feat(discovery-agent): add DnsZone resource type support (#2695)

YXShang97 · tomkerkhove · web-flow · commit 8261296d50b8 · 2025-10-28T07:55:10.000+01:00
Co-authored-by: Tom Kerkhove &lt;kerkhove.tom@gmail.com&gt;
diff --git a/changelog/content/experimental/unreleased.md b/changelog/content/experimental/unreleased.md
@@ -8,8 +8,9 @@ version:
 
 - {{% tag fixed %}} Azure Monitor Scraper: batch based on aggregation in addition to existing criteria
 - {{% tag feature %}} Azure Monitor Scraper: make query lookback range configurable in minutes
+- {{% tag feature %}} Azure DNS Zone: support for scraping DNS zone metrics
 - {{% tag feature %}} Azure Monitor Scraper: add health check based on data freshness
 
 #### Resource Discovery
 
-None.
+- {{% tag feature %}} Azure DNS Zone: support for discovering DNS zones
diff --git a/config/promitor/resource-discovery/resource-discovery-declaration.yaml b/config/promitor/resource-discovery/resource-discovery-declaration.yaml
@@ -31,6 +31,8 @@ resourceDiscoveryGroups:
   type: DataFactory
 - name: data-share-landscape
   type: DataShare
+- name: dns-zones
+  type: DnsZone
 - name: dps
   type: DeviceProvisioningService
 - name: event-hubs-landscape
diff --git a/config/promitor/scraper/metrics.yaml b/config/promitor/scraper/metrics.yaml
@@ -421,6 +421,15 @@ metrics:
             type: Count
     resourceDiscoveryGroups:
         - name: powerbi-dedicated
+  - name: azure_dns_zone_record_capacity_utilization_discovered
+    description: "Record set capacity utilization percentage for discovered DNS zones"
+    resourceType: DnsZone
+    azureMetricConfiguration:
+      metricName: RecordSetCapacityUtilization
+      aggregation:
+        type: Average
+    resourceDiscoveryGroups:
+      - name: dns-zones
 
   # This uses our large-scale data set containing 1000+ Azure Logic App instances
   # Uncomment if you want to test with this scale
diff --git a/src/Promitor.Agents.ResourceDiscovery/Graph/ResourceDiscoveryFactory.cs b/src/Promitor.Agents.ResourceDiscovery/Graph/ResourceDiscoveryFactory.cs
@@ -38,6 +38,8 @@ public static ResourceDiscoveryQuery UseResourceDiscoveryFor(ResourceType resour
                     return new DataFactoryDiscoveryQuery();
                 case ResourceType.DataShare:
                     return new DataShareDiscoveryQuery();
+                case ResourceType.DnsZone:
+                    return new DnsZoneDiscoveryQuery();
                 case ResourceType.DeviceProvisioningService:
                     return new DeviceProvisioningServiceDiscoveryQuery();
                 case ResourceType.EventHubs:
diff --git a/src/Promitor.Agents.ResourceDiscovery/Graph/ResourceTypes/DnsZoneDiscoveryQuery.cs b/src/Promitor.Agents.ResourceDiscovery/Graph/ResourceTypes/DnsZoneDiscoveryQuery.cs
@@ -0,0 +1,21 @@
+using GuardNet;
+using Newtonsoft.Json.Linq;
+using Promitor.Core.Contracts;
+using Promitor.Core.Contracts.ResourceTypes;
+
+namespace Promitor.Agents.ResourceDiscovery.Graph.ResourceTypes
+{
+    public class DnsZoneDiscoveryQuery : ResourceDiscoveryQuery
+    {
+        public override string[] ResourceTypes => new[] { "microsoft.network/dnszones" };
+        public override string[] ProjectedFieldNames => new[] { "subscriptionId", "resourceGroup", "type", "name" };
+
+        public override AzureResourceDefinition ParseResults(JToken resultRowEntry)
+        {
+            Guard.NotNull(resultRowEntry, nameof(resultRowEntry));
