Add instructions to build Windows package on Windows

Fixes #37

PKG_WINDOWS.md

@@ -0,0 +1,117 @@
+# Build RabbitMQ Windows Package using Windows
+
+Last updated: `2018-11-08 12:31:19`
+
+## Environment
+
+Windows 8.1 using this `Vagrantfile`:
+
+```
+Vagrant.configure("2") do |config|
+  config.vm.box = "inclusivedesign/windows81-eval-x64"
+  config.vm.provider "virtualbox" do |v|
+    v.gui = true
+  end
+end
+```
+
+## Initial Steps
+
+Bring up the VM and go through the process of updating Windows and VirtualBox
+tools. You'll notice that the evaluation license is expired. Re-arm it by
+running this command via an administrative prompt:
+
+```
+slmgr -rearm
+```
+
+This part of the process will take a while as Windows is updated. Go make some
+coffee and check your email.
+
+## Install Erlang and Elixir
+
+Using Chocolatey is the easiest method to install the most recent version of
+Erlang and Elixir. Install Chocolatey [using these
+instructions](https://chocolatey.org/install#installing-chocolatey)
+([link](https://chocolatey.org/install#installing-chocolatey)), then install
+both Erlang and Elixir using this command from an *administrative* `cmd.exe` or
+Powershell terminal:
+
+```
+choco install elixir which
+```
+
+To confirm installation, open a new command prompt and run the following:
+
+```
+erl -version
+elixir -v
+which erl
+which elixir
+```
+
+## Install MSYS2 and NSIS
+
+Chocolatey is also an easy way to install `msys2` and the NSIS install script
+builder. Run the following from an *administrative* command prompt:
+
+```
+choco install msys2 nsis
+```
+
+As a bonus, it will update your `msys2` installation for you during the initial
+install process.
+
+## Install MSYS2 packages
+
+Start up an `msys2` shell by running the following command (does not have to be
+admin):
+
+```
+C:\tools\msys64\msys2_shell.cmd
+```
+
+In that shell, install all of these dependencies. If you are prompted for
+input, just hit ENTER to choose the default:
+
+```
+pacman -S --needed git make tar rsync python zip unzip dos2unix man
+```
+
+## Build RabbitMQ
+
+### Clone this repository
+
+From within your MSYS2 shell:
+
+```
+git clone https://github.com/rabbitmq/rabbitmq-server-release.git
+```
+
+### Set `PATH`
+
+```
+export PATH="$PATH:/c/ProgramData/Chocolatey/bin:/c/ProgramData/Chocolatey/lib/Elixir/bin:/c/Program Files (x86)/NSIS/bin"
+```
+
+### Fetch and build deps
+
+*Note:* as of this writing, RabbitMQ `3.7.8` is the latest version. Be sure to check out the tag appropriate for your use:
+
+```
+cd rabbitmq-server-release
+
+# the following checks out the "next to be released" branch
+# this branch and version 3.7.9 have a necessary fix for building
+# on windows, see this: https://github.com/rabbitmq/rabbitmq-server-release/pull/89
+
+git checkout v3.7.x
+
+make deps
+```
+
+### Build Windows package
+
+```
+make UNIX_TO_DOS=unix2dos package-windows
+```

README.md

@@ -204,15 +204,18 @@ flavors, accepts the `RPM_OS` variable to set the flavor. It can be:
 ### Windows package
 
 We create two artefacts:
+
 * a Zip archive, resembling the `generic-unix` package;
 * an installer.
 
 To create them:
+
 ```
 make package-windows
 ```
 
 To create them separately:
+
 ```
 make -C packaging/windows     # the Zip archive
 make -C packaging/windows-exe # the installer
@@ -228,6 +231,7 @@ one requires the Zip archive as its input, not the source archive.
 
 So you need to built the Zip archive first, then the installer. You can
 specify the path to the Zip archive using the `ZIP` variable:
+
 ```
 make -C packaging/windows-exe ZIP=/path/to/rabbitmq-server-windows.zip
 ```
@@ -237,10 +241,14 @@ everything following the third integer was replaced by `.0`. Thus it's
 only fine if the version is a semver-based version (eg. 3.8.1-pre.3 or
 3.8.2). If the version doesn't conform to that, you need to set the
 `PRODUCT_VERSION` variable:
+
 ```
 make package-windows PROJECT_VERSION=3.8.1-rc.1 PRODUCT_VERSION=3.8.1.0
 ```
 
+To build the Windows package using a Windows machine, follow the
+instructions in [`PKG_WINDOWS.md`](PKG_WINDOWS.md).
+
 ### Standalone package
 
 This is the equivalent of the `generic-unix` package with Erlang