From 1ef45d8073d20c8880448b847401ccf84ca19b99 Mon Sep 17 00:00:00 2001
From: Brian Cain <bcain@hashicorp.com>
Date: Thu, 26 Apr 2018 10:47:28 -0700
Subject: [PATCH] Add warning if vagrant-triggers plugin is installed

To allow users to continue to use the community plugin, this commit adds
a switch that will not load the core trigger feature if it detects the
community plugin is installed. It also allows the user to disable the
warning so they can continue to use the plugin without extra output.
---
 plugins/kernel_v2/plugin.rb                   | 25 ++++++++++++++++---
 .../other/environmental-variables.html.md     |  5 ++++
 2 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/plugins/kernel_v2/plugin.rb b/plugins/kernel_v2/plugin.rb
index 4c836424f..280470d19 100644
--- a/plugins/kernel_v2/plugin.rb
+++ b/plugins/kernel_v2/plugin.rb
@@ -40,9 +40,28 @@ module VagrantPlugins
         VMConfig
       end
 
-      config("trigger") do
-        require File.expand_path("../config/trigger", __FILE__)
-        TriggerConfig
+      plugins = Vagrant::Plugin::Manager.instance.installed_plugins
+      if !plugins.keys.include?("vagrant-triggers")
+        config("trigger") do
+          require File.expand_path("../config/trigger", __FILE__)
+          TriggerConfig
+        end
+      else
+        if !ENV["VAGRANT_USE_VAGRANT_TRIGGERS"]
+        $stderr.puts <<-EOF
+WARNING: Vagrant has detected the `vagrant-triggers` plugin. This plugin conflicts
+with the internal triggers implementation. Please uninstall the `vagrant-triggers`
+plugin and run the command again if you wish to use the core trigger feature. To
+uninstall the plugin, run the command shown below:
+
+  vagrant plugin uninstall vagrant-triggers
+
+Note that the community plugin `vagrant-triggers` and the core trigger feature
+in Vagrant do not have compatible syntax.
+
+To disable this warning, set the environment variable `VAGRANT_USE_VAGRANT_TRIGGERS`.
+EOF
+        end
       end
     end
   end
diff --git a/website/source/docs/other/environmental-variables.html.md b/website/source/docs/other/environmental-variables.html.md
index 0ede26818..35fbbb8c0 100644
--- a/website/source/docs/other/environmental-variables.html.md
+++ b/website/source/docs/other/environmental-variables.html.md
@@ -243,3 +243,8 @@ of PowerShell. Occasionally the default can be too low and Vagrant will report
 being unable to detect the installed version of PowerShell. This environment
 variable can be used to extend the timeout used during PowerShell version
 detection.
+
+## `VAGRANT_USE_VAGRANT_TRIGGERS`
+
+Vagrant will not display the warning about disabling the core trigger feature if
+the community plugin is installed.