feat: Improve WASM deployment by preventing caching, pinning Emscripten SDK, and enabling minimal downtime updates.

Author: vlvovch

deploy/wasm/Caddyfile

@@ -8,6 +8,10 @@
     # Serve QtThermalFIST.html as index
     try_files {path} /QtThermalFIST.html
 
+    # Prevent browser from caching stale WASM builds
+    @wasm_assets path *.js *.wasm
+    header @wasm_assets Cache-Control "no-cache, must-revalidate"
+
     # Enable compression
     encode gzip
 }

deploy/wasm/Dockerfile.base

@@ -22,9 +22,9 @@ RUN apt-get update && apt-get install -y \
 # Install aqtinstall for downloading Qt
 RUN pip3 install aqtinstall
 
-# Install Emscripten 4.0.7
+# Install Emscripten 4.0.7 (pin emsdk to the 4.0.7 release tag for reproducibility)
 WORKDIR /opt
-RUN git clone https://github.com/emscripten-core/emsdk.git
+RUN git clone --depth 1 -b 4.0.7 https://github.com/emscripten-core/emsdk.git
 WORKDIR /opt/emsdk
 RUN ./emsdk install 4.0.7 && \
     ./emsdk activate 4.0.7

deploy/wasm/update_docker.sh

@@ -23,8 +23,9 @@ if ! docker image inspect thermal-fist-wasm-base >/dev/null 2>&1; then
 fi
 
 echo "=== Building Thermal-FIST WASM ==="
-docker compose down
+# Build new image while old container keeps serving traffic
 docker compose build --build-arg CACHEBUST=$(date +%s)
+# Recreate container with new image (only seconds of downtime)
 docker compose up -d
 echo ""
 echo "=== Done ==="