+
+            var resource = new DnsZoneResourceDefinition(resultRowEntry[0]?.ToString(), resultRowEntry[1]?.ToString(), resultRowEntry[3]?.ToString());
+            return resource;
+        }
+    }
+}
diff --git a/src/Promitor.Agents.Scraper/Validation/Factories/MetricValidatorFactory.cs b/src/Promitor.Agents.Scraper/Validation/Factories/MetricValidatorFactory.cs
@@ -41,6 +41,8 @@ internal static IMetricValidator GetValidatorFor(ResourceType resourceType)
                     return new DataFactoryMetricValidator();
                 case ResourceType.DataShare:
                     return new DataShareMetricValidator();
+                case ResourceType.DnsZone:
+                    return new DnsZoneMetricValidator();
                 case ResourceType.DeviceProvisioningService:
                     return new DeviceProvisioningServiceMetricValidator();
                 case ResourceType.EventHubs:
diff --git a/src/Promitor.Agents.Scraper/Validation/MetricDefinitions/ResourceTypes/DnsZoneMetricValidator.cs b/src/Promitor.Agents.Scraper/Validation/MetricDefinitions/ResourceTypes/DnsZoneMetricValidator.cs
@@ -0,0 +1,25 @@
+using System.Collections.Generic;
+using System.Linq;
+using GuardNet;
+using Promitor.Agents.Scraper.Validation.MetricDefinitions.Interfaces;
+using Promitor.Core.Contracts.ResourceTypes;
+using Promitor.Core.Scraping.Configuration.Model.Metrics;
+
+namespace Promitor.Agents.Scraper.Validation.MetricDefinitions.ResourceTypes
+{
+    internal class DnsZoneMetricValidator : IMetricValidator
+    {
+        public IEnumerable<string> Validate(MetricDefinition metricDefinition)
+        {
+            Guard.NotNull(metricDefinition, nameof(metricDefinition));
+
+            foreach (var resourceDefinition in metricDefinition.Resources.Cast<DnsZoneResourceDefinition>())
+            {
+                if (string.IsNullOrWhiteSpace(resourceDefinition.ZoneName))
+                {
+                    yield return "No DNS Zone name is configured";
+                }
+            }
+        }
+    }
+}
diff --git a/src/Promitor.Core.Contracts/ResourceType.cs b/src/Promitor.Core.Contracts/ResourceType.cs
@@ -57,5 +57,6 @@ public enum ResourceType
         PowerBiDedicated = 52,
         AzureFirewall = 53,
         CognitiveServicesAccount = 54,
+        DnsZone = 55,
     }
 }
diff --git a/src/Promitor.Core.Contracts/ResourceTypes/DnsZoneResourceDefinition.cs b/src/Promitor.Core.Contracts/ResourceTypes/DnsZoneResourceDefinition.cs
@@ -0,0 +1,25 @@
+namespace Promitor.Core.Contracts.ResourceTypes
+{
+    /// <summary>
+    /// Represents an Azure DNS Zone resource.
+    /// </summary>
+    public class DnsZoneResourceDefinition : AzureResourceDefinition
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="DnsZoneResourceDefinition" /> class.
+        /// </summary>
+        /// <param name="subscriptionId">Specify a subscription to scrape that defers from the default subscription.</param>
+        /// <param name="resourceGroupName">The name of the resource group the DNS zone is in.</param>
+        /// <param name="zoneName">The DNS zone name (e.g., example.com).</param>
+        public DnsZoneResourceDefinition(string subscriptionId, string resourceGroupName, string zoneName)
+            : base(ResourceType.DnsZone, subscriptionId, resourceGroupName, zoneName)
+        {
+            ZoneName = zoneName;
+        }
+
+        /// <summary>
+        /// The DNS zone name.
