Define ExternalURL as a net/url.URL and add tests and sanitization

Closes: https://github.com/happyDomain/happydomain/issues/9

api/routes.go

@@ -83,8 +83,9 @@ func DeclareRoutes(cfg *config.Options, router *gin.Engine) {
 	declareUsersAuthRoutes(cfg, apiAuthRoutes)
 
 	// Expose Swagger
-	if cfg.ExternalURL != "" {
-		docs.SwaggerInfo.Host = cfg.ExternalURL[strings.Index(cfg.ExternalURL, "://")+3:]
+	if cfg.ExternalURL.URL.Host != "" {
+		tmp := cfg.ExternalURL.URL.String()
+		docs.SwaggerInfo.Host = tmp[strings.Index(tmp, "://")+3:]
 	} else {
 		docs.SwaggerInfo.Host = fmt.Sprintf("localhost%s", cfg.Bind[strings.Index(cfg.Bind, ":"):])
 	}

api/user_auth.go

@@ -37,7 +37,6 @@ import (
 	"fmt"
 	"log"
 	"net/http"
-	"strings"
 	"time"
 
 	"github.com/gin-gonic/gin"
@@ -154,7 +153,7 @@ func logout(opts *config.Options, c *gin.Context) {
 		-1,
 		opts.BaseURL+"/",
 		"",
-		opts.DevProxy == "" && !strings.HasPrefix(opts.ExternalURL, "http://"),
+		opts.DevProxy == "" && opts.ExternalURL.URL.Scheme != "http",
 		true,
 	)
 	c.Status(http.StatusNoContent)
@@ -260,7 +259,7 @@ func completeAuth(opts *config.Options, c *gin.Context, userprofile UserProfile)
 		30*24*3600,       // maxAge
 		opts.BaseURL+"/", // path
 		"",               // domain
-		opts.DevProxy == "" && !strings.HasPrefix(opts.ExternalURL, "http://"), // secure
+		opts.DevProxy == "" && opts.ExternalURL.URL.Scheme != "http", // secure
 		true, // httpOnly
 	)
 

config/cli.go

@@ -43,7 +43,7 @@ func (o *Options) declareFlags() {
 	flag.StringVar(&o.DevProxy, "dev", o.DevProxy, "Proxify traffic to this host for static assets")
 	flag.StringVar(&o.AdminBind, "admin-bind", o.AdminBind, "Bind port/socket for administration interface")
 	flag.StringVar(&o.Bind, "bind", ":8081", "Bind port/socket")
-	flag.StringVar(&o.ExternalURL, "externalurl", o.ExternalURL, "Begining of the URL, before the base, that should be used eg. in mails")
+	flag.Var(&o.ExternalURL, "externalurl", "Begining of the URL, before the base, that should be used eg. in mails")
 	flag.StringVar(&o.BaseURL, "baseurl", o.BaseURL, "URL prepended to each URL")
 	flag.StringVar(&o.DefaultNameServer, "default-ns", o.DefaultNameServer, "Adress to the default name server")
 	flag.Var(&o.StorageEngine, "storage-engine", fmt.Sprintf("Select the storage engine between %v", storage.GetStorageEngines()))

config/config.go

@@ -36,6 +36,7 @@ import (
 	"flag"
 	"fmt"
 	"log"
+	"net/url"
 	"os"
 	"path"
 	"strings"
@@ -54,7 +55,7 @@ type Options struct {
 
 	// ExternalURL keeps the URL used in communications (such as email,
 	// ...), when it needs to use complete URL, not only relative parts.
-	ExternalURL string
+	ExternalURL URL
 
 	// BaseURL is the relative path where begins the root of the app.
 	BaseURL string
@@ -94,11 +95,13 @@ func (o *Options) BuildURL_noescape(url string, args ...interface{}) string {
 //
 // Should be called only one time.
 func ConsolidateConfig() (opts *Options, err error) {
+	u, _ := url.Parse("http://localhost:8081")
+
 	// Define defaults options
 	opts = &Options{
 		Bind:              ":8081",
 		AdminBind:         "./happydomain.sock",
-		ExternalURL:       "http://localhost:8081",
+		ExternalURL:       URL{URL: u},
 		BaseURL:           "/",
 		DefaultNameServer: "127.0.0.1:53",
 		StorageEngine:     storage.StorageEngine("leveldb"),
@@ -148,6 +151,27 @@ func ConsolidateConfig() (opts *Options, err error) {
 		opts.BaseURL = ""
 	}
 
+	if opts.ExternalURL.URL.Host == "" || opts.ExternalURL.URL.Scheme == "" {
+		u, err2 := url.Parse("http://" + opts.ExternalURL.URL.String())
+		if err2 == nil {
+			opts.ExternalURL.URL = u
+		} else {
+			err = fmt.Errorf("You defined an external URL without a scheme. The expected value is eg. http://localhost:8081")
+			return
+		}
+	}
+	if len(opts.ExternalURL.URL.Path) > 1 {
+		if opts.BaseURL != "" && opts.BaseURL != opts.ExternalURL.URL.Path {
+			err = fmt.Errorf("You defined both baseurl and a path to externalurl that are different. Define only one of those.")
+			return
+		}
+
+		opts.BaseURL = path.Clean(opts.ExternalURL.URL.Path)
+	}
+	opts.ExternalURL.URL.Path = ""
+	opts.ExternalURL.URL.Fragment = ""
+	opts.ExternalURL.URL.RawQuery = ""
+
 	if len(opts.JWTSecretKey) == 0 {
 		opts.JWTSecretKey = make([]byte, 32)
 		_, err = rand.Read(opts.JWTSecretKey)