Implement repo.pinning logic

* Ubuntu pinning params allow to be used
     multiply times. In same time, old `list`
     format now allowing to be predictable
     iterated inside jinja

Related-Bug: PROD-21604 (PROD:21604)

Change-Id: If1c0f0f834a296b9a19d0af5fc7673c9229a7ac5

README.rst

                priority: 900
                package: '*'
 
+If you need to add multiple pin rules for one repo, please use new,ordered definition format
+('pinning' definition will be in priotity to use):
+
+.. code-block:: yaml
+
+  linux:
+    system:
+      repo:
+        mcp_saltstack:
+          source: "deb [arch=amd64] http://repo.saltstack.com/apt/ubuntu/16.04/amd64/2017.7/ xenial main"
+          architectures: amd64
+          clean_file: true
+          pinning:
+            10:
+              enabled: true
+              pin: 'release o=SaltStack'
+              priority: 50
+              package: 'libsodium18'
+            20:
+              enabled: true
+              pin: 'release o=SaltStack'
+              priority: 1100
+              package: '*'
+
+
 .. note:: For old Ubuntu releases (<xenial)
           extra packages for apt transport, like ``apt-transport-https``
           may be required to be installed manually.

linux/files/preferences_repo

 {%- from "linux/map.jinja" import system with context %}
 {%- set repo = system.repo[repo_name] %}
-{%- for pin in repo.pin %}
-{%- set package = pin.get('package', '*') %}
+{%- if repo.pinning is defined  %}
+  {%- for id,pin in repo.pinning|dictsort %}
+    {%- if pin.get('enabled', False) %}
+Package: {{ pin.get('package','*') }}
+Pin: {{ pin.pin }}
+Pin-Priority: {{ pin.priority }}
+    {%- endif %}
+  {% endfor %}
+{%- elif repo.pin is defined %}
+  {%- for pin in repo.pin %}
+    {%- set package = pin.get('package', '*') %}
 Package: {{ package }}
 Pin: {{ pin.pin }}
 Pin-Priority: {{ pin.priority }}
-{% endfor %}
+  {% endfor %}
+{%- endif %}

linux/system/repo.sls

   file.absent
       {%- endif %}
 
-      {%- if repo.pin is defined %}
+      {%- if repo.pin is defined or repo.pinning is defined %}
 linux_repo_{{ name }}_pin:
   file.managed:
     - name: /etc/apt/preferences.d/{{ name }}

tests/pillar/system.sls

         proxy:
           enabled: true
           https: https://127.0.5.1:443
+      saltstack:
+        source: "deb [arch=amd64] http://repo.saltstack.com/apt/ubuntu/16.04/amd64/2017.7/ xenial main"
+        key_url: "http://repo.saltstack.com/apt/ubuntu/16.04/amd64/2017.7/SALTSTACK-GPG-KEY.pub"
+        architectures: amd64
+        clean_file: true
+        pinning:
+          10:
+            enabled: true
+            pin: 'release o=SaltStack'
+            priority: 50
+            package: 'libsodium18'
+          20:
+            enabled: true
+            pin: 'release o=SaltStack'
+            priority: 1100
+            package: '*'
       opencontrail:
         source: "deb http://ppa.launchpad.net/tcpcloud/contrail-3.0/ubuntu xenial main"
         keyid: E79EE90C