feat: make use of Nix files to set up dev env

Dockerfile

@@ -9,25 +9,54 @@ RUN useradd --uid $USER_UID --gid $USER_GID --shell /bin/bash --create-home deve
 
 # Install sudo first
 RUN apt-get update
-RUN DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends sudo
+RUN DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends ca-certificates curl git git-restore-mtime sudo xz-utils
 
 # No Sudo Prompt - thanks Electron for this
 RUN echo 'developer ALL=NOPASSWD: ALL' >> /etc/sudoers.d/developer
 RUN echo 'Defaults    env_keep += "DEBIAN_FRONTEND"' >> /etc/sudoers.d/env_keep
 
 ENV DEBIAN_FRONTEND=1
-ENV PATH=/usr/lib/ccache:$PATH
 
 # 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/ccache.sh
 
 USER developer
 RUN /home/developer/scripts/clone.sh
+
+# Installing Nix using the same script test-shared workflow uses upstream.
+# See https://github.com/nodejs/node/blob/HEAD/.github/workflows/test-shared.yml
+# See https://github.com/cachix/install-nix-action/blob/HEAD/install-nix.sh
+RUN curl -L "https://github.com/$(sed -nE 's#.*(cachix/install-nix-action)@([a-f0-9]+).*#\1/raw/\2#p' /home/developer/nodejs/node/.github/workflows/test-shared.yml)/install-nix.sh" | \
+      USER=developer \
+      INPUT_SET_AS_TRUSTED_USER=true \
+      INPUT_ENABLE_KVM=true \
+      INPUT_EXTRA_NIX_CONFIG= \
+      INPUT_INSTALL_OPTIONS= \
+      RUNNER_TEMP=$(mktemp -d) GITHUB_ENV=/dev/null GITHUB_PATH=/dev/null bash
+ENV NIX_PROFILES="/nix/var/nix/profiles/default /home/developer/.nix-profile"
+ENV NIX_SSL_CERT_FILE=/etc/ssl/certs/ca-certificates.crt
+ENV PATH="/home/developer/.local/bin:/home/developer/.nix-profile/bin:${PATH}"
+# Installing Cachix, and set it up to reuse binaries build by the CI.
+RUN nix-env -iA cachix -f https://cachix.org/api/v1/install
+RUN USER=developer cachix use nodejs
+
+# Installing direnv
+RUN nix profile add nixpkgs#nix-direnv nixpkgs#direnv -I nixpkgs=/home/developer/nodejs/node/tools/nix/pkgs.nix
+RUN mkdir -p /home/developer/.config/direnv && \
+    echo 'source $HOME/.nix-profile/share/nix-direnv/direnvrc' > /home/developer/.config/direnv/direnvrc
+RUN echo 'eval "$(direnv hook bash)"' >> /home/developer/.bashrc
+
+# Setting up direnv for the local clone, see envrc/README.md for more info
+COPY --chown=root:developer --chmod=0644 ./envrc/ /home/developer/envrc/
+ARG IMAGE_VARIANT=static-libs
+RUN cp "/home/developer/envrc/${IMAGE_VARIANT}.envrc" /home/developer/nodejs/node/.envrc
+RUN direnv allow /home/developer/nodejs/node
+
 RUN /home/developer/scripts/build.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
+
+# direnv will automatically load the nix environment when entering the directory
+ENTRYPOINT ["/bin/bash", "-l"]

README.md

@@ -71,7 +71,7 @@ Do this from your local system, not in the container. The `git` configuration wi
 Some useful commands:
 - `docker build .` - build the current Dockerfile
 - `docker image ls` - list the images and IDs
-- `docker run -it <image id> /bin/bash` - run a container and shell into it
+- `docker run -it <image id>` - run a container and shell into it
 - `docker tag <image id> devcontainer:nightly` - run to tag an image as `nightly`
 
