Cli parser fixups

.vscode/launch.json

@@ -26,6 +26,9 @@
  "preLaunchTask": "", //"build",
  "program": "${workspaceFolder}/out/dotnet/source/Mlos.Agent.Server/objd/AnyCPU/Mlos.Agent.Server.dll",
  "args": [
+ //"--optimizer-uri",
+ //"http://localhost:50051",
+ "--executable",
  "${workspaceFolder}/out/cmake/Debug/source/Mlos.UnitTest/Mlos.UnitTest"
  ],
  "env": {
@@ -42,10 +45,10 @@
  "preLaunchTask": "", //"build",
  "program": "${workspaceFolder}/out/dotnet/source/Mlos.Agent.Server/objd/AnyCPU/Mlos.Agent.Server.dll",
  "args": [
+ //"--optimizer-uri",
+ //"http://localhost:50051",
  "--executable",
- "${workspaceFolder}/out/cmake/Debug/source/Examples/SmartCache/SmartCache",
- "--optimizer-uri",
- "http://localhost:50051"
+ "${workspaceFolder}/out/cmake/Debug/source/Examples/SmartCache/SmartCache"
  ],
  "env": {
  "MLOS_SETTINGS_REGISTRY_PATH": "${workspaceFolder}/out/dotnet/source/Examples/SmartCache/SmartCache.SettingsRegistry/objd/AnyCPU"

source/Mlos.Agent.Server/MlosAgentServer.cs

@@ -7,11 +7,14 @@
 // -----------------------------------------------------------------------
 
 using System;
+using System.Collections.Generic;
 using System.IO;
+using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
 
 using CommandLine;
+using CommandLine.Text;
 
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.AspNetCore.Server.Kestrel.Core;
@@ -57,21 +60,30 @@ public static void Main(string[] args)
  {
  string executableFilePath = null;
  Uri optimizerAddressUri = null;
+ IEnumerable<string> extraArgs = null;
 
- var cliOptsParseResult = CommandLine.Parser.Default.ParseArguments<CliOptions>(args)
+ var cliOptsParser = new Parser(with => with.HelpWriter = null);
+ var cliOptsParseResult = cliOptsParser.ParseArguments<CliOptions>(args)
  .WithParsed(parsedOptions =>
  {
  executableFilePath = parsedOptions.Executable;
  optimizerAddressUri = parsedOptions.OptimizerUri;
+ extraArgs = parsedOptions.ExtraArgs;
  });
  if (cliOptsParseResult.Tag == ParserResultType.NotParsed)
  {
- // CommandLine already prints the help text for us in this case.
- //
- Console.Error.WriteLine("Failed to parse command line options.");
- Environment.Exit(1);
+ cliOptsParseResult.WithNotParsed(errs => ShowUsageHelp(
+ cliOptsParseResult,
+ errors: errs,
+ msg: "Failed to parse command line options."));
+ }
+ else if (extraArgs != null && extraArgs.Any())
+ {
+ ShowUsageHelp(cliOptsParseResult, msg: "Extra arguments found.");
  }
 
+ cliOptsParser.Dispose();
+
  // Check for the executable before setting up any shared memory to
  // reduce cleanup issues.
  //
@@ -220,6 +232,71 @@ public static void Main(string[] args)
  Console.WriteLine("Mlos.Agent exited.");
  }
 
+ private static void ShowUsageHelp<T>(ParserResult<T> parserResult, IEnumerable<Error> errors = null, string msg = null)
+ {
+ if (msg != null)
+ {
+ Console.Error.WriteLine(msg);
+ Console.Error.WriteLine(string.Empty);
+ }
+
+ if (errors == null)
+ {
+ errors = new List<Error>();
+ }
+
+ HelpText helpText = null;
+ if (errors.IsVersion())
+ {
+ helpText = HelpText.AutoBuild(parserResult);
+ }
+ else
+ {
+ helpText = HelpText.AutoBuild(
+ parserResult,
+ onError: ht =>
+ {
+ return HelpText.DefaultParsingErrorsHandler(parserResult, ht);
+ },
+ e => e);
+ helpText.AddNewLineBetweenHelpSections = true;
+ helpText.AddPreOptionsLines(new[]
+ {
+ // Use a single long line of text to let the help output get wrapped automatically for us.
+ "The Mlos.Agent.Server acts as an external agent for MLOS integrated components, allowing them to "
+ + "send it messages over shared memory, which it can process and use to interface with an optimizer "
+ + "service to tune the components over their shared memory communication channels.",
+ string.Empty,
+
+ // Indent the actual commands to make them stand out a bit more.
+ // Note: The help out preserves the indent across wrapping.
+ "usage mode 1: Wait for an application to register over global shared memory, without an optimizer.",
+ " dotnet Mlos.Agent.Server.dll",
+ string.Empty,
+
+ "usage mode 2: Wait for an application to register over global shared memory, and prepare to "
+ + "communicate with an MLOS optimizer listening at the given Grpc URI.",
+ " dotnet Mlos.Agent.Server.dll --optimizer-uri http://localhost:50051",
+ string.Empty,
+
+ "usage mode 3: Start an executable to communicate over freshly prepared global shared memory.",
+ " dotnet Mlos.Agent.Server.dll --executable path/to/executable",
+ string.Empty,
+
+ "usage mode 4: Start an executable to communicate over freshly prepared global shared memory and "
+ + "prepare to communicate with an MLOS optimizer listening at the given Grpc URI.",
+ " dotnet Mlos.Agent.Server.dll --executable path/to/executable --optimizer-uri http://localhost:50051",
+ string.Empty,
+
+ "Note: the optimizer service used in these examples can be started using the 'start_optimizer_microservice "
+ + "launch --port 50051' command from the mlos Python module.",
+ });
+ }
+
+ Console.WriteLine(helpText);
+ Environment.Exit(1);
+ }
+
  /// <summary>
  /// The command line options for this application.
  /// </summary>
@@ -230,6 +307,13 @@ private class CliOptions
 
  [Option("optimizer-uri", Required = false, Default = null, HelpText = "A URI to connect to the MLOS Optimizer service over GRPC (e.g. 'http://localhost:50051').")]
  public Uri OptimizerUri { get; set; }
+
+ /// <remarks>
+ /// Just used to detect any extra arguments so we can throw a warning.
+ /// See Also: https://github.com/microsoft/MLOS/issues/112.
+ /// </remarks>
+ [CommandLine.Value(0)]
+ public IEnumerable<string> ExtraArgs { get; set; }
  }
  }
 }