fix(dev): update environment for website development

The `nodejs` and `npm` packages installed from the stock Ubuntu Focal repository are outdated for the
current website dependencies. This commit installs an updated Node.js (current LTS version) directly
from the NodeSource repository instead.

The `yarn` package in the stock Ubuntu Focal repository is not the Yarn package manager.
The package is actually an alias package for the unrelated `cmdtest` package
(ref: <https://packages.ubuntu.com/focal/yarn>). This commit installs (enables) the correct `yarn`
command using the same updated Node.js installation above.

Website development requires two tools not currently installed in the environment:

* Hugo (static site generator).
* htmltest (HTML checker for the website content).

This commit also installs these tools directly from their GitHub release assets. In the case of
Hugo, the installed version matches the version currently specified in 'netlify.toml'.

In addition to all the above, this commit also improves the Ubuntu bootstrap script:

* Switches `apt` for `apt-get` as recommended for non-interactive scripts.
* Add missing temporary directory cleaning commands.

After all the above changes, the following now works properly in `website/` in the environment:

    make serve
    make local-preview-build

Signed-off-by: Hugo Hromic <[email protected]>

scripts/environment/bootstrap-ubuntu-20.04.sh

@@ -13,17 +13,17 @@ export ACCEPT_EULA=Y
 
 echo 'Acquire::Retries "5";' > /etc/apt/apt.conf.d/80-retries
 
-apt update --yes
+apt-get update --yes
 
-apt install --yes \
+apt-get install --yes \
   software-properties-common \
   apt-utils \
   apt-transport-https
 
-apt upgrade --yes
+apt-get upgrade --yes
 
 # Deps
-apt install --yes --no-install-recommends \
+apt-get install --yes --no-install-recommends \
     awscli \
     build-essential \
     ca-certificates \
@@ -40,8 +40,6 @@ apt install --yes --no-install-recommends \
     libssl-dev \
     llvm \
     locales \
-    nodejs \
-    npm \
     pkg-config \
     python3-pip \
     rename \
@@ -50,8 +48,7 @@ apt install --yes --no-install-recommends \
     shellcheck \
     sudo \
     unzip \
-    wget \
-    yarn
+    wget
 
 # Cue
 TEMP=$(mktemp -d)
@@ -62,6 +59,7 @@ tar \
     -xvf "${TEMP}/cue_v0.5.0_linux_amd64.tar.gz" \
     -C "${TEMP}"
 cp "${TEMP}/cue" /usr/bin/cue
+rm -rf "$TEMP"
 
 # Grease
 # Grease is used for the `make release-github` task.
@@ -73,6 +71,7 @@ tar \
     -xvf "${TEMP}/grease-1.0.1-linux-amd64.tar.gz" \
     -C "${TEMP}"
 cp "${TEMP}/grease/bin/grease" /usr/bin/grease
+rm -rf "$TEMP"
 
 # Locales
 locale-gen en_US.UTF-8
@@ -102,8 +101,8 @@ if ! [ -x "$(command -v docker)" ]; then
         xenial \
         stable"
     # Install those new things
-    apt update --yes
-    apt install --yes docker-ce docker-ce-cli containerd.io
+    apt-get update --yes
+    apt-get install --yes docker-ce docker-ce-cli containerd.io
 
     # ubuntu user doesn't exist in scripts/environment/Dockerfile which runs this
     usermod --append --groups docker ubuntu || true
@@ -117,8 +116,49 @@ fi
 
 bash scripts/environment/install-protoc.sh
 
+# Node.js, npm and yarn.
+# Note: the current LTS for the Node.js toolchain is 18.x
+if ! [ -x "$(command -v node)" ]; then
+    curl -fsSL https://deb.nodesource.com/gpgkey/nodesource-repo.gpg.key | apt-key add -
+    add-apt-repository \
+        "deb [arch=$(dpkg --print-architecture)] https://deb.nodesource.com/node_18.x \
+        nodistro \
+        main"
+    # Install those new things
+    apt-get update --yes
+    apt-get install --yes nodejs
+
+    # enable corepack (enables the yarn and pnpm package managers)
+    # ref: https://nodejs.org/docs/latest-v18.x/api/corepack.html
+    corepack enable
+fi
+
+# Hugo (static site generator).
+# Hugo is used to build the website content.
+# Note: the installed version should match the version specified in 'netlify.toml'
+TEMP=$(mktemp -d)
+curl \
+    -L https://github.com/gohugoio/hugo/releases/download/v0.84.0/hugo_extended_0.84.0_Linux-64bit.tar.gz \
+    -o "${TEMP}/hugo_extended_0.84.0_Linux-64bit.tar.gz"
+tar \
+    -xvf "${TEMP}/hugo_extended_0.84.0_Linux-64bit.tar.gz" \
+    -C "${TEMP}"
+cp "${TEMP}/hugo" /usr/bin/hugo
+rm -rf "$TEMP"
+
+# htmltest (HTML checker for the website content)
+TEMP=$(mktemp -d)
+curl \
+    -L https://github.com/wjdp/htmltest/releases/download/v0.17.0/htmltest_0.17.0_linux_amd64.tar.gz \
+    -o "${TEMP}/htmltest_0.17.0_linux_amd64.tar.gz"
+tar \
+    -xvf "${TEMP}/htmltest_0.17.0_linux_amd64.tar.gz" \
+    -C "${TEMP}"
+cp "${TEMP}/htmltest" /usr/bin/htmltest
+rm -rf "$TEMP"
+
 # Apt cleanup
-apt clean
+apt-get clean
 
 # Set up the default "deny all warnings" build flags
 CARGO_OVERRIDE_DIR="${HOME}/.cargo"
@@ -146,6 +186,7 @@ if [ -z "${DISABLE_MOLD:-""}" ] ; then
         -C "${TEMP}"
     cp "${TEMP}/${MOLD_TARGET}/bin/mold" /usr/bin/mold
     cp "${TEMP}/${MOLD_TARGET}/lib/mold/mold-wrapper.so" /usr/bin/mold-wrapper.so
+    rm -rf "$TEMP"
 
     # Create our rustc wrapper script that we'll use to actually invoke `rustc` such that `mold` will wrap it and intercept
     # anything linking calls to use `mold` instead of `ld`, etc.