From 7b482cca9b48deba49ce0662842283f14d2535c7 Mon Sep 17 00:00:00 2001
From: stack72 <public@paulstack.co.uk>
Date: Fri, 17 Jun 2016 11:32:30 +0100
Subject: [PATCH] provider/mysql: Empty Provider Credentials Caused Panic

There are currently no checks on username and endpoint in the provider
schema from being an empty value. This PR adds support to make sure that
endpoint and username are not empty strings as that can cause a panic

Results of the PR:

```
 % terraform apply
There are warnings and/or errors related to your configuration. Please
fix these before continuing.

Errors:

  * provider.mysql: Endpoint must not be an empty string
```
---
 builtin/providers/mysql/provider.go | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/builtin/providers/mysql/provider.go b/builtin/providers/mysql/provider.go
index 3afd7db4c..bd3401979 100644
--- a/builtin/providers/mysql/provider.go
+++ b/builtin/providers/mysql/provider.go
@@ -17,12 +17,28 @@ func Provider() terraform.ResourceProvider {
 				Type:        schema.TypeString,
 				Required:    true,
 				DefaultFunc: schema.EnvDefaultFunc("MYSQL_ENDPOINT", nil),
+				ValidateFunc: func(v interface{}, k string) (ws []string, errors []error) {
+					value := v.(string)
+					if value == "" {
+						errors = append(errors, fmt.Errorf("Endpoint must not be an empty string"))
+					}
+
+					return
+				},
 			},
 
 			"username": &schema.Schema{
 				Type:        schema.TypeString,
 				Required:    true,
 				DefaultFunc: schema.EnvDefaultFunc("MYSQL_USERNAME", nil),
+				ValidateFunc: func(v interface{}, k string) (ws []string, errors []error) {
+					value := v.(string)
+					if value == "" {
+						errors = append(errors, fmt.Errorf("Username must not be an empty string"))
+					}
+
+					return
+				},
 			},
 
 			"password": &schema.Schema{