expose apiPort via commndline (dotnet#1481)

Co-authored-by: Waldek Mastykarz <waldek@mastykarz.nl>

Author: niteshsinghal85

DevProxy.Abstractions/Proxy/IProxyConfiguration.cs

@@ -20,7 +20,7 @@ public enum ReleaseType
 
 public interface IProxyConfiguration
 {
-    int ApiPort { get; }
+    int ApiPort { get; set; }
     bool AsSystemProxy { get; set; }
     string ConfigFile { get; }
 #pragma warning disable CA2227

DevProxy/Commands/DevProxyCommand.cs

@@ -17,6 +17,7 @@ sealed class DevProxyCommand : RootCommand
     private WebApplication? _app;
 
     internal const string PortOptionName = "--port";
+    internal const string ApiPortOptionName = "--api-port";
     internal const string IpAddressOptionName = "--ip-address";
     internal const string LogLevelOptionName = "--log-level";
     internal const string RecordOptionName = "--record";
@@ -196,6 +197,12 @@ private void ConfigureCommand()
             HelpName = "port"
         };
 
+        var apiPortOption = new Option<int?>(ApiPortOptionName)
+        {
+            Description = "The port for the Dev Proxy API to listen on",
+            HelpName = "api-port"
+        };
+
         var recordOption = new Option<bool?>(RecordOptionName)
         {
             Description = "Use this option to record all request logs"
@@ -307,6 +314,7 @@ private void ConfigureCommand()
 
         var options = new List<Option>
         {
+            apiPortOption,
             asSystemProxyOption,
             configFileOption,
             discoverOption,
@@ -350,6 +358,11 @@ private void ConfigureFromOptions(ParseResult parseResult)
         {
             _proxyConfiguration.Port = port.Value;
         }
+        var apiPort = parseResult.GetValueOrDefault<int?>(ApiPortOptionName);
+        if (apiPort is not null)
+        {
+            _proxyConfiguration.ApiPort = apiPort.Value;
+        }
         var ipAddress = parseResult.GetValueOrDefault<string?>(IpAddressOptionName);
         if (ipAddress is not null)
         {

DevProxy/Commands/DevProxyConfigOptions.cs

@@ -17,6 +17,7 @@ public string? ConfigFile
         }
     }
 
+    public int? ApiPort => _parseResult?.GetValueOrDefault<int?>(DevProxyCommand.ApiPortOptionName);
     public bool Discover => _parseResult?.GetValueOrDefault<bool?>(DevProxyCommand.DiscoverOptionName) ?? false;
     public string? IPAddress => _parseResult?.GetValueOrDefault<string?>(DevProxyCommand.IpAddressOptionName);
     public LogLevel? LogLevel => _parseResult?.GetValueOrDefault<LogLevel?>(DevProxyCommand.LogLevelOptionName);
@@ -113,13 +114,16 @@ public DevProxyConfigOptions()
                 }
             }
         };
+        var apiPortOption = new Option<int?>(DevProxyCommand.ApiPortOptionName);
+        
         var discoverOption = new Option<bool>(DevProxyCommand.DiscoverOptionName, "--discover")
         {
             Arity = ArgumentArity.Zero
         };
 
         var options = new List<Option>
         {
+            apiPortOption,
             ipAddressOption,
             configFileOption,
             urlsToWatchOption,

DevProxy/Program.cs

@@ -21,9 +21,11 @@ static WebApplication BuildApplication(DevProxyConfigOptions options)
     var ipAddress = options.IPAddress ??
         builder.Configuration.GetValue("ipAddress", defaultIpAddress) ??
         defaultIpAddress;
+    var defaultApiPort = 8897;
+    var apiPort = options.ApiPort ??
+        builder.Configuration.GetValue("apiPort", defaultApiPort);
     _ = builder.WebHost.ConfigureKestrel(options =>
     {
-        var apiPort = builder.Configuration.GetValue("apiPort", 8897);
         options.Listen(IPAddress.Parse(ipAddress), apiPort);
     });