Add support for remote shell provisioner script

CHANGELOG.md

@@ -22,6 +22,7 @@ FEATURES:
     `knife` if configured to do so.
   - `vagrant up` has a `--no-destroy-on-error` flag that will not destroy
     the VM if a fatal error occurs. [GH-2011]
+  - Support for remote shell provisioning scripts [GH-1787]
 
 IMPROVEMENTS:
 

plugins/provisioners/shell/config.rb

@@ -1,3 +1,5 @@
+require 'uri'
+
 module VagrantPlugins
   module Shell
     class Config < Vagrant.plugin("2", :config)
@@ -33,8 +35,8 @@ module VagrantPlugins
           errors << I18n.t("vagrant.provisioners.shell.no_path_or_inline")
         end
 
-        # Validate the existence of a script to upload
-        if path
+        # If it is not an URL, we validate the existence of a script to upload
+        if path && ! remote?
           expanded_path = Pathname.new(path).expand_path(machine.env.root_path)
           if !expanded_path.file?
             errors << I18n.t("vagrant.provisioners.shell.path_invalid",
@@ -54,6 +56,10 @@ module VagrantPlugins
 
         { "shell provisioner" => errors }
       end
+
+      def remote?
+        path =~ URI::regexp(["ftp", "http", "https"])
+      end
     end
   end
 end

plugins/provisioners/shell/provisioner.rb

@@ -1,6 +1,8 @@
 require "pathname"
 require "tempfile"
 
+require "vagrant/util/downloader"
+
 module VagrantPlugins
   module Shell
     class Provisioner < Vagrant.plugin("2", :provisioner)
@@ -52,7 +54,15 @@ module VagrantPlugins
       def with_script_file
         script = nil
 
-        if config.path
+        if config.remote?
+          download_path = @machine.env.tmp_path.join("#{@machine.id}-remote-script")
+          download_path.delete if download_path.file?
+
+          Vagrant::Util::Downloader.new(config.path, download_path).download!
+          script = download_path.read
+
+          download_path.delete
+        elsif config.path
           # Just yield the path to that file...
           root_path = @machine.env.root_path
           script = Pathname.new(config.path).expand_path(root_path).read