vmalert: support specifying full http url in notifier static_configs target (#5261)

* vmalert: support specifying full http or https urls in notifier static_configs target address
* show right label results in ui

app/vmalert/README.md

@@ -1399,8 +1399,11 @@ For example:
 ```yaml
 static_configs:
   - targets:
+      # support using full url
+      - 'http://alertmanager:9093/test/api/v2/alerts'
+      - 'https://alertmanager:9093/api/v2/alerts'
+      # the following target with only host:port will be used as <scheme>://localhost:9093/<path_prefix>/api/v2/alerts
       - localhost:9093
-      - localhost:9095
 
 consul_sd_configs:
   - server: localhost:8500

app/vmalert/notifier/config.go

@@ -3,7 +3,6 @@ package notifier
 import (
 	"crypto/md5"
 	"fmt"
-	"gopkg.in/yaml.v2"
 	"net/url"
 	"os"
 	"path"
@@ -11,6 +10,8 @@ import (
 	"strings"
 	"time"
 
+	"gopkg.in/yaml.v2"
+
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/promauth"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/promrelabel"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/promscrape/discovery/consul"
@@ -142,26 +143,23 @@ func parseLabels(target string, metaLabels *promutils.Labels, cfg *Config) (stri
 	if labels.Len() == 0 {
 		return "", nil, nil
 	}
-	schemeRelabeled := labels.Get("__scheme__")
-	if len(schemeRelabeled) == 0 {
-		schemeRelabeled = "http"
+	scheme := labels.Get("__scheme__")
+	if len(scheme) == 0 {
+		scheme = "http"
 	}
-	addressRelabeled := labels.Get("__address__")
-	if len(addressRelabeled) == 0 {
+	alertsPath := labels.Get("__alerts_path__")
+	if !strings.HasPrefix(alertsPath, "/") {
+		alertsPath = "/" + alertsPath
+	}
+	address := labels.Get("__address__")
+	if len(address) == 0 {
 		return "", nil, nil
 	}
-	if strings.Contains(addressRelabeled, "/") {
-		return "", nil, nil
-	}
-	addressRelabeled = addMissingPort(schemeRelabeled, addressRelabeled)
-	alertsPathRelabeled := labels.Get("__alerts_path__")
-	if !strings.HasPrefix(alertsPathRelabeled, "/") {
-		alertsPathRelabeled = "/" + alertsPathRelabeled
-	}
-	u := fmt.Sprintf("%s://%s%s", schemeRelabeled, addressRelabeled, alertsPathRelabeled)
+	address = addMissingPort(scheme, address)
+	u := fmt.Sprintf("%s://%s%s", scheme, address, alertsPath)
 	if _, err := url.Parse(u); err != nil {
 		return "", nil, fmt.Errorf("invalid url %q for scheme=%q (%q), target=%q, metrics_path=%q (%q): %w",
-			u, cfg.Scheme, schemeRelabeled, target, addressRelabeled, alertsPathRelabeled, err)
+			u, cfg.Scheme, scheme, target, address, alertsPath, err)
 	}
 	return u, labels, nil
 }
@@ -181,9 +179,24 @@ func addMissingPort(scheme, target string) string {
 func mergeLabels(target string, metaLabels *promutils.Labels, cfg *Config) *promutils.Labels {
 	// See https://prometheus.io/docs/prometheus/latest/configuration/configuration/#relabel_config
 	m := promutils.NewLabels(3 + metaLabels.Len())
-	m.Add("__address__", target)
-	m.Add("__scheme__", cfg.Scheme)
-	m.Add("__alerts_path__", path.Join("/", cfg.PathPrefix, alertManagerPath))
+	address := target
+	scheme := cfg.Scheme
+	alertsPath := path.Join("/", cfg.PathPrefix, alertManagerPath)
+	// try to extract optional scheme and alertsPath from __address__.
+	if strings.HasPrefix(address, "http://") {
+		scheme = "http"
+		address = address[len("http://"):]
+	} else if strings.HasPrefix(address, "https://") {
+		scheme = "https"
+		address = address[len("https://"):]
+	}
+	if n := strings.IndexByte(address, '/'); n >= 0 {
+		alertsPath = address[n:]
+		address = address[:n]
+	}
+	m.Add("__address__", address)
+	m.Add("__scheme__", scheme)
+	m.Add("__alerts_path__", alertsPath)
 	m.AddFrom(metaLabels)
 	return m
 }

app/vmalert/notifier/config_watcher_test.go

@@ -318,3 +318,47 @@ func TestMergeHTTPClientConfigs(t *testing.T) {
 		t.Fatalf("expected BasicAuth tp be present")
 	}
 }
+
+func TestParseLabels(t *testing.T) {
+	testCases := []struct {
+		name            string
+		target          string
+		cfg             *Config
+		expectedAddress string
