Files
freemoto/app/web/main.go
2025-09-17 10:39:49 +00:00

249 lines
7.6 KiB
Go

package main
import (
"context"
"fmt"
"io"
"log"
"net/http"
"os"
"strings"
"sync/atomic"
"time"
"github.com/joho/godotenv"
)
type ctxKey string
const ctxReqID ctxKey = "reqID"
// atomic counter for simple request IDs
var reqIDCounter uint64
// log levels
const (
levelDebug = iota
levelInfo
levelWarn
levelError
)
var currentLogLevel = levelInfo
func parseLogLevel(s string) int {
switch strings.ToLower(s) {
case "debug":
return levelDebug
case "info", "":
return levelInfo
case "warn", "warning":
return levelWarn
case "error", "err":
return levelError
default:
return levelInfo
}
}
func logf(level int, format string, args ...any) {
if level < currentLogLevel {
return
}
prefix := "INFO"
switch level {
case levelDebug:
prefix = "DEBUG"
case levelInfo:
prefix = "INFO"
case levelWarn:
prefix = "WARN"
case levelError:
prefix = "ERROR"
}
// Prepend the prefix as the first argument
log.Printf("[%s] "+format, append([]any{prefix}, args...)...)
}
func main() {
_ = godotenv.Load(".env") // Load .env file
valhallaURL := os.Getenv("VALHALLA_URL")
if valhallaURL == "" {
valhallaURL = "http://valhalla:8002/route"
}
nominatimBase := os.Getenv("NOMINATIM_URL")
if nominatimBase == "" {
nominatimBase = "https://nominatim.openstreetmap.org"
}
nominatimUA := os.Getenv("NOMINATIM_USER_AGENT")
if nominatimUA == "" {
nominatimUA = "FreeMoto/1.0 (+https://fm.ztsw.de/)"
}
currentLogLevel = parseLogLevel(os.Getenv("LOG_LEVEL"))
port := os.Getenv("PORT")
if port == "" {
port = "8080"
}
http.Handle("/static/", withLogging(http.StripPrefix("/static/", http.FileServer(http.Dir("./static")))))
http.Handle("/healthz", withLogging(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.WriteHeader(http.StatusOK)
_, _ = w.Write([]byte("ok"))
})))
http.Handle("/route", withLogging(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
proxyToValhalla(w, r, valhallaURL)
})))
// Nominatim proxy endpoints
http.Handle("/geocode", withLogging(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
proxyToNominatimGET(w, r, nominatimBase+"/search", nominatimUA)
})))
http.Handle("/reverse", withLogging(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
proxyToNominatimGET(w, r, nominatimBase+"/reverse", nominatimUA)
})))
http.Handle("/", withLogging(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
if r.URL.Path == "/" {
http.ServeFile(w, r, "./static/index.html")
return
}
http.ServeFile(w, r, "./static/"+r.URL.Path[1:])
})))
logf(levelInfo, "Listening on :%s", port)
http.ListenAndServe(":"+port, nil)
}
func proxyToValhalla(w http.ResponseWriter, r *http.Request, valhallaURL string) {
// Create outbound request with caller context and preserve headers
req, err := http.NewRequestWithContext(r.Context(), http.MethodPost, valhallaURL, r.Body)
if err != nil {
http.Error(w, err.Error(), http.StatusBadRequest)
return
}
req.Header = r.Header.Clone()
client := http.Client{Timeout: 15 * time.Second}
start := time.Now()
resp, err := client.Do(req)
if err != nil {
if rid, ok := r.Context().Value(ctxReqID).(string); ok {
logf(levelError, "rid=%s upstream=valhalla error=%v", rid, err)
} else {
logf(levelError, "upstream=valhalla error=%v", err)
}
http.Error(w, err.Error(), http.StatusBadGateway)
return
}
defer resp.Body.Close()
// Propagate relevant headers and status code
for key, values := range resp.Header {
// Optionally filter headers; here we forward common ones
if key == "Content-Type" || key == "Content-Encoding" || key == "Cache-Control" || key == "Vary" {
for _, v := range values {
w.Header().Add(key, v)
}
}
}
w.WriteHeader(resp.StatusCode)
_, _ = io.Copy(w, resp.Body)
if rid, ok := r.Context().Value(ctxReqID).(string); ok {
logf(levelDebug, "rid=%s upstream=valhalla status=%d dur=%s", rid, resp.StatusCode, time.Since(start))
} else {
logf(levelDebug, "upstream=valhalla status=%d dur=%s", resp.StatusCode, time.Since(start))
}
}
// proxyToNominatimGET proxies GET requests to Nominatim endpoints (search/reverse),
// sets a descriptive User-Agent, and enforces a timeout.
