Cache downloaded fonts

Author: camdecoster

.github/actions/setup-image-env/action.yml

@@ -21,6 +21,15 @@ runs:
       with:
         version: ${{ inputs.uv-version }}
 
+    - name: Cache apt font packages
+      uses: actions/cache@v4
+      id: apt-cache
+      with:
+        path: ~/.cache/apt-fonts
+        key: apt-fonts-${{ runner.os }}-${{ hashFiles('.github/scripts/env_image.sh') }}
+
     - name: Install Kaleido, plotly.io and required fonts
       run: .github/scripts/env_image.sh
       shell: bash
+      env:
+        APT_CACHE_HIT: ${{ steps.apt-cache.outputs.cache-hit }}

.github/scripts/env_image.sh

@@ -1,19 +1,36 @@
 #!/bin/sh
 set -e
-# install required fonts
-sudo apt-get install fonts-liberation2 fonts-open-sans fonts-noto-cjk fonts-noto-color-emoji
 
-# install additional fonts (committed in .github/fonts/)
+APT_PACKAGES="fonts-liberation2 fonts-open-sans fonts-noto-cjk fonts-noto-color-emoji fontconfig"
+APT_CACHE_DIR="${HOME}/.cache/apt-fonts"
+
+if [ "$APT_CACHE_HIT" = "true" ] && [ -d "$APT_CACHE_DIR" ]; then
+    echo "Installing font packages from cache..."
+    sudo dpkg -i "$APT_CACHE_DIR"/*.deb 2>/dev/null || sudo apt-get install -yf
+else
+    echo "Downloading and installing font packages..."
+    sudo apt-get update -q
+    sudo apt-get install -y --no-install-recommends $APT_PACKAGES
+    # Save debs for future cache
+    mkdir -p "$APT_CACHE_DIR"
+    for pkg in $APT_PACKAGES; do
+        cp /var/cache/apt/archives/${pkg}_*.deb "$APT_CACHE_DIR/" 2>/dev/null || true
+    done
+fi
+
+# Rebuild font cache
+sudo fc-cache -f
+
+# Install additional fonts (committed in .github/fonts/)
 sudo cp -r .github/fonts/ /usr/share/
-sudo apt install fontconfig
 sudo fc-cache -f
 
-# install Kaleido & Plotly
+# Install Kaleido & Plotly
 uv pip install --system kaleido==1.2 plotly==6.6.0 --no-progress
 
-# install numpy i.e. to convert arrays to typed arrays
+# Install numpy i.e. to convert arrays to typed arrays
 uv pip install --system numpy==2.4.3
 
-# verify version of python and versions of installed python packages
+# Verify version of python and versions of installed python packages
 python --version
 uv pip freeze --system