Rename and export some types, other minor changes

6 files changed, 141 insertions, 99 deletions

diff --git a/modules/caddyhttp/caddyhttp.go b/modules/caddyhttp/caddyhttp.go
index e309053..dfb2ea0 100644
--- a/modules/caddyhttp/caddyhttp.go
+++ b/modules/caddyhttp/caddyhttp.go
@@ -22,29 +22,31 @@ func init() {
 
 	err := caddy2.RegisterModule(caddy2.Module{
 		Name: "http",
-		New:  func() (interface{}, error) { return new(httpModuleConfig), nil },
+		New:  func() (interface{}, error) { return new(App), nil },
 	})
 	if err != nil {
 		log.Fatal(err)
 	}
 }
 
-type httpModuleConfig struct {
-	HTTPPort    int                          `json:"http_port"`
-	HTTPSPort   int                          `json:"https_port"`
-	GracePeriod caddy2.Duration              `json:"grace_period"`
-	Servers     map[string]*httpServerConfig `json:"servers"`
+// App is the HTTP app for Caddy.
+type App struct {
+	HTTPPort    int                `json:"http_port"`
+	HTTPSPort   int                `json:"https_port"`
+	GracePeriod caddy2.Duration    `json:"grace_period"`
+	Servers     map[string]*Server `json:"servers"`
 
 	servers []*http.Server
 }
 
-func (hc *httpModuleConfig) Provision() error {
+// Provision sets up the app.
+func (hc *App) Provision() error {
 	for _, srv := range hc.Servers {
-		err := srv.Routes.setup()
+		err := srv.Routes.Provision()
 		if err != nil {
 			return fmt.Errorf("setting up server routes: %v", err)
 		}
-		err = srv.Errors.Routes.setup()
+		err = srv.Errors.Routes.Provision()
 		if err != nil {
 			return fmt.Errorf("setting up server error handling routes: %v", err)
 		}
@@ -53,7 +55,8 @@ func (hc *httpModuleConfig) Provision() error {
 	return nil
 }
 
-func (hc *httpModuleConfig) Validate() error {
+// Validate ensures the app's configuration is valid.
+func (hc *App) Validate() error {
 	// each server must use distinct listener addresses
 	lnAddrs := make(map[string]string)
 	for srvName, srv := range hc.Servers {
@@ -74,7 +77,8 @@ func (hc *httpModuleConfig) Validate() error {
 	return nil
 }
 
-func (hc *httpModuleConfig) Start(handle caddy2.Handle) error {
+// Start runs the app. It sets up automatic HTTPS if enabled.
+func (hc *App) Start(handle caddy2.Handle) error {
 	err := hc.automaticHTTPS(handle)
 	if err != nil {
 		return fmt.Errorf("enabling automatic HTTPS: %v", err)
@@ -129,7 +133,7 @@ func (hc *httpModuleConfig) Start(handle caddy2.Handle) error {
 }
 
 // Stop gracefully shuts down the HTTP server.
-func (hc *httpModuleConfig) Stop() error {
+func (hc *App) Stop() error {
 	ctx := context.Background()
 	if hc.GracePeriod > 0 {
 		var cancel context.CancelFunc
@@ -145,7 +149,7 @@ func (hc *httpModuleConfig) Stop() error {
 	return nil
 }
 
-func (hc *httpModuleConfig) automaticHTTPS(handle caddy2.Handle) error {
+func (hc *App) automaticHTTPS(handle caddy2.Handle) error {
 	tlsAppIface, err := handle.App("tls")
 	if err != nil {
 		return fmt.Errorf("getting tls app: %v", err)
@@ -153,7 +157,7 @@ func (hc *httpModuleConfig) automaticHTTPS(handle caddy2.Handle) error {
 	tlsApp := tlsAppIface.(*caddytls.TLS)
 
 	lnAddrMap := make(map[string]struct{})
-	var redirRoutes routeList
+	var redirRoutes RouteList
 
 	for srvName, srv := range hc.Servers {
 		srv.tlsApp = tlsApp
@@ -222,7 +226,7 @@ func (hc *httpModuleConfig) automaticHTTPS(handle caddy2.Handle) error {
 				}
 				redirTo += "{request.uri}"
 
