ip-checker/main.go

133 lines
2.9 KiB
Go

package main
import (
"fmt"
"html/template"
"log"
"net"
"net/http"
"os"
"strings"
"sync"
"github.com/oschwald/geoip2-golang"
)
var (
db *geoip2.Reader
tmpl *template.Template
config ServerConfig
ipCache sync.Map
)
type ServerConfig struct {
listen string
countrydb string
}
func main() {
config = ServerConfig{
listen: getEnvOr("IP_CHECKER_LISTEN", ":8080"),
countrydb: os.Getenv("IP_CHECKER_COUNTRY_DB"),
}
if config.countrydb != "" {
var err error
db, err = geoip2.Open(config.countrydb)
if err != nil {
log.Fatalf("Error opening GeoIP database: %v", err)
}
defer db.Close()
}
tmpl = template.Must(template.ParseFiles("assets/index.html"))
http.Handle("/static/", http.StripPrefix("/static/", http.FileServer(http.Dir("./assets/static"))))
http.HandleFunc("/{$}", handleRequest)
http.HandleFunc("/robots.txt", func(w http.ResponseWriter, r *http.Request) {
fmt.Fprintf(w, `User-Agent: *
Disallow: /harming/humans
Disallow: /ignoring/human/orders
Disallow: /harm/to/self
`)
})
log.Printf("Starting server on %s", config.listen)
log.Fatal(http.ListenAndServe(config.listen, nil))
}
func getIPCountry(ip string) string {
if config.countrydb == "" {
return "unknown"
}
if country, found := ipCache.Load(ip); found {
return country.(string)
}
record, err := db.Country(net.ParseIP(ip))
if err != nil {
log.Print(err)
return "an error occurred"
}
country := record.Country.Names["en"]
ipCache.Store(ip, country) // Cache the result
return country
}
func handleRequest(w http.ResponseWriter, r *http.Request) {
sourceIP := func() string {
if ip := r.Header.Get("X-Forwarded-For"); ip != "" {
return strings.Split(ip, ",")[0]
}
host, _, err := net.SplitHostPort(r.RemoteAddr)
if err != nil {
errorText := fmt.Sprintf("Unable to parse remote address: %v", err)
log.Printf(errorText)
return errorText
}
return host
}()
isHeadless := strings.HasPrefix(r.Header.Get("User-Agent"), "curl/")
log.Printf("r.URL.Path: %s, sourceIP: %s, isHeadless: %t, User-Agent: %s", r.URL.Path, sourceIP, isHeadless, r.Header.Get("User-Agent"))
if isHeadless {
fmt.Fprintf(w, "%s\n", sourceIP)
} else {
csp := []string{
"default-src 'none'",
"img-src 'self'",
"script-src-elem 'self'",
"style-src-elem 'self' fonts.googleapis.com",
"font-src fonts.gstatic.com",
"connect-src api.ip.sb api-v3.speedtest.cn api.ipapi.is",
}
w.Header().Set("Content-Security-Policy", strings.Join(csp, "; "))
data := map[string]string{
"sourceIP": sourceIP,
"sourceCountry": getIPCountry(sourceIP),
}
err := tmpl.Execute(w, data)
if err != nil {
http.Error(w, "Unable to load template", http.StatusInternalServerError)
log.Printf("Template execution error: %v", err)
return
}
}
}
func getEnvOr(key, defaultValue string) string {
if value, exists := os.LookupEnv(key); exists {
return value
}
return defaultValue
}