initial commit

This commit is contained in:
Evan Reichard 2025-09-19 14:59:07 -04:00
commit 84ea3802b8
9 changed files with 545 additions and 0 deletions

136
cmd/link.go Normal file
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package cmd
import (
"bytes"
"fmt"
"io"
"log"
"net/http"
"github.com/gorilla/websocket"
"github.com/spf13/cobra"
)
type TunnelRequest struct {
ID string `json:"id"`
Method string `json:"method"`
URL string `json:"url"`
Headers map[string]string `json:"headers"`
Body []byte `json:"body"`
}
type TunnelResponse struct {
ID string `json:"id"`
StatusCode int `json:"status_code"`
Headers map[string]string `json:"headers"`
Body []byte `json:"body"`
}
var serverAddr string
var linkCmd = &cobra.Command{
Use: "link <vhost_location> <local_port>",
Short: "Create a tunnel link",
Args: cobra.ExactArgs(2),
Run: func(cmd *cobra.Command, args []string) {
vhostLoc := args[0]
localPort := args[1]
fmt.Printf("Creating tunnel: %s -> localhost:%s\n", vhostLoc, localPort)
if err := startTunnel(vhostLoc, localPort); err != nil {
log.Fatal("Failed to start tunnel:", err)
}
},
}
func init() {
linkCmd.Flags().StringVarP(&serverAddr, "server", "s", "localhost:8080", "Conduit server address")
}
func startTunnel(vhost, localPort string) error {
// Connect to WebSocket
wsURL := fmt.Sprintf("ws://%s/_conduit/tunnel?vhost=%s", serverAddr, vhost)
conn, _, err := websocket.DefaultDialer.Dial(wsURL, nil)
if err != nil {
return fmt.Errorf("failed to connect: %v", err)
}
defer conn.Close()
fmt.Printf("Tunnel active! %s.example.com -> localhost:%s\n", vhost, localPort)
// Handle incoming requests
for {
var req TunnelRequest
if err := conn.ReadJSON(&req); err != nil {
log.Printf("Error reading request: %v", err)
break
}
go handleTunnelRequest(conn, &req, localPort)
}
return nil
}
func handleTunnelRequest(conn *websocket.Conn, req *TunnelRequest, localPort string) {
// Make request to local service
localURL := fmt.Sprintf("http://localhost:%s%s", localPort, req.URL)
httpReq, err := http.NewRequest(req.Method, localURL, bytes.NewReader(req.Body))
if err != nil {
sendErrorResponse(conn, req.ID, 500, "Failed to create request")
return
}
// Set headers
for k, v := range req.Headers {
httpReq.Header.Set(k, v)
}
// Make the request
client := &http.Client{}
resp, err := client.Do(httpReq)
if err != nil {
sendErrorResponse(conn, req.ID, 502, "Failed to reach local service")
return
}
defer resp.Body.Close()
// Read response body
body, err := io.ReadAll(resp.Body)
if err != nil {
sendErrorResponse(conn, req.ID, 500, "Failed to read response")
return
}
// Convert response headers
headers := make(map[string]string)
for k, v := range resp.Header {
if len(v) > 0 {
headers[k] = v[0]
}
}
// Send response back
tunnelResp := &TunnelResponse{
ID: req.ID,
StatusCode: resp.StatusCode,
Headers: headers,
Body: body,
}
if err := conn.WriteJSON(tunnelResp); err != nil {
log.Printf("Error sending response: %v", err)
}
}
func sendErrorResponse(conn *websocket.Conn, reqID string, statusCode int, message string) {
resp := &TunnelResponse{
ID: reqID,
StatusCode: statusCode,
Headers: map[string]string{"Content-Type": "text/plain"},
Body: []byte(message),
}
conn.WriteJSON(resp)
}

26
cmd/root.go Normal file
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package cmd
import (
"fmt"
"os"
"github.com/spf13/cobra"
)
var rootCmd = &cobra.Command{
Use: "conduit",
Short: "A tunneling service similar to ngrok",
Long: `Conduit allows you to expose local services through secure tunnels`,
}
func Execute() {
if err := rootCmd.Execute(); err != nil {
fmt.Println(err)
os.Exit(1)
}
}
func init() {
rootCmd.AddCommand(serveCmd)
rootCmd.AddCommand(linkCmd)
}

30
cmd/serve.go Normal file
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package cmd
import (
"fmt"
"log"
"reichard.io/conduit/server"
"github.com/spf13/cobra"
)
var port string
var serveCmd = &cobra.Command{
Use: "serve",
Short: "Start the conduit server",
Long: `Start the conduit server to handle incoming tunnel requests`,
Run: func(cmd *cobra.Command, args []string) {
fmt.Printf("Starting Conduit server on port %s...\n", port)
srv := server.NewServer()
if err := srv.Start(":" + port); err != nil {
log.Fatal("Failed to start server:", err)
}
},
}
func init() {
serveCmd.Flags().StringVarP(&port, "port", "p", "8080", "Port to run the server on")
}