-				redirRoutes = append(redirRoutes, serverRoute{
+				redirRoutes = append(redirRoutes, ServerRoute{
 					matchers: []RouteMatcher{
 						matchProtocol("http"),
 						matchHost(domains),
@@ -255,7 +259,7 @@ func (hc *httpModuleConfig) automaticHTTPS(handle caddy2.Handle) error {
 			}
 			lnAddrs = append(lnAddrs, addr)
 		}
-		hc.Servers["auto_https_redirects"] = &httpServerConfig{
+		hc.Servers["auto_https_redirects"] = &Server{
 			Listen:           lnAddrs,
 			Routes:           redirRoutes,
 			DisableAutoHTTPS: true,
@@ -265,7 +269,7 @@ func (hc *httpModuleConfig) automaticHTTPS(handle caddy2.Handle) error {
 	return nil
 }
 
-func (hc *httpModuleConfig) listenerTaken(network, address string) bool {
+func (hc *App) listenerTaken(network, address string) bool {
 	for _, srv := range hc.Servers {
 		for _, addr := range srv.Listen {
 			netw, addrs, err := parseListenAddr(addr)
@@ -284,12 +288,13 @@ func (hc *httpModuleConfig) listenerTaken(network, address string) bool {
 
 var defaultALPN = []string{"h2", "http/1.1"}
 
-type httpServerConfig struct {
+// Server is an HTTP server.
+type Server struct {
 	Listen                []string                    `json:"listen"`
 	ReadTimeout           caddy2.Duration             `json:"read_timeout"`
 	ReadHeaderTimeout     caddy2.Duration             `json:"read_header_timeout"`
 	HiddenFiles           []string                    `json:"hidden_files"` // TODO:... experimenting with shared/common state
-	Routes                routeList                   `json:"routes"`
+	Routes                RouteList                   `json:"routes"`
 	Errors                httpErrorConfig             `json:"errors"`
 	TLSConnPolicies       caddytls.ConnectionPolicies `json:"tls_connection_policies"`
 	DisableAutoHTTPS      bool                        `json:"disable_auto_https"`
@@ -299,23 +304,24 @@ type httpServerConfig struct {
 }
 
 type httpErrorConfig struct {
-	Routes routeList `json:"routes"`
-	// TODO: some way to configure the logging of errors, probably? standardize the logging configuration first.
+	Routes RouteList `json:"routes"`
+	// TODO: some way to configure the logging of errors, probably? standardize
+	// the logging configuration first.
 }
 
 // ServeHTTP is the entry point for all HTTP requests.
-func (s httpServerConfig) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+func (s Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	if s.tlsApp.HandleHTTPChallenge(w, r) {
 		return
 	}
 
 	// set up the replacer
-	repl := &Replacer{req: r, resp: w, custom: make(map[string]string)}
+	repl := NewReplacer(r, w)
 	ctx := context.WithValue(r.Context(), ReplacerCtxKey, repl)
 	r = r.WithContext(ctx)
 
 	// build and execute the main middleware chain
-	stack := s.Routes.buildMiddlewareChain(w, r)
+	stack := s.Routes.BuildHandlerChain(w, r)
 	err := executeMiddlewareChain(w, r, stack)
 	if err != nil {
 		// add the error value to the request context so
@@ -328,7 +334,7 @@ func (s httpServerConfig) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 			// TODO: implement a default error handler?
 			log.Printf("[ERROR] %s", err)
 		} else {
-			errStack := s.Errors.Routes.buildMiddlewareChain(w, r)
+			errStack := s.Errors.Routes.BuildHandlerChain(w, r)
 			err := executeMiddlewareChain(w, r, errStack)
 			if err != nil {
 				// TODO: what should we do if the error handler has an error?
@@ -411,6 +417,7 @@ func parseListenAddr(a string) (network string, addrs []string, err error) {
 	if err != nil {
 		return
 	}
+	host = NewReplacer(nil, nil).Replace(host, "")
 	ports := strings.SplitN(port, "-", 2)
 	if len(ports) == 1 {
 		ports = append(ports, ports[0])
@@ -474,9 +481,6 @@ func (mrw middlewareResponseWriter) Write(b []byte) (int, error) {
 	return mrw.ResponseWriterWrapper.Write(b)
 }
 
