adding page on user controlled variables (eg, cache)

Author: vsoch

_data/sidebars/user_docs.yml

@@ -31,7 +31,11 @@ entries:
       url: /docs-content
       output: web, pdf
 
-    - title: Bind Paths and Files
+    - title: User Control
+      url: /docs-control
+      output: web, pdf
+
+    - title: Bind Paths and Mounts
       url: /docs-mount
       output: web, pdf
 

pages/docs/user-docs/docs-control.md

@@ -0,0 +1,29 @@
+---
+title: Controlling Your Build
+sidebar: user_docs
+permalink: user-control
+folder: docs
+---
+
+This document will cover various environment variables that you can set to control the build of your image. If you are looking for the admin setup for Singularity on a shared resource, see the separate <a href="/admin-guide">Singularity Administration Guide</a>.
+
+
+## Cache Folders
+To make download of layers for <a href="/docs-import">import</a> and <a href="/docs-pull">pull</a> faster and less redundant, we use a caching strategy. By default, the Singularity software will create a set of folders in your `$HOME` directory for docker layers, Singularity Hub images, and Docker metadata, respectively:
+
+```
+$HOME/.singularity
+$HOME/.singularity/docker
+$HOME/.singularity/shub
+$HOME/.singularity/metadata
+```
+
+Fear not, you have control to customize this behavior! If you don't want the cache to be created (and a temporary directory will be used), set `SINGULARITY_DISABLE_CACHE` to True/yes, or if you want to move it elsewhere, set `SINGULARITY_CACHEDIR` to the full path where you want to cache. Remember that when you run commands as sudo (for example, with <a href="/docs-bootstrap">bootstrap</a> this will use root's home at `/root` and not your user's home. 
+
+## Pull Folder
+For details about customizing the output location of <a href="/docs-pull">pull</a>, see the<a href="/docs-pull">pull docs.</a> You have the similar ability to set it to be something different, or to customize the name of the pulled image.
+
+
+## Support
+
+Have a question, or need further information? <a href="/support">Reach out to us.</a>

pages/docs/user-docs/user-guide.md

@@ -161,10 +161,15 @@ One the left side, you have your laptop, workstation, or a server that you contr
 ### Examples
 How do the commands work? We recommend you look at examples for each:
 
-- [shell](/docs-shell)
-- [exec](/docs-exec)
-- [run](/docs-run)
-- [bootstrap](/docs-bootstrap)
+- [bootstrap](/docs-bootstrap): Bootstrap a Singularity build specification to build an image
+- [exec](/docs-exec): Execute a command to your container
+- [inspect](/docs-inspect): See labels, run and test scripts, and environment variables
+- [import](/docs-import): import layers or other file content to your image
+- [pull](/docs-pull): pull an image from Docker or Singularity Hub
+- [run](/docs-run): Run your image as an executable
+- [shell](/docs-shell): Shell into your image
+- [user control](/docs-control): The environment commands you can set to control the workflow 
+
 
 
 ## Support