Two small GHA patches

.github/actions/bootc-ubuntu-setup/action.yml

@@ -1,5 +1,10 @@
 name: 'Bootc Ubuntu Setup'
 description: 'Default host setup'
+inputs:
+  libvirt:
+    description: 'Install libvirt and virtualization stack'
+    required: false
+    default: 'false'
 runs:
   using: 'composite'
   steps:
@@ -45,3 +50,20 @@ runs:
       id: set_arch
       shell: bash
       run: echo "ARCH=$(arch)" >> $GITHUB_ENV
+    # We often use Rust, so set up opinionated default caching
+    - name: Setup Rust cache
+      uses: Swatinem/rust-cache@v2
+      with:
+        cache-all-crates: true
+        # Only generate caches on push to git main
+        save-if: ${{ github.ref == 'refs/heads/main' }}
+        # Suppress actually using the cache for builds running from
+        # git main so that we avoid incremental compilation bugs
+        lookup-only: ${{ github.ref == 'refs/heads/main' }}
+    # Install libvirt stack if requested
+    - name: Install libvirt and virtualization stack
+      if: ${{ inputs.libvirt == 'true' }}
+      shell: bash
+      run: |
+        set -eux
+        sudo apt install -y libkrb5-dev pkg-config libvirt-dev genisoimage qemu-utils qemu-kvm qemu-utils libvirt-daemon-system

.github/workflows/ci.yml

@@ -32,12 +32,6 @@ jobs:
       - uses: actions/checkout@v4
       - name: Bootc Ubuntu Setup
         uses: ./.github/actions/bootc-ubuntu-setup
-      - name: Setup Rust cache
-        uses: Swatinem/rust-cache@v2
-        with:
-          cache-all-crates: true
-          save-if: ${{ github.ref == 'refs/heads/main' }}
-          lookup-only: ${{ github.ref == 'refs/heads/main' }}
       - name: Validate (default)
         run: just validate
   # Build container with continuous repository enabled
@@ -47,12 +41,6 @@ jobs:
       - uses: actions/checkout@v4
       - name: Bootc Ubuntu Setup
         uses: ./.github/actions/bootc-ubuntu-setup
-      - name: Setup Rust cache
-        uses: Swatinem/rust-cache@v2
-        with:
-          cache-all-crates: true
-          save-if: ${{ github.ref == 'refs/heads/main' }}
-          lookup-only: ${{ github.ref == 'refs/heads/main' }}
       - name: Build with continuous repo enabled
         run: sudo just build --build-arg=continuous_repo=1
   # Check for security vulnerabilities and license compliance
@@ -74,12 +62,6 @@ jobs:
         uses: actions/checkout@v4
       - name: Bootc Ubuntu Setup
         uses: ./.github/actions/bootc-ubuntu-setup
-      - name: Setup Rust cache
-        uses: Swatinem/rust-cache@v2
-        with:
-          cache-all-crates: true
-          save-if: ${{ github.ref == 'refs/heads/main' }}
-          lookup-only: ${{ github.ref == 'refs/heads/main' }}
       - name: Enable fsverity for /
         run: sudo tune2fs -O verity $(findmnt -vno SOURCE /)
       - name: Install utils
@@ -133,12 +115,6 @@ jobs:
       - uses: actions/checkout@v4
       - name: Bootc Ubuntu Setup
         uses: ./.github/actions/bootc-ubuntu-setup
-      - name: Setup Rust cache
-        uses: Swatinem/rust-cache@v2
-        with:
-          cache-all-crates: true
-          save-if: ${{ github.ref == 'refs/heads/main' }}
-          lookup-only: ${{ github.ref == 'refs/heads/main' }}
       - name: Build mdbook
         run: just build-mdbook
   # Build containers and disk images for integration testing across OS matrix
@@ -154,14 +130,8 @@ jobs:
       - uses: actions/checkout@v4
       - name: Bootc Ubuntu Setup
         uses: ./.github/actions/bootc-ubuntu-setup
-      - name: Setup Rust cache
-        uses: Swatinem/rust-cache@v2
         with:
-          cache-all-crates: true
-          save-if: ${{ github.ref == 'refs/heads/main' }}
-          lookup-only: ${{ github.ref == 'refs/heads/main' }}
-      - name: Install qemu-utils
-        run: sudo apt install -y qemu-utils
+          libvirt: true
 
       - name: Build container and disk image
         run: |
@@ -192,12 +162,10 @@ jobs:
       - uses: actions/checkout@v4
       - name: Bootc Ubuntu Setup
         uses: ./.github/actions/bootc-ubuntu-setup
-      - name: Install deps
-        run: |
-          sudo apt-get update
-          # see https://tmt.readthedocs.io/en/stable/overview.html#install
-          sudo apt install -y libkrb5-dev pkg-config libvirt-dev genisoimage qemu-kvm qemu-utils libvirt-daemon-system just
-          pip install --user "tmt[provision-virtual]"
+        with:
+          libvirt: true
+      - name: Install tmt
+        run: pip install --user "tmt[provision-virtual]"
 
       - name: Create folder to save disk image
         run: mkdir -p target