Merge branch 'INFRA-9686_add_obtaining_IPv4' into 'master'

feat: add ServiceDiscoveryIPv4 to EnvironmentInfo

See merge request vostok-libraries/commons.environment!1

CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.1.5 (03-09-2024):
+
+Added `ServiceDiscoveryIPv4` to `EnvironmentInfo`
+
 ## 0.1.4 (22-08-2022):
 
 Read Home Directory from `System.Environment.SpecialFolder.UserProfile`.

Vostok.Commons.Environment.Tests/EnvironmentInfo_Tests.cs

@@ -15,7 +15,7 @@ public static void Application_name_should_be_not_null_or_empty()
 
         [Test]
         public static void Host_name_should_be_not_null_or_empty()
-            => string.IsNullOrEmpty(EnvironmentInfo.Application).Should().BeFalse();
+            => string.IsNullOrEmpty(EnvironmentInfo.Host).Should().BeFalse();
 
         [Test]
         public void FQDN_should_not_be_null_or_empty()
@@ -25,6 +25,14 @@ public void FQDN_should_not_be_null_or_empty()
             Console.Out.WriteLine(EnvironmentInfo.FQDN);
         }
 
+        [Test]
+        public void ServiceDiscoveryIPv4_should_be_null_if_environment_variable_is_not_set()
+        {
+            EnvironmentInfo.ServiceDiscoveryIPv4.Should().BeNull();
+
+            Console.Out.WriteLine(EnvironmentInfo.ServiceDiscoveryIPv4);
+        }
+
         [Test]
         public void HomeDirectory_should_not_be_null_or_empty()
         {

Vostok.Commons.Environment/EnvironmentInfo.cs

@@ -4,6 +4,7 @@
 using System.Linq;
 using System.Net;
 using System.Net.NetworkInformation;
+using System.Net.Sockets;
 using System.Reflection;
 using System.Runtime.InteropServices;
 using JetBrains.Annotations;
@@ -18,10 +19,12 @@ internal static class EnvironmentInfo
     {
         public const string LocalHostnameVariable = "VOSTOK_LOCAL_HOSTNAME";
         public const string LocalFQDNVariable = "VOSTOK_LOCAL_FQDN";
+        public const string LocalServiceDiscoveryIPv4Variable = "VOSTOK_LOCAL_SERVICE_DISCOVERY_IPV4";
 
         private static Lazy<string> application = new Lazy<string>(ObtainApplicationName);
         private static Lazy<string> host = new Lazy<string>(ObtainHostname);
         private static Lazy<string> fqdn = new Lazy<string>(ObtainFQDN);
+        private static Lazy<string> serviceDiscoveryIPv4 = new Lazy<string>(ObtainServiceDiscoveryIPv4);
         private static Lazy<string> processName = new Lazy<string>(GetProcessNameOrNull);
         private static Lazy<string> homeDirectory = new Lazy<string>(ObtainHomeDirectory);
         private static Lazy<int?> processId = new Lazy<int?>(GetProcessIdOrNull);
@@ -41,6 +44,12 @@ internal static class EnvironmentInfo
         /// </summary>
         public static string FQDN => fqdn.Value;
 
+        /// <summary>
+        /// Returns the IPv4 through which the application is accessible on the hosting network.
+        /// This value is obtained once when the application starts and is cached for subsequent calls.
+        /// </summary>
+        public static string ServiceDiscoveryIPv4 => serviceDiscoveryIPv4.Value;
+
         /// <summary>
         /// Returns the name of current process. 
         /// </summary>
@@ -193,6 +202,22 @@ private static string ObtainFQDN()
             }
         }
 
+        private static string ObtainServiceDiscoveryIPv4()
+        {
+            try
+            {
+                var localIPv4 = System.Environment.GetEnvironmentVariable(LocalServiceDiscoveryIPv4Variable);
+                if (!string.IsNullOrEmpty(localIPv4))
+                    return localIPv4;
+
+                return null;
+            }
+            catch
+            {
+                return null;
+            }
+        }
+
         private static string GetWindowsDomainName()
         {
             try