From 63b7f1147176ce5cfd21c3b74094fcc8154298df Mon Sep 17 00:00:00 2001
From: Luke Kingland <lkingland2038@gmail.com>
Date: Mon, 22 Mar 2021 23:41:07 +0900
Subject: [PATCH] feat: create templates archive on go generate

---
 Makefile    | 24 ++++++++++-------
 generate.go | 77 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 92 insertions(+), 9 deletions(-)
 create mode 100644 generate.go

diff --git a/Makefile b/Makefile
index 3db429469..e08d374a6 100644
--- a/Makefile
+++ b/Makefile
@@ -1,9 +1,9 @@
 REPO := quay.io/boson/func
-BIN  := func
 
-DARWIN=$(BIN)_darwin_amd64
-LINUX=$(BIN)_linux_amd64
-WINDOWS=$(BIN)_windows_amd64.exe
+BIN     := func
+DARWIN  :=$(BIN)_darwin_amd64
+LINUX   :=$(BIN)_linux_amd64
+WINDOWS :=$(BIN)_windows_amd64.exe
 
 CODE := $(shell find . -name '*.go')
 DATE := $(shell date -u +"%Y%m%dT%H%M%SZ")
@@ -14,6 +14,8 @@ VTAG := $(shell git tag --points-at HEAD)
 # unless explicitly, synchronously tagging as is done in ci.yaml
 VERS ?= $(shell [ -z $(VTAG) ] && echo 'tip' || echo $(VTAG) )
 
+LDFLAGS := -X main.date=$(DATE) -X main.vers=$(VERS) -X main.hash=$(HASH)
+
 build: all
 all: $(BIN)
 
@@ -33,16 +35,20 @@ linux: $(LINUX) ## Build for Linux
 windows: $(WINDOWS) ## Build for Windows
 
 $(BIN): $(CODE)  ## Build using environment defaults
-	env CGO_ENABLED=0 go build -ldflags "-X main.date=$(DATE) -X main.vers=$(VERS) -X main.hash=$(HASH)" ./cmd/$(BIN)
+	go generate
+	env CGO_ENABLED=0 go build -ldflags "$(LDFLAGS)" ./cmd/$(BIN)
 
 $(DARWIN):
-	env CGO_ENABLED=0 GOOS=darwin GOARCH=amd64 go build -o $(DARWIN) -ldflags "-X main.date=$(DATE) -X main.vers=$(VERS) -X main.hash=$(HASH)" ./cmd/$(BIN)
+	go generate
+	env CGO_ENABLED=0 GOOS=darwin GOARCH=amd64 go build -o $(DARWIN) -ldflags "$(LDFLAGS)" ./cmd/$(BIN)
 
 $(LINUX):
-	env CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -o $(LINUX) -ldflags "-X main.date=$(DATE) -X main.vers=$(VERS) -X main.hash=$(HASH)" ./cmd/$(BIN)
+	go generate
+	env CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -o $(LINUX) -ldflags "$(LDFLAGS)" ./cmd/$(BIN)
 
 $(WINDOWS):
-	env CGO_ENABLED=0 GOOS=windows GOARCH=amd64 go build -o $(WINDOWS) -ldflags "-X main.date=$(DATE) -X main.vers=$(VERS) -X main.hash=$(HASH)" ./cmd/$(BIN)
+	go generate
+	env CGO_ENABLED=0 GOOS=windows GOARCH=amd64 go build -o $(WINDOWS) -ldflags "$(LDFLAGS)" ./cmd/$(BIN)
 
 test: test-binary test-node test-python test-quarkus test-go
 
@@ -102,5 +108,5 @@ cluster: ## Set up a local cluster for integraiton tests.
 	./hack/allocate.sh && ./hack/configure.sh
 
 clean:
-	rm -f $(BIN) $(WINDOWS) $(LINUX) $(DARWIN)
+	rm -f $(BIN) $(WINDOWS) $(LINUX) $(DARWIN) $(TEMPLATES)
 	-rm -f coverage.out
diff --git a/generate.go b/generate.go
new file mode 100644
index 000000000..11c9ce673
--- /dev/null
+++ b/generate.go
@@ -0,0 +1,77 @@
+// +build generate
+
+package main
+
+import (
+	"archive/tar"
+	"compress/gzip"
+	"fmt"
+	"io"
+	"io/fs"
+	"os"
+	"path/filepath"
+)
+
+const (
+	archive = "templates.tgz"
+	files   = "templates"
+)
+
+// on 'go generate' create templates archive (tar -czf templates.tgz templates)
+func main() {
+	if err := create(archive, files); err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+}
+
+func create(name, source string) (err error) {
+	// Create file on disk
+	tarball, err := os.Create(name)
+	if err != nil {
+		return
+	}
+	defer tarball.Close()
+
+	// A gzip compressor which writes to the file
+	compressor := gzip.NewWriter(tarball)
+	defer compressor.Close()
+
+	// A tar writer which writes to gzip compressor
+	w := tar.NewWriter(compressor)
+	defer w.Close()
+
+	// File walking function which writes tar entries for each file.
+	return filepath.WalkDir(source, func(path string, d fs.DirEntry, e error) (err error) {
+		if e != nil {
+			return e // abort on any failed ReadDir calls.
+		}
+
+		// Header
+		fi, err := d.Info()
+		if err != nil {
+			return
+		}
+		h, err := tar.FileInfoHeader(fi, d.Name())
+		if err != nil {
+			return
+		}
+		h.Name = filepath.ToSlash(path)
+		if err = w.WriteHeader(h); err != nil {
+			return
+		}
+
+		// Done if directory
+		if d.IsDir() {
+			return
+		}
+
+		// Data
+		data, err := os.Open(path)
+		if err != nil {
+			return
+		}
+		_, err = io.Copy(w, data)
+		return
+	})
+}