feat: add goreleaser build

.github/workflows/gorelease.yml

@@ -0,0 +1,27 @@
+name: Releaser
+on:
+  push:
+    tags:
+      - '*'
+jobs:
+  goreleaser:
+    runs-on: ubuntu-latest
+    steps:
+      -
+        name: Checkout
+        uses: actions/checkout@v2
+        with:
+          fetch-depth: 0
+      -
+        name: Set up Go
+        uses: actions/setup-go@v2
+        with:
+          go-version: 1.15
+      -
+        name: Run GoReleaser
+        uses: goreleaser/goreleaser-action@v2
+        with:
+          version: latest
+          args: release --rm-dist
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.goreleaser.yml

@@ -0,0 +1,21 @@
+project_name: optgen
+env:
+  - GO111MODULE=on
+builds:
+  -
+    main: main.go
+    binary: optgen
+    ldflags:
+      - -s -w
+      - -X main.Version={{.Major}}.{{.Minor}}.{{.Patch}}
+    env:
+      - CGO_ENABLED=0
+    goos:
+      - darwin
+      - linux
+      - windows
+    goarch:
+      - amd64
+    hooks:
+      post:
+       - upx --brute "{{ .Path }}"

main.go

@@ -17,8 +17,10 @@ import (
 )
 
 var (
-	sourceFile, tagName, structName string
-	writeMode, allFields            bool
+	sourceFile, tagName, structName   string
+	writeMode, allFields, showVersion bool
+
+	version string = "dev"
 
 	funcMap = template.FuncMap{
 		"title":   strings.Title,
@@ -31,16 +33,25 @@ func initCLI() {
 	flag.StringVar(&tagName, "tag", "opt", "custom tag")
 	flag.StringVar(&structName, "name", "", "struct name")
 	flag.BoolVar(&writeMode, "w", false, "enable write mode")
+	flag.BoolVar(&showVersion, "v", false, "show version")
 	flag.BoolVar(&allFields, "all", false, "generate all fields")
 	flag.Parse()
+}
+
+func main() {
+	initCLI()
+
+	if showVersion {
+		fmt.Printf("version: %s", version)
+
+		return
+	}
+
 	const exampleMessage = "e.g: optgen -file sample-file.go -name Thing"
 	if sourceFile == "" || structName == "" {
 		log.Fatalf("Source file and struct name must be provided.\n%s", exampleMessage)
 	}
-}
 
-func main() {
-	initCLI()
 	source, err := ioutil.ReadFile(sourceFile)
 	if err != nil {
 		log.Fatal(err)