custom images: clarify building CVM images

bpmct · bpmct · commit 0acd2faec8e3 · 2021-06-29T12:35:51.000-04:00
diff --git a/images/writing.md b/images/writing.md
@@ -7,8 +7,8 @@ Custom images allow you to define workspaces that include the dependencies,
 scripts, and user preferences helpful for your project.
 
 > If you're unfamiliar with how to create, build, and push Docker Images, please
-> review [this tutorial by
-> Docker](http://blog.shippable.com/build-a-docker-image-and-push-it-to-docker-hub)
+> review
+> [this tutorial by Docker](http://blog.shippable.com/build-a-docker-image-and-push-it-to-docker-hub)
 > before proceeding.
 
 ## Creating a custom image
@@ -32,11 +32,17 @@ Please note:
   [image minimum requirements](https://github.com/cdr/enterprise-images/#image-minimums)
   to make sure that your image will work with all of Coder's features.
 
-- You can build images inside a Coder workspace using the
-  [Docker Sandbox](https://github.com/bpmct/cdr-images/tree/master/docker-sandbox).
-  If, however, you're using [CVMs](../admin/workspace-management/cvms.md),
-  you'll need to have the [sysbox runtime](https://github.com/nestybox/sysbox)
-  on your machine.
+- You can build images inside a
+  ([CVM](../admin/workspace-management/cvms.md)-enabled) Coder workspace with
+  Docker installed, such as our
+  [base image](https://github.com/cdr/enterprise-images/tree/main/images/base).
+
+- If you're using CVM-only features during an image's build time, such as
+  [pre-loading images](https://github.com/nestybox/sysbox/blob/master/docs/quickstart/images.md#building-a-system-container-that-includes-inner-container-images--v012-)
+  in workspaces, you will need to install the
+  [sysbox runtime](https://github.com/nestybox/sysbox) on your local machine and
+  build images there. This is usually not necessary, even if your image installs
+  and enables Docker.
 
 ## Example: Installing an IntelliJ IDE
 
