PLEASE ALSO MANUALLY RUN 'sudo cupsctl' AND 'sudo cupsd -t' TO VERIFY /etc/cups/cupsd.conf
#   command: cupsctl --no-remote-admin --no-remote-any --no-share-printers --no-user-cancel-any --no-debug-logging
#   when: not cups_enabled

# - name: "2021-07-14: EXPERIMENTALLY ADD DIRECTIVES TO /etc/cups/cupsd.conf followed by 'systemctl restart cups'.  As should no longer be nec thanks to NEW cups/templates/cups.conf for /etc/nginx/conf.d/cups.conf (followed by 'systemctl restart nginx').  Which FIXED URL'S LIKE: http://box/print, http://box.lan/print, http://192.168.0.x/print, http://{{ lan_ip }}/print and http://10.8.0.x/print (WITH OR WITHOUT THE TRAILING SLASH!)  RECAP: (1) So be it that these 2 URL'S STILL DON'T WORK: http://box:631, http://box.lan:631 (due to CUPS' internal web server's overly stringent hostname checks, i.e. '400 Bad Request' and 'Request from \"localhost\" using invalid Host: field \"box[.lan]:631\".' in /var/log/cups/error_log) -- (2) While these 2 URL'S STILL DO WORK: http://localhost:631, http://127.0.0.1:631 -- (3) Whereas these 3 URL'S MAY WORK, DEPENDING ON 'cupsctl' COMMAND(S) ABOVE: http://192.168.0.x:631, http://{{ lan_ip }}:631, http://10.8.0.x:631"
#   lineinfile:
#     path: /etc/cups/cupsd.conf
#     line: "{{ item }}"
#     insertbefore: '^Listen .*/run/cups/cups.sock$'    # Also matches old form: '^Listen /var/run/cups/cups.sock$'
#   with_items:
#     - "HostNameLookups On"    # More False Leads: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=530027
#     - "ServerAlias *"
#     - "#ServerName {{ iiab_hostname }}.{{ iiab_domain }}"    # box.lan
#     - "#Listen {{ lan_ip }}:631"    # e.g. 10.10.10.10
#     - "#Listen 127.0.0.1:631"
#     - "#Listen 0.0.0.0:631"
#     - "#Listen *:631"

# - name: "OPTIONAL: Change 'MaxLogSize 0' (no log rotation) to 'MaxLogSize 1m' (log rotation at 1MB) in /etc/cups/cupsd.conf (EITHER WAY LOG BLOAT IS A RISK!)"
#   lineinfile:
#     path: /etc/cups/cupsd.conf
#     regexp: '^MaxLogSize '
#     insertbefore: 'Listen '
#     firstmatch: yes
#     line: "MaxLogSize 1m"    # CUPS Documentation (claims!) log rotation at "1m" is the default.  But In Practice: 'MaxLogSize 0' (no log rotation) is now part of /usr/share/cups/cupsd.conf.default

# REMINDER: 3 SYSTEMD SERVICES WILL BE RESTARTED (cups, cups-browsed, nginx)
# LATER IN enable-or-disable.yml, SO /etc/cups/cupsd.conf (ETC) TAKE EFFECT!


# RECORD CUPS AS INSTALLED

- name: Record (final) disk space used
  shell: df -B1 --output=used / | tail -1
  register: df2

- name: Add 'cups_disk_usage = {{ df2.stdout|int - df1.stdout|int }}' to {{ iiab_ini_file }}
  ini_file:
    path: "{{ iiab_ini_file }}"    # /etc/iiab/iiab.ini
    section: cups
    option: cups_disk_usage
    value: "{{ df2.stdout|int - df1.stdout|int }}"

- name: "Set 'cups_installed: True'"
  set_fact:
    cups_installed: True

- name: "Add 'cups_installed: True' to {{ iiab_state_file }}"
  lineinfile:
    path: "{{ iiab_state_file }}"    # /etc/iiab/iiab_state.yml
    regexp: '^cups_installed'
    line: 'cups_installed: True'