Adds normalization of localhost urls in targets page react (#6794)

* support for globalurls in targets page react
Signed-off-by: NHarkishen Singh <harkishensingh@hotmail.com>

* fixed tests
Signed-off-by: NHarkishen Singh <harkishensingh@hotmail.com>

* removed fmts
Signed-off-by: NHarkishen Singh <harkishensingh@hotmail.com>

* implemented suggestions
Signed-off-by: NHarkishen Singh <harkishensingh@hotmail.com>

* formatted
Signed-off-by: NHarkishen Singh <harkishensingh@hotmail.com>

* implemented suggestions. fixed tests.
Signed-off-by: NHarkishen Singh <harkishensingh@hotmail.com>

* formated go code
Signed-off-by: NHarkishen Singh <harkishensingh@hotmail.com>

* implemented suggestions
Signed-off-by: NHarkishen Singh <harkishensingh@hotmail.com>

web/api/v1/api.go

@@ -18,6 +18,7 @@ import (
 	"fmt"
 	"math"
 	"math/rand"
+	"net"
 	"net/http"
 	"net/url"
 	"os"
@@ -79,12 +80,15 @@ const (
 	errorNotFound    errorType = "not_found"
 )
 
-var remoteReadQueries = prometheus.NewGauge(prometheus.GaugeOpts{
-	Namespace: namespace,
-	Subsystem: subsystem,
-	Name:      "remote_read_queries",
-	Help:      "The current number of remote read queries being executed or waiting.",
-})
+var (
+	LocalhostRepresentations = []string{"127.0.0.1", "localhost"}
+	remoteReadQueries        = prometheus.NewGauge(prometheus.GaugeOpts{
+		Namespace: namespace,
+		Subsystem: subsystem,
+		Name:      "remote_read_queries",
+		Help:      "The current number of remote read queries being executed or waiting.",
+	})
+)
 
 type apiError struct {
 	typ errorType
@@ -175,6 +179,7 @@ type API struct {
 	config                func() config.Config
 	flagsMap              map[string]string
 	ready                 func(http.HandlerFunc) http.HandlerFunc
+	globalURLOptions      GlobalURLOptions
 
 	db                        func() TSDBAdmin
 	enableAdmin               bool
@@ -200,6 +205,7 @@ func NewAPI(
 	ar alertmanagerRetriever,
 	configFunc func() config.Config,
 	flagsMap map[string]string,
+	globalURLOptions GlobalURLOptions,
 	readyFunc func(http.HandlerFunc) http.HandlerFunc,
 	db func() TSDBAdmin,
 	enableAdmin bool,
@@ -222,6 +228,7 @@ func NewAPI(
 		config:                    configFunc,
 		flagsMap:                  flagsMap,
 		ready:                     readyFunc,
+		globalURLOptions:          globalURLOptions,
 		db:                        db,
 		enableAdmin:               enableAdmin,
 		rulesRetriever:            rr,
@@ -583,6 +590,7 @@ type Target struct {
 
 	ScrapePool string `json:"scrapePool"`
 	ScrapeURL  string `json:"scrapeUrl"`
+	GlobalURL  string `json:"globalUrl"`
 
 	LastError          string              `json:"lastError"`
 	LastScrape         time.Time           `json:"lastScrape"`
@@ -602,6 +610,54 @@ type TargetDiscovery struct {
 	DroppedTargets []*DroppedTarget `json:"droppedTargets"`
 }
 
