remove buildkit from dockerfile, unsupported by porter (#2854)

.github/workflows/test-backend.yml

@@ -5,14 +5,24 @@ jobs:
   testing_matrix:
     strategy:
       matrix:
-        go-version: [1.20.x]
         os: [ubuntu-latest]
         folder: [cli, api, cmd, internal, provisioner]
-    name: Running ${{ matrix.folder }} tests on Go ${{ matrix.go-version }} on ${{ matrix.os }}
+    name: Running Go Tests
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v3
+      - name: Setup Go Cache
+        uses: actions/cache@v3
+        with:
+          path: |
+            ~/.cache/go-build
+            ~/go/pkg/mod
+          key: porter-go-${{ hashFiles('**/go.sum') }}
+      - name: Download Go Modules
+        run: go mod download
       - uses: actions/setup-go@v4
         with:
-          go-version: ${{ matrix.go-version }}
-      - run: go test ./${{ matrix.folder }}/...
+          go-version-file: go.mod
+          cache: false
+      - name: Run Go tests
+        run: go test ./${{ matrix.folder }}/...

ee/docker/provisioner.Dockerfile

@@ -19,8 +19,7 @@ COPY /pkg ./pkg
 RUN go install google.golang.org/protobuf/cmd/protoc-gen-go@v1.26
 RUN go install google.golang.org/grpc/cmd/protoc-gen-go-grpc@v1.1
 
-RUN --mount=type=cache,target=$GOPATH/pkg/mod \
-    go mod download
+RUN go mod download
 
 # Go build environment
 # --------------------
@@ -29,17 +28,13 @@ FROM base AS build-go
 # build proto files
 RUN sh ./scripts/build/proto.sh
 
-RUN --mount=type=cache,target=/root/.cache/go-build \
-    --mount=type=cache,target=$GOPATH/pkg/mod \
-    go build -ldflags '-w -s' -a -tags ee -o ./bin/provisioner ./cmd/provisioner
+RUN go build -ldflags '-w -s' -a -tags ee -o ./bin/provisioner ./cmd/provisioner
 
 # Go test environment
 # -------------------
 FROM base AS porter-test
 
-RUN --mount=type=cache,target=/root/.cache/go-build \
-    --mount=type=cache,target=$GOPATH/pkg/mod \
-    go test ./...
+RUN go test ./...
 
 # Deployment environment
 # ----------------------