package main
import (
"database/sql"
"fmt"
"html/template"
"log"
"net"
"net/http"
"os"
"slices"
"strconv"
"strings"
"time"
"github.com/patrickmn/go-cache"
_ "github.com/lib/pq" // PostgreSQL driver
)
var (
db *sql.DB // Global database connection
c = cache.New(5*time.Minute, 10*time.Minute)
oauthAllowedHost = os.Getenv("OAUTH_ALLOWED_HOST") // URL authorized for device code
oauthDeviceCodeAllowedIPs = strings.Split(os.Getenv("OAUTH_DEVICE_CODE_ALLOWED_IPS"), ",") // IPS autorisées pour /retrieve
)
// dbConnection initializes the database connection.
func dbConnection() (*sql.DB, error) {
connStr := os.Getenv("DATABASE_URL") // You should set this env var, e.g., postgres://username:password@localhost/dbname?sslmode=disable
return sql.Open("postgres", connStr)
}
// livenessHandler is used by Kubernetes to check if the app is alive.
func livenessHandler(w http.ResponseWriter, r *http.Request) {
w.WriteHeader(http.StatusOK)
fmt.Fprintf(w, "OK")
}
// readinessHandler is used by Kubernetes to check if the app is ready to serve traffic.
func readinessHandler(w http.ResponseWriter, r *http.Request) {
// Check if the database connection is alive
err := db.Ping()
if err != nil {
log.Printf("Readiness probe failed: Database connection error: %v", err)
w.WriteHeader(http.StatusServiceUnavailable)
fmt.Fprintf(w, "NOT READY")
return
}
// If the database is reachable, return 200 OK
w.WriteHeader(http.StatusOK)
fmt.Fprintf(w, "OK")
}
// indexHandler serves the HTML form for the query.
func indexHandler(w http.ResponseWriter, r *http.Request) {
tmpl := `
Query Form
Query Form
`
fmt.Fprintf(w, tmpl)
}
// selectHandler handles HTTP requests and executes a SQL query.
func selectHandler(w http.ResponseWriter, r *http.Request) {
// Get the 'param' query parameter
paramStr := r.URL.Query().Get("param")
if paramStr == "" {
http.Error(w, "Missing 'param' query parameter", http.StatusBadRequest)
return
}
// Convert the param to an integer
param, err := strconv.Atoi(paramStr)
if err != nil {
http.Error(w, "Invalid 'param' query parameter. Must be an integer.", http.StatusBadRequest)
return
}
// Prepare the SQL query to prevent SQL injection
query := "SELECT 42 + $1"
// Execute the query with the provided parameter
var result int
err = db.QueryRow(query, param).Scan(&result)
if err != nil {
log.Printf("Failed to execute query: %v", err)
http.Error(w, "Internal Server Error", http.StatusInternalServerError)
return
}
// Return the result in a simple HTML response
fmt.Fprintf(w, "
Result: %d
", result)
}
// Structure de base pour passer les données au template HTML
type CallbackData struct {
Code string
State string
Other map[string]string
}
// oauth2_callback handles HTTP requests and display a message according to queryParams
func oauth2_callback(w http.ResponseWriter, r *http.Request) {
// Vérifier le référent (ou origine)
hostHeader := strings.Trim(r.Header.Get("X-Forwarded-Host"), "[]")
if oauthAllowedHost != "" && hostHeader != oauthAllowedHost {
fmt.Fprintln(os.Stderr, "X-Forwarded-Host: "+hostHeader)
fmt.Fprintln(os.Stderr, "received headers")
for key, value := range r.Header {
fmt.Fprintf(os.Stderr, "%s='%s'\n", key, value)
}
http.Error(w, "Access denied: invalid referer or origin", http.StatusForbidden)
return
}
// Récupération des paramètres query
queryParams := r.URL.Query()
code := queryParams.Get("code")
state := queryParams.Get("state")
// Stocker state et code dans le cache avec TTL de 5 minutes
if state != "" && code != "" {
c.Set(state, code, cache.DefaultExpiration)
}