+// GlobalURLOptions contains fields used for deriving the global URL for local targets.
+type GlobalURLOptions struct {
+	ListenAddress string
+	Host          string
+	Scheme        string
+}
+
+func getGlobalURL(u *url.URL, opts GlobalURLOptions) (*url.URL, error) {
+	host, port, err := net.SplitHostPort(u.Host)
+	if err != nil {
+		return u, err
+	}
+
+	for _, lhr := range LocalhostRepresentations {
+		if host == lhr {
+			_, ownPort, err := net.SplitHostPort(opts.ListenAddress)
+			if err != nil {
+				return u, err
+			}
+
+			if port == ownPort {
+				// Only in the case where the target is on localhost and its port is
+				// the same as the one we're listening on, we know for sure that
+				// we're monitoring our own process and that we need to change the
+				// scheme, hostname, and port to the externally reachable ones as
+				// well. We shouldn't need to touch the path at all, since if a
+				// path prefix is defined, the path under which we scrape ourselves
+				// should already contain the prefix.
+				u.Scheme = opts.Scheme
+				u.Host = opts.Host
+			} else {
+				// Otherwise, we only know that localhost is not reachable
+				// externally, so we replace only the hostname by the one in the
+				// external URL. It could be the wrong hostname for the service on
+				// this port, but it's still the best possible guess.
+				host, _, err := net.SplitHostPort(opts.Host)
+				if err != nil {
+					return u, err
+				}
+				u.Host = host + ":" + port
+			}
+			break
+		}
+	}
+
+	return u, nil
+}
+
 func (api *API) targets(r *http.Request) apiFuncResult {
 	sortKeys := func(targets map[string][]*scrape.Target) ([]string, int) {
 		var n int
@@ -641,12 +697,22 @@ func (api *API) targets(r *http.Request) apiFuncResult {
 					lastErrStr = lastErr.Error()
 				}
 
+				globalURL, err := getGlobalURL(target.URL(), api.globalURLOptions)
+
 				res.ActiveTargets = append(res.ActiveTargets, &Target{
-					DiscoveredLabels:   target.DiscoveredLabels().Map(),
-					Labels:             target.Labels().Map(),
-					ScrapePool:         key,
-					ScrapeURL:          target.URL().String(),
-					LastError:          lastErrStr,
+					DiscoveredLabels: target.DiscoveredLabels().Map(),
+					Labels:           target.Labels().Map(),
+					ScrapePool:       key,
+					ScrapeURL:        target.URL().String(),
+					GlobalURL:        globalURL.String(),
+					LastError: func() string {
+						if err == nil && lastErrStr == "" {
+							return ""
+						} else if err != nil {
+							return errors.Wrapf(err, lastErrStr).Error()
+						}
+						return lastErrStr
+					}(),
 					LastScrape:         target.LastScrape(),
 					LastScrapeDuration: target.LastScrapeDuration().Seconds(),
 					Health:             target.Health(),

web/api/v1/api_test.go

@@ -826,8 +826,9 @@ func testEndpoints(t *testing.T, api *API, tr *testTargetRetriever, testLabelAPI
 						},
 						ScrapePool:         "blackbox",
 						ScrapeURL:          "http://localhost:9115/probe?target=example.com",
+						GlobalURL:          "http://localhost:9115/probe?target=example.com",
 						Health:             "down",
-						LastError:          "failed",
+						LastError:          "failed: missing port in address",
 						LastScrape:         scrapeStart,
 						LastScrapeDuration: 0.1,
 					},
@@ -838,6 +839,7 @@ func testEndpoints(t *testing.T, api *API, tr *testTargetRetriever, testLabelAPI
 						},
 						ScrapePool:         "test",
 						ScrapeURL:          "http://example.com:8080/metrics",
+						GlobalURL:          "http://example.com:8080/metrics",
 						Health:             "up",
 						LastError:          "",
 						LastScrape:         scrapeStart,
@@ -870,8 +872,9 @@ func testEndpoints(t *testing.T, api *API, tr *testTargetRetriever, testLabelAPI
 						},
 						ScrapePool:         "blackbox",
 						ScrapeURL:          "http://localhost:9115/probe?target=example.com",
+						GlobalURL:          "http://localhost:9115/probe?target=example.com",
 						Health:             "down",
-						LastError:          "failed",
+						LastError:          "failed: missing port in address",
 						LastScrape:         scrapeStart,
 						LastScrapeDuration: 0.1,
 					},
@@ -882,6 +885,7 @@ func testEndpoints(t *testing.T, api *API, tr *testTargetRetriever, testLabelAPI
 						},
 						ScrapePool:         "test",
 						ScrapeURL:          "http://example.com:8080/metrics",
+						GlobalURL:          "http://example.com:8080/metrics",
 						Health:             "up",
 						LastError:          "",
 						LastScrape:         scrapeStart,
@@ -914,8 +918,9 @@ func testEndpoints(t *testing.T, api *API, tr *testTargetRetriever, testLabelAPI
 						},
 						ScrapePool:         "blackbox",
 						ScrapeURL:          "http://localhost:9115/probe?target=example.com",
+						GlobalURL:          "http://localhost:9115/probe?target=example.com",
 						Health:             "down",
-						LastError:          "failed",
+						LastError:          "failed: missing port in address",
 						LastScrape:         scrapeStart,
 						LastScrapeDuration: 0.1,
 					},
@@ -926,6 +931,7 @@ func testEndpoints(t *testing.T, api *API, tr *testTargetRetriever, testLabelAPI
 						},
 						ScrapePool:         "test",
 						ScrapeURL:          "http://example.com:8080/metrics",
+						GlobalURL:          "http://example.com:8080/metrics",
 						Health:             "up",
 						LastError:          "",
 						LastScrape:         scrapeStart,

