From 3770d23fff767be48a4b81bd030ef3f638531858 Mon Sep 17 00:00:00 2001
From: Nathan Willoughby <nathan.willoughby@octopus.com>
Date: Thu, 30 Nov 2023 11:36:37 +1000
Subject: [PATCH] Enable Halibut TCP Keep Alives by default

---
 .../TentacleCommunicationsModuleFixture.cs    | 90 +++++++++++++++++++
 .../TentacleCommunicationsModule.cs           |  7 +-
 2 files changed, 96 insertions(+), 1 deletion(-)
 create mode 100644 source/Octopus.Tentacle.Tests/Communications/TentacleCommunicationsModuleFixture.cs

diff --git a/source/Octopus.Tentacle.Tests/Communications/TentacleCommunicationsModuleFixture.cs b/source/Octopus.Tentacle.Tests/Communications/TentacleCommunicationsModuleFixture.cs
new file mode 100644
index 000000000..9efad79ed
--- /dev/null
+++ b/source/Octopus.Tentacle.Tests/Communications/TentacleCommunicationsModuleFixture.cs
@@ -0,0 +1,90 @@
+using System;
+using Autofac;
+using FluentAssertions;
+using Halibut;
+using NUnit.Framework;
+using Octopus.Tentacle.Communications;
+using Octopus.Tentacle.Configuration;
+using Octopus.Tentacle.Tests.Commands;
+using Octopus.Tentacle.Variables;
+
+namespace Octopus.Tentacle.Tests.Communications
+{
+    public class TentacleCommunicationsModuleFixture
+    {
+        [Test]
+        public void HalibutTcpKeepAlivesShouldBeEnabledByDefault()
+        {
+            var container = BuildContainer();
+
+            var halibutRuntime = container.Resolve<HalibutRuntime>();
+
+            halibutRuntime.TimeoutsAndLimits.TcpKeepAliveEnabled.Should().BeTrue();
+        }
+
+        [Test]
+        [NonParallelizable]
+        public void HalibutTcpKeepAlivesCanBeDisabledWithAnEnvironmentVariable()
+        {
+            try
+            {
+                Environment.SetEnvironmentVariable(EnvironmentVariables.TentacleTcpKeepAliveEnabled, "False");
+
+                var container = BuildContainer();
+
+                var halibutRuntime = container.Resolve<HalibutRuntime>();
+
+                halibutRuntime.TimeoutsAndLimits.TcpKeepAliveEnabled.Should().BeFalse();
+            }
+            finally
+            {
+                Environment.SetEnvironmentVariable(EnvironmentVariables.TentacleTcpKeepAliveEnabled, "");
+            }
+        } 
+        
+        [Test]
+        [NonParallelizable]
+        public void AnEmptyHalibutTcpKeepAlivesEnvironmentVariableIsIgnored()
+        {
+            Environment.SetEnvironmentVariable(EnvironmentVariables.TentacleTcpKeepAliveEnabled, "");
+
+            var container = BuildContainer();
+
+            var halibutRuntime = container.Resolve<HalibutRuntime>();
+
+            halibutRuntime.TimeoutsAndLimits.TcpKeepAliveEnabled.Should().BeTrue();
+        } 
+
+        [Test]
+        [NonParallelizable]
+        public void AnInvalidHalibutTcpKeepAlivesEnvironmentVariableIsIgnored()
+        {
+            try
+            {
+                Environment.SetEnvironmentVariable(EnvironmentVariables.TentacleTcpKeepAliveEnabled, "NOTABOOL");
+
+                var container = BuildContainer();
+
+                var halibutRuntime = container.Resolve<HalibutRuntime>();
+
+                halibutRuntime.TimeoutsAndLimits.TcpKeepAliveEnabled.Should().BeTrue();
+            }
+            finally
+            {
+                Environment.SetEnvironmentVariable(EnvironmentVariables.TentacleTcpKeepAliveEnabled, "");
+            }
+        } 
+
+        static IContainer BuildContainer()
+        {
+            var builder = new ContainerBuilder();
+            var configuration = new StubTentacleConfiguration();
+            configuration.TentacleCertificate = configuration.GenerateNewCertificate();
+            configuration.AddOrUpdateTrustedOctopusServer(new OctopusServerConfiguration("NOPE"));
+            builder.RegisterInstance(configuration).As<ITentacleConfiguration>();
+            builder.RegisterModule<TentacleCommunicationsModule>();
+            var container = builder.Build();
+            return container;
+        }
+    }
+}
\ No newline at end of file
diff --git a/source/Octopus.Tentacle/Communications/TentacleCommunicationsModule.cs b/source/Octopus.Tentacle/Communications/TentacleCommunicationsModule.cs
index 1b3c3f114..95e34c10a 100644
--- a/source/Octopus.Tentacle/Communications/TentacleCommunicationsModule.cs
+++ b/source/Octopus.Tentacle/Communications/TentacleCommunicationsModule.cs
@@ -25,7 +25,12 @@ protected override void Load(ContainerBuilder builder)
                 var configuration = c.Resolve<ITentacleConfiguration>();
                 var services = c.Resolve<IServiceFactory>();
 
-                bool.TryParse(Environment.GetEnvironmentVariable(EnvironmentVariables.TentacleTcpKeepAliveEnabled), out var tcpKeepAliveEnabled);
+                if (!bool.TryParse(Environment.GetEnvironmentVariable(EnvironmentVariables.TentacleTcpKeepAliveEnabled), out var tcpKeepAliveEnabled))
+                {
+                    // Default to enabled if the environment variable is not provided
+                    tcpKeepAliveEnabled = true;
+                }
+
                 bool.TryParse(Environment.GetEnvironmentVariable(EnvironmentVariables.TentacleUseRecommendedTimeoutsAndLimits), out var useRecommendedTimeoutsAndLimits);
 
                 var halibutTimeoutsAndLimits = useRecommendedTimeoutsAndLimits