Merge pull request #12 from ddelnano/use-reflection-to-improve-respon…

…se-parsing Use reflection to improve response parsing
ddelnano · May 3, 2020 · f728ff2 · f728ff2
2 parents a217572 + be7b8cd
commit f728ff2
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Showing 10 changed files with 464 additions and 227 deletions.
diff --git a/client/client.go b/client/client.go
@@ -1,10 +1,12 @@
 package client
 
 import (
+	"errors"
 	"fmt"
 	"log"
 	"math"
 	"os"
+	"reflect"
 	"strconv"
 	"strings"
 	"time"
@@ -19,135 +21,74 @@ type Mikrotik struct {
 	Password string
 }
 
-type DnsRecord struct {
-	// .id field that mikrotik uses as the 'real' ID
-	Id      string
-	Name    string
-	Ttl     int
-	Address string
-}
+func Unmarshal(reply routeros.Reply, v interface{}) error {
+	rv := reflect.ValueOf(v)
+	elem := rv.Elem()
 
-func NewClient(host, username, password string) Mikrotik {
-	return Mikrotik{
-		Host:     host,
-		Username: username,
-		Password: password,
+	if rv.Kind() != reflect.Ptr {
+		panic("Unmarshal cannot work without a pointer")
 	}
-}
-
-func GetConfigFromEnv() (host, username, password string) {
-	host = os.Getenv("MIKROTIK_HOST")
-	username = os.Getenv("MIKROTIK_USER")
-	password = os.Getenv("MIKROTIK_PASSWORD")
-	if host == "" || username == "" || password == "" {
-		// panic("Unable to find the MIKROTIK_HOST, MIKROTIK_USER or MIKROTIK_PASSWORD environment variable")
-	}
-	return host, username, password
-}
-
-func (client Mikrotik) getMikrotikClient() (c *routeros.Client, err error) {
-	address := client.Host
-	username := client.Username
-	password := client.Password
-	c, err = routeros.Dial(address, username, password)
 
-	if err != nil {
-		log.Printf("[ERROR] Failed to login to routerOS with error: %v", err)
-	}
-
-	return
-}
-
-func (client Mikrotik) AddDnsRecord(name, address string, ttl int) (*routeros.Reply, error) {
-	c, err := client.getMikrotikClient()
-
-	if err != nil {
-		return nil, err
-	}
-	cmd := strings.Split(fmt.Sprintf("/ip/dns/static/add =name=%s =address=%s =ttl=%d", name, address, ttl), " ")
-	log.Printf("[INFO] Running the mikrotik command: `%s`", cmd)
-	r, err := c.RunArgs(cmd)
-	return r, err
-}
-
-func (client Mikrotik) FindDnsRecord(name string) (*DnsRecord, error) {
-	c, err := client.getMikrotikClient()
+	switch elem.Kind() {
+	case reflect.Slice:
+		l := len(reply.Re)
+		if l <= 1 {
+			panic(fmt.Sprintf("Cannot Unmarshal %d sentence(s) into a slice", l))
+		}
 
-	if err != nil {
-		return nil, err
-	}
-	cmd := "/ip/dns/static/print"
-	log.Printf("[INFO] Running the mikrotik command: `%s`", cmd)
-	r, err := c.Run(cmd)
-	found := false
-	var sentence *proto.Sentence
+		t := elem.Type()
+		d := reflect.MakeSlice(t, l, l)
 
-	if err != nil {
-		return nil, err
-	}
+		for i := 0; i < l; i++ {
+			item := d.Index(i)
+			sentence := reply.Re[i]
 
-	for _, reply := range r.Re {
-		for _, item := range reply.List {
-			if item.Value == name {
-				found = true
-				sentence = reply
-				log.Printf("[DEBUG] Found dns record we were looking for: %v", sentence)
-			}
+			parseStruct(&item, *sentence)
 		}
-	}
-
-	if !found {
-		return nil, nil
-	}
-
-	// TODO: Add error checking
+		elem.Set(d)
 