web/ui/react-app/src/pages/targets/EndpointLink.test.tsx

@@ -6,19 +6,21 @@ import EndpointLink from './EndpointLink';
 describe('EndpointLink', () => {
   it('renders a simple anchor if the endpoint has no query params', () => {
     const endpoint = 'http://100.104.208.71:15090/stats/prometheus';
-    const endpointLink = shallow(<EndpointLink endpoint={endpoint} />);
+    const globalURL = 'http://100.104.208.71:15090/stats/prometheus';
+    const endpointLink = shallow(<EndpointLink endpoint={endpoint} globalUrl={globalURL} />);
     const anchor = endpointLink.find('a');
-    expect(anchor.prop('href')).toEqual(endpoint);
+    expect(anchor.prop('href')).toEqual(globalURL);
     expect(anchor.children().text()).toEqual(endpoint);
     expect(endpointLink.find('br')).toHaveLength(0);
   });
 
   it('renders an anchor targeting endpoint but with query param labels if the endpoint has query params', () => {
     const endpoint = 'http://100.99.128.71:9115/probe?module=http_2xx&target=http://some-service';
-    const endpointLink = shallow(<EndpointLink endpoint={endpoint} />);
+    const globalURL = 'http://100.99.128.71:9115/probe?module=http_2xx&target=http://some-service';
+    const endpointLink = shallow(<EndpointLink endpoint={endpoint} globalUrl={globalURL} />);
     const anchor = endpointLink.find('a');
     const badges = endpointLink.find(Badge);
-    expect(anchor.prop('href')).toEqual(endpoint);
+    expect(anchor.prop('href')).toEqual(globalURL);
     expect(anchor.children().text()).toEqual('http://100.99.128.71:9115/probe');
     expect(endpointLink.find('br')).toHaveLength(1);
     expect(badges).toHaveLength(2);
@@ -29,7 +31,7 @@ describe('EndpointLink', () => {
   });
 
   it('renders an alert if url is invalid', () => {
-    const endpointLink = shallow(<EndpointLink endpoint={'afdsacas'} />);
+    const endpointLink = shallow(<EndpointLink endpoint={'afdsacas'} globalUrl={'afdsacas'} />);
     const err = endpointLink.find(Alert);
     expect(err.render().text()).toEqual('Error: Invalid URL');
   });

web/ui/react-app/src/pages/targets/EndpointLink.tsx

@@ -3,9 +3,10 @@ import { Badge, Alert } from 'reactstrap';
 
 export interface EndpointLinkProps {
   endpoint: string;
+  globalUrl: string;
 }
 
