Cleanup, use multi-stage Dockerfile to minimize size

.devcontainer/cache/before-cache.sh

@@ -1,11 +1,11 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
-# This file establishes a basline for the reposuitory before any steps in the "prepare.sh"
+# This file establishes a basline for the repository before any steps in the "prepare.sh"
 # are run. Its just a find command that filters out a few things we don't need to watch.
 
 set -e
 
-SCRIPT_PATH="$(cd "$(dirname $0)" && pwd)"
+SCRIPT_PATH="$(cd $(dirname "${BASH_SOURCE[0]}") && pwd)"
 SOURCE_FOLDER="${1:-"."}"
 
 cd "${SOURCE_FOLDER}"

.devcontainer/cache/build-cache-image.sh

@@ -6,7 +6,7 @@
 
 set -e
 
-SCRIPT_PATH="$(cd "$(dirname $0)" && pwd)"
+SCRIPT_PATH="$(cd $(dirname "${BASH_SOURCE[0]}") && pwd)"
 CONTAINER_IMAGE_REPOSITORY="$1"
 BRANCH="${2:-"main"}"
 

.devcontainer/cache/cache-diff.sh

@@ -1,12 +1,11 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # This file is used to archive off a copy of any differences in the source tree into another location
-# in the image. Once the codespace is up, this will be restored into its proper location (which is
-# quick and happens parallel to other startup activities)
+# in the image. Once the codespace / container is up, this will be restored into its proper location.
 
 set -e
 
-SCRIPT_PATH="$(cd "$(dirname $0)" && pwd)"
+SCRIPT_PATH="$(cd $(dirname "${BASH_SOURCE[0]}") && pwd)"
 SOURCE_FOLDER="${1:-"."}"
 CACHE_FOLDER="${2:-"/usr/local/etc/devcontainer-cache"}"
 

.devcontainer/cache/cache.Dockerfile

@@ -1,7 +1,8 @@
 # This dockerfile is used to build up from a base image to create an image with cached results of running "prepare.sh".
 # Other image contents: https://github.com/microsoft/vscode-dev-containers/blob/master/repository-containers/images/github.com/microsoft/vscode/.devcontainer/base.Dockerfile
-FROM mcr.microsoft.com/vscode/devcontainers/repos/microsoft/vscode:dev
 
+# First stage generates the cache tar
+FROM mcr.microsoft.com/vscode/devcontainers/repos/microsoft/vscode:dev as cache
 ARG USERNAME=node
 COPY --chown=${USERNAME}:${USERNAME} . /repo-source-tmp/
 RUN mkdir /usr/local/etc/devcontainer-cache \
@@ -10,5 +11,11 @@ RUN mkdir /usr/local/etc/devcontainer-cache \
 		cd /repo-source-tmp \
 		&& .devcontainer/cache/before-cache.sh \
 		&& .devcontainer/prepare.sh \
-		&& .devcontainer/cache/cache-diff.sh" \
-	&& rm -rf /repo-source-tmp
+		&& .devcontainer/cache/cache-diff.sh"
+
+# Second stage is the acual output that includes only the tar - restore-diff.sh is then fired on postCreateCommand to expand it
+FROM mcr.microsoft.com/vscode/devcontainers/repos/microsoft/vscode:dev as dev-container
+ARG USERNAME=node
+ARG CACHE_FOLDER="/usr/local/etc/devcontainer-cache"
+RUN mkdir -p "${CACHE_FOLDER}" && chown "${USERNAME}:${USERNAME}" "${CACHE_FOLDER}"
+COPY --from=cache ${CACHE_FOLDER}/cache.tar ${CACHE_FOLDER}/

.devcontainer/cache/restore-diff.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # This file restores the results of the "prepare.sh" into their proper locations
 # once the container has been created. It runs as a postCreateCommand which

.devcontainer/prepare.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # This file contains the steps that should be run when creating the intermediary image that contains
 # contents for that should be in the image by default. It will be used to build up from the base image