start working on context root configuration

README.md

@@ -139,6 +139,7 @@ Note that you can also add environment variables in the configuration file (i.e.
 | `disable-monitoring-lock`                | Whether to [disable the monitoring lock](#disable-monitoring-lock)            | `false`        |
 | `web.address`                            | Address to listen on                                                          | `0.0.0.0`      |
 | `web.port`                               | Port to listen on                                                             | `8080`         |
+| `web.context-root`                       | Context root which should be used by the web frontent                         | `/`            |
 
 For Kubernetes configuration, see [Kubernetes](#kubernetes-alpha)
 

config/config.go

@@ -28,6 +28,9 @@ const (
 
 	// DefaultPort is the default port the service will listen on
 	DefaultPort = 8080
+
+	// DefaultContextRoot is the default context root of the web application
+	DefaultContextRoot = "/"
 )
 
 var (

config/web.go

@@ -3,6 +3,8 @@ package config
 import (
 	"fmt"
 	"math"
+	"net/url"
+	"strings"
 )
 
 // webConfig is the structure which supports the configuration of the endpoint
@@ -13,6 +15,10 @@ type webConfig struct {
 
 	// Port to listen on (default to 8080 specified by DefaultPort)
 	Port int `yaml:"port"`
+
+	ContextRoot string `yaml:"context-root"`
+
+	safeContextRoot string
 }
 
 // validateAndSetDefaults checks and sets missing values based on the defaults
@@ -26,9 +32,43 @@ func (web *webConfig) validateAndSetDefaults() {
 	} else if web.Port < 0 || web.Port > math.MaxUint16 {
 		panic(fmt.Sprintf("port has an invalid: value should be between %d and %d", 0, math.MaxUint16))
 	}
+	if len(web.ContextRoot) == 0 {
+		web.safeContextRoot = DefaultContextRoot
+	} else {
+		// url.PathEscape escapes all "/", in order to build a secure path
+		// (1) split into path fragements using "/" as delimiter
+		// (2) use url.PathEscape() on each fragment
+		// (3) re-concatinate the path using "/" as join character
+		const splitJoinChar = "/"
+		pathes := strings.Split(web.ContextRoot, splitJoinChar)
+		escapedPathes := make([]string, len(pathes))
+		for i, path := range pathes {
+			escapedPathes[i] = url.PathEscape(path)
+		}
+
+		web.safeContextRoot = strings.Join(escapedPathes, splitJoinChar)
+
+		// assure that we have still a valid url
+		_, err := url.Parse(web.safeContextRoot)
+		if err != nil {
+			panic(fmt.Sprintf("Invalid context root %s - Error %s", web.ContextRoot, err))
+		}
+	}
 }
 
 // SocketAddress returns the combination of the Address and the Port
 func (web *webConfig) SocketAddress() string {
 	return fmt.Sprintf("%s:%d", web.Address, web.Port)
 }
+
+// CtxRoot returns the context root
+func (web *webConfig) CtxRoot() string {
+	return web.safeContextRoot
+}
+
+// AppendToCtxRoot appends the given string to the context root
+// AppendToCtxRoot takes care of having only one "/" character at
+// the join point and exactly on "/" at the end
+func (web *webConfig) AppendToCtxRoot(fragment string) string {
+	return strings.TrimSuffix(web.safeContextRoot, "/") + "/" + strings.Trim(fragment, "/") + "/"
+}

