r/squid: Support custom cache rules

Instead of hard-coding a single cache directory and a set of refresh
patterns, the *squid* role can now have custom cache rules defined with
the `squid_cache_dir` variable (which now takes a list of `cache_dir`
settings) and the `squid_refresh_pattern` variable (which takes a list
of refresh patterns).  If neither of these are defined, the default
configuration is used.

This is a breaking change, since `squid_cache_dir` used to refer to a
directory, and the previous default was to configure one cache path.
There are no extant users of this role, though, so it doesn't really
matter.

roles/squid/tasks/main.yml

@@ -7,12 +7,15 @@
 
 - name: ensure squid cache dir exists
   file:
-    path={{ squid_cache_dir }}
-    owner=squid
-    group=squid
-    mode=0750
-    setype=squid_cache_t
-    state=directory
+    path: '{{ item.split()[1] }}'
+    owner: squid
+    group: squid
+    mode: u=rwx,g=rx,o=
+    setype: squid_cache_t
+    state: directory
+  loop: '{{ squid_cache_dir|d([]) }}'
+  notify:
+  - initialize squid cache directories
 
 - name: ensure squid is configured
   template:
@@ -22,12 +25,9 @@
     owner=root
     group=squid
     setype=squid_conf_t
-  notify: reload squid
-
-- name: ensure squid cache directory exists
-  command:
-    /usr/sbin/squid -N -z -F -f /etc/squid/squid.conf
-    creates={{ squid_cache_dir }}/00
+  notify:
+  - initialize squid cache directories
+  - reload squid
 
 - meta: flush_handlers
 - name: ensure squid service starts at boot
@@ -46,3 +46,6 @@
     immediate=yes
     state=enabled
   notify: save firewalld configuration
+  when: host_uses_firewalld|d(true)
+  tags:
+  - firewall