CI/build: reuse a cache when dependencies did not change

Author: dannywillems

.github/actions/setup-rust/action.yml

@@ -1,5 +1,5 @@
 name: 'Setup Rust Toolchain'
-description: 'Setup Rust toolchain with components and caching'
+description: 'Setup Rust toolchain with components and caching based on Cargo.lock'
 inputs:
   toolchain:
     description: 'Rust toolchain version'
@@ -26,10 +26,32 @@ runs:
         toolchain: ${{ inputs.toolchain }}
         components: ${{ inputs.components }}
 
-    - name: Setup Rust Cache
+    - name: Generate Cargo.lock hash
+      if: inputs.enable-cache == 'true'
+      id: cargo-lock-hash
+      shell: bash
+      run: |
+        if [ -f "Cargo.lock" ]; then
+          echo "hash=${{ hashFiles('**/Cargo.lock') }}" >> $GITHUB_OUTPUT
+        else
+          echo "hash=no-cargo-lock" >> $GITHUB_OUTPUT
+        fi
+
+    - name: Setup Rust Cache (Cargo.lock based)
       if: inputs.enable-cache == 'true'
       uses: Swatinem/rust-cache@v2
       with:
-        prefix-key: ${{ inputs.cache-prefix }}-${{ inputs.toolchain }}
-        shared-key: shared-${{ inputs.toolchain }}
-        save-if: ${{ github.ref == 'refs/heads/develop' || github.ref == 'refs/heads/main' }}
+        # Use Cargo.lock hash as the primary cache key
+        key: ${{ inputs.cache-prefix }}-${{ inputs.toolchain }}-${{ steps.cargo-lock-hash.outputs.hash }}
+        # Shared cache key for fallback (without Cargo.lock hash)
+        shared-key: ${{ inputs.cache-prefix }}-${{ inputs.toolchain }}-shared
+        # Save cache on develop and main branches
+        save-if: ${{ github.ref == 'refs/heads/develop' || github.ref == 'refs/heads/main' }}
+        # Cache these directories for faster builds
+        cache-directories: |
+          ~/.cargo/registry/index
+          ~/.cargo/registry/cache
+          ~/.cargo/git
+          target/
+        # Don't cache the entire target directory for PRs to save space
+        cache-targets: ${{ github.event_name == 'pull_request' && 'false' || 'true' }}

.github/actions/setup-wasm/action.yml

@@ -1,5 +1,5 @@
 name: 'Setup WebAssembly Build Environment'
-description: 'Setup Rust with WASM target and wasm-bindgen-cli'
+description: 'Setup Rust with WASM target and wasm-bindgen-cli with Cargo.lock based caching'
 inputs:
   toolchain:
     description: 'Rust toolchain version'
@@ -22,7 +22,30 @@ runs:
       run: |
         make setup-wasm
 
-    - name: Setup Rust Cache
+    - name: Generate Cargo.lock hash
+      id: cargo-lock-hash
+      shell: bash
+      run: |
+        if [ -f "Cargo.lock" ]; then
+          echo "hash=${{ hashFiles('**/Cargo.lock') }}" >> $GITHUB_OUTPUT
+        else
+          echo "hash=no-cargo-lock" >> $GITHUB_OUTPUT
+        fi
+
+    - name: Setup Rust Cache (Cargo.lock based)
       uses: Swatinem/rust-cache@v2
       with:
-        prefix-key: ${{ inputs.cache-prefix }}
+        # Use Cargo.lock hash as the primary cache key
+        key: ${{ inputs.cache-prefix }}-${{ inputs.toolchain }}-${{ steps.cargo-lock-hash.outputs.hash }}
+        # Shared cache key for fallback
+        shared-key: ${{ inputs.cache-prefix }}-${{ inputs.toolchain }}-shared
+        # Save cache on develop and main branches
+        save-if: ${{ github.ref == 'refs/heads/develop' || github.ref == 'refs/heads/main' }}
+        # Cache these directories for WASM builds
+        cache-directories: |
+          ~/.cargo/registry/index
+          ~/.cargo/registry/cache
+          ~/.cargo/git
+          target/
+        # Don't cache the entire target directory for PRs to save space
+        cache-targets: ${{ github.event_name == 'pull_request' && 'false' || 'true' }}

.github/workflows/build-reusable.yaml

@@ -50,7 +50,7 @@ jobs:
         uses: ./.github/actions/setup-rust
         with:
           toolchain: 1.84
-          cache-prefix: build-${{ inputs.os }}-${{ inputs.cache-prefix }}v0
+          cache-prefix: build-${{ inputs.os }}-${{ inputs.cache-prefix }}v1
 
       - name: Release build
         run: make build-release
@@ -91,7 +91,7 @@ jobs:
         uses: ./.github/actions/setup-rust
         with:
           toolchain: 1.84
-          cache-prefix: build-tests-${{ inputs.os }}-${{ inputs.cache-prefix }}v0
+          cache-prefix: build-tests-${{ inputs.os }}-${{ inputs.cache-prefix }}v1
 
       - name: Build tests
         run: make build-tests
@@ -115,7 +115,7 @@ jobs:
         uses: ./.github/actions/setup-rust
         with:
           toolchain: 1.84
-          cache-prefix: build-tests-webrtc-${{ inputs.os }}-${{ inputs.cache-prefix }}v0
+          cache-prefix: build-tests-webrtc-${{ inputs.os }}-${{ inputs.cache-prefix }}v1
 
       - name: Build tests
         run: make build-tests-webrtc
@@ -139,7 +139,7 @@ jobs:
       - name: Setup WebAssembly environment
         uses: ./.github/actions/setup-wasm
         with:
-          cache-prefix: wasm-${{ inputs.os }}-${{ inputs.cache-prefix }}v0
+          cache-prefix: wasm-${{ inputs.os }}-${{ inputs.cache-prefix }}v1
 
       - name: Release build
         run: make build-wasm