build: "Quick Checks" no longer uses goenv

goenv was making things more complicated than needed since it's really
designed to help with interactive use in a shell more than automated use
like this.

Instead, we'll follow the same strategy that our build.yml was doing of
just reading the .go-version file directly and then using the official
actions/setup-go action to do the actual installation. The key advantage
here is that Go ends up installed in a way where just running "go" will
do the right thing, and we no longer need to fuss with shims and
version-based path prefixes.

Rather than duplicating the logic from build.yml, instead it's factored
out into a separate composite action which both build.yml and checks.yml
will now share, in case we want to change the Go version selection
methodology in the future.

.github/actions/go-version/action.yml

@@ -0,0 +1,23 @@
+name: 'Determine Go Toolchain Version'
+description: 'Uses the .go-version file to determine which Go toolchain to use for any Go-related actions downstream.'
+outputs:
+  version:
+    description: "Go toolchain version"
+    value: ${{ steps.go.outputs.version }}
+runs:
+  using: "composite"
+  steps:
+    # We use goenv to make sure we're always using the same Go version we'd
+    # use for releases, as recorded in the .go-version file.
+    - name: "Determine Go version"
+      id: go
+      shell: bash
+      # We use .go-version as our source of truth for current Go
+      # version, because "goenv" can react to it automatically.
+      # However, we don't actually use goenv for our automated
+      # steps in GitHub Actions, because it's primarily for
+      # interactive use in shells and makes things unnecessarily
+      # complex for automation.
+      run: |
+        echo "Building with Go $(cat .go-version)"
+        echo "::set-output name=version::$(cat .go-version)"

.github/workflows/build.yml

@@ -68,17 +68,13 @@ jobs:
     name: "Determine Go toolchain version"
     runs-on: ubuntu-latest
     outputs:
-      go-version: ${{ steps.get-go-version.outputs.go-version }}
+      go-version: ${{ steps.get-go-version.outputs.version }}
 
     steps:
       - uses: actions/checkout@v2
       - name: Determine Go version
         id: get-go-version
-        # We use .go-version as our source of truth for current Go
-        # version, because "goenv" can react to it automatically.
-        run: |
-          echo "Building with Go $(cat .go-version)"
-          echo "::set-output name=go-version::$(cat .go-version)"
+        uses: ./.github/actions/go-version
 
   generate-metadata-file:
     name: "Generate release metadata"

.github/workflows/checks.yml

@@ -33,44 +33,43 @@ jobs:
       - name: "Fetch source code"
         uses: actions/checkout@v2
 
-      - name: "Install Go"
+      - name: Determine Go version
         id: go
-        uses: ./.github/actions/go-setup
+        uses: ./.github/actions/go-version
+
+      - name: Install Go toolchain
+        uses: actions/setup-go@v2
+        with:
+          go-version: ${{ steps.go.outputs.version }}
 
       # NOTE: This cache is shared with the e2e-tests job, so the corresponding
       # step in that job must always be identical to this one.
       - name: Cache Go modules
         uses: actions/cache@v3
         with:
-          path: "${{steps.go.outputs.gopath}}/pkg"
+          path: "~/go/pkg"
           key: go-mod-${{ hashFiles('go.sum') }}
           restore-keys: |
             go-mod-
 
       - name: "go.mod and go.sum consistency check"
         run: |
-          "${{steps.go.outputs.go}}" mod tidy
+          go mod tidy
           if [[ -n "$(git status --porcelain)" ]]; then
             echo "go.mod/go.sum are not up-to-date. Run 'go mod tidy' and then commit the updated files."
             exit 1
           fi
 
       - name: "Unit tests"
         run: |
-          "${{steps.go.outputs.go}}" test ./...
+          go test ./...
 
       # We'll also deal with some general consistency/lint/style checks
       # here just because they are relatively fast and so not worth running
       # concurrently given the cost of _yet again_ installing Go and checking
       # out the source code in another worker.
       - name: "Code consistency checks"
         run: |
-          # We do need to fully init goenv in this one case because we're
-          # going to run Go indirectly via make and some shell scripts, so
-          # we need PATH set up correctly.
-          export PATH="${{steps.go.outputs.goenv-bin-dir}}":$PATH
-          eval "$(goenv init -)"
-          go version
           make fmtcheck generate staticcheck exhaustive protobuf
           if [[ -n "$(git status --porcelain)" ]]; then
             echo "Generated files are inconsistent. Run 'make generate' and 'make protobuf' locally and then commit the updated files."
@@ -90,20 +89,25 @@ jobs:
       - name: "Fetch source code"
         uses: actions/checkout@v2
 
-      - name: "Install Go"
+      - name: Determine Go version
         id: go
-        uses: ./.github/actions/go-setup
+        uses: ./.github/actions/go-version
+
+      - name: Install Go toolchain
+        uses: actions/setup-go@v2
+        with:
+          go-version: ${{ steps.go.outputs.version }}
 
       # NOTE: This cache is shared with the e2e-tests job, so the corresponding
       # step in that job must always be identical to this one.
       - name: Cache Go modules
         uses: actions/cache@v3
         with:
-          path: "${{steps.go.outputs.gopath}}/pkg"
+          path: "~/go/pkg"
           key: go-mod-${{ hashFiles('go.sum') }}
           restore-keys: |
             go-mod-
 
       - name: "End-to-end tests"
         run: |
-          TF_ACC=1 "${{steps.go.outputs.go}}" test -v ./internal/command/e2etest
+          TF_ACC=1 go test -v ./internal/command/e2etest