+        /// </summary>
+        public string ZoneName { get; }
+    }
+}
diff --git a/src/Promitor.Core.Scraping/Configuration/Serialization/v1/Core/AzureResourceDeserializerFactory.cs b/src/Promitor.Core.Scraping/Configuration/Serialization/v1/Core/AzureResourceDeserializerFactory.cs
@@ -66,6 +66,9 @@ public IDeserializer<AzureResourceDefinitionV1> GetDeserializerFor(ResourceType
                 case ResourceType.DataShare:
                     var dataShareLogger = _loggerFactory.CreateLogger<DataShareDeserializer>();
                     return new DataShareDeserializer(dataShareLogger);
+                case ResourceType.DnsZone:
+                    var dnsZoneLogger = _loggerFactory.CreateLogger<DnsZoneDeserializer>();
+                    return new DnsZoneDeserializer(dnsZoneLogger);
                 case ResourceType.DeviceProvisioningService:
                     var deviceProvisioningServiceLogger = _loggerFactory.CreateLogger<DeviceProvisioningServiceDeserializer>();
                     return new DeviceProvisioningServiceDeserializer(deviceProvisioningServiceLogger);
diff --git a/src/Promitor.Core.Scraping/Configuration/Serialization/v1/Mapping/V1MappingProfile.cs b/src/Promitor.Core.Scraping/Configuration/Serialization/v1/Mapping/V1MappingProfile.cs
@@ -41,6 +41,7 @@ public V1MappingProfile()
             CreateMap<DataExplorerClusterResourceV1, DataExplorerClusterResourceDefinition>();
             CreateMap<DataFactoryResourceV1, DataFactoryResourceDefinition>();
             CreateMap<DataShareResourceV1, DataShareResourceDefinition>();
+            CreateMap<DnsZoneResourceV1, DnsZoneResourceDefinition>();
             CreateMap<DeviceProvisioningServiceResourceV1, DeviceProvisioningServiceResourceDefinition>();
             CreateMap<CosmosDbResourceV1, CosmosDbResourceDefinition>();
             CreateMap<EventHubsResourceV1, EventHubResourceDefinition>();
@@ -103,6 +104,7 @@ public V1MappingProfile()
                 .Include<DataExplorerClusterResourceV1, DataExplorerClusterResourceDefinition>()
                 .Include<DataFactoryResourceV1, DataFactoryResourceDefinition>()
                 .Include<DataShareResourceV1, DataShareResourceDefinition>()
+                .Include<DnsZoneResourceV1, DnsZoneResourceDefinition>()
                 .Include<DeviceProvisioningServiceResourceV1, DeviceProvisioningServiceResourceDefinition>()
                 .Include<EventHubsResourceV1, EventHubResourceDefinition>()
                 .Include<ExpressRouteCircuitResourceV1, ExpressRouteCircuitResourceDefinition>()
diff --git a/src/Promitor.Core.Scraping/Configuration/Serialization/v1/Model/ResourceTypes/DnsZoneResourceV1.cs b/src/Promitor.Core.Scraping/Configuration/Serialization/v1/Model/ResourceTypes/DnsZoneResourceV1.cs
@@ -0,0 +1,13 @@
+namespace Promitor.Core.Scraping.Configuration.Serialization.v1.Model.ResourceTypes
+{
+    /// <summary>
+    /// Configuration required to scrape an Azure DNS Zone.
+    /// </summary>
+    public class DnsZoneResourceV1 : AzureResourceDefinitionV1
+    {
+        /// <summary>
+        /// The DNS zone name (e.g., example.com).
+        /// </summary>
+        public string ZoneName { get; set; }
+    }
+}
diff --git a/src/Promitor.Core.Scraping/Configuration/Serialization/v1/Providers/DnsZoneDeserializer.cs b/src/Promitor.Core.Scraping/Configuration/Serialization/v1/Providers/DnsZoneDeserializer.cs
@@ -0,0 +1,14 @@
+using Microsoft.Extensions.Logging;
+using Promitor.Core.Scraping.Configuration.Serialization.v1.Model.ResourceTypes;
+
+namespace Promitor.Core.Scraping.Configuration.Serialization.v1.Providers
+{
+    public class DnsZoneDeserializer : ResourceDeserializer<DnsZoneResourceV1>
+    {
+        public DnsZoneDeserializer(ILogger<DnsZoneDeserializer> logger) : base(logger)
+        {
+            Map(resource => resource.ZoneName)
+                .IsRequired();
