build(deps): bump github.com/gorilla/mux from 1.7.3 to 1.7.4

Bumps [github.com/gorilla/mux](https://github.com/gorilla/mux) from 1.7.3 to 1.7.4.
- [Release notes](https://github.com/gorilla/mux/releases)
- [Commits](https://github.com/gorilla/mux/compare/v1.7.3...v1.7.4)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>
Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>

11 files changed, 203 insertions, 72 deletions

diff --git a/go.mod b/go.mod
index 994746704..bff133516 100644
--- a/go.mod
+++ b/go.mod
@@ -38,7 +38,7 @@ require (
 	github.com/google/shlex v0.0.0-20181106134648-c34317bd91bf
 	github.com/google/uuid v1.1.1
 	github.com/gorilla/handlers v1.4.2 // indirect
-	github.com/gorilla/mux v1.7.3
+	github.com/gorilla/mux v1.7.4
 	github.com/gorilla/schema v1.1.0
 	github.com/hashicorp/go-multierror v1.0.0
 	github.com/hpcloud/tail v1.0.0
diff --git a/go.sum b/go.sum
index 0b959646c..5afaaa31a 100644
--- a/go.sum
+++ b/go.sum
@@ -213,6 +213,8 @@ github.com/gorilla/handlers v1.4.2/go.mod h1:Qkdc/uu4tH4g6mTK6auzZ766c4CA0Ng8+o/
 github.com/gorilla/mux v0.0.0-20170217192616-94e7d24fd285/go.mod h1:1lud6UwP+6orDFRuTfBEV8e9/aOM/c4fVVCaMa2zaAs=
 github.com/gorilla/mux v1.7.3 h1:gnP5JzjVOuiZD07fKKToCAOjS0yOpj/qPETTXCCS6hw=
 github.com/gorilla/mux v1.7.3/go.mod h1:1lud6UwP+6orDFRuTfBEV8e9/aOM/c4fVVCaMa2zaAs=
+github.com/gorilla/mux v1.7.4 h1:VuZ8uybHlWmqV03+zRzdwKL4tUnIp1MAQtp1mIFE1bc=
+github.com/gorilla/mux v1.7.4/go.mod h1:DVbg23sWSpFRCP0SfiEN6jmj59UnW/n46BH5rLB71So=
 github.com/gorilla/schema v1.1.0 h1:CamqUDOFUBqzrvxuz2vEwo8+SUdwsluFh7IlzJh30LY=
 github.com/gorilla/schema v1.1.0/go.mod h1:kgLaKoK1FELgZqMAVxx/5cbj0kT+57qxUrAlIO2eleU=
 github.com/gotestyourself/gotestyourself v2.2.0+incompatible/go.mod h1:zZKM6oeNM8k+FRljX1mnzVYeS8wiGgQyvST1/GafPbY=
diff --git a/vendor/github.com/gorilla/mux/README.md b/vendor/github.com/gorilla/mux/README.md
index 92e422eed..35eea9f10 100644
--- a/vendor/github.com/gorilla/mux/README.md
+++ b/vendor/github.com/gorilla/mux/README.md
@@ -1,11 +1,10 @@
 # gorilla/mux
 
 [![GoDoc](https://godoc.org/github.com/gorilla/mux?status.svg)](https://godoc.org/github.com/gorilla/mux)
-[![Build Status](https://travis-ci.org/gorilla/mux.svg?branch=master)](https://travis-ci.org/gorilla/mux)
 [![CircleCI](https://circleci.com/gh/gorilla/mux.svg?style=svg)](https://circleci.com/gh/gorilla/mux)
 [![Sourcegraph](https://sourcegraph.com/github.com/gorilla/mux/-/badge.svg)](https://sourcegraph.com/github.com/gorilla/mux?badge)
 
-![Gorilla Logo](http://www.gorillatoolkit.org/static/images/gorilla-icon-64.png)
+![Gorilla Logo](https://cloud-cdn.questionable.services/gorilla-icon-64.png)
 
 https://www.gorillatoolkit.org/pkg/mux
 
@@ -26,6 +25,7 @@ The name mux stands for "HTTP request multiplexer". Like the standard `http.Serv
 * [Examples](#examples)
 * [Matching Routes](#matching-routes)
 * [Static Files](#static-files)
+* [Serving Single Page Applications](#serving-single-page-applications) (e.g. React, Vue, Ember.js, etc.)