+		expectedErr     bool
+	}{
+		{
+			"invalid address",
+			"invalid:*//url",
+			&Config{},
+			"",
+			true,
+		},
+		{
+			"use some default params",
+			"alertmanager:9093",
+			&Config{PathPrefix: "test"},
+			"http://alertmanager:9093/test/api/v2/alerts",
+			false,
+		},
+		{
+			"use target address",
+			"https://alertmanager:9093/api/v1/alerts",
+			&Config{Scheme: "http", PathPrefix: "test"},
+			"https://alertmanager:9093/api/v1/alerts",
+			false,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			address, _, err := parseLabels(tc.target, nil, tc.cfg)
+			if err == nil == tc.expectedErr {
+				t.Fatalf("unexpected error; got %t; want %t", err != nil, tc.expectedErr)
+			}
+			if address != tc.expectedAddress {
+				t.Fatalf("unexpected address; got %q; want %q", address, tc.expectedAddress)
+			}
+		})
+	}
+}

app/vmalert/notifier/testdata/static.good.yaml

@@ -5,6 +5,7 @@ static_configs:
   - targets:
       - localhost:9093
       - localhost:9095
+      - https://localhost:9093/test/api/v2/alerts
     basic_auth:
       username: foo
       password: bar

docs/CHANGELOG.md

@@ -49,6 +49,7 @@ The sandbox cluster installation is running under the constant load generated by
   This also means that `datasource.queryTimeAlignment` command-line flag becomes deprecated now and will have no effect if configured. If `datasource.queryTimeAlignment` was set to `false` before, then `eval_alignment` has to be set to `false` explicitly under group.
   See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5049).
 * FEATURE: [vmalert](https://docs.victoriametrics.com/vmalert.html): add `-rule.evalDelay` flag and `eval_delay` attribute for [Groups](https://docs.victoriametrics.com/vmalert.html#groups). The new flag and param can be used to adjust the `time` parameter for rule evaluation requests to match [intentional query delay](https://docs.victoriametrics.com/keyConcepts.html#query-latency) from the datasource. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5155).
+* FEATURE: [vmalert](https://docs.victoriametrics.com/vmalert.html): allow specifying full url in notifier static_configs target address, like `http://alertmanager:9093/test/api/v2/alerts`. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5184).
 * FEATURE: [vmagent](https://docs.victoriametrics.com/vmagent.html): support data ingestion from [NewRelic infrastructure agent](https://docs.newrelic.com/docs/infrastructure/install-infrastructure-agent). See [these docs](https://docs.victoriametrics.com/Single-server-VictoriaMetrics.html#how-to-send-data-from-newrelic-agent), [this feature request](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3520) and [this pull request](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/4712).
 * FEATURE: [vmagent](https://docs.victoriametrics.com/vmagent.html): do not exit on startup when [scrape_configs](https://docs.victoriametrics.com/sd_configs.html#scrape_configs) refer to non-existing or invalid files with auth configs, since these files may appear / updated later. See [this feature request](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4959) and [this pull request](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5153).
 * FEATURE: [vmagent](https://docs.victoriametrics.com/vmagent.html): allow loading TLS certificates from HTTP and HTTPS urls by specifying these urls at `cert_file` and `key_file` options inside `tls_config` and `proxy_tls_config` sections at [http client settings](https://docs.victoriametrics.com/sd_configs.html#http-api-client-options).

docs/vmalert.md

@@ -1410,8 +1410,11 @@ For example:
 ```yaml
 static_configs:
   - targets:
+      # support using full url
+      - 'http://alertmanager:9093/test/api/v2/alerts'
+      - 'https://alertmanager:9093/api/v2/alerts'
+      # the following target with only host:port will be used as <scheme>://localhost:9093/<path_prefix>/api/v2/alerts
       - localhost:9093
-      - localhost:9095
 
 consul_sd_configs:
   - server: localhost:8500