+        }
+    }
+}
diff --git a/src/Promitor.Core.Scraping/Factories/MetricScraperFactory.cs b/src/Promitor.Core.Scraping/Factories/MetricScraperFactory.cs
@@ -67,6 +67,8 @@ public IScraper<IAzureResourceDefinition> CreateScraper(ResourceType metricDefin
                     return new DataFactoryScraper(scraperConfiguration);
                 case ResourceType.DataShare:
                     return new DataShareScraper(scraperConfiguration);
+                case ResourceType.DnsZone:
+                    return new DnsZoneScraper(scraperConfiguration);
                 case ResourceType.DeviceProvisioningService:
                     return new DeviceProvisioningServiceScraper(scraperConfiguration);
                 case ResourceType.EventHubs:
diff --git a/src/Promitor.Core.Scraping/ResourceTypes/DnsZoneScraper.cs b/src/Promitor.Core.Scraping/ResourceTypes/DnsZoneScraper.cs
@@ -0,0 +1,23 @@
+using Promitor.Core.Contracts;
+using Promitor.Core.Contracts.ResourceTypes;
+using Promitor.Core.Scraping.Configuration.Model.Metrics;
+
+namespace Promitor.Core.Scraping.ResourceTypes
+{
+    /// <summary>
+    /// Scrapes an Azure DNS Zone
+    /// </summary>
+    public class DnsZoneScraper : AzureMonitorScraper<DnsZoneResourceDefinition>
+    {
+        private const string ResourceUriTemplate = "subscriptions/{0}/resourceGroups/{1}/providers/Microsoft.Network/dnszones/{2}";
+
+        public DnsZoneScraper(ScraperConfiguration scraperConfiguration) : base(scraperConfiguration)
+        {
+        }
+
+        protected override string BuildResourceUri(string subscriptionId, ScrapeDefinition<IAzureResourceDefinition> scrapeDefinition, DnsZoneResourceDefinition resource)
+        {
+            return string.Format(ResourceUriTemplate, subscriptionId, scrapeDefinition.ResourceGroupName, resource.ZoneName);
+        }
+    }
+}
diff --git a/src/Promitor.Tests.Unit/Builders/Metrics/v1/MetricsDeclarationBuilder.cs b/src/Promitor.Tests.Unit/Builders/Metrics/v1/MetricsDeclarationBuilder.cs
@@ -376,6 +376,24 @@ public MetricsDeclarationBuilder WithDataFactoryMetric(string metricName = "prom
             return this;
         }
 
+        public MetricsDeclarationBuilder WithDnsZoneMetric(string metricName = "promitor-dns-zone",
+            string metricDescription = "Description for a metric",
+            string zoneName = "promitor-dns-zone.com",
+            string azureMetricName = "RecordSetCapacityUtilization",
+            string resourceDiscoveryGroupName = "",
+            int? azureMetricLimit = null,
+            bool omitResource = false)
+        {
+            var resource = new DnsZoneResourceV1
+            {
+                ZoneName = zoneName
+            };
+
+            CreateAndAddMetricDefinition(ResourceType.DnsZone, metricName, metricDescription, resourceDiscoveryGroupName, omitResource, azureMetricName, azureMetricLimit, resource);
+
+            return this;
+        }
+
         public MetricsDeclarationBuilder WithDeviceProvisioningServiceMetric(string metricName = "promitor-dps",
             string metricDescription = "Description for a metric",
             string deviceProvisioningServiceName = "promitor-dps",
diff --git a/src/Promitor.Tests.Unit/Discovery/Query/DnsZoneDiscoveryQueryUnitTest.cs b/src/Promitor.Tests.Unit/Discovery/Query/DnsZoneDiscoveryQueryUnitTest.cs
@@ -0,0 +1,50 @@
+using System;
+using System.ComponentModel;
+using Newtonsoft.Json.Linq;
+using Promitor.Agents.ResourceDiscovery.Graph.ResourceTypes;
+using Promitor.Core.Contracts.ResourceTypes;
+using Xunit;
+
+namespace Promitor.Tests.Unit.Discovery.Query
+{
+    [Category("Unit")]
+    public class DnsZoneDiscoveryQueryUnitTest : UnitTest
+    {
+        [Fact]
+        public void ParseResults_ValidRow_Succeeds()
+        {
+            // Arrange
+            var subscriptionId = Guid.NewGuid().ToString();
+            var resourceGroup = "dns-rg";