-// ReplacerCtxKey is the context key for the request's replacer.
-const ReplacerCtxKey caddy2.CtxKey = "replacer"
-
 const (
 	// DefaultHTTPPort is the default port for HTTP.
 	DefaultHTTPPort = 80
diff --git a/modules/caddyhttp/caddyhttp_test.go b/modules/caddyhttp/caddyhttp_test.go
index 8d25332..dee3977 100644
--- a/modules/caddyhttp/caddyhttp_test.go
+++ b/modules/caddyhttp/caddyhttp_test.go
@@ -1,6 +1,7 @@
 package caddyhttp
 
 import (
+	"os"
 	"reflect"
 	"testing"
 )
@@ -114,6 +115,11 @@ func TestJoinListenerAddr(t *testing.T) {
 }
 
 func TestParseListenerAddr(t *testing.T) {
+	hostname, err := os.Hostname()
+	if err != nil {
+		t.Fatalf("Cannot ascertain system hostname: %v", err)
+	}
+
 	for i, tc := range []struct {
 		input         string
 		expectNetwork string
@@ -170,6 +176,11 @@ func TestParseListenerAddr(t *testing.T) {
 			expectNetwork: "tcp",
 			expectAddrs:   []string{"localhost:0"},
 		},
+		{
+			input:         "{system.hostname}:0",
+			expectNetwork: "tcp",
+			expectAddrs:   []string{hostname + ":0"},
+		},
 	} {
 		actualNetwork, actualAddrs, err := parseListenAddr(tc.input)
 		if tc.expectErr && err == nil {
diff --git a/modules/caddyhttp/matchers_test.go b/modules/caddyhttp/matchers_test.go
index 07c98e3..7da09a6 100644
--- a/modules/caddyhttp/matchers_test.go
+++ b/modules/caddyhttp/matchers_test.go
@@ -205,7 +205,7 @@ func TestPathREMatcher(t *testing.T) {
 
 		// set up the fake request and its Replacer
 		req := &http.Request{URL: &url.URL{Path: tc.input}}
-		repl := &Replacer{req: req, resp: httptest.NewRecorder(), custom: make(map[string]string)}
+		repl := NewReplacer(req, httptest.NewRecorder())
 		ctx := context.WithValue(req.Context(), ReplacerCtxKey, repl)
 		req = req.WithContext(ctx)
 
@@ -322,7 +322,7 @@ func TestHeaderREMatcher(t *testing.T) {
 
 		// set up the fake request and its Replacer
 		req := &http.Request{Header: tc.input, URL: new(url.URL)}
-		repl := &Replacer{req: req, resp: httptest.NewRecorder(), custom: make(map[string]string)}
+		repl := NewReplacer(req, httptest.NewRecorder())
 		ctx := context.WithValue(req.Context(), ReplacerCtxKey, repl)
 		req = req.WithContext(ctx)
 
diff --git a/modules/caddyhttp/replacer.go b/modules/caddyhttp/replacer.go
index 644cfc1..1fd3428 100644
--- a/modules/caddyhttp/replacer.go
+++ b/modules/caddyhttp/replacer.go
@@ -5,18 +5,31 @@ import (
 	"net/http"
 	"os"
 	"strings"
+
+	"bitbucket.org/lightcodelabs/caddy2"
 )
 
 // Replacer can replace values in strings based
 // on a request and/or response writer. The zero
-// Replacer is not valid; it must be initialized
-// within this package.
+// Replacer is not valid; use NewReplacer() to
+// initialize one.
 type Replacer struct {
 	req    *http.Request
 	resp   http.ResponseWriter
 	custom map[string]string
 }
 
