lib/promscrape, vmagent: fix path to files (#2801)

vmagent: respect `-pathPrefix` flag for static files and links

app/vmagent/main.go

@@ -7,6 +7,7 @@ import (
 	"io"
 	"net/http"
 	"os"
+	"path"
 	"strings"
 	"sync/atomic"
 	"time"
@@ -158,6 +159,11 @@ func main() {
 }
 
 func requestHandler(w http.ResponseWriter, r *http.Request) bool {
+	pathPrefix := httpserver.GetPathPrefix()
+	if pathPrefix == "" {
+		pathPrefix = "/"
+	}
+
 	if r.URL.Path == "/" {
 		if r.Method != "GET" {
 			return false
@@ -167,24 +173,24 @@ func requestHandler(w http.ResponseWriter, r *http.Request) bool {
 		fmt.Fprintf(w, "See docs at <a href='https://docs.victoriametrics.com/vmagent.html'>https://docs.victoriametrics.com/vmagent.html</a></br>")
 		fmt.Fprintf(w, "Useful endpoints:</br>")
 		httpserver.WriteAPIHelp(w, [][2]string{
-			{"targets", "status for discovered active targets"},
-			{"service-discovery", "labels before and after relabeling for discovered targets"},
-			{"api/v1/targets", "advanced information about discovered targets in JSON format"},
-			{"config", "-promscrape.config contents"},
-			{"metrics", "available service metrics"},
-			{"flags", "command-line flags"},
-			{"-/reload", "reload configuration"},
+			{path.Join(pathPrefix, "targets"), "status for discovered active targets"},
+			{path.Join(pathPrefix, "service-discovery"), "labels before and after relabeling for discovered targets"},
+			{path.Join(pathPrefix, "api/v1/targets"), "advanced information about discovered targets in JSON format"},
+			{path.Join(pathPrefix, "config"), "-promscrape.config contents"},
+			{path.Join(pathPrefix, "metrics"), "available service metrics"},
+			{path.Join(pathPrefix, "flags"), "command-line flags"},
+			{path.Join(pathPrefix, "-/reload"), "reload configuration"},
 		})
 		return true
 	}
 
-	path := strings.Replace(r.URL.Path, "//", "/", -1)
-	if strings.HasPrefix(path, "datadog/") {
+	updatedPath := strings.Replace(r.URL.Path, "//", "/", -1)
+	if strings.HasPrefix(updatedPath, "datadog/") {
 		// Trim suffix from paths starting from /datadog/ in order to support legacy DataDog agent.
 		// See https://github.com/VictoriaMetrics/VictoriaMetrics/pull/2670
-		path = strings.TrimSuffix(path, "/")
+		updatedPath = strings.TrimSuffix(updatedPath, "/")
 	}
-	switch path {
+	switch updatedPath {
 	case "/api/v1/write":
 		prometheusWriteRequests.Inc()
 		if err := promremotewrite.InsertHandler(nil, r); err != nil {
@@ -350,7 +356,7 @@ func requestHandler(w http.ResponseWriter, r *http.Request) bool {
 			return true
 		}
 		if remotewrite.MultitenancyEnabled() {
-			return processMultitenantRequest(w, r, path)
+			return processMultitenantRequest(w, r, updatedPath)
 		}
 		return false
 	}

docs/CHANGELOG.md

@@ -52,6 +52,7 @@ scrape_configs:
 * BUGFIX: limit max memory occupied by the cache, which stores parsed regular expressions. Previously too long regular expressions passed in [MetricsQL queries](https://docs.victoriametrics.com/MetricsQL.html) could result in big amounts of used memory (e.g. multiple of gigabytes). Now the max cache size for parsed regexps is limited to a a few megabytes.
 * BUGFIX: [vmagent](https://docs.victoriametrics.com/vmagent.html): make sure that [stale markers](https://docs.victoriametrics.com/vmagent.html#prometheus-staleness-markers) are generated with the actual timestamp when unsuccessful scrape occurs. This should prevent from possible time series overlap on scrape target restart in dynmaic envirnoments such as Kubernetes.
 * BUGFIX: [vmagent](https://docs.victoriametrics.com/vmagent.html): properly reload changed `-promscrape.config` file when `-promscrape.configCheckInterval` option is set. The changed config file wasn't reloaded in this case since [v1.69.0](#v1690). See [this pull request](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/2786). Thanks to @ttyv for the fix.
+* BUGFIX: [vmagent](https://docs.victoriametrics.com/vmagent.html): respect `-http.pathPrefix` for static and relative links in vmagent's UI. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/2799)
 * BUGFIX: [VictoriaMetrics cluster](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html): assume that the response is complete if `-search.denyPartialResponse` is enabled and up to `-replicationFactor - 1` `vmstorage` nodes are unavailable. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1767).
 * BUGFIX: [vmselect](https://docs.victoriametrics.com/#vmselect): update `vm_partial_results_total` metric labels to be consistent with `vm_requests_total` labels.
 

lib/promscrape/targetstatus.qtpl

@@ -96,9 +96,10 @@
 {% endfunc %}
 
 {% func commonHeader() %}
+    {% code pathPrefix := httpserver.GetPathPrefix() %}
     <meta charset="utf-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1" />
-    <link href="static/css/bootstrap.min.css" rel="stylesheet" />
+    <link href="{%s pathPrefix %}/static/css/bootstrap.min.css" rel="stylesheet" />
 {% endfunc %}
 
 {% func navbar() %}

lib/promscrape/targetstatus.qtpl.go

@@ -323,7 +323,7 @@ func ServiceDiscoveryResponse(tsr *targetsStatusResult, filter *requestFilter) s
 //line lib/promscrape/targetstatus.qtpl:98
 func streamcommonHeader(qw422016 *qt422016.Writer) {
 //line lib/promscrape/targetstatus.qtpl:98
-	qw422016.N().S(`<meta charset="utf-8" /><meta name="viewport" content="width=device-width, initial-scale=1" /><link href="static/css/bootstrap.min.css" rel="stylesheet" />`)
+	qw422016.N().S(`<meta charset="utf-8" /><meta name="viewport" content="width=device-width, initial-scale=1" /><link href="/static/css/bootstrap.min.css" rel="stylesheet" />`)
 //line lib/promscrape/targetstatus.qtpl:102
 }