Fix permission and make ninja build cache work

This patch fixes the permission, so that the node distribution
from the local build as well as node-core-utils are installed
as the developer, not as root, which is less likely to incur
permission issues.

This also uses git-mtime-restore to match the mtime of the
project files with the timestamp from git, so that when a
devcontainer is mounted on the working directory, ninja
can easily pick up the cache already in the container and
enable fast incremental builds. Update the README accordingly
to provide information about how to mount the project to pick
up the build cache.

Author: joyeecheung

Dockerfile

@@ -18,13 +18,16 @@ RUN echo 'Defaults    env_keep += "DEBIAN_FRONTEND"' >> /etc/sudoers.d/env_keep
 ENV DEBIAN_FRONTEND=1
 ENV PATH=/usr/lib/ccache:$PATH
 
-COPY --chown=root:developer ./scripts/ /home/developer/scripts/
+# Copy scripts and make them executable by both root and developer
+COPY --chown=root:developer --chmod=0755 ./scripts/ /home/developer/scripts/
 RUN /home/developer/scripts/install.sh
-RUN /home/developer/scripts/mkdir.sh
 RUN /home/developer/scripts/ccache.sh
+
+USER developer
 RUN /home/developer/scripts/clone.sh
 RUN /home/developer/scripts/build.sh
-RUN make install -C /home/developer/nodejs/node
-RUN /home/developer/scripts/ncu.sh
 
+ENV PATH=/home/developer/.local/bin:$PATH
 WORKDIR /home/developer/nodejs/node
+RUN /home/developer/scripts/install-node.sh
+RUN /home/developer/scripts/ncu.sh

README.md

@@ -8,26 +8,53 @@
 
 To run locally on your machine, you'll want to install [Docker Desktop](https://www.docker.com/products/docker-desktop/) and start it up.
 
-Once you've got Docker Destop running, you can run the following command to pull and start the image:
+It's recommended to use Visual Studio Code with the [Dev Containers extension](https://marketplace.visualstudio.com/items?itemName=ms-vscode-remote.remote-containers)
+installed, but you can also run the container directly with Docker CLI or the [Dev Container CLI](https://github.com/devcontainers/cli), or attach any editor that supports the concept of [`devcontainers`](https://containers.dev/) to this container.
+
+Once you've got Docker Desktop running, you can run the following command to pull and start the image:
 
 ```sh
 docker pull nodejs/devcontainer:nightly
 docker run -it nodejs/devcontainer:nightly /bin/bash
 ```
 
-Once you've run those commands, you'll be in a shell inside the running container. If you need to escape, type `exit`. You should be good to jump to [Working in the Container](#working-in-the-container).
+To use it as a devcontainer, create a `.devcontainer/devcontainer.json` file in the project with the following content:
+
+```json
+{
+  "name": "Node.js Dev Container",
+  "image": "nodejs/devcontainer:nightly",
+  "workspaceMount": "source=${localWorkspaceFolder},target=/home/developer/nodejs/node,type=bind,consistency=cached",
+  "workspaceFolder": "/home/developer/nodejs/node",
+  "remoteUser": "developer",
+  "mounts": [
+    "source=build-cache,target=/home/developer/nodejs/node/out,type=volume"
+  ],
+  "postCreateCommand": "git restore-mtime"
+}
+```
+
+For example, to use it with Visual Studio Code, use the "Dev Containers: Reopen in Container" command from the Command Palette (`Ctrl+Shift+P` or `Cmd+Shift+P`). After the container is built and started, you should be inside the container with the project mounted in the working directory, while the build cache volume mounted at `out/` to speed up builds.
 
 ### Working in the Container
 
-- The project is located at `/home/developer/nodejs/node`.
-  - Once this directory is your active directory, you should be good to go.
-  - If you want to build the project in the container, run with ninja (rather than just make):
-    - `/home/developer/nodejs/node/configure --ninja && make -C /home/developer/nodejs/node`
-- You should be able to attach any editor that supports the concept of [`devcontainers`](https://containers.dev/) to this 
+- The project is located at `/home/developer/nodejs/node`. After the container is started, you should be automatically placed in this directory.
+- If you want to build the project in the container, run with `ninja` (rather than just `make`):
+  - To build the release build, run `ninja -C out/Release`
+  - The container comes with a release build that can be picked up by `ninja`. As long as your mounted local checkout is not too far behind the checkout in the container, incremental builds should be fast.
+  - If you notice that the build is not picking up your changes after checking out a different branch, run `git restore-mtime` in the container to sync the mtimes of the files in your checkout with the git commit timestamps.
+  - You can also set up a git hook to sync the mtime automatically on checkout to keep the build cache effective. From the container, run:
+
+    ```bash
+    mkdir -p /home/developer/nodejs/node/.git/hooks
+    cp /home/developer/scripts/post-checkout /home/developer/nodejs/node/.git/hooks/post-checkout
+    ```
+
+    Note that if you install this git hook to your mounted project, and you still wish to run `git checkout` from you local system, you will need to install [`git-restore-mtime`](https://github.com/MestreLion/git-tools) on your local system as well.
 
 ### Personal Configuration
 
-Assuming you've already got the Docker container running:
+Do this from your local system, not in the container. The `git` configuration will be used in the container since the project is mounted from your local system.
 
 - Set the git `origin` to your own fork rather than `nodejs/node`
   - Example, where `USERNAME` is your GitHub username: `$ git remote set-url origin https://github.com/USERNAME/node.git`

scripts/clone.sh

@@ -2,8 +2,9 @@
 
 set -e # Exit with nonzero exit code if anything fails 
 
+mkdir -p /home/developer/nodejs
 cd /home/developer/nodejs
 git clone https://github.com/nodejs/node.git --single-branch --branch main --depth 1
 cd /home/developer/nodejs/node
 git remote add upstream https://github.com/nodejs/node.git
-git fetch upstream
+git restore-mtime  # Restore file modification times to commit times for build cache to match.

scripts/install-node.sh

@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+
+set -e # Exit with nonzero exit code if anything fails
+
+make install PREFIX=/home/developer/.local -C /home/developer/nodejs/node
+echo '' >> /home/developer/.bashrc
+echo 'export PATH=/home/developer/.local/bin:$PATH' >> /home/developer/.bashrc

scripts/install.sh

@@ -20,7 +20,8 @@ package_list="
   pkg-config \
   locales \
   gpg \
-  wget"
+  wget \
+  git-restore-mtime"
 
 # Install Packages
 apt-get update

scripts/mkdir.sh

@@ -0,0 +1,2 @@
+#!/bin/bash
+git-restore-mtime