From 76dd0252ee95dc03ddb23c2c6ccfedab68635623 Mon Sep 17 00:00:00 2001
From: Jose Diaz-Gonzalez <email@josediazgonzalez.com>
Date: Tue, 19 Dec 2017 00:54:20 -0500
Subject: [PATCH] feat: add pre-start trigger for notifying on application
 start

Closes #2713
---
 docs/development/plugin-triggers.md | 18 ++++++++++++++++++
 plugins/ps/functions                |  1 +
 2 files changed, 19 insertions(+)

diff --git a/docs/development/plugin-triggers.md b/docs/development/plugin-triggers.md
index d3d1058fe..c5d947c54 100644
--- a/docs/development/plugin-triggers.md
+++ b/docs/development/plugin-triggers.md
@@ -932,6 +932,24 @@ APP="$1"; verify_app_name "$APP"
 # TODO
 ```
 
+### `pre-start`
+
+- Description: Can be used to run commands before an application is started
+- Invoked by: `dokku ps:start`
+- Arguments: `$APP`
+- Example:
+
+```shell
+#!/usr/bin/env bash
+# Notifies an example url that an application is starting
+
+set -eo pipefail; [[ $DOKKU_TRACE ]] && set -x
+
+APP="$1";
+
+curl "https://example.com/starting/${APP}" || true
+```
+
 ### `proxy-build-config`
 
 - Description: Builds the proxy implementation configuration for a given app
diff --git a/plugins/ps/functions b/plugins/ps/functions
index 25f6ce401..e4816403f 100755
--- a/plugins/ps/functions
+++ b/plugins/ps/functions
@@ -93,6 +93,7 @@ ps_start() {
   local IMAGE_TAG=$(get_running_image_tag "$APP");
 
   if (is_deployed "$APP"); then
+    plugn trigger pre-start "$APP"
     if ! (is_app_running "$APP"); then
       release_and_deploy "$APP" "$IMAGE_TAG"
     else