fix: ensure formula works across all platforms

Before:

* https://travis-ci.org/github/myii/timezone-formula/builds/665820454

After:

* https://travis-ci.org/github/myii/timezone-formula/builds/665975767
* https://travis-ci.org/github/myii/timezone-formula/builds/666039725 (all platforms)

Includes:

* fix(init.sls): ensure `dbus` is available for `timezone.system` state
* fix(init.sls): use symlink to `UTC` if `localtime` does not exist
* fix(init.sls): force the creation of the initial symlink
* fix: avoid running `dbus` service on `ubuntu-16.04`, `amazonlinux-1` & `centos-6`

timezone/defaults.yaml

@@ -3,8 +3,13 @@
 ---
 timezone:
   name: Europe/Berlin
+  tz_UTC: Etc/UTC
   utc: true
   path_localtime: /etc/localtime
   path_zoneinfo: /usr/share/zoneinfo/
   pkg:
     name: tzdata
+  dbus:
+    pkg: dbus
+    service: dbus
+    run_service: true

timezone/init.sls

@@ -5,23 +5,44 @@
 {%- set tplroot = tpldir.split('/')[0] %}
 {%- from tplroot ~ "/map.jinja" import timezone with context %}
 
+{%- if grains.os not in ('MacOS', 'Windows') %}
+timezone_packages:
+  {#- Work around bug in Salt for certain platforms where symlink isn't available #}
+  {%- if not salt['file.file_exists'](timezone.path_localtime) %}
+  file.symlink:
+    - name: {{ timezone.path_localtime }}
+    - target: {{ timezone.path_zoneinfo }}{{ timezone.tz_UTC }}
+    - force: true
+    - require_in:
+      # Required for unattended installation of the timezone package
+      - pkg: timezone_packages
+      # Required for timezone comparison (symlink must be present for checking the current timezone)
+      - timezone: timezone_setting
+  {%- endif %}
+  pkg.installed:
+    - name: {{ timezone.pkg.name }}
+    - require_in:
+      # Required for timezone comparison (current and proposed)
+      - timezone: timezone_setting
+
+dbus_for_timezone:
+  pkg.installed:
+    - name: {{ timezone.dbus.pkg }}
+    - require_in:
+      - timezone: timezone_setting
+  {%- if timezone.dbus.run_service %}
+  service.running:
+    - name: {{ timezone.dbus.service }}
+    - enable: true
+    - require:
+      - pkg: dbus_for_timezone
+    - require_in:
+      # `dbus` is required for running `timedatectl`
+      - timezone: timezone_setting
+  {%- endif %}
+{%- endif %}
+
 timezone_setting:
   timezone.system:
     - name: {{ timezone.name }}
     - utc: {{ timezone.utc }}
-
-{%- if grains.os not in ('MacOS', 'Windows') %}
-
-timezone_packages:
-  pkg.installed:
-    - name: {{ timezone.pkg.name }}
-
-timezone_symlink:
-  file.symlink:
-    - name: {{ timezone.path_localtime }}
-    - target: {{ timezone.path_zoneinfo }}{{ timezone.name }}
-    - force: true
-    - require:
-      - pkg: {{ timezone.pkg.name }}
-
-{%- endif %}

timezone/osfamilymap.yaml

@@ -10,16 +10,34 @@
 # you will need to provide at least an empty dict in this file, e.g.
 # osfamilymap: {}
 ---
+Debian: {}
+
+RedHat: {}
+
 Suse:
   pkg:
     name: timezone
-
+  dbus:
-FreeBSD:
+    pkg: dbus-1
-  pkg:
-    name: zoneinfo
 
 Gentoo:
   pkg:
     name: sys-libs/timezone-data
 
+Arch: {}
+
+Alpine: {}
+
+FreeBSD:
+  pkg:
+    name: zoneinfo
+
+OpenBSD:
+  pkg:
+    name: zoneinfo
+
+Solaris: {}
+
+Windows: {}
+
 MacOS: {}

timezone/osfingermap.yaml

@@ -10,4 +10,42 @@
 # you will need to provide at least an empty dict in this file, e.g.
 # osfingermap: {}
 ---
-osfingermap: {}
+# os: Debian
+Debian-10: {}
+Debian-9: {}
+Debian-8: {}
+
+# os: Ubuntu
+Ubuntu-18.04: {}
+Ubuntu-16.04:
+  dbus:
+    run_service: false
+
+# os: Fedora
+Fedora-31: {}
+Fedora-30: {}
+
+# os: CentOS
+CentOS Linux-8: {}
+CentOS Linux-7: {}
+CentOS-6:
+  dbus:
+    run_service: false
+
+# os: Amazon
+Amazon Linux-2: {}
+Amazon Linux AMI-2018:
+  dbus:
+    run_service: false
+
+# os: SUSE
+Leap-15: {}
+
+# os: FreeBSD
+FreeBSD-12: {}
+
+# os: Windows
+Windows-8.1: {}
+
+# os: Gentoo
+Gentoo-2: {}

timezone/osmap.yaml

@@ -10,4 +10,24 @@
 # you will need to provide at least an empty dict in this file, e.g.
 # osmap: {}
 ---
-osmap: {}
+# os_family: Debian
+Ubuntu: {}
+Raspbian: {}
+
+# os_family: RedHat
+Fedora: {}
+CentOS: {}
+Amazon: {}
+
+# os_family: Suse
+SUSE: {}
+openSUSE: {}
+
+# os_family: Gentoo
+Funtoo: {}
+
+# os_family: Arch
+Manjaro: {}
+
+# os_family: Solaris
+SmartOS: {}