 * [Registered URLs](#registered-urls)
 * [Walking Routes](#walking-routes)
 * [Graceful Shutdown](#graceful-shutdown)
@@ -212,6 +212,93 @@ func main() {
 }
 ```
 
+### Serving Single Page Applications
+
+Most of the time it makes sense to serve your SPA on a separate web server from your API,
+but sometimes it's desirable to serve them both from one place. It's possible to write a simple
+handler for serving your SPA (for use with React Router's [BrowserRouter](https://reacttraining.com/react-router/web/api/BrowserRouter) for example), and leverage
+mux's powerful routing for your API endpoints.
+
+```go
+package main
+
+import (
+	"encoding/json"
+	"log"
+	"net/http"
+	"os"
+	"path/filepath"
+	"time"
+
+	"github.com/gorilla/mux"
+)
+
+// spaHandler implements the http.Handler interface, so we can use it
+// to respond to HTTP requests. The path to the static directory and
+// path to the index file within that static directory are used to
+// serve the SPA in the given static directory.
+type spaHandler struct {
+	staticPath string
+	indexPath  string
+}
+
+// ServeHTTP inspects the URL path to locate a file within the static dir
+// on the SPA handler. If a file is found, it will be served. If not, the
+// file located at the index path on the SPA handler will be served. This
+// is suitable behavior for serving an SPA (single page application).
+func (h spaHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+    // get the absolute path to prevent directory traversal
+	path, err := filepath.Abs(r.URL.Path)
+	if err != nil {
+        // if we failed to get the absolute path respond with a 400 bad request
+        // and stop
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+
+    // prepend the path with the path to the static directory
+	path = filepath.Join(h.staticPath, path)
+
+    // check whether a file exists at the given path
+	_, err = os.Stat(path)
+	if os.IsNotExist(err) {
+		// file does not exist, serve index.html
+		http.ServeFile(w, r, filepath.Join(h.staticPath, h.indexPath))
+		return
+	} else if err != nil {
+        // if we got an error (that wasn't that the file doesn't exist) stating the
+        // file, return a 500 internal server error and stop
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+    // otherwise, use http.FileServer to serve the static dir
+	http.FileServer(http.Dir(h.staticPath)).ServeHTTP(w, r)
+}
+
+func main() {
+	router := mux.NewRouter()
+
+	router.HandleFunc("/api/health", func(w http.ResponseWriter, r *http.Request) {
+		// an example API handler
+		json.NewEncoder(w).Encode(map[string]bool{"ok": true})
+	})
+
+	spa := spaHandler{staticPath: "build", indexPath: "index.html"}
+	router.PathPrefix("/").Handler(spa)
+
+	srv := &http.Server{
+		Handler: router,
+		Addr:    "127.0.0.1:8000",
+		// Good practice: enforce timeouts for servers you create!
+		WriteTimeout: 15 * time.Second,
+		ReadTimeout:  15 * time.Second,
+	}
+
+	log.Fatal(srv.ListenAndServe())
+}
+```
+
 ### Registered URLs
 
 Now let's see how to build registered URLs.
diff --git a/vendor/github.com/gorilla/mux/context.go b/vendor/github.com/gorilla/mux/context.go
deleted file mode 100644
index 665940a26..000000000
--- a/vendor/github.com/gorilla/mux/context.go
+++ /dev/null
@@ -1,18 +0,0 @@
-package mux
-
-import (
-	"context"
-	"net/http"
-)
-
-func contextGet(r *http.Request, key interface{}) interface{} {
-	return r.Context().Value(key)
-}
-
-func contextSet(r *http.Request, key, val interface{}) *http.Request {
-	if val == nil {
-		return r
-	}
-
-	return r.WithContext(context.WithValue(r.Context(), key, val))
-}
diff --git a/vendor/github.com/gorilla/mux/go.mod b/vendor/github.com/gorilla/mux/go.mod
index cfc8ede58..df170a399 100644
--- a/vendor/github.com/gorilla/mux/go.mod
+++ b/vendor/github.com/gorilla/mux/go.mod
@@ -1 +1,3 @@
 module github.com/gorilla/mux
+
+go 1.12
diff --git a/vendor/github.com/gorilla/mux/middleware.go b/vendor/github.com/gorilla/mux/middleware.go
index cf2b26dc0..cb51c565e 100644
--- a/vendor/github.com/gorilla/mux/middleware.go
+++ b/vendor/github.com/gorilla/mux/middleware.go
@@ -58,22 +58,17 @@ func CORSMethodMiddleware(r *Router) MiddlewareFunc {
 func getAllMethodsForRoute(r *Router, req *http.Request) ([]string, error) {
 	var allMethods []string
 
-	err := r.Walk(func(route *Route, _ *Router, _ []*Route) error {
-		for _, m := range route.matchers {
-			if _, ok := m.(*routeRegexp); ok {
-				if m.Match(req, &RouteMatch{}) {
-					methods, err := route.GetMethods()
-					if err != nil {
-						return err
-					}
-
-					allMethods = append(allMethods, methods...)
