tweak: allows prom addr with http path (#1563)

pkg/apiserver/metrics/prom_resolve.go

@@ -43,7 +43,7 @@ func normalizeCustomizedPromAddress(addr string) (string, error) {
 		return "", fmt.Errorf("invalid Prometheus address format")
 	}
 	// Normalize the address, remove unnecessary parts.
-	addr = fmt.Sprintf("%s://%s", u.Scheme, u.Host)
+	addr = fmt.Sprintf("%s://%s%s", u.Scheme, u.Host, strings.TrimSuffix(u.Path, "/"))
 	return addr, nil
 }
 

pkg/apiserver/metrics/prom_resolve_test.go

@@ -0,0 +1,24 @@
+// Copyright 2023 PingCAP, Inc. Licensed under Apache-2.0.
+
+package metrics
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+// https://github.com/pingcap/tidb-dashboard/issues/1560
+func Test_normalizeCustomizedPromAddress(t *testing.T) {
+	addr, err := normalizeCustomizedPromAddress("http://infra-tidb-monitoring-shadow2-prod-0a01da41:9090")
+	require.NoError(t, err)
+	require.Equal(t, "http://infra-tidb-monitoring-shadow2-prod-0a01da41:9090", addr)
+
+	addr, err = normalizeCustomizedPromAddress("http://infra-tidb-monitoring-shadow2-prod-0a01da41:9090/")
+	require.NoError(t, err)
+	require.Equal(t, "http://infra-tidb-monitoring-shadow2-prod-0a01da41:9090", addr)
+
+	addr, err = normalizeCustomizedPromAddress("http://infra-tidb-monitoring-shadow2-prod-0a01da41:9090/_/tsdb/")
+	require.NoError(t, err)
+	require.Equal(t, "http://infra-tidb-monitoring-shadow2-prod-0a01da41:9090/_/tsdb", addr)
+}