Provide empty asset offsets without codegen

This removes the necessity to generate the empty asset file in the
Makefile. Switch between the empty and generated files at compile time
via the noembedbins go build tag.

Signed-off-by: Tom Wieczorek <[email protected]>

.github/workflows/go.yml

@@ -137,12 +137,7 @@ jobs:
             build/cache/go/mod
 
       - name: Run unit tests
-        env:
-          EMBEDDED_BINS_BUILDMODE: none
-        run: |
-          make bindata
-          make --touch codegen
-          make check-unit
+        run: make check-unit
 
       - name: Validate OCI images manifests
         run: make check-image-validity

Makefile

@@ -30,7 +30,8 @@ EMBEDDED_BINS_BUILDMODE ?= docker
 TARGET_OS ?= linux
 BUILD_UID ?= $(shell id -u)
 BUILD_GID ?= $(shell id -g)
-BUILD_GO_FLAGS := -tags osusergo -buildvcs=false -trimpath
+BUILD_GO_TAGS ?= osusergo
+BUILD_GO_FLAGS = -tags $(subst $(space),$(comma),$(BUILD_GO_TAGS)) -buildvcs=false -trimpath
 BUILD_CGO_CFLAGS :=
 BUILD_GO_LDFLAGS_EXTRA :=
 DEBUG ?= false
@@ -157,17 +158,11 @@ static/zz_generated_assets.go: $(shell find $(static_asset_dirs) -type f)
 	CGO_ENABLED=0 $(GO) install github.com/kevinburke/go-bindata/go-bindata@v$(go-bindata_version)
 	$(GO_ENV) go-bindata -o '$@' -pkg static -prefix static $(patsubst %,%/...,$(static_asset_dirs))
 
-codegen_targets += pkg/assets/zz_generated_offsets_$(TARGET_OS).go
-zz_os = $(patsubst pkg/assets/zz_generated_offsets_%.go,%,$@)
-print_empty_generated_offsets = printf "%s\n\n%s\n%s\n" \
-			"package assets" \
-			"var BinData = map[string]struct{ offset, size, originalSize int64 }{}" \
-			"var BinDataSize int64"
 ifeq ($(EMBEDDED_BINS_BUILDMODE),none)
-pkg/assets/zz_generated_offsets_linux.go pkg/assets/zz_generated_offsets_windows.go:
-	rm -f bindata_$(zz_os) && touch bindata_$(zz_os)
-	$(print_empty_generated_offsets) > $@
+BUILD_GO_TAGS += noembedbins
 else
+codegen_targets += pkg/assets/zz_generated_offsets_$(TARGET_OS).go
+zz_os = $(patsubst pkg/assets/zz_generated_offsets_%.go,%,$@)
 pkg/assets/zz_generated_offsets_linux.go: .bins.linux.stamp
 pkg/assets/zz_generated_offsets_windows.go: .bins.windows.stamp
 pkg/assets/zz_generated_offsets_linux.go pkg/assets/zz_generated_offsets_windows.go: .k0sbuild.docker-image.k0s go.sum
@@ -176,10 +171,6 @@ pkg/assets/zz_generated_offsets_linux.go pkg/assets/zz_generated_offsets_windows
 	     -prefix embedded-bins/staging/$(zz_os)/ embedded-bins/staging/$(zz_os)/bin
 endif
 
-# needed for unit tests on macos
-pkg/assets/zz_generated_offsets_darwin.go:
-	$(print_empty_generated_offsets) > $@
-
 k0s: TARGET_OS = linux
 k0s: BUILD_GO_CGO_ENABLED = 1
 k0s: .k0sbuild.docker-image.k0s
@@ -189,11 +180,15 @@ k0s.exe: BUILD_GO_CGO_ENABLED = 0
 
 k0s.exe k0s: $(GO_SRCS) $(codegen_targets) go.sum
 	CGO_ENABLED=$(BUILD_GO_CGO_ENABLED) CGO_CFLAGS='$(BUILD_CGO_CFLAGS)' GOOS=$(TARGET_OS) $(GO) build $(BUILD_GO_FLAGS) -ldflags='$(LD_FLAGS)' -o $@.code main.go
-	cat $@.code bindata_$(TARGET_OS) > $@.tmp \
-		&& rm -f $@.code \
-		&& printf "\nk0s size: %s\n\n" "$$(du -sh $@.tmp | cut -f1)" \
-		&& chmod +x $@.tmp \
-		&& mv $@.tmp $@
+ifeq ($(EMBEDDED_BINS_BUILDMODE),none)
+	mv -- [email protected] [email protected]
+else
+	cat -- [email protected] bindata_$(TARGET_OS) >[email protected]
+	rm -f -- [email protected]
+endif
+	chmod +x -- [email protected]
+	mv -- [email protected] $@
+	printf '\nk0s size: %s\n\n' "$$(du -sh -- $@ | cut -f1)"
 
 .bins.windows.stamp .bins.linux.stamp: embedded-bins/Makefile.variables
 	$(MAKE) -C embedded-bins \
@@ -253,8 +248,8 @@ check-unit: GO_TEST_RACE ?=
 else
 check-unit: GO_TEST_RACE ?= -race
 endif
-check-unit: go.sum codegen
-	CGO_CFLAGS='$(BUILD_CGO_CFLAGS)' $(GO) test -tags=hack $(GO_TEST_RACE) -ldflags='$(LD_FLAGS)' `$(GO) list -tags=hack $(GO_CHECK_UNIT_DIRS)`
+check-unit: go.sum static/zz_generated_assets.go
+	CGO_CFLAGS='$(BUILD_CGO_CFLAGS)' $(GO) test -tags=hack,noembedbins $(GO_TEST_RACE) -ldflags='$(LD_FLAGS)' `$(GO) list -tags=hack $(GO_CHECK_UNIT_DIRS)`
 
 .PHONY: check-image-validity
 check-image-validity: go.sum

hack/gen-bindata/gen_bindata.go

@@ -180,7 +180,8 @@ func GenBindata(name string, args ...string) error {
 	})
 }
 
-var packageTemplate = template.Must(template.New("").Parse(`// Code generated by go generate; DO NOT EDIT.
+var packageTemplate = template.Must(template.New("").Parse(`//go:build !noembedbins
+// Code generated by go generate; DO NOT EDIT.
 
 // datafile: {{ .OutFile }}
 

hack/gen-bindata/gen_bindata_test.go

@@ -49,7 +49,8 @@ func TestGenBindata_BasicExecution(t *testing.T) {
 	tmpDir := t.TempDir()
 	defer testutil.Chdir(t, tmpDir)()
 
-	const expected = `// Code generated by go generate; DO NOT EDIT.
+	const expected = `//go:build !noembedbins
+// Code generated by go generate; DO NOT EDIT.
 
 // datafile: ./bindata
 

pkg/assets/offsets_noembedbins.go

@@ -0,0 +1,22 @@
+//go:build noembedbins || (!linux && !windows)
+
+/*
+Copyright 2024 k0s authors
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package assets
+
+var BinData = map[string]struct{ offset, size, originalSize int64 }{}
+var BinDataSize int64