Allow environment variables for Tapeti.Cmd connection parameters

Output connection parameters and their sources to the console

Tapeti.Cmd/Program.cs

@@ -17,6 +17,9 @@ namespace Tapeti.Cmd
                 .Where(t => t.GetCustomAttribute<ExecutableVerbAttribute>() != null)
                 .ToArray();
 
+            using var consoleWrapper = new ConsoleWrapper();
+
+            // ReSharper disable AccessToDisposedClosure
             CommandLine.Parser.Default.ParseArguments(args, verbTypes.ToArray())
                 .WithParsed(o =>
                 {
@@ -28,33 +31,33 @@ namespace Tapeti.Cmd
                         // Should have been validated by the ExecutableVerbAttribute
                         Debug.Assert(executer != null, nameof(executer) + " != null");
 
-                        using var consoleWrapper = new ConsoleWrapper();
-
                         executer.Execute(consoleWrapper);
                         exitCode = 0;
                     }
                     catch (Exception e)
                     {
-                        Console.WriteLine(e.Message);
+                        using var consoleWriter = consoleWrapper.GetPermanentWriter();
-                        DebugConfirmClose();
+                        consoleWriter.WriteLine(e.Message);
+                        DebugConfirmClose(consoleWrapper);
                     }
                 })
                 .WithNotParsed(_ =>
                 {
-                    DebugConfirmClose();
+                    DebugConfirmClose(consoleWrapper);
                 });
+            // ReSharper restore AccessToDisposedClosure
 
             return exitCode;
         }
 
 
-        private static void DebugConfirmClose()
+        private static void DebugConfirmClose(IConsole console)
         {
             if (!Debugger.IsAttached)
                 return;
 
-            Console.WriteLine("Press any Enter key to continue...");
+            using var consoleWriter = console.GetPermanentWriter();
-            Console.ReadLine();
+            consoleWriter.Confirm("Press any key to continue...");
         }
     }
 }

Tapeti.Cmd/Verbs/BaseConnectionOptions.cs

@@ -1,22 +1,93 @@
-using CommandLine;
+using System;
+using CommandLine;
+using RabbitMQ.Client;
+using Tapeti.Cmd.ConsoleHelper;
 
 namespace Tapeti.Cmd.Verbs
 {
     public class BaseConnectionOptions
     {
-        [Option('h', "host", HelpText = "Hostname of the RabbitMQ server.", Default = "localhost")]
+        [Option('h', "host", HelpText = "(Default: localhost) Hostname of the RabbitMQ server. Can also be set using the TAPETI_HOST environment variable.")]
         public string Host { get; set; }
 
-        [Option("port", HelpText = "AMQP port of the RabbitMQ server.", Default = 5672)]
+        [Option("port", HelpText = "(Default: 5672) AMQP port of the RabbitMQ server. Can also be set using the TAPETI_PORT environment variable.")]
-        public int Port { get; set; }
+        public int? Port { get; set; }
 
-        [Option('v', "virtualhost", HelpText = "Virtual host used for the RabbitMQ connection.", Default = "/")]
+        [Option('v', "virtualhost", HelpText = "(Default: /) Virtual host used for the RabbitMQ connection. Can also be set using the TAPETI_VIRTUALHOST environment variable.")]
         public string VirtualHost { get; set; }
 
-        [Option('u', "username", HelpText = "Username used to connect to the RabbitMQ server.", Default = "guest")]
+        [Option('u', "username", HelpText = "(Default: guest) Username used to connect to the RabbitMQ server. Can also be set using the TAPETI_USERNAME environment variable.")]
         public string Username { get; set; }
 