+// NewReplacer makes a new Replacer, initializing all necessary
+// fields. The request and response writer are optional, but
+// necessary for most replacements to work.
+func NewReplacer(req *http.Request, rw http.ResponseWriter) *Replacer {
+	return &Replacer{
+		req:    req,
+		resp:   rw,
+		custom: make(map[string]string),
+	}
+}
+
 // Map sets a custom variable mapping to a value.
 func (r *Replacer) Map(variable, value string) {
 	r.custom[variable] = value
@@ -48,51 +61,58 @@ func (r *Replacer) replaceAll(input, empty string, mapping map[string]string) st
 
 func (r *Replacer) defaults() map[string]string {
 	m := map[string]string{
-		"request.host": func() string {
+		"system.hostname": func() string {
+			// OK if there is an error; just return empty string
+			name, _ := os.Hostname()
+			return name
+		}(),
+	}
+
+	if r.req != nil {
+		m["request.host"] = func() string {
 			host, _, err := net.SplitHostPort(r.req.Host)
 			if err != nil {
 				return r.req.Host // OK; there probably was no port
 			}
 			return host
-		}(),
-		"request.hostport": r.req.Host, // may include both host and port
-		"request.method":   r.req.Method,
-		"request.port": func() string {
+		}()
+		m["request.hostport"] = r.req.Host // may include both host and port
+		m["request.method"] = r.req.Method
+		m["request.port"] = func() string {
 			// if there is no port, there will be an error; in
 			// that case, port is the empty string anyway
 			_, port, _ := net.SplitHostPort(r.req.Host)
 			return port
-		}(),
-		"request.scheme": func() string {
+		}()
+		m["request.scheme"] = func() string {
 			if r.req.TLS != nil {
 				return "https"
 			}
 			return "http"
-		}(),
-		"request.uri": r.req.URL.RequestURI(),
-		"system.hostname": func() string {
-			// OK if there is an error; just return empty string
-			name, _ := os.Hostname()
-			return name
-		}(),
-	}
+		}()
+		m["request.uri"] = r.req.URL.RequestURI()
+		m["request.uri.path"] = r.req.URL.Path
 
-	// TODO: why should header fields, cookies, and query params get special treatment like this?
-	// maybe they should be scoped by words like "request.header." just like everything else.
-	for field, vals := range r.req.Header {
-		m[">"+strings.ToLower(field)] = strings.Join(vals, ",")
-	}
-	for field, vals := range r.resp.Header() {
-		m["<"+strings.ToLower(field)] = strings.Join(vals, ",")
-	}
-	for _, cookie := range r.req.Cookies() {
-		m["~"+cookie.Name] = cookie.Value
-	}
-	for param, vals := range r.req.URL.Query() {
-		m["?"+param] = strings.Join(vals, ",")
+		// TODO: why should header fields, cookies, and query params get special treatment like this?
+		// maybe they should be scoped by words like "request.header." just like everything else.
+		for field, vals := range r.req.Header {
+			m[">"+strings.ToLower(field)] = strings.Join(vals, ",")
+		}
+		for field, vals := range r.resp.Header() {
+			m["<"+strings.ToLower(field)] = strings.Join(vals, ",")
+		}
+		for _, cookie := range r.req.Cookies() {
+			m["~"+cookie.Name] = cookie.Value
+		}
+		for param, vals := range r.req.URL.Query() {
+			m["?"+param] = strings.Join(vals, ",")
+		}
 	}
 
 	return m
 }
 
 const phOpen, phClose = "{", "}"
+
+// ReplacerCtxKey is the context key for the request's replacer.
+const ReplacerCtxKey caddy2.CtxKey = "replacer"
diff --git a/modules/caddyhttp/routes.go b/modules/caddyhttp/routes.go
index 48a5000..cd612ac 100644
--- a/modules/caddyhttp/routes.go
+++ b/modules/caddyhttp/routes.go
@@ -8,7 +8,10 @@ import (
 	"bitbucket.org/lightcodelabs/caddy2"
 )
 
-type serverRoute struct {
+// ServerRoute represents a set of matching rules,
+// middlewares, and a responder for handling HTTP
+// requests.
+type ServerRoute struct {
 	Matchers map[string]json.RawMessage `json:"match"`
 	Apply    []json.RawMessage          `json:"apply"`
 	Respond  json.RawMessage            `json:"respond"`
@@ -21,9 +24,49 @@ type serverRoute struct {
 	responder  Handler
 }
 