61
flake.lock generated Normal file
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{
"nodes": {
"flake-utils": {
"inputs": {
"systems": "systems"
},
"locked": {
"lastModified": 1731533236,
"narHash": "sha256-l0KFg5HjrsfsO/JpG+r7fRrqm12kzFHyUHqHCVpMMbI=",
"owner": "numtide",
"repo": "flake-utils",
"rev": "11707dc2f618dd54ca8739b309ec4fc024de578b",
"type": "github"
},
"original": {
"owner": "numtide",
"repo": "flake-utils",
"type": "github"
}
},
"nixpkgs": {
"locked": {
"lastModified": 1754292888,
"narHash": "sha256-1ziydHSiDuSnaiPzCQh1mRFBsM2d2yRX9I+5OPGEmIE=",
"owner": "NixOS",
"repo": "nixpkgs",
"rev": "ce01daebf8489ba97bd1609d185ea276efdeb121",
"type": "github"
},
"original": {
"owner": "NixOS",
"ref": "nixos-25.05",
"repo": "nixpkgs",
"type": "github"
}
},
"root": {
"inputs": {
"flake-utils": "flake-utils",
"nixpkgs": "nixpkgs"
}
},
"systems": {
"locked": {
"lastModified": 1681028828,
"narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
"owner": "nix-systems",
"repo": "default",
"rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
"type": "github"
},
"original": {
"owner": "nix-systems",
"repo": "default",
"type": "github"
}
}
},
"root": "root",
"version": 7
}

26
flake.nix Normal file
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{
description = "Development Environment";
inputs = {
nixpkgs.url = "github:NixOS/nixpkgs/nixos-25.05";
flake-utils.url = "github:numtide/flake-utils";
};
outputs = { self, nixpkgs, flake-utils }:
flake-utils.lib.eachDefaultSystem (system:
let
pkgs = nixpkgs.legacyPackages.${system};
in
{
devShells.default = pkgs.mkShell {
packages = with pkgs; [
go
golangci-lint
];
shellHook = ''
export PATH=$PATH:~/go/bin
'';
};
}
);
}

10
go.mod Normal file
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module reichard.io/conduit
go 1.24.4
require (
github.com/gorilla/websocket v1.5.3 // indirect
github.com/inconshreveable/mousetrap v1.1.0 // indirect
github.com/spf13/cobra v1.10.1 // indirect
github.com/spf13/pflag v1.0.9 // indirect
)

12
go.sum Normal file
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github.com/cpuguy83/go-md2man/v2 v2.0.6/go.mod h1:oOW0eioCTA6cOiMLiUPZOpcVxMig6NIQQ7OS05n1F4g=
github.com/gorilla/websocket v1.5.3 h1:saDtZ6Pbx/0u+bgYQ3q96pZgCzfhKXGPqt7kZ72aNNg=
github.com/gorilla/websocket v1.5.3/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
github.com/inconshreveable/mousetrap v1.1.0/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
github.com/spf13/cobra v1.10.1 h1:lJeBwCfmrnXthfAupyUTzJ/J4Nc1RsHC/mSRU2dll/s=
github.com/spf13/cobra v1.10.1/go.mod h1:7SmJGaTHFVBY0jW4NXGluQoLvhqFQM+6XSKD+P4XaB0=
github.com/spf13/pflag v1.0.9 h1:9exaQaMOCwffKiiiYk6/BndUBv+iRViNW+4lEMi0PvY=
github.com/spf13/pflag v1.0.9/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

7
main.go Normal file
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package main
import "reichard.io/conduit/cmd"
func main() {
cmd.Execute()
}

