Add ipchecker

.gitignore

@@ -1,2 +1,7 @@
 main.exe
 echo-ip.tar
+ip-checker/main.log
+ip-checker/.env
+ip-checker/ip-notifier.tar
+ip-checker/ip
+ip-checker/ip-checker.tar

ip-checker/deploy.sh

@@ -0,0 +1,3 @@
+go build main
+docker build -t ip-checker .
+docker save -o ip-checker.tar ip-checker

ip-checker/dockerfile

@@ -0,0 +1,32 @@
+FROM golang:1.22.4-bullseye as base
+
+RUN adduser \
+	--disabled-password \
+	--gecos "" \
+	--home "/nonexistent" \
+	--shell "/sbin/nologin" \
+	--no-create-home \
+	--uid 65532 \
+	small-user
+
+WORKDIR $GOPATH/src/app/
+
+COPY . .
+
+RUN go mod download
+RUN go mod verify
+
+RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -o /main .
+
+FROM scratch
+
+COPY --from=base /usr/share/zoneinfo /usr/share/zoneinfo
+COPY --from=base /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
+COPY --from=base /etc/passwd /etc/passwd
+COPY --from=base /etc/group /etc/group
+
+COPY --from=base /main .
+
+USER small-user:small-user
+
+CMD ["/main"]

ip-checker/go.mod

@@ -0,0 +1,5 @@
+module main
+
+go 1.22.4
+
+require github.com/joho/godotenv v1.5.1

ip-checker/go.sum

@@ -0,0 +1,2 @@
+github.com/joho/godotenv v1.5.1 h1:7eLL/+HRGLY0ldzfGMeQkb7vMd0as4CfYvUVzLqw0N0=
+github.com/joho/godotenv v1.5.1/go.mod h1:f4LDr5Voq0i2e/R5DDNOoa2zzDfwtkZa6DnEwAbqwq4=

ip-checker/main.go

@@ -0,0 +1,143 @@
+package main
+
+import (
+	_ "embed"
+	"fmt"
+	"io"
+	"log"
+	"net/http"
+	"net/smtp"
+	"os"
+	"strings"
+	"time"
+
+	"github.com/joho/godotenv"
+)
+
+//go:embed .env
+var env string
+var envvar map[string]string
+
+var Error *log.Logger
+
+func init() {
+	log.SetFlags(log.Lmicroseconds | log.Ldate)
+	// logFile, err := os.Create("main.log")
+	// if err != nil {
+	// 	log.Printf("Error creating log file: %v", err)
+	// 	os.Exit(1)
+	// }
+	logger := io.MultiWriter(os.Stdout)
+	log.SetOutput(logger)
+
+	Error = log.New(io.MultiWriter(os.Stderr, os.Stdout),
+		fmt.Sprintf("%sERROR:%s ", "\033[0;101m", "\033[0m"),
+		log.Lmicroseconds|log.Lshortfile)
+}
+
+var oldIP, newIP string
+
+const REMOTE_URL = "http://141.147.53.95:5000"
+const IP_FILE = "ip"
+
+var ipFile *os.File
+var lastMailed time.Time
+
+func main() {
+	var err error
+	envvar, err = godotenv.Parse(strings.NewReader(env))
+	if err != nil {
+		Error.Fatalf("Error parsing .env file: %v", err)
+		os.Exit(1)
+	}
+	ipFile, err = os.OpenFile(IP_FILE, os.O_RDWR|os.O_CREATE, 0644)
+	if err != nil {
+		Error.Fatalf("Error opening IP file: %v", err)
+		os.Exit(1)
+	}
+
+	fileIP, err := io.ReadAll(ipFile)
+	if err != nil {
+		Error.Fatalf("Error reading IP file: %v", err)
+		os.Exit(1)
+	}
+	oldIP = string(fileIP)
+
+	for {
+		newIP = checkIP()
+		if newIP != oldIP {
+			err := doNotify()
+			if err != nil {
+				Error.Fatalf("Error sending email: %v", err)
+			}
+
+			oldIP = newIP
+			ipFile.Truncate(0)
+			ipFile.Seek(0, 0)
+			_, err = ipFile.WriteString(newIP)
+			if err != nil {
+				Error.Fatalf("Error writing to IP file: %v", err)
+			}
+		} else {
+			log.Println("ips same")
+		}
+		time.Sleep(1 * time.Second)
+	}
+}
+
+func checkIP() string {
+	http.NewRequest("GET", REMOTE_URL, nil)
+	resp, err := http.Get(REMOTE_URL)
+	if err != nil {
+		Error.Fatalf("Error getting IP: %v", err)
+		return ""
+	}
+	defer resp.Body.Close()
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		Error.Fatalf("Error reading response body: %v", err)
+		return ""
+	}
+
+	return string(body)
+}
+
+func doNotify() error {
+	if time.Since(lastMailed) < 30*time.Minute {
+		return nil
+	}
+
+	smtpHost, ok := envvar["SMTP_HOST"]
+	if !ok {
+		return fmt.Errorf("error getting env var SMTP_HOST")
+	}
+	smtpPort, ok := envvar["SMTP_PORT"]
+	if !ok {
+		return fmt.Errorf("error getting env var SMTP_PORT")
+	}
+	smtpUser, ok := envvar["SMTP_USER"]
+	if !ok {
+		return fmt.Errorf("error getting env var SMTP_USER")
+	}
+	smtpPass, ok := envvar["SMTP_PASSWORD"]
+	if !ok {
+		return fmt.Errorf("error getting env var SMTP_PASSWORD")
+	}
+
+	from := "admin@quack-lab.dev"
+	to := []string{"david.majdandzic@hotmail.com"}
+	subject := "IP Changed!"
+	body := fmt.Sprintf("Old IP: %s; New IP: %s", oldIP, newIP)
+
+	msg := []byte(fmt.Sprintf("Subject: %s\nFrom: %s\nTo: %s\n\n%s", subject, from, strings.Join(to, ","), body))
+
+	auth := smtp.PlainAuth("", smtpUser, smtpPass, smtpHost)
+	err := smtp.SendMail(smtpHost+":"+smtpPort, auth, from, to, msg)
+	if err != nil {
+		return err
+	}
+	log.Println("Sent mail")
+	lastMailed = time.Now()
+	return nil
+}