Adds request method and host template placeholders (#1716)

Signed-off-by: Alexander Yastrebov <[email protected]>

docs/reference/filters.md

@@ -22,11 +22,13 @@ Several filters support template placeholders (`${var}`) in string parameters.
 
 Template placeholder is replaced by the value that is looked up in the following sources:
 
+* request method (`${request.method}`)
+* request host (`${request.host}`)
 * request url path (`${request.path}`)
 * request url query (if starts with `request.query.` prefix, e.g `${request.query.q}` is replaced by `q` query parameter value)
 * request headers (if starts with `request.header.` prefix, e.g `${request.header.Content-Type}` is replaced by `Content-Type` request header value)
 * request cookies (if starts with `request.cookie.` prefix, e.g `${request.cookie.PHPSESSID}` is replaced by `PHPSESSID` request cookie value)
-* request IP address 
+* request IP address
     - `${request.source}` - first IP address from `X-Forwarded-For` header or request remote IP address if header is absent, similar to [Source](predicates.md#source) predicate
     - `${request.sourceFromLast}` - last IP address from `X-Forwarded-For` header or request remote IP address if header is absent, similar to [SourceFromLast](predicates.md#sourcefromlast) predicate
     - `${request.clientIP}` - request remote IP address similar to [ClientIP](predicates.md#clientip) predicate

eskip/template.go

@@ -75,6 +75,10 @@ func (t *Template) ApplyContext(ctx TemplateContext) (string, bool) {
 			return ""
 		}
 		switch key {
+		case "request.method":
+			return ctx.Request().Method
+		case "request.host":
+			return ctx.Request().Host
 		case "request.path":
 			return ctx.Request().URL.Path
 		case "request.source":

eskip/template_test.go

@@ -72,6 +72,13 @@ func TestTemplateApplyContext(t *testing.T) {
 		}
 		return u
 	}
+	request := func(method, url string) *http.Request {
+		r, err := http.NewRequest(method, url, nil)
+		if err != nil {
+			t.Fatal(err)
+		}
+		return r
+	}
 
 	for _, ti := range []struct {
 		name     string
@@ -327,6 +334,14 @@ func TestTemplateApplyContext(t *testing.T) {
 		},
 		"192.168.0.1",
 		true,
+	}, {
+		"request method host",
+		"${request.method} ${request.host}",
+		&filtertest.Context{
+			FRequest: request("GET", "https://example.com/test/1"),
+		},
+		"GET example.com",
+		true,
 	},
 	} {
 		t.Run(ti.name, func(t *testing.T) {