config/web_test.go

@@ -11,3 +11,68 @@ func TestWebConfig_SocketAddress(t *testing.T) {
 		t.Errorf("expected %s, got %s", "0.0.0.0:8081", web.SocketAddress())
 	}
 }
+
+func TestWebConfig_ContextRoot(t *testing.T) {
+	const expected = "/status/"
+
+	web := &webConfig{
+		ContextRoot: "/status/",
+	}
+
+	web.validateAndSetDefaults()
+
+	if web.CtxRoot() != expected {
+		t.Errorf("expected %s, got %s", expected, web.CtxRoot())
+	}
+}
+
+func TestWebConfig_ContextRootWithEscapableChars(t *testing.T) {
+	const expected = "/s%3F=ta%20t%20u&s/"
+
+	web := &webConfig{
+		ContextRoot: "/s?=ta t u&s/",
+	}
+
+	web.validateAndSetDefaults()
+
+	if web.CtxRoot() != expected {
+		t.Errorf("expected %s, got %s", expected, web.CtxRoot())
+	}
+}
+
+func TestWebConfig_ContextRootMultiPath(t *testing.T) {
+	const expected = "/app/status"
+	web := &webConfig{
+		ContextRoot: "/app/status",
+	}
+
+	web.validateAndSetDefaults()
+
+	if web.CtxRoot() != expected {
+		t.Errorf("expected %s, got %s", expected, web.CtxRoot())
+	}
+}
+
+func TestWebConfig_ContextRootAppendWithEmptyContextRoot(t *testing.T) {
+	const expected = "/bla/"
+	web := &webConfig{}
+
+	web.validateAndSetDefaults()
+
+	if web.AppendToCtxRoot("/bla/") != expected {
+		t.Errorf("expected %s, got %s", expected, web.AppendToCtxRoot("/bla/"))
+	}
+}
+
+func TestWebConfig_ContextRootAppendWithContext(t *testing.T) {
+	const expected = "/app/status/bla/"
+	web := &webConfig{
+		ContextRoot: "/app/status",
+	}
+
+	web.validateAndSetDefaults()
+
+	if web.AppendToCtxRoot("/bla/") != expected {
+		t.Errorf("expected %s, got %s", expected, web.AppendToCtxRoot("/bla/"))
+	}
+}

main.go

@@ -29,13 +29,16 @@ func main() {
 	if cfg.Security != nil && cfg.Security.IsValid() {
 		resultsHandler = security.Handler(serviceResultsHandler, cfg.Security)
 	}
-	http.HandleFunc("/api/v1/results", resultsHandler)
-	http.HandleFunc("/health", healthHandler)
-	http.Handle("/", GzipHandler(http.FileServer(http.Dir("./static"))))
+	// favicon needs to be always served from the root
+	http.HandleFunc("/favicon.ico", favIconHandler)
+	http.HandleFunc(cfg.Web.AppendToCtxRoot("/api/v1/results"), resultsHandler)
+	http.HandleFunc(cfg.Web.AppendToCtxRoot("/health"), healthHandler)
+	http.Handle(cfg.Web.CtxRoot(), GzipHandler(http.StripPrefix(cfg.Web.CtxRoot(), http.FileServer(http.Dir("./static")))))
+
 	if cfg.Metrics {
-		http.Handle("/metrics", promhttp.Handler())
+		http.Handle(cfg.Web.AppendToCtxRoot("/metrics"), promhttp.Handler())
 	}
-	log.Printf("[main][main] Listening on %s\n", cfg.Web.SocketAddress())
+	log.Printf("[main][main] Listening on %s%s\n", cfg.Web.SocketAddress(), cfg.Web.CtxRoot())
 	go watchdog.Monitor(cfg)
 	log.Fatal(http.ListenAndServe(cfg.Web.SocketAddress(), nil))
 }
@@ -88,3 +91,8 @@ func healthHandler(writer http.ResponseWriter, _ *http.Request) {
 	writer.WriteHeader(http.StatusOK)
 	_, _ = writer.Write([]byte("{\"status\":\"UP\"}"))
 }
+
+// favIconHanlder responds to /favicon.ico requests
+func favIconHandler(writer http.ResponseWriter, request *http.Request) {
+	http.ServeFile(writer, request, "./static/favicon.ico")
+}

static/index.html

@@ -3,7 +3,7 @@
 <head>
 	<title>Health Dashboard</title>
 	<meta name="viewport" content="width=device-width, initial-scale=1" />
-	<link rel="stylesheet" href="/bootstrap.min.css" />
+	<link rel="stylesheet" href="./bootstrap.min.css" />
 	<style>
 		html, body {
 			background-color: #f7f9fb;
@@ -129,11 +129,11 @@
 		</div>
 	</div>
 
-	<script src="/jquery.min.js"></script>
+	<script src="./jquery.min.js"></script>
 
 	<div id="social">
 		<a href="https://github.com/TwinProduction/gatus" target="_blank" title="Gatus on GitHub">
-			<img src="/github.png" alt="GitHub" width="32" height="auto" />
+			<img src="./github.png" alt="GitHub" width="32" height="auto" />
 		</a>
 	</div>
 
@@ -220,7 +220,7 @@
 		}
 
 		function refreshResults() {
-			$.getJSON("/api/v1/results", function (data) {
+			$.getJSON("./api/v1/results", function (data) {
 				// Update the table only if there's a change
 				if (JSON.stringify(serviceStatuses) !== JSON.stringify(data)) {
 					serviceStatuses = data;