-				}
-				break
+	for _, route := range r.routes {
+		var match RouteMatch
+		if route.Match(req, &match) || match.MatchErr == ErrMethodMismatch {
+			methods, err := route.GetMethods()
+			if err != nil {
+				return nil, err
 			}
+
+			allMethods = append(allMethods, methods...)
 		}
-		return nil
-	})
+	}
 
-	return allMethods, err
+	return allMethods, nil
 }
diff --git a/vendor/github.com/gorilla/mux/mux.go b/vendor/github.com/gorilla/mux/mux.go
index a2cd193e4..c9ba64707 100644
--- a/vendor/github.com/gorilla/mux/mux.go
+++ b/vendor/github.com/gorilla/mux/mux.go
@@ -5,6 +5,7 @@
 package mux
 
 import (
+	"context"
 	"errors"
 	"fmt"
 	"net/http"
@@ -58,8 +59,7 @@ type Router struct {
 
 	// If true, do not clear the request context after handling the request.
 	//
-	// Deprecated: No effect when go1.7+ is used, since the context is stored
-	// on the request itself.
+	// Deprecated: No effect, since the context is stored on the request itself.
 	KeepContext bool
 
 	// Slice of middlewares to be called after a match is found
@@ -111,10 +111,8 @@ func copyRouteConf(r routeConf) routeConf {
 		c.regexp.queries = append(c.regexp.queries, copyRouteRegexp(q))
 	}
 
-	c.matchers = make([]matcher, 0, len(r.matchers))
-	for _, m := range r.matchers {
-		c.matchers = append(c.matchers, m)
-	}
+	c.matchers = make([]matcher, len(r.matchers))
+	copy(c.matchers, r.matchers)
 
 	return c
 }
@@ -197,8 +195,8 @@ func (r *Router) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 	var handler http.Handler
 	if r.Match(req, &match) {
 		handler = match.Handler
-		req = setVars(req, match.Vars)
-		req = setCurrentRoute(req, match.Route)
+		req = requestWithVars(req, match.Vars)
+		req = requestWithRoute(req, match.Route)
 	}
 
 	if handler == nil && match.MatchErr == ErrMethodMismatch {
@@ -428,7 +426,7 @@ const (
 
 // Vars returns the route variables for the current request, if any.
 func Vars(r *http.Request) map[string]string {
-	if rv := contextGet(r, varsKey); rv != nil {
+	if rv := r.Context().Value(varsKey); rv != nil {
 		return rv.(map[string]string)
 	}
 	return nil
@@ -440,18 +438,20 @@ func Vars(r *http.Request) map[string]string {
 // after the handler returns, unless the KeepContext option is set on the
 // Router.