-const EndpointLink: FC<EndpointLinkProps> = ({ endpoint }) => {
+const EndpointLink: FC<EndpointLinkProps> = ({ endpoint, globalUrl }) => {
   let url: URL;
   try {
     url = new URL(endpoint);
@@ -22,7 +23,7 @@ const EndpointLink: FC<EndpointLinkProps> = ({ endpoint }) => {
 
   return (
     <>
-      <a href={endpoint}>{`${protocol}//${host}${pathname}`}</a>
+      <a href={globalUrl}>{`${protocol}//${host}${pathname}`}</a>
       {params.length > 0 ? <br /> : null}
       {params.map(([labelName, labelValue]: [string, string]) => {
         return (

web/ui/react-app/src/pages/targets/ScrapePoolPanel.tsx

@@ -49,6 +49,7 @@ const ScrapePoolPanel: FC<PanelProps> = ({ scrapePool, targetGroup }) => {
                 labels,
                 scrapePool,
                 scrapeUrl,
+                globalUrl,
                 lastError,
                 lastScrape,
                 lastScrapeDuration,
@@ -59,7 +60,7 @@ const ScrapePoolPanel: FC<PanelProps> = ({ scrapePool, targetGroup }) => {
               return (
                 <tr key={scrapeUrl}>
                   <td className={styles.endpoint}>
-                    <EndpointLink endpoint={scrapeUrl} />
+                    <EndpointLink endpoint={scrapeUrl} globalUrl={globalUrl} />
                   </td>
                   <td className={styles.state}>
                     <Badge color={color}>{health.toUpperCase()}</Badge>

web/ui/react-app/src/pages/targets/__testdata__/testdata.ts

@@ -20,6 +20,7 @@ export const targetGroups: ScrapePools = Object.freeze({
         },
         scrapePool: 'blackbox',
         scrapeUrl: 'http://127.0.0.1:9115/probe?module=http_2xx&target=http%3A%2F%2Fprometheus.io',
+        globalUrl: 'http://localhost.localdomain:9115/probe?module=http_2xx&target=http%3A%2F%2Fprometheus.io',
         lastError: '',
         lastScrape: '2019-11-04T11:52:14.759299-07:00',
         lastScrapeDuration: 36560147,
@@ -39,6 +40,7 @@ export const targetGroups: ScrapePools = Object.freeze({
         },
         scrapePool: 'blackbox',
         scrapeUrl: 'http://127.0.0.1:9115/probe?module=http_2xx&target=https%3A%2F%2Fprometheus.io',
+        globalUrl: 'http://localhost.localdomain:9115/probe?module=http_2xx&target=https%3A%2F%2Fprometheus.io',
         lastError: '',
         lastScrape: '2019-11-04T11:52:24.731096-07:00',
         lastScrapeDuration: 49448763,
@@ -58,6 +60,7 @@ export const targetGroups: ScrapePools = Object.freeze({
         },
         scrapePool: 'blackbox',
         scrapeUrl: 'http://127.0.0.1:9115/probe?module=http_2xx&target=http%3A%2F%2Fexample.com%3A8080',
+        globalUrl: 'http://localhost.localdomain:9115/probe?module=http_2xx&target=http%3A%2F%2Fexample.com%3A8080',
         lastError: '',
         lastScrape: '2019-11-04T11:52:13.516654-07:00',
         lastScrapeDuration: 120916592,
@@ -81,6 +84,7 @@ export const targetGroups: ScrapePools = Object.freeze({
         },
         scrapePool: 'node_exporter',
         scrapeUrl: 'http://localhost:9100/metrics',
+        globalUrl: 'http://localhost.localdomain:9100/metrics',
         lastError: '',
         lastScrape: '2019-11-04T11:52:14.145703-07:00',
         lastScrapeDuration: 3842307,
@@ -104,6 +108,7 @@ export const targetGroups: ScrapePools = Object.freeze({
         },
         scrapePool: 'prometheus',
         scrapeUrl: 'http://localhost:9090/metrics',
+        globalUrl: 'http://localhost.localdomain:9000/metrics',
         lastError: '',
         lastScrape: '2019-11-04T11:52:18.479731-07:00',
         lastScrapeDuration: 4050976,

web/ui/react-app/src/pages/targets/target.ts

@@ -7,6 +7,7 @@ export interface Target {
   labels: Labels;
   scrapePool: string;
   scrapeUrl: string;
+  globalUrl: string;
   lastError: string;
   lastScrape: string;
   lastScrapeDuration: number;

web/web.go

@@ -70,24 +70,20 @@ import (
 	"github.com/prometheus/prometheus/web/ui"
 )
 
