-
Notifications
You must be signed in to change notification settings - Fork 0
/
main.go
167 lines (154 loc) · 4.13 KB
/
main.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
package main
import (
"encoding/json"
"fmt"
"io/ioutil"
"log"
"net"
"net/http"
"os"
"strings"
"time"
)
var (
APIKey string = os.Getenv("APIKey")
Zone string = os.Getenv("Zone")
RecordName string = os.Getenv("RecordName")
tr = &http.Transport{
MaxIdleConns: 10,
IdleConnTimeout: 5 * time.Second,
DisableCompression: true,
}
previousIP string
recType string
)
func main() {
log.Printf("Getting initial IP address\n")
ip, err := getIP()
if err != nil {
log.Printf("Failed to get IP: %v\n", err)
os.Exit(-1)
}
log.Printf("Determining IP type\n")
parsedIP := net.ParseIP(ip)
if parsedIP.To4() != nil {
recType = "A"
} else {
recType = "AAAA"
}
log.Printf("Getting the ID of the record (%s)\n", Zone)
recID, err := getRecordID()
if err != nil {
log.Printf("Failed to get the ID of the record %v (%s)\n", err, recType)
os.Exit(-1)
}
log.Printf("Got record ID: %s\n", recID)
for {
ip, err := getIP()
if err == nil {
if previousIP == ip {
log.Println("No change to public IP")
} else {
log.Printf("Current public IP: %s\n", ip)
err = setIP(ip, recID)
if err != nil {
log.Printf("Error setting IP: %v\n", err)
} else {
log.Println("Updated!")
previousIP = ip
}
}
}
time.Sleep(1 * time.Minute)
}
}
// DNSRecords holds the result of Cloudflare's DNS record listing.
type DNSRecords struct {
Success bool `json:"success"`
Errors []interface{} `json:"errors"`
Messages []interface{} `json:"messages"`
Result []struct {
ID string `json:"id"`
Type string `json:"type"`
Name string `json:"name"`
Content string `json:"content"`
Proxiable bool `json:"proxiable"`
Proxied bool `json:"proxied"`
TTL int `json:"ttl"`
Locked bool `json:"locked"`
ZoneID string `json:"zone_id"`
ZoneName string `json:"zone_name"`
CreatedOn time.Time `json:"created_on"`
ModifiedOn time.Time `json:"modified_on"`
Data struct {
} `json:"data"`
Meta struct {
AutoAdded bool `json:"auto_added"`
Source string `json:"source"`
} `json:"meta"`
} `json:"result"`
}
func setHeaders(req *http.Request) {
req.Header.Set("Authorization", "Bearer "+APIKey)
req.Header.Set("Content-Type", "application/json")
}
func newClient() *http.Client {
return &http.Client{
Transport: tr,
Timeout: time.Second * 10,
}
}
// getRecordID gets the record ID of a DNS record based on the record name
func getRecordID() (string, error) {
client := newClient()
url := "https://api.cloudflare.com/client/v4/zones/" + Zone + "/dns_records?type=" + recType + "&name=" + RecordName
req, err := http.NewRequest("GET", url, nil)
if err != nil {
return "", fmt.Errorf("cannot create request: %v", err)
}
setHeaders(req)
resp, err := client.Do(req)
s, err := ioutil.ReadAll(resp.Body)
if err != nil {
return "", err
}
if resp.StatusCode != http.StatusOK {
return "", fmt.Errorf("cloudflare returned non-OK status: %s", resp.Status)
}
var recs DNSRecords
err = json.Unmarshal(s, &recs)
if len(recs.Result) == 0 {
return "", fmt.Errorf("cannot find record: %s", RecordName)
}
return recs.Result[0].ID, nil
}
// setIP sets the IP address based on record ID.
func setIP(ip string, recID string) error {
client := newClient()
body := `{"type":"` + recType + `","name":"` + RecordName + `","content":"` + ip + `","ttl":120,"proxied":false}`
url := "https://api.cloudflare.com/client/v4/zones/" + Zone + "/dns_records/" + recID
req, err := http.NewRequest("PUT", url, strings.NewReader(body))
if err != nil {
return fmt.Errorf("cannot create request: %v", err)
}
setHeaders(req)
resp, err := client.Do(req)
if resp.StatusCode != http.StatusOK {
return fmt.Errorf("cloudflare returned non-OK status: %s", resp.Status)
}
return nil
}
// getIP returns the public IP address.
func getIP() (string, error) {
client := newClient()
req, err := http.NewRequest("GET", "https://icanhazip.com", nil)
resp, err := client.Do(req)
if err != nil {
return "", err
}
s, err := ioutil.ReadAll(resp.Body)
if err != nil {
return "", err
}
return strings.TrimSpace(string(s)), nil
}