Verify docker image working on CI

.github/workflows/test.yml

@@ -65,3 +65,5 @@ jobs:
         uses: goreleaser/goreleaser-action@v6
         with:
           args: release --snapshot
+      - name: Verify docker images working
+        run: docker run --rm ghcr.io/chatwork/aws-checkercanary-amd64 aws-checker version

goreleaser.yml

@@ -8,6 +8,7 @@ builds:
       - CGO_ENABLED=0
     ldflags:
       - -s -w
+      - -X main.Version={{.Version}}
     goos:
       - darwin
       - linux

main.go

@@ -19,13 +19,20 @@ import (
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 )
 
+var Version = "dev"
+
 func main() {
+	opts, code := parseFlags(os.Args[1:])
+	if code != nil {
+		os.Exit(*code)
+	}
+
 	// Create a channel to receive OS signals
 	sigs := make(chan os.Signal, 1)
 	// Register the channel to receive SIGINT, SIGTERM signals
 	signal.Notify(sigs, syscall.SIGINT, syscall.SIGTERM)
 
-	if err := Run(ContextWithSignal(context.Background(), sigs)); err != nil {
+	if err := Run(ContextWithSignal(context.Background(), sigs), opts...); err != nil {
 		log.Fatalf("Error: %v", err)
 	}
 }

parse.go

@@ -0,0 +1,42 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+)
+
+func parseFlags(args []string) ([]Option, *int) {
+	fs := flag.NewFlagSet("aws-checker", flag.ContinueOnError)
+	fs.Usage = func() {
+		fmt.Fprintf(fs.Output(), "%s is a toolkit for checking availability of AWS services.\n", fs.Name())
+		fmt.Fprintf(fs.Output(), "Run '%s -help' for usage.\n", fs.Name())
+	}
+
+	var code int
+
+	if err := fs.Parse(args); err != nil {
+		if err != flag.ErrHelp {
+			code = 2
+		}
+	} else {
+		switch fs.NArg() {
+		case 0:
+			return []Option{}, nil
+		case 1:
+			switch fs.Arg(0) {
+			case "version":
+				fmt.Fprintf(fs.Output(), "%s %s", fs.Name(), Version)
+			default:
+				fmt.Fprintf(fs.Output(), "unknown command %q for %q\n", fs.Arg(0), fs.Name())
+				fmt.Fprintf(fs.Output(), "Run '%s -help' for usage.\n", fs.Name())
+				code = 2
+			}
+		default:
+			fmt.Fprintf(fs.Output(), "too many arguments\n")
+			fmt.Fprintf(fs.Output(), "Run '%s -help' for usage.\n", fs.Name())
+			code = 2
+		}
+	}
+
+	return nil, &code
+}