 func CurrentRoute(r *http.Request) *Route {
-	if rv := contextGet(r, routeKey); rv != nil {
+	if rv := r.Context().Value(routeKey); rv != nil {
 		return rv.(*Route)
 	}
 	return nil
 }
 
-func setVars(r *http.Request, val interface{}) *http.Request {
-	return contextSet(r, varsKey, val)
+func requestWithVars(r *http.Request, vars map[string]string) *http.Request {
+	ctx := context.WithValue(r.Context(), varsKey, vars)
+	return r.WithContext(ctx)
 }
 
-func setCurrentRoute(r *http.Request, val interface{}) *http.Request {
-	return contextSet(r, routeKey, val)
+func requestWithRoute(r *http.Request, route *Route) *http.Request {
+	ctx := context.WithValue(r.Context(), routeKey, route)
+	return r.WithContext(ctx)
 }
 
 // ----------------------------------------------------------------------------
diff --git a/vendor/github.com/gorilla/mux/regexp.go b/vendor/github.com/gorilla/mux/regexp.go
index ac1abcd47..96dd94ad1 100644
--- a/vendor/github.com/gorilla/mux/regexp.go
+++ b/vendor/github.com/gorilla/mux/regexp.go
@@ -181,21 +181,21 @@ func (r *routeRegexp) Match(req *http.Request, match *RouteMatch) bool {
 			}
 		}
 		return r.regexp.MatchString(host)
-	} else {
-		if r.regexpType == regexpTypeQuery {
-			return r.matchQueryString(req)
-		}
-		path := req.URL.Path
-		if r.options.useEncodedPath {
-			path = req.URL.EscapedPath()
-		}
-		return r.regexp.MatchString(path)
 	}
+
+	if r.regexpType == regexpTypeQuery {
+		return r.matchQueryString(req)
+	}
+	path := req.URL.Path
+	if r.options.useEncodedPath {
+		path = req.URL.EscapedPath()
+	}
+	return r.regexp.MatchString(path)
 }
 
 // url builds a URL part using the given values.
 func (r *routeRegexp) url(values map[string]string) (string, error) {
-	urlValues := make([]interface{}, len(r.varsN))
+	urlValues := make([]interface{}, len(r.varsN), len(r.varsN))
 	for k, v := range r.varsN {
 		value, ok := values[v]
 		if !ok {
@@ -230,14 +230,51 @@ func (r *routeRegexp) getURLQuery(req *http.Request) string {
 		return ""
 	}
 	templateKey := strings.SplitN(r.template, "=", 2)[0]
-	for key, vals := range req.URL.Query() {
-		if key == templateKey && len(vals) > 0 {
-			return key + "=" + vals[0]
-		}
+	val, ok := findFirstQueryKey(req.URL.RawQuery, templateKey)
+	if ok {
+		return templateKey + "=" + val
 	}
 	return ""
 }
 
+// findFirstQueryKey returns the same result as (*url.URL).Query()[key][0].
+// If key was not found, empty string and false is returned.
+func findFirstQueryKey(rawQuery, key string) (value string, ok bool) {
+	query := []byte(rawQuery)
+	for len(query) > 0 {
+		foundKey := query
+		if i := bytes.IndexAny(foundKey, "&;"); i >= 0 {
+			foundKey, query = foundKey[:i], foundKey[i+1:]
+		} else {
+			query = query[:0]
+		}
+		if len(foundKey) == 0 {
+			continue
+		}
+		var value []byte
+		if i := bytes.IndexByte(foundKey, '='); i >= 0 {
+			foundKey, value = foundKey[:i], foundKey[i+1:]
+		}
+		if len(foundKey) < len(key) {
+			// Cannot possibly be key.
+			continue
+		}
+		keyString, err := url.QueryUnescape(string(foundKey))
+		if err != nil {
+			continue
+		}
+		if keyString != key {
+			continue
+		}
+		valueString, err := url.QueryUnescape(string(value))
+		if err != nil {
+			continue
+		}
+		return valueString, true
+	}
+	return "", false
+}
+
 func (r *routeRegexp) matchQueryString(req *http.Request) bool {
 	return r.regexp.MatchString(r.getURLQuery(req))
 }
diff --git a/vendor/github.com/gorilla/mux/route.go b/vendor/github.com/gorilla/mux/route.go
index 8479c68c1..750afe570 100644
--- a/vendor/github.com/gorilla/mux/route.go
+++ b/vendor/github.com/gorilla/mux/route.go
@@ -74,7 +74,7 @@ func (r *Route) Match(req *http.Request, match *RouteMatch) bool {
 		return false
 	}
 
-	if match.MatchErr == ErrMethodMismatch {
+	if match.MatchErr == ErrMethodMismatch && r.handler != nil {
 		// We found a route which matches request method, clear MatchErr
 		match.MatchErr = nil
 		// Then override the mis-matched handler
@@ -412,11 +412,30 @@ func (r *Route) Queries(pairs ...string) *Route {
 type schemeMatcher []string
 
 func (m schemeMatcher) Match(r *http.Request, match *RouteMatch) bool {
-	return matchInArray(m, r.URL.Scheme)
+	scheme := r.URL.Scheme
+	// https://golang.org/pkg/net/http/#Request
+	// "For [most] server requests, fields other than Path and RawQuery will be
+	// empty."
