Support for PostgresApp on MacOS

[noelmcloughlin]

This PR introduces support for the PostgresApp package on MacOS. The package is first downloaded from http://postgresapp.com, sha-256 is verified, and installed natively on MacOS.

The tested baseline included #176 and #177 so hopefully those commits are merged first.

** top_state **
base:
  '*':
    - postgres

** Pillars **
postgres:
{% if grains.os == 'MacOS' %}

  # Set to 'postgresapp' to install that upstream MacOS package
  use_upstream_repo: 'postgresapp'

{% else %}
  # Set False to use distro packaged postgresql.
  # Set True to use upstream postgresql.org repo for YUM/APT/ZYPP
  use_upstream_repo: False

  # Upstream version
  version: '9.6'

  # Additional packages to install with PostgreSQL server,
  # this should be in a list format and correctly named.
  pkgs_extra:
  - postgresql-contrib
  - postgresql-plpython

  # These are Debian/Ubuntu specific package names
  pkg: 'postgresql-9.6'
  pkg_client: 'postgresql-client-9.6'

  #Debian alternatives priority incremental. 0 disables feature.
  linux:
    altpriority: 30
{% endif %}

  limits:
    soft: 64000
    hard: 64000

... rest as per pillar.example ....


** Result on OS X El Capitan **

local:
----------
          ID: pg-remove-prev-archive
    Function: file.absent
        Name: /tmp/postgrestmp/postgres.dmg
      Result: True
     Comment: Removed file /tmp/postgrestmp/postgres.dmg
     Started: 10:26:44.473380
    Duration: 11.411 ms
     Changes:   
              ----------
              removed:
                  /tmp/postgrestmp/postgres.dmg
----------
          ID: pg-extract-dirs
    Function: file.directory
        Name: /tmp/postgrestmp
      Result: True
     Comment: Directory /tmp/postgrestmp is in the correct state
              Directory /tmp/postgrestmp updated
     Started: 10:26:44.484917
    Duration: 0.752 ms
     Changes:   
----------
          ID: pg-download-archive
    Function: pkg.installed
        Name: curl
      Result: True
     Comment: Package curl is already installed
     Started: 10:26:46.269667
    Duration: 733.215 ms
     Changes:   
----------
          ID: pg-download-archive
    Function: cmd.run
        Name: curl -s -L -o '/tmp/postgrestmp/postgres.dmg' https://github.com/PostgresApp/PostgresApp/releases/download/v2.1.1/Postgres-2.1.1.dmg
      Result: True
     Comment: Command "curl -s -L -o '/tmp/postgrestmp/postgres.dmg' https://github.com/PostgresApp/PostgresApp/releases/download/v2.1.1/Postgres-2.1.1.dmg" run
     Started: 10:26:47.005116
    Duration: 229067.193 ms
     Changes:   
              ----------
              pid:
                  5116
              retcode:
                  0
              stderr:
              stdout:
----------
          ID: pg-package-install
    Function: macpackage.installed
        Name: /tmp/postgrestmp/postgres.dmg
      Result: True
     Comment: Postgres.app installed
     Started: 10:30:36.295101
    Duration: 18240.587 ms
     Changes:   
              ----------
              installed:
                  - Postgres.app
----------
          ID: pg-package-install
    Function: file.append
        Name: /Users/messi/.bash_profile
      Result: True
     Comment: Appended 1 lines
     Started: 10:30:54.536223
    Duration: 20.205 ms
     Changes:   
              ----------
              diff:
                  --- 
                  
                  +++ 
                  
                  @@ -26,3 +26,4 @@
                  
                   #### HOSTS #####
                   alias tm='cd && ssh tm'
                   export PATH="/usr/local/sbin:$PATH"
                  +export PATH=$PATH:/Applications/Postgres.app/Contents/Versions/latest/bin
----------
          ID: pg-remove-archive
    Function: file.absent
        Name: /tmp/postgrestmp
      Result: True
     Comment: Removed directory /tmp/postgrestmp
     Started: 10:30:54.556690
    Duration: 2.163 ms
     Changes:   
              ----------
              removed:
                  /tmp/postgrestmp
----------
          ID: postgres_maxfiles_limits_conf
    Function: file.managed
        Name: /Library/LaunchDaemons/limit.maxfiles.plist
      Result: True
     Comment: File /Library/LaunchDaemons/limit.maxfiles.plist is in the correct state
     Started: 10:30:54.558930
    Duration: 13.938 ms
     Changes:   
----------
          ID: postgres-desktop-shortcut-clean
    Function: file.absent
        Name: /Users/messi/Desktop/postgres
      Result: True
     Comment: File /Users/messi/Desktop/postgres is not present
     Started: 10:30:54.572969
    Duration: 0.427 ms
     Changes:   
----------
          ID: postgres-desktop-shortcut-add
    Function: file.managed
        Name: /tmp/mac_shortcut.sh
      Result: True
     Comment: File /tmp/mac_shortcut.sh updated
     Started: 10:30:54.573711
    Duration: 7.17 ms
     Changes:   
              ----------
              diff:
                  New file
              mode:
                  0755
              user:
                  messi
----------
          ID: postgres-desktop-shortcut-add
    Function: cmd.run
        Name: /tmp/mac_shortcut.sh postgresapp
      Result: True
     Comment: Command "/tmp/mac_shortcut.sh postgresapp" run
     Started: 10:30:54.581287
    Duration: 440.299 ms
     Changes:   
              ----------
              pid:
                  5168
              retcode:
                  0
              stderr:
              stdout:
                  alias file Postgres of folder Desktop of folder messi of folder Users of startup disk

Summary for local
-------------
Succeeded: 11 (changed=7)
Failed:     0
-------------
Total states run:     11
Total run time:  248.537 s

[noelmcloughlin]

rebased as #191