docs: add bind mount docs for docker from docker (#343)

Co-authored-by: ptn <ptn@cct-technology.com>

1 files changed, 37 insertions, 8 deletions

diff --git a/src/docker-from-docker/NOTES.md b/src/docker-from-docker/NOTES.md
index 6729044..fe658bc 100644
--- a/src/docker-from-docker/NOTES.md
+++ b/src/docker-from-docker/NOTES.md
@@ -1,25 +1,54 @@
 ## Limitations
 
-* As the name implies, the Feature is expected to work when the host is running Docker (or the OSS Moby container engine it is built on). It may be possible to get running in other container engines, but it has not been tested with them.
-* The host and the container must be running on the same chip architecture. You will not be able to use it with an emulated x86 image with Docker Desktop on an Apple Silicon Mac, for example.
-* This approach does not currently enable bind mounting the workspace folder by default, and cannot support folders outside of the workspace folder. Consider whether the [Docker-in-Docker Feature](../docker-in-docker) would better meet your needs given it does not have this limitation.
+- As the name implies, the Feature is expected to work when the host is running Docker (or the OSS Moby container engine it is built on). It may be possible to get running in other container engines, but it has not been tested with them.
+- The host and the container must be running on the same chip architecture. You will not be able to use it with an emulated x86 image with Docker Desktop on an Apple Silicon Mac, for example.
+- This approach does not currently enable bind mounting the workspace folder by default, and cannot support folders outside of the workspace folder. Consider whether the [Docker-in-Docker Feature](../docker-in-docker) would better meet your needs given it does not have this limitation.
 
 ## Supporting bind mounts from the workspace folder
 
-A common question that comes up is how you can use `bind` mounts from the Docker CLI from within the a dev container using this Feature (e.g. via `-v`). If you cannot use the [Docker-in-Docker Feature](../docker-in-docker), the only way to work around this is to use the **host**'s folder paths instead of the container's paths.
+A common question that comes up is how you can use `bind` mounts from the Docker CLI from within the a dev container using this Feature (e.g. via `-v`). If you cannot use the [Docker-in-Docker Feature](../docker-in-docker), the only way to work around this is to use the **host**'s folder paths instead of the container's paths. There are 2 ways to do this
 
-A simple way to do this is to put `${localWorkspaceFolder}` in an environment variable that you then use when doing bind mounts inside the container.
+### 1. Use the `${localWorkspaceFolder}` as environment variable in your code
 
-Add the following to `devcontainer.json`:
+1. Add the following to `devcontainer.json`:
 
 ```json
 "remoteEnv": { "LOCAL_WORKSPACE_FOLDER": "${localWorkspaceFolder}" }
 ```
 
-Then reference the env var when running Docker commands from the terminal inside the container.
+2. Usage with Docker commands
 
 ```bash
 docker run -it --rm -v ${LOCAL_WORKSPACE_FOLDER}:/workspace debian bash
 ```
 
-> **Note:** There is no `${localWorkspaceFolder}` when using the **Clone Repository in Container Volume** command in the VS Code Dev Containers extension ([info](https://github.com/microsoft/vscode-remote-release/issues/6160#issuecomment-1014701007)).
\ No newline at end of file
+3. Usage with Docker-compose
+
+```yaml
+version: "3.9"
+
+services:
+  debian:
+    image: debian
+    volumes:
+      - ${LOCAL_WORKSPACE_FOLDER:-./}:/workspace
+```
+
+- The defaults value `./` is added so that the `docker-compose.yaml` file can work when it is run outside of the container
+
+### Change the workspace to `${localWorkspaceFolder}`
+
+- This is useful if we don't want to edit the `docker-compose.yaml` file
+
+1. Add the following to `devcontainer.json`
+
+```json
+"workspaceFolder": "${localWorkspaceFolder}",
+"workspaceMount": "source=${localWorkspaceFolder},target=${localWorkspaceFolder},type=bind"
+```
+
+2. Rebuild the container.
+3. When the container first started with this settings, select the Workspace with the absolute path to the working directory inside the container
+4. Docker commands with bind mount should work as they did outside of the devcontainer
+
+> **Note:** There is no `${localWorkspaceFolder}` when using the **Clone Repository in Container Volume** command in the VS Code Dev Containers extension ([info](https://github.com/microsoft/vscode-remote-release/issues/6160#issuecomment-1014701007)).