Adding doc that explains how to configure/use logging

website/source/docs/internals/debugging.html.md

@@ -0,0 +1,15 @@
+---
+layout: "docs"
+page_title: "Debugging"
+sidebar_current: "docs-internals-debug"
+description: |-
+  Terraform has detailed logs which can be enabled by setting the TF_LOG environmental variable to any value. This will cause detailed logs to appear on stderr
+---
+
+# Debugging Terraform
+
+Terraform has detailed logs which can be enabled by setting the TF_LOG environmental variable to any value. This will cause detailed logs to appear on stderr.
+
+To persist logged output you can set TF_LOG_PATH in order to force the log to always go to a specific file when logging is enabled. Note that even when TF_LOG_PATH is set, TF_LOG must be set in order for any logging to be enabled.
+
+If you find a bug with Terraform, please include the detailed log by using a service such as gist.

website/source/layouts/docs.erb

@@ -216,6 +216,10 @@
 				<li<%= sidebar_current("docs-internals") %>>
 				<a href="/docs/internals/index.html">Internals</a>
 				<ul class="nav">
+					<li<%= sidebar_current("docs-internals-debug") %>>
+					<a href="/docs/internals/debugging.html">Debugging Terraform</a>
+					</li>
+
 					<li<%= sidebar_current("docs-internals-graph") %>>
 					<a href="/docs/internals/graph.html">Resource Graph</a>
 					</li>