redirect: determine the FromScheme at runtime (#1297)

Signed-off-by: Tw <tw19881113@gmail.com>

caddyhttp/redirect/redirect.go

@@ -34,13 +34,14 @@ func (rd Redirect) ServeHTTP(w http.ResponseWriter, r *http.Request) (int, error
 }
 
 func schemeMatches(rule Rule, req *http.Request) bool {
-	return (rule.FromScheme == "https" && req.TLS != nil) ||
-		(rule.FromScheme != "https" && req.TLS == nil)
+	return (rule.FromScheme() == "https" && req.TLS != nil) ||
+		(rule.FromScheme() != "https" && req.TLS == nil)
 }
 
 // Rule describes an HTTP redirect rule.
 type Rule struct {
-	FromScheme, FromPath, To string
+	FromScheme   func() string
+	FromPath, To string
 	Code         int
 	Meta         bool
 	httpserver.RequestMatcher

caddyhttp/redirect/redirect_test.go

@@ -47,16 +47,16 @@ func TestRedirect(t *testing.T) {
 				return 0, nil
 			}),
 			Rules: []Rule{
-				{FromPath: "/from", To: "/to", Code: http.StatusMovedPermanently, RequestMatcher: httpserver.IfMatcher{}},
-				{FromPath: "/a", To: "/b", Code: http.StatusTemporaryRedirect, RequestMatcher: httpserver.IfMatcher{}},
+				{FromScheme: func() string { return "http" }, FromPath: "/from", To: "/to", Code: http.StatusMovedPermanently, RequestMatcher: httpserver.IfMatcher{}},
+				{FromScheme: func() string { return "http" }, FromPath: "/a", To: "/b", Code: http.StatusTemporaryRedirect, RequestMatcher: httpserver.IfMatcher{}},
 
 				// These http and https schemes would never actually be mixed in the same
 				// redirect rule with Caddy because http and https schemes have different listeners,
 				// so they don't share a redirect rule. So although these tests prove something
 				// impossible with Caddy, it's extra bulletproofing at very little cost.
-				{FromScheme: "http", FromPath: "/scheme", To: "https://localhost/scheme", Code: http.StatusMovedPermanently, RequestMatcher: httpserver.IfMatcher{}},
-				{FromScheme: "https", FromPath: "/scheme2", To: "http://localhost/scheme2", Code: http.StatusMovedPermanently, RequestMatcher: httpserver.IfMatcher{}},
-				{FromScheme: "", FromPath: "/scheme3", To: "https://localhost/scheme3", Code: http.StatusMovedPermanently, RequestMatcher: httpserver.IfMatcher{}},
+				{FromScheme: func() string { return "http" }, FromPath: "/scheme", To: "https://localhost/scheme", Code: http.StatusMovedPermanently, RequestMatcher: httpserver.IfMatcher{}},
+				{FromScheme: func() string { return "https" }, FromPath: "/scheme2", To: "http://localhost/scheme2", Code: http.StatusMovedPermanently, RequestMatcher: httpserver.IfMatcher{}},
+				{FromScheme: func() string { return "" }, FromPath: "/scheme3", To: "https://localhost/scheme3", Code: http.StatusMovedPermanently, RequestMatcher: httpserver.IfMatcher{}},
 			},
 		}
 
@@ -90,7 +90,7 @@ func TestRedirect(t *testing.T) {
 func TestParametersRedirect(t *testing.T) {
 	re := Redirect{
 		Rules: []Rule{
-			{FromPath: "/", Meta: false, To: "http://example.com{uri}", RequestMatcher: httpserver.IfMatcher{}},
+			{FromScheme: func() string { return "http" }, FromPath: "/", Meta: false, To: "http://example.com{uri}", RequestMatcher: httpserver.IfMatcher{}},
 		},
 	}
 
@@ -108,7 +108,7 @@ func TestParametersRedirect(t *testing.T) {
 
 	re = Redirect{
 		Rules: []Rule{
-			{FromPath: "/", Meta: false, To: "http://example.com/a{path}?b=c&{query}", RequestMatcher: httpserver.IfMatcher{}},
+			{FromScheme: func() string { return "http" }, FromPath: "/", Meta: false, To: "http://example.com/a{path}?b=c&{query}", RequestMatcher: httpserver.IfMatcher{}},
 		},
 	}
 
@@ -127,8 +127,8 @@ func TestParametersRedirect(t *testing.T) {
 func TestMetaRedirect(t *testing.T) {
 	re := Redirect{
 		Rules: []Rule{
-			{FromPath: "/whatever", Meta: true, To: "/something", RequestMatcher: httpserver.IfMatcher{}},
-			{FromPath: "/", Meta: true, To: "https://example.com/", RequestMatcher: httpserver.IfMatcher{}},
+			{FromScheme: func() string { return "http" }, FromPath: "/whatever", Meta: true, To: "/something", RequestMatcher: httpserver.IfMatcher{}},
+			{FromScheme: func() string { return "http" }, FromPath: "/", Meta: true, To: "https://example.com/", RequestMatcher: httpserver.IfMatcher{}},
 		},
 	}
 

caddyhttp/redirect/setup.go

@@ -34,10 +34,11 @@ func redirParse(c *caddy.Controller) ([]Rule, error) {
 	cfg := httpserver.GetConfig(c)
 
 	initRule := func(rule *Rule, defaultCode string, args []string) error {
+		rule.FromScheme = func() string {
 			if cfg.TLS.Enabled {
-			rule.FromScheme = "https"
-		} else {
-			rule.FromScheme = "http"
+				return "https"
+			}
+			return "http"
 		}
 
 		var (