dynamically populate from struct

Author: davidcheung

internal/util/util.go

@@ -10,6 +10,7 @@ import (
 	"os/exec"
 	"path"
 	"path/filepath"
+	"reflect"
 	"strconv"
 	"strings"
 	"text/template"
@@ -142,3 +143,34 @@ func ItemInSlice(slice []string, target string) bool {
 	}
 	return false
 }
+
+// Given a resource of struct type as
+// type AWSCreds struct{
+// 	AccessKeyID  string `yaml:"accessKeyId,omitempty"`
+// 	SecretAccessKey  string `yaml:"accessKeyId,omitempty"`
+// }{
+// 	AccessKeyID: "FOO",
+// 	SecretAccessKey: "BAR",
+// }
+// It will base on the tag, fill in the value to supplied map[string]string
+func ReflectStructValueIntoMap(resource interface{}, tagName string, paramsToFill map[string]string) {
+	t := reflect.ValueOf(resource)
+
+	for i := 0; i < t.NumField(); i++ {
+
+		childStruct := t.Type().Field(i)
+		childValue := t.Field(i)
+		if childValue.Kind().String() != "string" {
+			continue
+		}
+		tag, _ := parseTag(childStruct.Tag.Get(tagName))
+		paramsToFill[tag] = childValue.String()
+	}
+}
+
+func parseTag(tag string) (string, string) {
+	if idx := strings.Index(tag, ","); idx != -1 {
+		return tag[:idx], tag[idx+1:]
+	}
+	return tag, ""
+}

pkg/credentials/credentials.go

@@ -8,6 +8,7 @@ import (
 	"regexp"
 
 	"github.com/aws/aws-sdk-go/aws/credentials"
+	"github.com/commitdev/zero/internal/util"
 )
 
 type AWSResourceConfig struct {
@@ -25,14 +26,25 @@ func awsCredsPath() string {
 	return filepath.Join(usr.HomeDir, ".aws/credentials")
 }
 
+func fetchAWSConfig(awsPath string, profileName string) (error, AWSResourceConfig) {
+
+	awsCreds, err := credentials.NewSharedCredentials(awsPath, profileName).Get()
+	if err != nil {
+		return err, AWSResourceConfig{}
+	}
+	return nil, AWSResourceConfig{
+		AccessKeyID:     awsCreds.AccessKeyID,
+		SecretAccessKey: awsCreds.SecretAccessKey,
+	}
+}
+
 func FillAWSProfile(profileName string, paramsToFill map[string]string) error {
 	awsPath := GetAWSCredsPath()
-	awsCreds, err := credentials.NewSharedCredentials(awsPath, profileName).Get()
+	err, awsCreds := fetchAWSConfig(awsPath, profileName)
 	if err != nil {
 		return err
 	}
-	paramsToFill["accessKeyId"] = awsCreds.AccessKeyID
-	paramsToFill["secretAccessKey"] = awsCreds.SecretAccessKey
+	util.ReflectStructValueIntoMap(awsCreds, "yaml", paramsToFill)
 	return nil
 }