-var (
-	localhostRepresentations = []string{"127.0.0.1", "localhost"}
-
-	// Paths that are handled by the React / Reach router that should all be served the main React app's index.html.
-	reactRouterPaths = []string{
-		"/",
-		"/alerts",
-		"/config",
-		"/flags",
-		"/graph",
-		"/rules",
-		"/service-discovery",
-		"/status",
-		"/targets",
-		"/tsdb-status",
-		"/version",
-	}
-)
+// Paths that are handled by the React / Reach router that should all be served the main React app's index.html.
+var reactRouterPaths = []string{
+	"/",
+	"/alerts",
+	"/config",
+	"/flags",
+	"/graph",
+	"/rules",
+	"/service-discovery",
+	"/status",
+	"/targets",
+	"/tsdb-status",
+	"/version",
+}
 
 // withStackTrace logs the stack trace in case the request panics. The function
 // will re-raise the error which will then be handled by the net/http package.
@@ -300,6 +296,11 @@ func New(logger log.Logger, o *Options) *Handler {
 			return *h.config
 		},
 		o.Flags,
+		api_v1.GlobalURLOptions{
+			ListenAddress: o.ListenAddress,
+			Host:          o.ExternalURL.Host,
+			Scheme:        o.ExternalURL.Scheme,
+		},
 		h.testReady,
 		func() api_v1.TSDBAdmin {
 			return h.options.TSDB()
@@ -973,7 +974,7 @@ func tmplFuncs(consolesPath string, opts *Options) template_text.FuncMap {
 			if err != nil {
 				return u
 			}
-			for _, lhr := range localhostRepresentations {
+			for _, lhr := range api_v1.LocalhostRepresentations {
 				if host == lhr {
 					_, ownPort, err := net.SplitHostPort(opts.ListenAddress)
 					if err != nil {

web/web_test.go

@@ -305,7 +305,11 @@ func TestRoutePrefix(t *testing.T) {
 		Notifier:       nil,
 		RoutePrefix:    "/prometheus",
 		EnableAdminAPI: true,
-		TSDB:           func() *libtsdb.DB { return db },
+		ExternalURL: &url.URL{
+			Host:   "localhost.localdomain:9090",
+			Scheme: "http",
+		},
+		TSDB: func() *libtsdb.DB { return db },
 	}
 
 	opts.Flags = map[string]string{}
@@ -391,7 +395,12 @@ func TestDebugHandler(t *testing.T) {
 		{"/foo", "/bar/debug/pprof/goroutine", 404},
 	} {
 		opts := &Options{
-			RoutePrefix: tc.prefix,
+			RoutePrefix:   tc.prefix,
+			ListenAddress: "somehost:9090",
+			ExternalURL: &url.URL{
+				Host:   "localhost.localdomain:9090",
+				Scheme: "http",
+			},
 		}
 		handler := New(nil, opts)
 		handler.Ready()
@@ -411,7 +420,14 @@ func TestDebugHandler(t *testing.T) {
 func TestHTTPMetrics(t *testing.T) {
 	t.Parallel()
 
-	handler := New(nil, &Options{RoutePrefix: "/"})
+	handler := New(nil, &Options{
+		RoutePrefix:   "/",
+		ListenAddress: "somehost:9090",
+		ExternalURL: &url.URL{
+			Host:   "localhost.localdomain:9090",
+			Scheme: "http",
+		},
+	})
 	getReady := func() int {
 		t.Helper()
 		w := httptest.NewRecorder()