ci: introduce new developer_productivity.yml

The new CI step tests the Nix toolchain

Author: phip1611

.github/workflows/developer_productivity.yml

@@ -0,0 +1,50 @@
+name: Developer Productivity
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  # Job to run change detection
+  changes:
+    runs-on: ubuntu-latest
+    # Set job outputs to values from filter step.
+    outputs:
+      nix-src: ${{ steps.filter.outputs.nix-src }}
+    steps:
+      - uses: dorny/paths-filter@v2
+        id: filter
+        with:
+          filters: |
+            nix-src:
+              - 'nix/**'
+              - 'shell.nix'
+
+  # This is a convenience test to verify that the toolchain provided by
+  # shell.nix is valid and can build + run the integration test.
+  #
+  # It only runs if the "nix-src" output of the "changes" job is true.
+  nix_shell_toolchain:
+    name: "Nix toolchain: cargo xtask run works"
+    needs: changes
+    if: ${{ needs.changes.outputs.nix-src == 'true' }}
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout sources
+      uses: actions/checkout@v3
+    - uses: Swatinem/rust-cache@v2
+    - uses: cachix/install-nix-action@v20
+      with:
+        # This channel is only required to invoke "nix-shell".
+        # Everything inside that nix-shell will use a pinned version of nixpkgs.
+        nix_path: nixpkgs=channel:nixos-23.05
+    # Dedicated step to separate all the
+    # "copying path '/nix/store/...' from 'https://cache.nixos.org'."
+    # messages from the actual build output. This job takes ~60secs.
+    - name: Prepare Nix Store
+      run: nix-shell --pure --run "cargo --version"
+    - name: Run VM tests
+      run: |
+        COMMAND="cargo +stable xtask run --target x86_64 --headless --ci --tpm=v1"
+        echo "Executing in nix shell now: $COMMAND"
+        nix-shell --pure --run "$COMMAND"

shell.nix

@@ -6,17 +6,18 @@
 , pkgs ? import sources.nixpkgs { }
 }:
 
-pkgs.mkShell rec {
+pkgs.mkShell {
   nativeBuildInputs = with pkgs; [
     # nix related stuff (such as dependency management)
     niv
     nixpkgs-fmt
 
-    rustup
+    # Integration test dependencies
+    swtpm
     qemu
-  ];
 
-  buildInputs = with pkgs; [
+    # Rust toolchain
+    rustup
   ];
 
   # Set ENV vars.