Mount overlay workspace into Dev Container via volume (#3524)

* Add volume for overlay
to avoid rebuilding it from scratch
whenever the dev container is rebuilt
this saves startup time locally when fiddling with the configs

* Append devcontainerId to volume name
to avoid conflicts with other devcontainers
note that devcontainerId is stable across rebuilds
- https://containers.dev/implementors/json_reference/#variables-in-devcontainerjson

* Call updateContentCommand from onCreateCommand
to deduplicate scripts and keep setup DRY
given the addition of a mounted overlay volume
which could include a prebuilt colcon workspace
well before the dev container is created/rebuilt

* Comment out colcon clean from setup
to avoid unintentional removal of built packages
from the persistent overlay workspace volume.
Users can uncomment the line locally
or simply remove the overlay workspace volume
if they want to rebuild packages from scratch.

* Format json

.devcontainer/devcontainer.json

@@ -1,11 +1,11 @@
 {
     "name": "Nav2",
-	"build": {
-		"dockerfile": "../Dockerfile",
+    "build": {
+        "dockerfile": "../Dockerfile",
         "context": "..",
         "target": "dever",
         "cacheFrom": "ghcr.io/ros-planning/navigation2:main"
-	},
+    },
     "runArgs": [
         "--privileged",
         "--network=host"
@@ -20,12 +20,17 @@
         "CCACHE_DIR": "/tmp/.ccache"
     },
     "mounts": [
-		{
-			"source": "ccache",
-			"target": "/tmp/.ccache",
-			"type": "volume"
-		}
-	],
+        {
+            "source": "ccache-${devcontainerId}",
+            "target": "/tmp/.ccache",
+            "type": "volume"
+        },
+        {
+            "source": "overlay-${devcontainerId}",
+            "target": "/opt/overlay_ws",
+            "type": "volume"
+        }
+    ],
     "features": {
         // "ghcr.io/devcontainers/features/desktop-lite:1": {},
         "ghcr.io/devcontainers/features/github-cli:1": {}

.devcontainer/on-create-command.sh

@@ -7,12 +7,6 @@ set -eo pipefail
 # set -x
 # env
 
-cd $OVERLAY_WS
-
 git config --global --add safe.directory "*"
-colcon cache lock
 
-. $UNDERLAY_WS/install/setup.sh
-colcon build \
-    --symlink-install \
-    --mixin $OVERLAY_MIXINS
+.devcontainer/update-content-command.sh

.devcontainer/update-content-command.sh

@@ -49,9 +49,9 @@ then
 fi
 echo BUILD_PACKAGES: $BUILD_PACKAGES
 
-colcon clean packages --yes \
-    --packages-select ${BUILD_PACKAGES} \
-    --base-select install
+# colcon clean packages --yes \
+#     --packages-select ${BUILD_PACKAGES} \
+#     --base-select install
 
 . $UNDERLAY_WS/install/setup.sh
 colcon build \