Configure interactive logon message

This is also covers the following CIS items
* CIS 1.7.1.5 Ensure permissions on /etc/issue are configured (Scored)

Change-Id: If8c237ff4db7e9ab7ee244278d28f632e73ecb56
Related-Prod: PROD-19166

README.rst

         bash:
           preserve_history: true
 
+Login banner message
+~~~~~~~~~~~~~~~~~~~~
+
+/etc/issue is a text file which contains a message or system
+identification to be printed before the login prompt.  It may contain
+various @char and \char sequences, if supported by the getty-type
+program employed on the system.
+
+Setting logon banner message is easy:
+
+.. code-block:: yaml
+
+    liunx:
+      system:
+        banner:
+          enabled: true
+          contents: |
+            UNAUTHORIZED ACCESS TO THIS SYSTEM IS PROHIBITED
+
+            You must have explicit, authorized permission to access or configure this
+            device. Unauthorized attempts and actions to access or use this system may
+            result in civil and/or criminal penalties.
+            All activities performed on this system are logged and monitored.
+
 Message of the day
 ~~~~~~~~~~~~~~~~~~
 

linux/map.jinja

     },
 }, grain='os_family', merge=salt['pillar.get']('linux:system')) %}
 
+{% set banner = salt['grains.filter_by']({
+    'BaseDefaults': {
+        'enabled': false,
+    },
+}, grain='os_family', merge=salt['pillar.get']('linux:system:banner'), base='BaseDefaults') %}
+
 {% set auth = salt['grains.filter_by']({
     'Arch': {
         'enabled': false,

linux/system/banner.sls

+{%- from "linux/map.jinja" import banner with context %}
+
+{%- if banner.get('enabled', False) %}
+/etc/issue:
+  file.managed:
+  - user: root
+  - group: root
+  - mode: 644
+  - contents_pillar: linux:system:banner:contents
+{%- endif %}

linux/system/init.sls

 {%- if system.auth is defined %}
 - linux.system.auth
 {%- endif %}
+{%- if system.banner is defined %}
+- linux.system.banner
+{%- endif %}

tests/pillar/system_banner.sls

+linux:
+  system:
+    enabled: true
+    banner:
+      enabled: true
+      contents: |
+        ================= WARNING =================
+        This is tcpcloud network.
+        Unauthorized access is strictly prohibited.
+        ===========================================