Fixed an ElasticBeanstalk deployment issue for Linux platform where Procfile was sometimes being generated with incorrect entrypoint when multiple runtimeconfig.json files were present.

.autover/changes/a4b5c0a2-7029-491b-90d1-12bba898c249.json

@@ -0,0 +1,11 @@
+{
+  "Projects": [
+    {
+      "Name": "Amazon.ElasticBeanstalk.Tools",
+      "Type": "Patch",
+      "ChangelogMessages": [
+        "Fixed an ElasticBeanstalk deployment issue for Linux platform where Procfile was sometimes being generated with incorrect entrypoint when multiple runtimeconfig.json files were present."
+      ]
+    }
+  ]
+}

src/Amazon.Common.DotNetCli.Tools/Utilities.cs

@@ -334,6 +334,18 @@ public static string LookupTargetFrameworkFromProjectFile(string projectLocation
             return null;
         }
 
+        /// <summary>
+        /// Looks up the assembly name from a project file.
+        /// </summary>
+        /// <param name="projectLocation">The location of the project file.</param>
+        /// <param name="msBuildParameters">Additonal MSBuild paramteres passed by the user from the commandline</param>
+        /// <returns>The assembly name of the project.</returns>
+        public static string LookupAssemblyNameFromProjectFile(string projectLocation, string msBuildParameters)
+        {
+            var properties = LookupProjectProperties(projectLocation, msBuildParameters, "AssemblyName");
+            return properties.TryGetValue("AssemblyName", out var assemblyName) ? assemblyName : null;
+        }
+
         /// <summary>
         /// Retrieve the `OutputType` property of a given project
         /// </summary>

src/Amazon.ElasticBeanstalk.Tools/Commands/DeployEnvironmentCommand.cs

@@ -183,7 +183,7 @@ protected override async Task<bool> PerformActionAsync()
                     }
 
                     this.Logger?.WriteLine("Configuring application bundle for a Linux deployment");
-                    EBUtilities.SetupPackageForLinux(this.Logger, this, this.DeployEnvironmentOptions, publishLocation, proxyServer, applicationPort);
+                    EBUtilities.SetupPackageForLinux(this.Logger, this, this.DeployEnvironmentOptions, publishLocation, proxyServer, applicationPort, projectLocation);
                 }
 
                 zipArchivePath = Path.Combine(Directory.GetParent(publishLocation).FullName, new DirectoryInfo(projectLocation).Name + "-" + DateTime.Now.Ticks + ".zip");

src/Amazon.ElasticBeanstalk.Tools/EBUtilities.cs

@@ -5,6 +5,7 @@
 using System.Linq;
 using System.Runtime.CompilerServices;
 using Amazon.Common.DotNetCli.Tools;
+using Amazon.Common.DotNetCli.Tools.Options;
 using Amazon.ElasticBeanstalk.Model;
 using Amazon.ElasticBeanstalk.Tools.Commands;
 using ThirdParty.Json.LitJson;
@@ -109,25 +110,23 @@ public static bool IsLoadBalancedEnvironmentType(string environmentType)
         }
 
 
-        public static void SetupPackageForLinux(IToolLogger logger, EBBaseCommand command, DeployEnvironmentProperties options, string publishLocation, string reverseProxy, int? applicationPort)
+        public static void SetupPackageForLinux(IToolLogger logger, EBBaseCommand command, DeployEnvironmentProperties options, string publishLocation, string reverseProxy, int? applicationPort, string projectLocation)
         {
             // Setup Procfile
             var procfilePath = Path.Combine(publishLocation, "Procfile");
 
-            if(File.Exists(procfilePath))
+            if (File.Exists(procfilePath))
             {
                 logger?.WriteLine("Found existing Procfile file found and using that for deployment");
                 return;
             }
 
             logger?.WriteLine("Writing Procfile for deployment bundle");
-
-            var runtimeConfigFilePath = Directory.GetFiles(publishLocation, "*.runtimeconfig.json").FirstOrDefault();
-            var runtimeConfigFileName = Path.GetFileName(runtimeConfigFilePath);
-            var executingAssembly = runtimeConfigFileName.Substring(0, runtimeConfigFileName.Length - "runtimeconfig.json".Length - 1);
+            var executingAssembly = Utilities.LookupAssemblyNameFromProjectFile(projectLocation, null);
+            var runtimeConfigFilePath = Directory.GetFiles(publishLocation, $"{executingAssembly}.runtimeconfig.json").FirstOrDefault();
 
             string webCommandLine;
-            if(IsSelfContainedPublish(runtimeConfigFilePath))
+            if (IsSelfContainedPublish(runtimeConfigFilePath))
             {
                 webCommandLine = $"./{executingAssembly}";
             }
@@ -136,7 +135,7 @@ public static void SetupPackageForLinux(IToolLogger logger, EBBaseCommand comman
                 webCommandLine = $"dotnet exec ./{executingAssembly}.dll";
             }
 
-            if(string.Equals(reverseProxy, EBConstants.PROXY_SERVER_NONE, StringComparison.InvariantCulture))
+            if (string.Equals(reverseProxy, EBConstants.PROXY_SERVER_NONE, StringComparison.InvariantCulture))
             {
                 logger?.WriteLine("... Proxy server disabled, configuring Kestrel to listen to traffic from all hosts");
                 var port = applicationPort.HasValue ? applicationPort.Value : EBConstants.DEFAULT_APPLICATION_PORT;