-        [Option('p', "password", HelpText = "Password used to connect to the RabbitMQ server.", Default = "guest")]
+        [Option('p', "password", HelpText = "(Default: guest) Password used to connect to the RabbitMQ server. Can also be set using the TAPETI_PASSWORD environment variable.")]
         public string Password { get; set; }
+
+
+        public ConnectionFactory CreateConnectionFactory(IConsole console)
+        {
+            var consoleWriter = console.GetPermanentWriter();
+            consoleWriter.WriteLine("Using connection parameters:");
+            
+            var factory = new ConnectionFactory
+            {
+                HostName    = GetOptionOrEnvironmentValue(consoleWriter, "  Host         : ", Host, "TAPETI_HOST", "localhost"),
+                Port        = GetOptionOrEnvironmentValue(consoleWriter, "  Port         : ", Port, "TAPETI_PORT", 5672),
+                VirtualHost = GetOptionOrEnvironmentValue(consoleWriter, "  Virtual host : ", VirtualHost, "TAPETI_VIRTUALHOST", "/"),
+                UserName    = GetOptionOrEnvironmentValue(consoleWriter, "  Username     : ", Username, "TAPETI_USERNAME", "guest"),
+                Password    = GetOptionOrEnvironmentValue(consoleWriter, "  Password     : ", Password, "TAPETI_PASSWORD", "guest", true)
+            };
+            
+            consoleWriter.WriteLine("");
+            return factory;
+        }
+
+
+        private static string GetOptionOrEnvironmentValue(IConsoleWriter consoleWriter, string consoleDisplayName, string optionValue, string environmentName, string defaultValue, bool hideValue = false)
+        {
+            string GetDisplayValue(string value)
+            {
+                return hideValue
+                    ? "<hidden>"
+                    : value;
+            }
+            
+            if (!string.IsNullOrEmpty(optionValue))
+            {
+                consoleWriter.WriteLine($"{consoleDisplayName}{GetDisplayValue(optionValue)} (from command-line)");
+                return optionValue;
+            }
+
+            var environmentValue = Environment.GetEnvironmentVariable(environmentName);
+            if (!string.IsNullOrEmpty(environmentValue))
+            {
+                consoleWriter.WriteLine($"{consoleDisplayName}{GetDisplayValue(environmentValue)} (from environment variable)");
+                return environmentValue;
+            }
+
+            consoleWriter.WriteLine($"{consoleDisplayName}{GetDisplayValue(defaultValue)} (default)");
+            return defaultValue;
+        }
+
+
+        private static int GetOptionOrEnvironmentValue(IConsoleWriter consoleWriter, string consoleDisplayName, int? optionValue, string environmentName, int defaultValue)
+        {
+            if (optionValue.HasValue)
+            {
+                consoleWriter.WriteLine($"{consoleDisplayName}{optionValue} (from command-line)");
+                return optionValue.Value;
+            }
+        
+
+            var environmentValue = Environment.GetEnvironmentVariable(environmentName);
+            if (!string.IsNullOrEmpty(environmentValue) && int.TryParse(environmentValue, out var environmentIntValue))
+            {
+                consoleWriter.WriteLine($"{consoleDisplayName}{environmentIntValue} (from environment variable)");
+                return environmentIntValue;
+            }
+
+            consoleWriter.WriteLine($"{consoleDisplayName}{defaultValue} (default)");
+            return defaultValue;
+        }
+
     }
 }

Tapeti.Cmd/Verbs/BindQueueVerb.cs

@@ -35,15 +35,7 @@ namespace Tapeti.Cmd.Verbs
             var consoleWriter = console.GetPermanentWriter();
             var bindings = BindingParser.Parse(options.Bindings);
 
-            var factory = new ConnectionFactory
+            var factory = options.CreateConnectionFactory(console);
-            {
-                HostName = options.Host,
-                Port = options.Port,
-                VirtualHost = options.VirtualHost,
-                UserName = options.Username,
-                Password = options.Password
-            };
-
             using var connection = factory.CreateConnection();
             using var channel = connection.CreateModel();
 

Tapeti.Cmd/Verbs/DeclareQueueVerb.cs

@@ -37,15 +37,7 @@ namespace Tapeti.Cmd.Verbs
             // Parse early to fail early
             var bindings = BindingParser.Parse(options.Bindings);
 
-            var factory = new ConnectionFactory
+            var factory = options.CreateConnectionFactory(console);
-            {
-                HostName = options.Host,
-                Port = options.Port,
-                VirtualHost = options.VirtualHost,
-                UserName = options.Username,
-                Password = options.Password
-            };
-
             using var connection = factory.CreateConnection();
             using var channel = connection.CreateModel();
 

Tapeti.Cmd/Verbs/ExportVerb.cs

@@ -40,15 +40,7 @@ namespace Tapeti.Cmd.Verbs
         public void Execute(IConsole console)
         {
             var consoleWriter = console.GetPermanentWriter();
-            var factory = new ConnectionFactory
+            var factory = options.CreateConnectionFactory(console);
-            {
-                HostName = options.Host,
-                Port = options.Port,
-                VirtualHost = options.VirtualHost,
-                UserName = options.Username,
-                Password = options.Password
-            };
-
             using var messageSerializer = GetMessageSerializer(options);
             using var connection = factory.CreateConnection();
             using var channel = connection.CreateModel();