+	// Since we're an http muxer, the scheme is either going to be http or https
+	// though, so we can just set it based on the tls termination state.
+	if scheme == "" {
+		if r.TLS == nil {
+			scheme = "http"
+		} else {
+			scheme = "https"
+		}
+	}
+	return matchInArray(m, scheme)
 }
 
 // Schemes adds a matcher for URL schemes.
 // It accepts a sequence of schemes to be matched, e.g.: "http", "https".
+// If the request's URL has a scheme set, it will be matched against.
+// Generally, the URL scheme will only be set if a previous handler set it,
+// such as the ProxyHeaders handler from gorilla/handlers.
+// If unset, the scheme will be determined based on the request's TLS
+// termination state.
+// The first argument to Schemes will be used when constructing a route URL.
 func (r *Route) Schemes(schemes ...string) *Route {
 	for k, v := range schemes {
 		schemes[k] = strings.ToLower(v)
@@ -493,8 +512,8 @@ func (r *Route) Subrouter() *Router {
 // This also works for host variables:
 //
 //     r := mux.NewRouter()
-//     r.Host("{subdomain}.domain.com").
-//       HandleFunc("/articles/{category}/{id:[0-9]+}", ArticleHandler).
+//     r.HandleFunc("/articles/{category}/{id:[0-9]+}", ArticleHandler).
+//       Host("{subdomain}.domain.com").
 //       Name("article")
 //
 //     // url.String() will be "http://news.domain.com/articles/technology/42"
@@ -502,6 +521,13 @@ func (r *Route) Subrouter() *Router {
 //                                      "category", "technology",
 //                                      "id", "42")
 //
+// The scheme of the resulting url will be the first argument that was passed to Schemes:
+//
+//     // url.String() will be "https://example.com"
+//     r := mux.NewRouter()
+//     url, err := r.Host("example.com")
+//                  .Schemes("https", "http").URL()
+//
 // All variables defined in the route are required, and their values must
 // conform to the corresponding patterns.
 func (r *Route) URL(pairs ...string) (*url.URL, error) {
@@ -635,7 +661,7 @@ func (r *Route) GetQueriesRegexp() ([]string, error) {
 	if r.regexp.queries == nil {
 		return nil, errors.New("mux: route doesn't have queries")
 	}
-	var queries []string
+	queries := make([]string, 0, len(r.regexp.queries))
 	for _, query := range r.regexp.queries {
 		queries = append(queries, query.regexp.String())
 	}
@@ -654,7 +680,7 @@ func (r *Route) GetQueriesTemplates() ([]string, error) {
 	if r.regexp.queries == nil {
 		return nil, errors.New("mux: route doesn't have queries")
 	}
-	var queries []string
+	queries := make([]string, 0, len(r.regexp.queries))
 	for _, query := range r.regexp.queries {
 		queries = append(queries, query.template)
 	}
diff --git a/vendor/github.com/gorilla/mux/test_helpers.go b/vendor/github.com/gorilla/mux/test_helpers.go
index 32ecffde4..5f5c496de 100644
--- a/vendor/github.com/gorilla/mux/test_helpers.go
+++ b/vendor/github.com/gorilla/mux/test_helpers.go
@@ -15,5 +15,5 @@ import "net/http"
 // can be set by making a route that captures the required variables,
 // starting a server and sending the request to that server.
 func SetURLVars(r *http.Request, val map[string]string) *http.Request {
-	return setVars(r, val)
+	return requestWithVars(r, val)
 }
diff --git a/vendor/modules.txt b/vendor/modules.txt
index 5c2485f38..a60f25ee3 100644
--- a/vendor/modules.txt
+++ b/vendor/modules.txt
@@ -291,7 +291,7 @@ github.com/google/gofuzz
 github.com/google/shlex
 # github.com/google/uuid v1.1.1
 github.com/google/uuid
-# github.com/gorilla/mux v1.7.3
+# github.com/gorilla/mux v1.7.4
 github.com/gorilla/mux
 # github.com/gorilla/schema v1.1.0
 github.com/gorilla/schema