-type routeList []serverRoute
+// RouteList is a list of server routes that can
+// create a middleware chain.
+type RouteList []ServerRoute
 
-func (routes routeList) buildMiddlewareChain(w http.ResponseWriter, r *http.Request) Handler {
+// Provision sets up all the routes by loading the modules.
+func (routes RouteList) Provision() error {
+	for i, route := range routes {
+		// matchers
+		for modName, rawMsg := range route.Matchers {
+			val, err := caddy2.LoadModule("http.matchers."+modName, rawMsg)
+			if err != nil {
+				return fmt.Errorf("loading matcher module '%s': %v", modName, err)
+			}
+			routes[i].matchers = append(routes[i].matchers, val.(RouteMatcher))
+		}
+		routes[i].Matchers = nil // allow GC to deallocate - TODO: Does this help?
+
+		// middleware
+		for j, rawMsg := range route.Apply {
+			mid, err := caddy2.LoadModuleInline("middleware", "http.middleware", rawMsg)
+			if err != nil {
+				return fmt.Errorf("loading middleware module in position %d: %v", j, err)
+			}
+			routes[i].middleware = append(routes[i].middleware, mid.(MiddlewareHandler))
+		}
+		routes[i].Apply = nil // allow GC to deallocate - TODO: Does this help?
+
+		// responder
+		if route.Respond != nil {
+			resp, err := caddy2.LoadModuleInline("responder", "http.responders", route.Respond)
+			if err != nil {
+				return fmt.Errorf("loading responder module: %v", err)
+			}
+			routes[i].responder = resp.(Handler)
+		}
+		routes[i].Respond = nil // allow GC to deallocate - TODO: Does this help?
+	}
+	return nil
+}
+
+// BuildHandlerChain creates a chain of handlers by
+// applying all the matching routes.
+func (routes RouteList) BuildHandlerChain(w http.ResponseWriter, r *http.Request) Handler {
 	if len(routes) == 0 {
 		return emptyHandler
 	}
@@ -68,38 +111,3 @@ routeLoop:
 
 	return stack
 }
-
-func (routes routeList) setup() error {
-	for i, route := range routes {
-		// matchers
-		for modName, rawMsg := range route.Matchers {
-			val, err := caddy2.LoadModule("http.matchers."+modName, rawMsg)
-			if err != nil {
-				return fmt.Errorf("loading matcher module '%s': %v", modName, err)
-			}
-			routes[i].matchers = append(routes[i].matchers, val.(RouteMatcher))
-		}
-		routes[i].Matchers = nil // allow GC to deallocate - TODO: Does this help?
-
-		// middleware
-		for j, rawMsg := range route.Apply {
-			mid, err := caddy2.LoadModuleInline("middleware", "http.middleware", rawMsg)
-			if err != nil {
-				return fmt.Errorf("loading middleware module in position %d: %v", j, err)
-			}
-			routes[i].middleware = append(routes[i].middleware, mid.(MiddlewareHandler))
-		}
-		routes[i].Apply = nil // allow GC to deallocate - TODO: Does this help?
-
-		// responder
-		if route.Respond != nil {
-			resp, err := caddy2.LoadModuleInline("responder", "http.responders", route.Respond)
-			if err != nil {
-				return fmt.Errorf("loading responder module: %v", err)
-			}
-			routes[i].responder = resp.(Handler)
-		}
-		routes[i].Respond = nil // allow GC to deallocate - TODO: Does this help?
-	}
-	return nil
-}
diff --git a/modules/caddyhttp/staticresp.go b/modules/caddyhttp/staticresp.go
index dca60cb..408de60 100644
--- a/modules/caddyhttp/staticresp.go
+++ b/modules/caddyhttp/staticresp.go
@@ -15,7 +15,6 @@ func init() {
 }
 
 // Static implements a simple responder for static responses.
-// It is Caddy's default responder. TODO: Or is it?
 type Static struct {
 	StatusCode int         `json:"status_code"`
 	Headers    http.Header `json:"headers"`