Test on alpine linux for musl

Author: bjorn3

.github/workflows/ci.yaml

@@ -272,36 +272,60 @@ jobs:
       - name: Run tests
         run: cargo test --workspace --all-targets --release
 
-  build-and-test-fedora:
+  build-and-test-container:
+    strategy:
+      matrix:
+        os: ["fedora", "alpine"]
     runs-on: ubuntu-latest
-    container: fedora:latest
+    container: "${{ matrix.os }}:latest"
 
     steps:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
 
-      - name: Install dependencies
+      - name: Install dependencies (fedora)
+        if: matrix.os == 'fedora'
         run: |
           dnf install -y cargo pam-devel
 
+      - name: Install dependencies (alpine)
+        if: matrix.os == 'alpine'
+        run: |
+          apk add cargo linux-pam-dev sudo tzdata coreutils-fmt
+
       - name: Rust Cache
         uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6
         with:
-          shared-key: "stable-fedora"
+          shared-key: "stable-${{matrix.os}}"
 
       - name: Register rust problem matcher
         run: echo "::add-matcher::.github/problem-matchers/rust.json"
 
-      - name: Reduce privileges
+      - name: Reduce privileges (fedora)
+        if: matrix.os == 'fedora'
         run: |
           useradd builder
           chown builder .
 
+      - name: Reduce privileges (alpine)
+        if: matrix.os == 'alpine'
+        run: |
+          adduser --disabled-password builder
+          chown builder .
+
       - name: Build
         run: sudo -ubuilder cargo build --workspace --all-targets --release
 
-      - name: Run tests
+      - name: Run tests (not alpine)
+        if: matrix.os != 'alpine'
         run: sudo -ubuilder cargo test --workspace --all-targets --release
 
+      - name: Run tests (alpine)
+        if: matrix.os == 'alpine'
+        run: |
+          # Alpine hasn't done usr-merge yet
+          sudo -ubuilder cargo test --workspace --all-targets --release \
+            -- --skip canonicalization --skip test_build_run_context
+
   build-and-test-32bit:
     runs-on: ubuntu-latest