func proxyToNominatimGET(w http.ResponseWriter, r *http.Request, target string, userAgent string) {
if r.Method != http.MethodGet {
http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
return
}
// Preserve original query parameters
url := target
if rq := r.URL.RawQuery; rq != "" {
url = url + "?" + rq
}
req, err := http.NewRequestWithContext(r.Context(), http.MethodGet, url, nil)
if err != nil {
http.Error(w, err.Error(), http.StatusBadRequest)
return
}
// Set a proper User-Agent per Nominatim usage policy
req.Header.Set("User-Agent", userAgent)
req.Header.Set("Accept", "application/json")
client := http.Client{Timeout: 10 * time.Second}
start := time.Now()
resp, err := client.Do(req)
if err != nil {
if rid, ok := r.Context().Value(ctxReqID).(string); ok {
logf(levelError, "rid=%s upstream=nominatim url=%s error=%v", rid, url, err)
} else {
logf(levelError, "upstream=nominatim url=%s error=%v", url, err)
}
http.Error(w, err.Error(), http.StatusBadGateway)
return
}
defer resp.Body.Close()
// Forward selected headers and status code
if ct := resp.Header.Get("Content-Type"); ct != "" {
w.Header().Set("Content-Type", ct)
}
w.WriteHeader(resp.StatusCode)
_, _ = io.Copy(w, resp.Body)
if rid, ok := r.Context().Value(ctxReqID).(string); ok {
logf(levelDebug, "rid=%s upstream=nominatim status=%d dur=%s", rid, resp.StatusCode, time.Since(start))
} else {
logf(levelDebug, "upstream=nominatim status=%d dur=%s", resp.StatusCode, time.Since(start))
}
}
// withLogging wraps handlers to add request ID, status, duration logging
func withLogging(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
rid := fmt.Sprintf("%x", atomic.AddUint64(&reqIDCounter, 1))
ctx := context.WithValue(r.Context(), ctxReqID, rid)
r = r.WithContext(ctx)
lrw := &loggingResponseWriter{ResponseWriter: w, status: 200}
start := time.Now()
next.ServeHTTP(lrw, r)
dur := time.Since(start)
logf(levelInfo, "rid=%s method=%s path=%s status=%d bytes=%d dur=%s ua=\"%s\" ip=%s",
rid, r.Method, r.URL.Path, lrw.status, lrw.bytes, dur, r.UserAgent(), clientIP(r))
})
}
type loggingResponseWriter struct {
http.ResponseWriter
status int
bytes int
}
func (lrw *loggingResponseWriter) WriteHeader(code int) {
lrw.status = code
lrw.ResponseWriter.WriteHeader(code)
}
func (lrw *loggingResponseWriter) Write(b []byte) (int, error) {
n, err := lrw.ResponseWriter.Write(b)
lrw.bytes += n
return n, err
}
func clientIP(r *http.Request) string {
// honor X-Forwarded-For if present (first IP)
if xff := r.Header.Get("X-Forwarded-For"); xff != "" {
return xff
}
return r.RemoteAddr
}