Allows running proxy without plugins or URLs to watch. Closes #1042 (#1071)

Author: waldekmastykarz

dev-proxy/CommandHandlers/ProxyCommandHandler.cs

@@ -32,6 +32,17 @@ public int Invoke(InvocationContext context)
 
     public async Task<int> InvokeAsync(InvocationContext context)
     {
+        if (Configuration.Plugins.Count == 0)
+        {
+            _logger.LogWarning("You haven't configured any plugins. Please add plugins to your configuration file. Dev Proxy will exit.");
+            return 1;
+        }
+        if (Configuration.UrlsToWatch.Count == 0)
+        {
+            _logger.LogWarning("You haven't configured any URLs to watch. Please add URLs to your configuration file or use the --urls-to-watch option. Dev Proxy will exit.");
+            return 1;
+        }
+
         ParseOptions(context);
         _pluginEvents.RaiseOptionsLoaded(new OptionsLoadedArgs(context, _options));
         await CheckForNewVersionAsync();
@@ -174,6 +185,20 @@ private async Task CheckForNewVersionAsync()
         var configObject = new ProxyConfiguration();
         configuration.Bind(configObject);
 
+        // Custom binding for internal properties, because it's not happening
+        // automatically
+        var pluginsSection = configuration.GetSection("Plugins");
+        if (pluginsSection.Exists())
+        {
+            configObject.Plugins = pluginsSection.Get<List<PluginReference>>() ?? [];
+        }
+
+        var urlsSection = configuration.GetSection("UrlsToWatch");
+        if (urlsSection.Exists())
+        {
+            configObject.UrlsToWatch = urlsSection.Get<List<string>>() ?? [];
+        }
+
         return configObject;
     });
 }

dev-proxy/PluginLoader.cs

@@ -63,19 +63,22 @@ public async Task<PluginLoaderResult> LoadPluginsAsync(IPluginEvents pluginEvent
                     (pluginUrls != null && pluginUrls.Any()) ? pluginUrls : defaultUrlsToWatch,
                     h.ConfigSection is null ? null : Configuration.GetSection(h.ConfigSection)
                 );
+                if (plugin is null)
+                {
+                    _logger?.LogError("Plugin {pluginName} could not be created. Skipping...", h.Name);
+                    continue;
+                }
                 _logger?.LogDebug("Registering plugin {pluginName}...", plugin.Name);
                 await plugin.RegisterAsync();
                 _logger?.LogDebug("Plugin {pluginName} registered.", plugin.Name);
                 plugins.Add(plugin);
             }
         }
 
-        return plugins.Count > 0
-            ? new PluginLoaderResult(globallyWatchedUrls.ToHashSet(), plugins)
-            : throw new InvalidDataException("No plugins were loaded");
+        return new PluginLoaderResult(globallyWatchedUrls.ToHashSet(), plugins);
     }
 
-    private IProxyPlugin CreatePlugin(
+    private IProxyPlugin? CreatePlugin(
         Assembly assembly,
         PluginReference pluginReference,
         IPluginEvents pluginEvents,
@@ -84,6 +87,12 @@ private IProxyPlugin CreatePlugin(
         IConfigurationSection? configSection = null
     )
     {
+        if (urlsToWatch is null || urlsToWatch.Count == 0)
+        {
+            _logger.LogError("Plugin {pluginName} must have at least one URL to watch. Please add a URL to watch in the configuration file or use the --urls-to-watch option.", pluginReference.Name);
+            return null;
+        }
+
         foreach (Type type in assembly.GetTypes())
         {
             if (type.Name == pluginReference.Name &&
@@ -151,10 +160,6 @@ private PluginConfig PluginConfig
                     _pluginConfig.UrlsToWatch = ProxyHost.UrlsToWatch.ToList();
                 }
             }
-            if (_pluginConfig == null || _pluginConfig.Plugins.Count == 0)
-            {
-                throw new InvalidDataException("The configuration must contain at least one plugin");
-            }
             return _pluginConfig;
         }
     }

dev-proxy/Program.cs

@@ -85,9 +85,10 @@
 {
     // we don't need to init plugins if the user is using a global option or
     // using a subcommand, so we can exit early
-    await rootCommand.InvokeAsync(args);
+    var exitCode = await rootCommand.InvokeAsync(args);
     // required to output all messages before closing the program
     loggerFactory.Dispose();
+    Environment.Exit(exitCode);
     return;
 }
 
@@ -121,6 +122,7 @@
     Console.Error.WriteLine("Unknown option(s): {0}", string.Join(" ", incomingOptions));
     Console.Error.WriteLine("TIP: Use --help view available options");
     Console.Error.WriteLine("TIP: Are you missing a plugin? See: https://aka.ms/devproxy/plugins");
+    Environment.Exit(1);
 }
 else
 {
@@ -131,5 +133,7 @@
     }
 
     rootCommand.Handler = proxyHost.GetCommandHandler(pluginEvents, [.. options], loaderResults.UrlsToWatch, logger);
-    await rootCommand.InvokeAsync(args);
+    var exitCode = await rootCommand.InvokeAsync(args);
+    loggerFactory.Dispose();
+    Environment.Exit(exitCode);
 }

dev-proxy/ProxyConfiguration.cs

@@ -33,11 +33,13 @@ public class ProxyConfiguration : IProxyConfiguration
     public bool NoFirstRun { get; set; } = false;
     [JsonConverter(typeof(JsonStringEnumConverter))]
     public ReleaseType NewVersionNotification { get; set; } = ReleaseType.Stable;
+    internal List<PluginReference> Plugins { get; set; } = [];
     public int Port { get; set; } = 8000;
     public bool Record { get; set; } = false;
     public bool ShowSkipMessages { get; set; } = true;
     public bool ShowTimestamps { get; set; } = true;
     public long? TimeoutSeconds { get; set; }
+    internal List<string> UrlsToWatch { get; set; } = [];
     public bool ValidateSchemas { get; set; } = true;
     public IEnumerable<int> WatchPids { get; set; } = new List<int>();
     public IEnumerable<string> WatchProcessNames { get; set; } = [];