Tapeti.Cmd/Verbs/ImportVerb.cs

@@ -54,16 +54,7 @@ namespace Tapeti.Cmd.Verbs
         public void Execute(IConsole console)
         {
             var consoleWriter = console.GetPermanentWriter();
-            var factory = new ConnectionFactory
+            var factory = options.CreateConnectionFactory(console); using var messageSerializer = GetMessageSerializer(options);
-            {
-                HostName = options.Host,
-                Port = options.Port,
-                VirtualHost = options.VirtualHost,
-                UserName = options.Username,
-                Password = options.Password
-            };
-
-            using var messageSerializer = GetMessageSerializer(options);
             using var connection = factory.CreateConnection();
             using var channel = connection.CreateModel();
             var rateLimiter = RateLimiterFactory.Create(console, options.MaxRate, options.BatchSize, options.BatchPauseTime);

Tapeti.Cmd/Verbs/PurgeVerb.cs

@@ -37,16 +37,7 @@ namespace Tapeti.Cmd.Verbs
                     return;
             }
 
-            var factory = new ConnectionFactory
+            var factory = options.CreateConnectionFactory(console); using var connection = factory.CreateConnection();
-            {
-                HostName = options.Host,
-                Port = options.Port,
-                VirtualHost = options.VirtualHost,
-                UserName = options.Username,
-                Password = options.Password
-            };
-
-            using var connection = factory.CreateConnection();
             using var channel = connection.CreateModel();
             
             var messageCount = channel.QueuePurge(options.QueueName);

Tapeti.Cmd/Verbs/RemoveQueueVerb.cs

@@ -41,15 +41,7 @@ namespace Tapeti.Cmd.Verbs
                     return;
             }
 
-            var factory = new ConnectionFactory
+            var factory = options.CreateConnectionFactory(console);
-            {
-                HostName = options.Host,
-                Port = options.Port,
-                VirtualHost = options.VirtualHost,
-                UserName = options.Username,
-                Password = options.Password
-            };
-
             uint messageCount;
 
             try

Tapeti.Cmd/Verbs/ShovelVerb.cs

@@ -61,15 +61,7 @@ namespace Tapeti.Cmd.Verbs
         
         public void Execute(IConsole console)
         {
-            var sourceFactory = new ConnectionFactory
+            var sourceFactory = options.CreateConnectionFactory(console);
-            {
-                HostName = options.Host,
-                Port = options.Port,
-                VirtualHost = options.VirtualHost,
-                UserName = options.Username,
-                Password = options.Password
-            };
-
             using var sourceConnection = sourceFactory.CreateConnection();
             using var sourceChannel = sourceConnection.CreateModel();
 
@@ -78,7 +70,7 @@ namespace Tapeti.Cmd.Verbs
                 var targetFactory = new ConnectionFactory
                 {
                     HostName = !string.IsNullOrEmpty(options.TargetHost) ? options.TargetHost : options.Host,
-                    Port = options.TargetPort ?? options.Port,
+                    Port = options.TargetPort ?? options.Port ?? 5672,
                     VirtualHost = !string.IsNullOrEmpty(options.TargetVirtualHost) ? options.TargetVirtualHost : options.VirtualHost,
                     UserName = !string.IsNullOrEmpty(options.TargetUsername) ? options.TargetUsername : options.Username,
                     Password = !string.IsNullOrEmpty(options.TargetPassword) ? options.TargetPassword : options.Password

Tapeti.Cmd/Verbs/UnbindQueueVerb.cs

@@ -35,15 +35,7 @@ namespace Tapeti.Cmd.Verbs
             var consoleWriter = console.GetPermanentWriter();
             var bindings = BindingParser.Parse(options.Bindings);
 
-            var factory = new ConnectionFactory
+            var factory = options.CreateConnectionFactory(console);
-            {
-                HostName = options.Host,
-                Port = options.Port,
-                VirtualHost = options.VirtualHost,
-                UserName = options.Username,
-                Password = options.Password
-            };
-
             using var connection = factory.CreateConnection();
             using var channel = connection.CreateModel();