+            var zoneName = "example.com";
+            var row = JArray.FromObject(new object[]
+            {
+                subscriptionId,
+                resourceGroup,
+                "microsoft.network/dnszones",
+                zoneName
+            });
+            var query = new DnsZoneDiscoveryQuery();
+
+            // Act
+            var result = query.ParseResults(row);
+
+            // Assert
+            var dnsDef = Assert.IsType<DnsZoneResourceDefinition>(result);
+            Assert.Equal(subscriptionId, dnsDef.SubscriptionId);
+            Assert.Equal(resourceGroup, dnsDef.ResourceGroupName);
+            Assert.Equal(zoneName, dnsDef.ZoneName);
+            Assert.Equal(zoneName, dnsDef.ResourceName);
+        }
+
+        [Fact]
+        public void ParseResults_NullRow_Throws()
+        {
+            // Arrange
+            var query = new DnsZoneDiscoveryQuery();
+
+            // Act & Assert
+            Assert.Throws<ArgumentNullException>(() => query.ParseResults(null));
+        }
+    }
+}
diff --git a/src/Promitor.Tests.Unit/Discovery/ResourceDiscoveryFactoryDnsZoneTests.cs b/src/Promitor.Tests.Unit/Discovery/ResourceDiscoveryFactoryDnsZoneTests.cs
@@ -0,0 +1,22 @@
+using System.ComponentModel;
+using Promitor.Agents.ResourceDiscovery.Graph;
+using Promitor.Agents.ResourceDiscovery.Graph.ResourceTypes;
+using Promitor.Core.Contracts;
+using Xunit;
+
+namespace Promitor.Tests.Unit.Discovery
+{
+    [Category("Unit")]
+    public class ResourceDiscoveryFactoryDnsZoneTests : UnitTest
+    {
+        [Fact]
+        public void UseResourceDiscoveryFor_DnsZone_ReturnsDnsZoneDiscoveryQuery()
+        {
+            // Act
+            var result = ResourceDiscoveryFactory.UseResourceDiscoveryFor(ResourceType.DnsZone);
+
+            // Assert
+            Assert.IsType<DnsZoneDiscoveryQuery>(result);
+        }
+    }
+}
diff --git a/src/Promitor.Tests.Unit/Serialization/ResourceTypes/DnsZoneSerializationTests.cs b/src/Promitor.Tests.Unit/Serialization/ResourceTypes/DnsZoneSerializationTests.cs
@@ -0,0 +1,35 @@
+using System.ComponentModel;
+using Newtonsoft.Json;
+using Newtonsoft.Json.Converters;
+using Promitor.Core.Contracts;
+using Promitor.Core.Contracts.ResourceTypes;
+using Xunit;
+
+namespace Promitor.Tests.Unit.Serialization.ResourceTypes
+{
+    [Category("Unit")]
+    public class DnsZoneSerializationTests : UnitTest
+    {
+        [Fact]
+        public void SerializeAndDeserialize_DnsZoneResourceDefinition_RoundTrips()
+        {
+            // Arrange
+            var definition = new DnsZoneResourceDefinition("sub-id","rg-dns","example.com");
+            var settings = new JsonSerializerSettings
+            {
+                NullValueHandling = NullValueHandling.Ignore,
+                TypeNameHandling = TypeNameHandling.Objects
+            };
+            settings.Converters.Add(new StringEnumConverter());
+
+            // Act
+            var json = JsonConvert.SerializeObject(definition, settings);
+            var roundTripped = JsonConvert.DeserializeObject<AzureResourceDefinition>(json, settings);
+
+            // Assert
+            var dnsDef = Assert.IsType<DnsZoneResourceDefinition>(roundTripped);
+            Assert.Equal(definition.ZoneName, dnsDef.ZoneName);
+            Assert.Equal(ResourceType.DnsZone, dnsDef.ResourceType);
+        }
+    }
+}
diff --git a/src/Promitor.Tests.Unit/Validation/Scraper/Metrics/ResourceTypes/DnsZoneMetricsDeclarationValidationStepsTests.cs b/src/Promitor.Tests.Unit/Validation/Scraper/Metrics/ResourceTypes/DnsZoneMetricsDeclarationValidationStepsTests.cs

Original file line number	Diff line number	Diff line change
`@@ -57,5 +57,6 @@ public enum ResourceType`
`57`	`57`	`PowerBiDedicated = 52,`
`58`	`58`	`AzureFirewall = 53,`
`59`	`59`	`CognitiveServicesAccount = 54,`
	`60`	`+ DnsZone = 55,`
`60`	`61`	`}`
`61`	`62`	`}`