-	address := ""
-	ttl := ""
-	id := ""
-	for _, pair := range sentence.List {
-		if pair.Key == ".id" {
-			id = pair.Value
+	case reflect.Struct:
+		if len(reply.Re) < 1 {
+			// This is an empty message
+			return nil
 		}
-		if pair.Key == "address" {
-			address = pair.Value
+		if len(reply.Re) > 1 {
+			msg := fmt.Sprintf("Failed to decode reply: %v", reply)
+			return errors.New(msg)
 		}
 
-		if pair.Key == "ttl" {
-			ttl = pair.Value
-		}
+		parseStruct(&elem, *reply.Re[0])
 	}
 
-	return &DnsRecord{
-		Id:      id,
-		Address: address,
-		Name:    name,
-		Ttl:     ttlToSeconds(ttl),
-	}, nil
-}
-
-func (client Mikrotik) UpdateDnsRecord(id, name, address string, ttl int) error {
-	c, err := client.getMikrotikClient()
-
-	if err != nil {
-		return err
-	}
-	cmd := strings.Split(fmt.Sprintf("/ip/dns/static/set =numbers=%s =name=%s =address=%s =ttl=%d", id, name, address, ttl), " ")
-	log.Printf("[INFO] Running the mikrotik command: `%s`", cmd)
-	_, err = c.RunArgs(cmd)
-	return err
+	return nil
 }
+func parseStruct(v *reflect.Value, sentence proto.Sentence) {
+	elem := *v
+	for i := 0; i < elem.NumField(); i++ {
+		field := elem.Field(i)
+		fieldType := elem.Type().Field(i)
+		tags := strings.Split(fieldType.Tag.Get("mikrotik"), ",")
+
+		path := strings.ToLower(fieldType.Name)
+		fieldName := tags[0]
+
+		for _, pair := range sentence.List {
+			if strings.Compare(pair.Key, path) == 0 || strings.Compare(pair.Key, fieldName) == 0 {
+				switch fieldType.Type.Kind() {
+				case reflect.String:
+					field.SetString(pair.Value)
+				case reflect.Bool:
+					b, _ := strconv.ParseBool(pair.Value)
+					field.SetBool(b)
+				case reflect.Int:
+					if contains(tags, "ttlToSeconds") {
+						field.SetInt(int64(ttlToSeconds(pair.Value)))
+					}
+				}
 
-func (client Mikrotik) DeleteDnsRecord(id string) error {
-	c, err := client.getMikrotikClient()
-
-	if err != nil {
-		return err
+			}
+		}
 	}
-	cmd := strings.Split(fmt.Sprintf("/ip/dns/static/remove =numbers=%s", id), " ")
-	log.Printf("[INFO] Running the mikrotik command: `%s`", cmd)
-	_, err = c.RunArgs(cmd)
-	return err
 }
 
 func ttlToSeconds(ttl string) int {
@@ -182,3 +123,43 @@ func ttlToSeconds(ttl string) int {
 	return 86400*days + int(d)/int(math.Pow10(9))
 
 }
+
+func contains(s []string, e string) bool {
+	for _, a := range s {
+		if a == e {
+			return true
+		}
+	}
+	return false
+}
+
+func NewClient(host, username, password string) Mikrotik {
+	return Mikrotik{
+		Host:     host,
+		Username: username,
+		Password: password,
+	}
+}
+
+func GetConfigFromEnv() (host, username, password string) {
+	host = os.Getenv("MIKROTIK_HOST")
+	username = os.Getenv("MIKROTIK_USER")
+	password = os.Getenv("MIKROTIK_PASSWORD")
+	if host == "" || username == "" || password == "" {
+		// panic("Unable to find the MIKROTIK_HOST, MIKROTIK_USER or MIKROTIK_PASSWORD environment variable")
+	}
+	return host, username, password
+}
+
+func (client Mikrotik) getMikrotikClient() (c *routeros.Client, err error) {
+	address := client.Host
+	username := client.Username
+	password := client.Password
+	c, err = routeros.Dial(address, username, password)
+
+	if err != nil {
+		log.Printf("[ERROR] Failed to login to routerOS with error: %v", err)
+	}
+
+	return
+}