build: Consolidate build-darwin job into just "build"

We can use an extra matrix dimension to select which execution environment
we'll use for each GOOS/GOARCH pair, and thus avoid duplicating the
job definition for darwin just to set runs-on: macos-latest for it.

This is not really an intended use of a matrix dimension because it's
directly related to the existing "goos" one, rather than being an
independent third dimension, but it doesn't matter in practice because
we're using the "include" option to specify exact combinations, and thus
we're not relying on the built-in functionality to generate all possible
matrix combinations.

.github/workflows/build.yml

@@ -62,10 +62,11 @@ jobs:
 
   generate-metadata-file:
     name: "Generate release metadata"
-    needs: get-product-version
     runs-on: ubuntu-latest
+    needs: get-product-version
     outputs:
       filepath: ${{ steps.generate-metadata-file.outputs.filepath }}
+
     steps:
       - uses: actions/checkout@v2
       - name: Generate package metadata
@@ -81,27 +82,31 @@ jobs:
           path: ${{ steps.generate-metadata-file.outputs.filepath }}
 
   build:
-    needs: ["get-product-version", "get-go-version"]
-    runs-on: ubuntu-latest
+    name: Build for ${{ matrix.goos }}_${{ matrix.goarch }}
+    runs-on: ${{ matrix.runson }}
+    needs:
+      - get-product-version
+      - get-go-version
+
     strategy:
       matrix:
         include:
-          - {goos: "freebsd", goarch: "386"}
-          - {goos: "freebsd", goarch: "amd64"}
-          - {goos: "freebsd", goarch: "arm"}
-          - {goos: "linux", goarch: "386"}
-          - {goos: "linux", goarch: "amd64"}
-          - {goos: "linux", goarch: "arm"}
-          - {goos: "linux", goarch: "arm64"}
-          - {goos: "openbsd", goarch: "386"}
-          - {goos: "openbsd", goarch: "amd64"}
-          - {goos: "solaris", goarch: "amd64"}
-          - {goos: "windows", goarch: "386"}
-          - {goos: "windows", goarch: "amd64"}
+          - {goos: "freebsd", goarch: "386", runson: "ubuntu-latest"}
+          - {goos: "freebsd", goarch: "amd64", runson: "ubuntu-latest"}
+          - {goos: "freebsd", goarch: "arm", runson: "ubuntu-latest"}
+          - {goos: "linux", goarch: "386", runson: "ubuntu-latest"}
+          - {goos: "linux", goarch: "amd64", runson: "ubuntu-latest"}
+          - {goos: "linux", goarch: "arm", runson: "ubuntu-latest"}
+          - {goos: "linux", goarch: "arm64", runson: "ubuntu-latest"}
+          - {goos: "openbsd", goarch: "386", runson: "ubuntu-latest"}
+          - {goos: "openbsd", goarch: "amd64", runson: "ubuntu-latest"}
+          - {goos: "solaris", goarch: "amd64", runson: "ubuntu-latest"}
+          - {goos: "windows", goarch: "386", runson: "ubuntu-latest"}
+          - {goos: "windows", goarch: "amd64", runson: "ubuntu-latest"}
+          - {goos: "darwin", goarch: "amd64", runson: "macos-latest"}
+          - {goos: "darwin", goarch: "arm64", runson: "macos-latest"}
       fail-fast: false
 
-    name: Build for ${{ matrix.goos }}_${{ matrix.goarch }}
-
     steps:
       - uses: actions/checkout@v2
 
@@ -110,13 +115,22 @@ jobs:
         with:
           go-version: ${{ needs.get-go-version.outputs.go-version }}
 
+      # FIXME: We're not currently setting the hard-coded version string in
+      # version/version.go at any point here, which means that the packages
+      # this process builds are not suitable for release. Once we're using
+      # Go 1.18 we may begin using the version information automatically
+      # embedded by the Go toolchain, at which point we won't need any
+      # special steps during build, but failing that we'll need to rework
+      # the version/version.go package so we can more readily update it
+      # using linker flags rather than direct code modification.
+
       - name: Build
         env:
           GOOS: ${{ matrix.goos }}
           GOARCH: ${{ matrix.goarch }}
         run: |
           mkdir dist out
-          go build -o dist/ .
+          go build -ldflags "-w -s" -o dist/ .
           zip -r -j out/${{ env.PKG_NAME }}_${{ needs.get-product-version.outputs.product-version }}_${{ matrix.goos }}_${{ matrix.goarch }}.zip dist/
 
       - uses: actions/upload-artifact@v2
@@ -145,6 +159,8 @@ jobs:
           echo "RPM_PACKAGE=$(basename out/*.rpm)" >> $GITHUB_ENV
           echo "DEB_PACKAGE=$(basename out/*.deb)" >> $GITHUB_ENV
 
+      # FIXME: Generate homebrew packages when targeting macOS.
+
       - uses: actions/upload-artifact@v2
         if: ${{ matrix.goos == 'linux' }}
         with:
@@ -157,41 +173,6 @@ jobs:
           name: ${{ env.DEB_PACKAGE }}
           path: out/${{ env.DEB_PACKAGE }}
 
-  build-darwin:
-    needs: ["get-product-version", "get-go-version"]
-    runs-on: macos-latest
-    strategy:
-      matrix:
-        include:
-          - {goos: "darwin", goarch: "amd64"}
-          - {goos: "darwin", goarch: "arm64"}
-      fail-fast: false
-
-    name: Build for ${{ matrix.goos }}_${{ matrix.goarch }}
-
-    env:
-      GOOS: ${{ matrix.goos }}
-      GOARCH: ${{ matrix.goarch }}
-
-    steps:
-      - uses: actions/checkout@v2
-
-      - name: Install Go toolchain
-        uses: actions/setup-go@v2
-        with:
-          go-version: ${{ needs.get-go-version.outputs.go-version }}
-
-      - name: Build
-        run: |
-          mkdir dist out
-          go build -o dist/
-          zip -r -j out/${{ env.PKG_NAME }}_${{ needs.get-product-version.outputs.product-version }}_${{ matrix.goos }}_${{ matrix.goarch }}.zip dist/
-
-      - uses: actions/upload-artifact@v2
-        with:
-          name: ${{ env.PKG_NAME }}_${{ needs.get-product-version.outputs.product-version }}_${{ matrix.goos }}_${{ matrix.goarch }}.zip
-          path: out/${{ env.PKG_NAME }}_${{ needs.get-product-version.outputs.product-version }}_${{ matrix.goos }}_${{ matrix.goarch }}.zip
-
   build-docker:
     name: Build Docker image for linux_${{ matrix.arch }}
     needs:
@@ -319,7 +300,7 @@ jobs:
     runs-on: macos-latest
     needs:
       - get-product-version
-      - build-darwin
+      - build
       - e2etest-build
 
     strategy: