A bit of cleanup and documentation
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This commit is contained in:
Tyler 2022-01-09 23:53:23 -05:00
parent c98b04f9c1
commit e6d3782450
4 changed files with 257 additions and 251 deletions

67
http.go
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@ -1,51 +1,52 @@
package main
import (
"fmt"
"net"
"net/http"
"net/url"
"path"
"fmt"
"net"
"net/http"
"net/url"
"path"
)
func statusRequest(w http.ResponseWriter, r *http.Request) {
w.WriteHeader(http.StatusOK)
w.WriteHeader(http.StatusOK)
}
func redirectRequest(w http.ResponseWriter, r *http.Request) {
ipStr, _, err := net.SplitHostPort(r.RemoteAddr)
ipStr, _, err := net.SplitHostPort(r.RemoteAddr)
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
ip := net.ParseIP(ipStr)
ip := net.ParseIP(ipStr)
if ip.IsPrivate() {
ip = net.ParseIP("1.1.1.1")
}
// TODO: This is temporary to allow testing on private addresses.
if ip.IsPrivate() {
ip = net.ParseIP("1.1.1.1")
}
server, distance, err := settings.Servers.Closest(ip)
server, distance, err := servers.Closest(ip)
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
scheme := r.URL.Scheme
scheme := r.URL.Scheme
if scheme == "" {
scheme = "https"
}
if scheme == "" {
scheme = "https"
}
u := &url.URL{
Scheme: scheme,
Host: server.Host,
Path: path.Join(server.Path, r.URL.Path),
}
u := &url.URL{
Scheme: scheme,
Host: server.Host,
Path: path.Join(server.Path, r.URL.Path),
}
w.Header().Set("X-Geo-Distance", fmt.Sprintf("%f", distance))
w.Header().Set("Location", u.String())
w.WriteHeader(http.StatusFound)
}
w.Header().Set("X-Geo-Distance", fmt.Sprintf("%f", distance))
w.Header().Set("Location", u.String())
w.WriteHeader(http.StatusFound)
}

165
main.go
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@ -1,117 +1,114 @@
package main
import (
"github.com/oschwald/maxminddb-golang"
log "github.com/sirupsen/logrus"
"github.com/spf13/viper"
"net"
"net/http"
"net/url"
"strings"
"github.com/oschwald/maxminddb-golang"
log "github.com/sirupsen/logrus"
"github.com/spf13/viper"
"net"
"net/http"
"net/url"
"strings"
)
var (
db *maxminddb.Reader
settings = &Settings{}
db *maxminddb.Reader
servers ServerList
)
// City represents a MaxmindDB city
type City struct {
Location struct {
Latitude float64 `maxminddb:"latitude"`
Longitude float64 `maxminddb:"longitude"`
} `maxminddb:"location"`
}
type Settings struct {
Servers ServerList
Location struct {
Latitude float64 `maxminddb:"latitude"`
Longitude float64 `maxminddb:"longitude"`
} `maxminddb:"location"`
}
func main() {
viper.SetConfigName("dlrouter") // name of config file (without extension)
viper.SetConfigType("yaml") // REQUIRED if the config file does not have the extension in the name
viper.AddConfigPath("/etc/dlrouter/") // path to look for the config file in
viper.AddConfigPath("$HOME/.dlrouter") // call multiple times to add many search paths
viper.AddConfigPath(".") // optionally look for config in the working directory
err := viper.ReadInConfig() // Find and read the config file
viper.SetConfigName("dlrouter") // name of config file (without extension)
viper.SetConfigType("yaml") // REQUIRED if the config file does not have the extension in the name
viper.AddConfigPath("/etc/dlrouter/") // path to look for the config file in
viper.AddConfigPath("$HOME/.dlrouter") // call multiple times to add many search paths
viper.AddConfigPath(".") // optionally look for config in the working directory
err := viper.ReadInConfig() // Find and read the config file
if err != nil { // Handle errors reading the config file
log.WithError(err).Fatalln("Unable to load config file")
}
if err != nil { // Handle errors reading the config file
log.WithError(err).Fatalln("Unable to load config file")
}
db, err = maxminddb.Open(viper.GetString("geodb"))
db, err = maxminddb.Open(viper.GetString("geodb"))
if err != nil {
log.WithError(err).Fatalln("Unable to open database")
}
if err != nil {
log.WithError(err).Fatalln("Unable to open database")
}
servers := viper.GetStringSlice("servers")
serverList := viper.GetStringSlice("servers")
for _, server := range servers {
var prefix string
for _, server := range serverList {
var prefix string
if !strings.HasPrefix(server, "http") {
prefix = "https://"
}
if !strings.HasPrefix(server, "http") {
prefix = "https://"
}
u, err := url.Parse(prefix + server)
u, err := url.Parse(prefix + server)
if err != nil {
log.WithFields(log.Fields{
"error": err,
"server": server,
}).Warning("Server is invalid")
continue
}
if err != nil {
log.WithFields(log.Fields{
"error": err,
"server": server,
}).Warning("Server is invalid")
continue
}
ips, err := net.LookupIP(u.Host)
ips, err := net.LookupIP(u.Host)
if err != nil {
log.WithFields(log.Fields{
"error": err,
"server": server,
}).Warning("Could not resolve address")
continue
}
if err != nil {
log.WithFields(log.Fields{
"error": err,
"server": server,
}).Warning("Could not resolve address")
continue
}
var city City
err = db.Lookup(ips[0], &city)
var city City
err = db.Lookup(ips[0], &city)
if err != nil {
log.WithFields(log.Fields{
"error": err,
"server": server,
}).Warning("Could not geolocate address")
continue
}
if err != nil {
log.WithFields(log.Fields{
"error": err,
"server": server,
}).Warning("Could not geolocate address")
continue
}
settings.Servers = append(settings.Servers, &Server{
Host: u.Host,
Path: u.Path,
Latitude: city.Location.Latitude,
Longitude: city.Location.Longitude,
})
servers = append(servers, &Server{
Host: u.Host,
Path: u.Path,
Latitude: city.Location.Latitude,
Longitude: city.Location.Longitude,
})
log.WithFields(log.Fields{
"server": u.Host,
"path": u.Path,
"latitude": city.Location.Latitude,
"longitude": city.Location.Longitude,
}).Info("Added server")
}
log.WithFields(log.Fields{
"server": u.Host,
"path": u.Path,
"latitude": city.Location.Latitude,
"longitude": city.Location.Longitude,
}).Info("Added server")
}
log.Info("Servers added, checking statuses")
// Force initial check before running
settings.Servers.Check()
log.Info("Servers added, checking statuses")
// Force initial check before running
servers.Check()
// Start check loop
go settings.Servers.checkLoop()
// Start check loop
go servers.checkLoop()
log.Info("Starting")
log.Info("Starting")
mux := http.NewServeMux()
mux := http.NewServeMux()
mux.HandleFunc("/status", RealIPMiddleware(statusRequest))
mux.HandleFunc("/", RealIPMiddleware(redirectRequest))
mux.HandleFunc("/status", RealIPMiddleware(statusRequest))
mux.HandleFunc("/", RealIPMiddleware(redirectRequest))
http.ListenAndServe(":8080", mux)
http.ListenAndServe(":8080", mux)
}

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@ -1,86 +1,87 @@
package main
import (
"net"
"net/http"
"strings"
"net"
"net/http"
"strings"
)
var (
xForwardedFor = http.CanonicalHeaderKey("X-Forwarded-For")
xForwardedProto = http.CanonicalHeaderKey("X-Forwarded-Proto")
xRealIP = http.CanonicalHeaderKey("X-Real-IP")
forwardLimit = 5
xForwardedFor = http.CanonicalHeaderKey("X-Forwarded-For")
xForwardedProto = http.CanonicalHeaderKey("X-Forwarded-Proto")
xRealIP = http.CanonicalHeaderKey("X-Real-IP")
forwardLimit = 5
)
// RealIPMiddleware is an implementation of reverse proxy checks.
// It uses the remote address to find the originating IP, as well as protocol
func RealIPMiddleware(f http.HandlerFunc) http.HandlerFunc {
return func(w http.ResponseWriter, r *http.Request) {
// Treat unix socket as 127.0.0.1
if r.RemoteAddr == "@" {
r.RemoteAddr = "127.0.0.1:0"
}
return func(w http.ResponseWriter, r *http.Request) {
// Treat unix socket as 127.0.0.1
if r.RemoteAddr == "@" {
r.RemoteAddr = "127.0.0.1:0"
}
host, _, err := net.SplitHostPort(r.RemoteAddr)
host, _, err := net.SplitHostPort(r.RemoteAddr)
if err != nil {
f.ServeHTTP(w, r)
return
}
if err != nil {
f.ServeHTTP(w, r)
return
}
if net.ParseIP(host).IsPrivate() {
f.ServeHTTP(w, r)
return
}
if net.ParseIP(host).IsPrivate() {
f.ServeHTTP(w, r)
return
}
if rip := realIP(r); len(rip) > 0 {
r.RemoteAddr = net.JoinHostPort(rip, "0")
}
if rip := realIP(r); len(rip) > 0 {
r.RemoteAddr = net.JoinHostPort(rip, "0")
}
if rproto := realProto(r); len(rproto) > 0 {
r.URL.Scheme = rproto
}
if rproto := realProto(r); len(rproto) > 0 {
r.URL.Scheme = rproto
}
f.ServeHTTP(w, r)
}
f.ServeHTTP(w, r)
}
}
func realIP(r *http.Request) string {
var ip string
var ip string
if xrip := r.Header.Get(xRealIP); xrip != "" {
ip = xrip
} else if xff := r.Header.Get(xForwardedFor); xff != "" {
p := 0
for i := forwardLimit; i > 0; i-- {
if p > 0 {
xff = xff[:p-2]
}
p = strings.LastIndex(xff, ", ")
if p < 0 {
p = 0
break
} else {
p += 2
}
}
if xrip := r.Header.Get(xRealIP); xrip != "" {
ip = xrip
} else if xff := r.Header.Get(xForwardedFor); xff != "" {
p := 0
for i := forwardLimit; i > 0; i-- {
if p > 0 {
xff = xff[:p-2]
}
p = strings.LastIndex(xff, ", ")
if p < 0 {
p = 0
break
} else {
p += 2
}
}
ip = xff[p:]
}
ip = xff[p:]
}
return ip
return ip
}
func realProto(r *http.Request) string {
proto := "http"
proto := "http"
if r.TLS != nil {
proto = "https"
}
if r.TLS != nil {
proto = "https"
}
if xproto := r.Header.Get(xForwardedProto); xproto != "" {
proto = xproto
}
if xproto := r.Header.Get(xForwardedProto); xproto != "" {
proto = xproto
}
return proto
return proto
}

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@ -1,107 +1,114 @@
package main
import (
log "github.com/sirupsen/logrus"
"math"
"net"
"net/http"
"runtime"
"strings"
"sync"
"time"
log "github.com/sirupsen/logrus"
"math"
"net"
"net/http"
"runtime"
"strings"
"sync"
"time"
)
var (
checkClient = &http.Client{
Timeout: 10 * time.Second,
}
checkClient = &http.Client{
Timeout: 10 * time.Second,
}
)
type Server struct {
Available bool
Host string
Path string
Latitude float64
Longitude float64
Available bool
Host string
Path string
Latitude float64
Longitude float64
}
type ServerList []*Server
func (s ServerList) checkLoop() {
t := time.NewTicker(60 * time.Second)
t := time.NewTicker(60 * time.Second)
for {
<- t.C
for {
<-t.C
s.Check()
}
s.Check()
}
}
// Check will request the index from all servers
// If a server does not respond in 10 seconds, it is considered offline.
// This will wait until all checks are complete.
func (s ServerList) Check() {
var wg sync.WaitGroup
var wg sync.WaitGroup
for _, server := range s {
wg.Add(1)
for _, server := range s {
wg.Add(1)
go func(server *Server) {
req, err := http.NewRequest(http.MethodGet, "https://" + server.Host + "/" + strings.TrimLeft(server.Path, "/"), nil)
go func(server *Server) {
req, err := http.NewRequest(http.MethodGet, "https://"+server.Host+"/"+strings.TrimLeft(server.Path, "/"), nil)
req.Header.Set("User-Agent", "ArmbianRouter/1.0 (Go " + runtime.Version() + ")")
req.Header.Set("User-Agent", "ArmbianRouter/1.0 (Go "+runtime.Version()+")")
if err != nil {
return
}
if err != nil {
// This should never happen.
log.WithError(err).Warning("Invalid request! This should not happen, please check config.")
return
}
res, err := checkClient.Do(req)
res, err := checkClient.Do(req)
if err != nil {
log.WithField("server", server.Host).Info("Server went offline")
server.Available = false
return
}
if err != nil {
log.WithField("server", server.Host).Info("Server went offline")
server.Available = false
return
}
if (res.StatusCode == http.StatusOK || res.StatusCode == http.StatusMovedPermanently || res.StatusCode == http.StatusFound) &&
!server.Available {
server.Available = true
log.WithField("server", server.Host).Info("Server is online")
}
wg.Done()
}(server)
}
if (res.StatusCode == http.StatusOK || res.StatusCode == http.StatusMovedPermanently || res.StatusCode == http.StatusFound) &&
!server.Available {
server.Available = true
log.WithField("server", server.Host).Info("Server is online")
}
wg.Done()
}(server)
}
wg.Wait()
wg.Wait()
}
// Closest will use GeoIP on the IP provided and find the closest server.
// Return values are the closest server, the distance, and if an error occurred.
func (s ServerList) Closest(ip net.IP) (*Server, float64, error) {
var city City
err := db.Lookup(ip, &city)
var city City
err := db.Lookup(ip, &city)
if err != nil {
return nil, -1, err
}
if err != nil {
return nil, -1, err
}
var closest *Server
var closestDistance float64 = -1
var closest *Server
var closestDistance float64 = -1
for _, server := range s {
if !server.Available {
continue
}
for _, server := range s {
if !server.Available {
continue
}
distance := Distance(city.Location.Latitude, city.Location.Longitude, server.Latitude, server.Longitude)
distance := Distance(city.Location.Latitude, city.Location.Longitude, server.Latitude, server.Longitude)
if closestDistance == -1 || distance < closestDistance {
closestDistance = distance
closest = server
}
}
if closestDistance == -1 || distance < closestDistance {
closestDistance = distance
closest = server
}
}
return closest, closestDistance, nil
return closest, closestDistance, nil
}
// haversin(θ) function
func hsin(theta float64) float64 {
return math.Pow(math.Sin(theta/2), 2)
return math.Pow(math.Sin(theta/2), 2)
}
// Distance function returns the distance (in meters) between two points of
@ -114,18 +121,18 @@ func hsin(theta float64) float64 {
// distance returned is METERS!!!!!!
// http://en.wikipedia.org/wiki/Haversine_formula
func Distance(lat1, lon1, lat2, lon2 float64) float64 {
// convert to radians
// must cast radius as float to multiply later
var la1, lo1, la2, lo2, r float64
la1 = lat1 * math.Pi / 180
lo1 = lon1 * math.Pi / 180
la2 = lat2 * math.Pi / 180
lo2 = lon2 * math.Pi / 180
// convert to radians
// must cast radius as float to multiply later
var la1, lo1, la2, lo2, r float64
la1 = lat1 * math.Pi / 180
lo1 = lon1 * math.Pi / 180
la2 = lat2 * math.Pi / 180
lo2 = lon2 * math.Pi / 180
r = 6378100 // Earth radius in METERS
r = 6378100 // Earth radius in METERS
// calculate
h := hsin(la2-la1) + math.Cos(la1)*math.Cos(la2)*hsin(lo2-lo1)
// calculate
h := hsin(la2-la1) + math.Cos(la1)*math.Cos(la2)*hsin(lo2-lo1)
return 2 * r * math.Asin(math.Sqrt(h))
}
return 2 * r * math.Asin(math.Sqrt(h))
}