 

envrc/README.md

@@ -0,0 +1,26 @@
+# Image variants using Nix and direnv
+
+`.envrc` files are consumed by [nix-direnv][], and will install software and
+environment variables defined in the [`shell.nix`][] in the nodejs/node repository.
+
+To add an image variant, add a new file starting with `use nix` with the flags such as:
+
+- [`--impure`][]: to make sure user can still access non-Nix software.
+- [`-I nixpkgs=/home/developer/nodejs/node/tools/nix/pkgs.nix`][`-I`]:
+  that defines which version of the [NixOS/nixpkgs][] repository it should load.
+- [`--arg <key> <nix-value>`][`--arg`]: Override the default values defines in the
+  [`shell.nix`][] with some custom value.
+- [`--argstr <key> <string-value>`][`--argstr`]: Useful to avoid the double quoting,
+  e.g. instead of `--arg icu '"small"'`, it is equivalent to pass `--argstr icu small`.
+
+It is possible to add custom environment variables, or to override Nix-defined ones by
+adding `export NAME_OF_THE_VAR=value` lines at the end of the file, however it is
+preferred to keep all environment variable definitions in one place.
+
+[nix-direnv]: https://github.com/nix-community/nix-direnv
+[`shell.nix`]: https://github.com/nodejs/node/blob/HEAD/shell.nix
+[NixOS/nixpkgs]: https://github.com/NixOS/nixpkgs
+[`--impure`]: https://nix.dev/manual/nix/2.33/command-ref/nix-shell.html#opt-impure
+[`-I`]: https://nix.dev/manual/nix/2.33/command-ref/nix-shell.html#opt-I
+[`--arg`]: https://nix.dev/manual/nix/2.33/command-ref/nix-shell.html#opt-arg
+[`--argstr`]: https://nix.dev/manual/nix/2.33/command-ref/nix-shell.html#opt-argstr

envrc/shared-libs.envrc

@@ -0,0 +1 @@
+use nix --impure -I nixpkgs=/home/developer/nodejs/node/tools/nix/pkgs.nix

envrc/static-libs.envrc

@@ -0,0 +1,3 @@
+use nix --impure -I nixpkgs=/home/developer/nodejs/node/tools/nix/pkgs.nix \
+        --arg sharedLibDeps '{}' \
+        --argstr icu full

scripts/build.sh

@@ -1,5 +1,10 @@
 #!/usr/bin/env bash
 
-set -e # Exit with nonzero exit code if anything fails 
+set -xe
 
-/home/developer/nodejs/node/configure --ninja && make -C /home/developer/nodejs/node
+cd /home/developer/nodejs/node
+eval "$(direnv export bash)"
+
+# Build tools and env variables (including e.g. BUILD_WITH=ninja) are
+# defined in https://github.com/nodejs/node/blob/HEAD/shell.nix
+make -C /home/developer/nodejs/node build-ci

scripts/clone.sh

@@ -1,10 +1,11 @@
 #!/usr/bin/env bash
 
-set -e # Exit with nonzero exit code if anything fails 
+set -xe
 
 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 restore-mtime  # Restore file modification times to commit times for build cache to match.
+git clone https://github.com/nodejs/node.git --depth 1 /home/developer/nodejs/node
+(
+  cd /home/developer/nodejs/node
+  git remote add upstream https://github.com/nodejs/node.git
+  git restore-mtime  # Restore file modification times to commit times for build cache to match.
+)

scripts/install-node.sh

@@ -1,7 +1,13 @@
 #!/usr/bin/env bash
 
-set -e # Exit with nonzero exit code if anything fails
+set -xe
+
+cd /home/developer/nodejs/node
+eval "$(direnv export bash)"
 
 make install PREFIX=/home/developer/.local -C /home/developer/nodejs/node
-echo '' >> /home/developer/.bashrc
-echo 'export PATH=/home/developer/.local/bin:$PATH' >> /home/developer/.bashrc
+{
+    echo ''
+    # Expose the PATH generated by Nix + the recently built `node` installation
+    echo 'export PATH=/home/developer/.local/bin:$PATH'
+} >> /home/developer/.bashrc

scripts/ncu.sh

@@ -1,8 +1,9 @@
 #!/usr/bin/env bash
 
-set -e # Exit with nonzero exit code if anything fails 
+set -xe
 
-npm install -g @node-core/utils
+cd /home/developer/nodejs/node
+eval "$(direnv export bash)"
 
 ncu-config set upstream upstream
 ncu-config set branch main