Try docker improvements

Author: alan-george-lk

.github/workflows/docker-images.yml

@@ -139,6 +139,8 @@ jobs:
           set -euxo pipefail
           docker buildx build \
             --platform linux/amd64 \
+            --cache-from type=registry,ref="${{ needs.detect-changes.outputs.base_image }}:buildcache-base-amd64" \
+            --cache-to type=registry,ref="${{ needs.detect-changes.outputs.base_image }}:buildcache-base-amd64",mode=max \
             --push \
             -t "${{ needs.detect-changes.outputs.base_image }}:base-${{ needs.detect-changes.outputs.base_hash }}-amd64" \
             -t "${{ needs.detect-changes.outputs.base_image }}:base-main-amd64" \
@@ -183,6 +185,8 @@ jobs:
           set -euxo pipefail
           docker buildx build \
             --platform linux/arm64 \
+            --cache-from type=registry,ref="${{ needs.detect-changes.outputs.base_image }}:buildcache-base-arm64" \
+            --cache-to type=registry,ref="${{ needs.detect-changes.outputs.base_image }}:buildcache-base-arm64",mode=max \
             --push \
             -t "${{ needs.detect-changes.outputs.base_image }}:base-${{ needs.detect-changes.outputs.base_hash }}-arm64" \
             -t "${{ needs.detect-changes.outputs.base_image }}:base-main-arm64" \
@@ -268,6 +272,8 @@ jobs:
           docker buildx build \
             --platform linux/amd64 \
             --build-arg BASE_IMAGE="${{ needs.detect-changes.outputs.base_image }}:base-${{ needs.detect-changes.outputs.base_hash }}-amd64" \
+            --cache-from type=registry,ref="${{ needs.detect-changes.outputs.sdk_image }}:buildcache-sdk-amd64" \
+            --cache-to type=registry,ref="${{ needs.detect-changes.outputs.sdk_image }}:buildcache-sdk-amd64",mode=max \
             --push \
             -t "${{ needs.detect-changes.outputs.sdk_image }}:sha-${{ github.sha }}-amd64" \
             -t "${{ needs.detect-changes.outputs.sdk_image }}:main-amd64" \
@@ -322,6 +328,8 @@ jobs:
           docker buildx build \
             --platform linux/arm64 \
             --build-arg BASE_IMAGE="${{ needs.detect-changes.outputs.base_image }}:base-${{ needs.detect-changes.outputs.base_hash }}-arm64" \
+            --cache-from type=registry,ref="${{ needs.detect-changes.outputs.sdk_image }}:buildcache-sdk-arm64" \
+            --cache-to type=registry,ref="${{ needs.detect-changes.outputs.sdk_image }}:buildcache-sdk-arm64",mode=max \
             --push \
             -t "${{ needs.detect-changes.outputs.sdk_image }}:sha-${{ github.sha }}-arm64" \
             -t "${{ needs.detect-changes.outputs.sdk_image }}:main-arm64" \

docker/Dockerfile.sdk

@@ -1,3 +1,5 @@
+# syntax=docker/dockerfile:1.7
+#
 # Copyright 2026 LiveKit
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -45,7 +47,11 @@ RUN mkdir -p /client-sdk-cpp/client-sdk-rust/.cargo \
 
 # Build and install the SDK into a fixed prefix so downstream projects can
 # consume the image as a prebuilt LiveKit SDK environment.
-RUN LLVM_VERSION="$(llvm-config --version | cut -d. -f1)" \
+RUN --mount=type=cache,target=/root/.cargo/registry,sharing=locked \
+    --mount=type=cache,target=/root/.cargo/git,sharing=locked \
+    --mount=type=cache,target=/client-sdk-cpp/client-sdk-rust/target,sharing=locked \
+    --mount=type=cache,target=/client-sdk-cpp/build-release,sharing=locked \
+    LLVM_VERSION="$(llvm-config --version | cut -d. -f1)" \
     && export LIBCLANG_PATH="/usr/lib/llvm-${LLVM_VERSION}/lib" \
     && export CXXFLAGS="-Wno-deprecated-declarations" \
     && export CFLAGS="-Wno-deprecated-declarations" \