first commit

go.mod

@@ -0,0 +1,3 @@
+module getenv
+
+go 1.15

main.go

@@ -0,0 +1,70 @@
+package main
+
+import (
+	"encoding/json"
+	"flag"
+	"fmt"
+	"net/http"
+	"os"
+	"strings"
+	"time"
+)
+
+func main() {
+	prefix := flag.String("prefix", "", "a string")
+	flag.Parse()
+	// keys := flag.Args()
+
+	var c = &http.Client{
+		Timeout: time.Second * 5,
+	}
+
+	req, err := http.NewRequest("GET", "http://metadata/computeMetadata/v1/instance/attributes?recursive=true", nil)
+	if err != nil {
+		fmt.Fprint(os.Stderr, err)
+		os.Exit(1)
+	}
+	req.Header.Add("Metadata-Flavor", "Google")
+	res, err := c.Do(req)
+	if err != nil {
+		fmt.Fprint(os.Stderr, err)
+		os.Exit(1)
+	}
+	defer res.Body.Close()
+	// data, err := ioutil.ReadAll(res.Body)
+	// if err != nil {
+	// 	fmt.Fprint(os.Stderr, err)
+	// 	os.Exit(1)
+	// }
+
+	if res.StatusCode != 200 {
+		fmt.Fprintf(os.Stderr, "couldn't fetch metadata attributes")
+		os.Exit(1)
+	}
+
+	items := make(map[string]string)
+	vars := make(map[string]string)
+
+	err = json.NewDecoder(res.Body).Decode(&items)
+	if err != nil {
+		fmt.Fprint(os.Stderr, err)
+		os.Exit(1)
+	}
+
+	for k, v := range items {
+		// matched, err := regexp.MatchString(`a.b`, "aaxbb")
+		// if err != nil {
+		// 	fmt.Fprint(os.Stderr, err)
+		// 	os.Exit(1)
+		// }
+		vars[strings.ToUpper(k)] = v
+	}
+
+	for k, v := range vars {
+		if *prefix != "" {
+			fmt.Printf("%s_%s=%s\n", *prefix, k, v)
+		} else {
+			fmt.Printf("%s=%s\n", k, v)
+		}
+	}
+}