Use Salt to install Python 3 on Windows machines

Use the Salt winrepo support to install Python 3.
Because we use gitfs and don't use the default file roots,
add a new file root on the master for winrepo files.

docs/salt.md

@@ -275,6 +275,9 @@ Installation is not yet scripted and must currently be done manually.
    configure the minion and autostart the minion.
    Make sure to provide the correct minion ID!
    `Salt-Minion-2016.3.3-AMD64-Setup.exe /S /master=servo-master1.servo.org /minion-name=servo-windowsN`
+3. Update the winrepo package database on the minion.
+   On the master, run: `root@servo-master1$ salt 'servo-windowsN' pkg.refresh_db`,
+   replacing `servo-windowsN` with the minion ID.
 
 #### Enabling a new Salt minion
 
@@ -294,6 +297,19 @@ on the new minion to set it up.
 See [the wiki](https://github.com/servo/servo/wiki/SaltStack-Administration)
 for more information about setting up new masters.
 
+When the master is created, the Windows repository data must be fetched:
+
+```console
+root@servo-master1$ salt-run winrepo.update_git_repos
+```
+
+This command is similar to `apt-get update` and can be run at any time.
+After each run, the minion databases must be updated as well:
+
+```console
+root@servo-master1$ salt -G 'os:Windows' pkg.refresh_db
+```
+
 ### Looking up previous runs
 
 Salt keeps track of the results of each `job` it performs,

python/init.sls

@@ -1,3 +1,14 @@
+python3:
+  pkg.installed:
+    {% if grains['os'] == 'Windows' %}
+    - name: python3_x64
+    - version: 3.5.2150.0  # Need to pin version to set $PATH
+    {% else %}
+    - pkgs:
+      - python3
+    {% endif %}
+
+{% if grains['os'] != 'Windows' %}
 python2:
   pkg.installed:
     - pkgs:
@@ -6,11 +17,6 @@ python2:
     - refresh: True
     {% endif %}
 
-python3:
-  pkg.installed:
-    - pkgs:
-      - python3
-
 {% if grains['os'] == 'Ubuntu' %}
 python2-dev:
   pkg.installed:
@@ -36,3 +42,4 @@ virtualenv:
       - virtualenv == 14.0.6
     - require:
       - pkg: pip
+{% endif %}

salt/map.jinja

@@ -7,15 +7,19 @@
           'config': {
             'fileserver_backend': [ 'roots', 'git' ],
             'file_roots': {
-              'base': [ '/tmp/salt-testing-root/saltfs' ]
+              'base': [
+                '/tmp/salt-testing-root/saltfs',
+                '/srv/salt-win'
+              ]
             },
             'gitfs_remotes': [ 'https://github.com/servo/saltfs.git' ],
             'gitfs_env_whitelist': [ 'base' ],
             'hash_type': 'sha384',
             'keep_jobs': 0,
             'pillar_roots': {
               'base': [ '/srv/pillar' ]
-            }
+            },
+            'winrepo_dir_ng': '/srv/salt-win/win/repo-ng'
           }
         },
         'Ubuntu': {

top.sls

@@ -1,6 +1,9 @@
 # NOTE: Ensure all node types are covered in .travis.yml
 
 base:
+  '*':
+    - python
+
   'not G@os:Windows':
     - match: compound
     - admin