237
server/server.go Normal file
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package server
import (
"fmt"
"io"
"log"
"net/http"
"strings"
"sync"
"time"
"github.com/gorilla/websocket"
)
type TunnelConnection struct {
conn *websocket.Conn
vhost string
responses map[string]chan *TunnelResponse
mu sync.RWMutex
}
type TunnelRequest struct {
ID string `json:"id"`
Method string `json:"method"`
URL string `json:"url"`
Headers map[string]string `json:"headers"`
Body []byte `json:"body"`
}
type TunnelResponse struct {
ID string `json:"id"`
StatusCode int `json:"status_code"`
Headers map[string]string `json:"headers"`
Body []byte `json:"body"`
}
type Server struct {
tunnels map[string]*TunnelConnection
mu sync.RWMutex
upgrader websocket.Upgrader
}
func NewServer() *Server {
return &Server{
tunnels: make(map[string]*TunnelConnection),
upgrader: websocket.Upgrader{
CheckOrigin: func(r *http.Request) bool {
return true
},
},
}
}
func (s *Server) Start(addr string) error {
http.HandleFunc("/", s.handleRequest)
http.HandleFunc("/_conduit/tunnel", s.handleTunnel)
http.HandleFunc("/_conduit/status", s.handleStatus)
log.Printf("Conduit server listening on %s", addr)
return http.ListenAndServe(addr, nil)
}
func (s *Server) handleRequest(w http.ResponseWriter, r *http.Request) {
host := r.Host
subdomain := s.extractSubdomain(host)
if subdomain == "" {
http.Error(w, "Invalid host", http.StatusBadRequest)
return
}
s.mu.RLock()
tunnel, exists := s.tunnels[subdomain]
s.mu.RUnlock()
if !exists {
http.Error(w, "Tunnel not found", http.StatusNotFound)
return
}
// Create unique request ID
reqID := fmt.Sprintf("%d", time.Now().UnixNano())
// Read request body
body, err := io.ReadAll(r.Body)
if err != nil {
http.Error(w, "Failed to read request body", http.StatusBadRequest)
return
}
defer r.Body.Close()
// Convert headers
headers := make(map[string]string)
for k, v := range r.Header {
if len(v) > 0 {
headers[k] = v[0]
}
}
// Create response channel for this request
respChan := make(chan *TunnelResponse, 1)
tunnel.mu.Lock()
tunnel.responses[reqID] = respChan
tunnel.mu.Unlock()
// Clean up response channel when done
defer func() {
tunnel.mu.Lock()
delete(tunnel.responses, reqID)
tunnel.mu.Unlock()
}()
tunnelReq := &TunnelRequest{
ID: reqID,
Method: r.Method,
URL: r.URL.String(),
Headers: headers,
Body: body,
}
// Send request to tunnel
if err := tunnel.conn.WriteJSON(tunnelReq); err != nil {
log.Printf("Error sending request to tunnel: %v", err)
http.Error(w, "Tunnel communication error", http.StatusServiceUnavailable)
return
}
// Wait for response
select {
case resp := <-respChan:
// Write response headers
for k, v := range resp.Headers {
w.Header().Set(k, v)
}
w.WriteHeader(resp.StatusCode)
w.Write(resp.Body)
case <-time.After(30 * time.Second):
http.Error(w, "Tunnel timeout", http.StatusGatewayTimeout)
}
}
func (s *Server) handleTunnel(w http.ResponseWriter, r *http.Request) {
vhost := r.URL.Query().Get("vhost")
if vhost == "" {
http.Error(w, "Missing vhost parameter", http.StatusBadRequest)
return
}
conn, err := s.upgrader.Upgrade(w, r, nil)
if err != nil {
log.Printf("WebSocket upgrade failed: %v", err)
return
}
tunnel := &TunnelConnection{
conn: conn,
vhost: vhost,
responses: make(map[string]chan *TunnelResponse),
}
s.mu.Lock()
s.tunnels[vhost] = tunnel
s.mu.Unlock()
log.Printf("Tunnel established: %s", vhost)
// Handle tunnel communication
s.handleTunnelConnection(tunnel)
}
func (s *Server) handleTunnelConnection(tunnel *TunnelConnection) {
defer func() {
s.mu.Lock()
delete(s.tunnels, tunnel.vhost)
s.mu.Unlock()
tunnel.conn.Close()
log.Printf("Tunnel closed: %s", tunnel.vhost)
}()
// Handle incoming responses from client
for {
var resp TunnelResponse
if err := tunnel.conn.ReadJSON(&resp); err != nil {
log.Printf("Error reading response from tunnel %s: %v", tunnel.vhost, err)
return
}
// Find the response channel for this request
tunnel.mu.RLock()
respChan, exists := tunnel.responses[resp.ID]
tunnel.mu.RUnlock()
if exists {
select {
case respChan <- &resp:
// Response delivered
default:
log.Printf("Response channel full for request %s", resp.ID)
}
} else {
log.Printf("No response channel found for request %s", resp.ID)
}
}
}
func (s *Server) handleStatus(w http.ResponseWriter, r *http.Request) {
s.mu.RLock()
defer s.mu.RUnlock()
w.Header().Set("Content-Type", "application/json")
fmt.Fprintf(w, `{"tunnels": %d, "active": [`, len(s.tunnels))
first := true
for vhost := range s.tunnels {
if !first {
fmt.Fprint(w, ",")
}
fmt.Fprintf(w, `{"vhost":"%s"}`, vhost)
first = false
}
fmt.Fprint(w, "]}")
}
func (s *Server) extractSubdomain(host string) string {
if idx := strings.Index(host, ":"); idx != -1 {
host = host[:idx]
}
parts := strings.Split(host, ".")
if len(parts) >= 1 {
return parts[0]
}
return ""
}