// Construction d'une map pour les autres paramètres
otherParams := make(map[string]string)
for key, values := range queryParams {
if key != "code" && key != "state" {
otherParams[key] = strings.Join(values, ", ")
}
}
// Définition du template HTML avec le comportement demandé
tmpl := `
OAuth2 Callback
{{if and .Code .State}}
{{end}}
`
// Parsing du template
t, err := template.New("callback").Parse(tmpl)
if err != nil {
http.Error(w, "Error parsing template", http.StatusInternalServerError)
return
}
// Remplissage des données et exécution du template
data := CallbackData{
Code: code,
State: state,
Other: otherParams,
}
w.Header().Set("Content-Type", "text/html")
if err := t.Execute(w, data); err != nil {
http.Error(w, "Error rendering template", http.StatusInternalServerError)
}
}
// Handler pour récupérer un code à partir d'un state avec une restriction d'IP
func retrieveHandler(w http.ResponseWriter, r *http.Request) {
// Récupérer l'IP de l'utilisateur
userIP, _, err := net.SplitHostPort(r.RemoteAddr)
userIPforwarded := r.Header.Get("X-Forwarded-For")
if err != nil ||
!slices.Contains(oauthDeviceCodeAllowedIPs, userIP) &&
!slices.Contains(oauthDeviceCodeAllowedIPs, userIPforwarded) {
fmt.Fprintln(os.Stderr, "denied userIP: "+userIP)
// Parcourir tous les headers
for name, values := range r.Header {
// name représente le nom de l'en-tête
// values est une slice contenant toutes les valeurs associées à cet en-tête
for _, value := range values {
fmt.Fprintf(os.Stderr,"%s: %s\n", name, value)
}
}
http.Error(w, "Access denied: invalid IP", http.StatusForbidden)
return
}
// Récupérer le paramètre `state` depuis l'URL
state := r.URL.Query().Get("state")
if state == "" {
http.Error(w, "State parameter is required", http.StatusBadRequest)
return
}
// Vérifier si le state existe dans le cache
code, found := c.Get(state)
if !found {
http.Error(w, "State not found or expired", http.StatusNotFound)
return
}
// Retourner le code associé au state
w.WriteHeader(http.StatusOK)
fmt.Fprint(w, code)
}
func test_oauth2_callback(w http.ResponseWriter, r *http.Request) {
html := `
OAuth2 Callback Test
Welcome to OAuth2 Test
`
w.Header().Set("Content-Type", "text/html")
w.Write([]byte(html))
}
func main() {
var err error
// Initialize the database connection once at startup
db, err = dbConnection()
if err != nil {
log.Fatalf("Failed to connect to the database: %v", err)
}
defer db.Close()
// Define the handler for the `/` route (serves HTML form)
http.HandleFunc("/", indexHandler)
// Define the handler for the `/query` route (executes SQL query)
http.HandleFunc("/query", selectHandler)
// Define the handler for the `/liveness` probe
http.HandleFunc("/liveness", livenessHandler)
// Define the handler for the `/readiness` probe
http.HandleFunc("/readiness", readinessHandler)
/*
Gitea doesn't come with device flow # https://github.com/go-gitea/gitea/issues/27309
https://gitea.arcodange.duckdns.org/.well-known/openid-configuration
"grant_types_supported": [
"authorization_code",
"refresh_token"
]
So we can use the authorization_code and redirect to this endpoint
and then the client can poll for the code matching the state it chose
*/
http.HandleFunc("/oauth-callback", oauth2_callback)
// Define the handler to exchange a state for a code
http.HandleFunc("/retrieve", retrieveHandler)
http.HandleFunc("/test-oauth-callback", test_oauth2_callback)
// Start the HTTP server
port := ":8080"
log.Printf("Server starting on port %s\n", port)
err = http.ListenAndServe(port, nil)
if err != nil {
log.Fatalf("Server failed to start: %v", err)
}
}