Merge pull request #7378 from coreydaley/github_rails_108

Updates Ruby on Rails example to include setting required env var

Author: bmcelvee

dev_guide/dev_tutorials/ruby_on_rails.adoc

@@ -303,7 +303,7 @@ $ oc get pods --watch
 To bring your application to {product-title}, you need to specify a repository in which your application lives, using once again the xref:../../dev_guide/application_lifecycle/new_app.adoc#dev-guide-new-app[`oc new-app`] command, in which you will need to specify database related xref:../../using_images/db_images/postgresql.adoc#postgresql-environment-variables[environment variables] we setup in the xref:creating-the-database-service[Creating the Database Service]:
 
 ----
-$ oc new-app path/to/source/code --name=rails-app -e POSTGRESQL_USER=username -e POSTGRESQL_PASSWORD=password -e POSTGRESQL_DATABASE=db_name
+$ oc new-app path/to/source/code --name=rails-app -e POSTGRESQL_USER=username -e POSTGRESQL_PASSWORD=password -e POSTGRESQL_DATABASE=db_name -e DATABASE_SERVICE_NAME=postgresql
 ----
 
 With this command, {product-title} fetches the source code, sets up the builder image, xref:../../dev_guide/builds/index.adoc#dev-guide-how-builds-work[builds] your application image, and deploys the newly created image together with the specified xref:../../using_images/db_images/postgresql.adoc#postgresql-environment-variables[environment variables]. The application is named `rails-app`.
@@ -329,7 +329,12 @@ env": [
     {
         "name": "POSTGRESQL_DATABASE",
         "value": "db_name"
+    },
+    {
+        "name": "DATABASE_SERVICE_NAME",
+        "value": "postgresql"
     }
+
 ],
 ----