Support setting WireMockServerSettings via Environment (#954)

* Support parsing environment variables (WireMockServerSettings__)

* case ignore

* fix

* SimpleSettingsParserTests

* .

* int

* more test

src/WireMock.Net.StandAlone/StandAloneApp.cs

@@ -1,3 +1,4 @@
+using System;
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Reflection;
@@ -24,7 +25,7 @@ public static class StandAloneApp
     [PublicAPI]
     public static WireMockServer Start(WireMockServerSettings settings)
     {
-        Guard.NotNull(settings, nameof(settings));
+        Guard.NotNull(settings);
 
         var server = WireMockServer.Start(settings);
 
@@ -42,7 +43,7 @@ public static class StandAloneApp
     [PublicAPI]
     public static WireMockServer Start(string[] args, IWireMockLogger? logger = null)
     {
-        Guard.NotNull(args, nameof(args));
+        Guard.NotNull(args);
 
         if (TryStart(args, out var server, logger))
         {
@@ -61,9 +62,9 @@ public static class StandAloneApp
     [PublicAPI]
     public static bool TryStart(string[] args, [NotNullWhen(true)] out WireMockServer? server, IWireMockLogger? logger = null)
     {
-        Guard.NotNull(args, nameof(args));
+        Guard.NotNull(args);
 
-        if (WireMockServerSettingsParser.TryParseArguments(args, out var settings, logger))
+        if (WireMockServerSettingsParser.TryParseArguments(args, Environment.GetEnvironmentVariables(), out var settings, logger))
         {
             settings.Logger?.Info("Version [{0}]", Version);
             settings.Logger?.Debug("Server arguments [{0}]", string.Join(", ", args.Select(a => $"'{a}'")));

src/WireMock.Net/Extensions/DictionaryExtensions.cs

@@ -0,0 +1,29 @@
+using System.Collections;
+using System.Diagnostics.CodeAnalysis;
+using Stef.Validation;
+
+namespace WireMock.Extensions;
+
+internal static class DictionaryExtensions
+{
+    public static bool TryGetStringValue(this IDictionary dictionary, string key, [NotNullWhen(true)] out string? value)
+    {
+        Guard.NotNull(dictionary);
+        
+        if (dictionary[key] is string valueIsString)
+        {
+            value = valueIsString;
+            return true;
+        }
+
+        var valueToString = dictionary[key]?.ToString();
+        if (valueToString != null)
+        {
+            value = valueToString;
+            return true;
+        }
+
+        value = default;
+        return false;
+    }
+}

src/WireMock.Net/Settings/SimpleSettingsParser.cs

@@ -1,17 +1,21 @@
 using System;
+using System.Collections;
 using System.Collections.Generic;
 using System.Linq;
+using WireMock.Extensions;
 
 namespace WireMock.Settings;
 
 // Based on http://blog.gauffin.org/2014/12/simple-command-line-parser/
-internal class SimpleCommandLineParser
+internal class SimpleSettingsParser
 {
     private const string Sigil = "--";
+    private const string Prefix = $"{nameof(WireMockServerSettings)}__";
+    private static readonly int PrefixLength = Prefix.Length;
 
     private IDictionary<string, string[]> Arguments { get; } = new Dictionary<string, string[]>(StringComparer.OrdinalIgnoreCase);
 
-    public void Parse(string[] arguments)
+    public void Parse(string[] arguments, IDictionary? environment = null)
     {
         string currentName = string.Empty;
 
@@ -44,6 +48,18 @@ internal class SimpleCommandLineParser
         {
             Arguments[currentName] = values.ToArray();
         }
+
+        // Now also parse environment
+        if (environment != null)
+        {
+            foreach (string key in environment.Keys)
+            {
+                if (key.StartsWith(Prefix, StringComparison.OrdinalIgnoreCase) && environment.TryGetStringValue(key, out var value))
+                {
+                    Arguments[key.Substring(PrefixLength)] = value.Split(' ').ToArray();
+                }
+            }
+        }
     }
 
     public bool Contains(string name)
@@ -85,7 +101,16 @@ internal class SimpleCommandLineParser
         return Contains(name);
     }
 
-    public int? GetIntValue(string name, int? defaultValue = null)
+    public int? GetIntValue(string name)
+    {
+        return GetValue<int?>(name, values =>
+        {
+            var value = values.FirstOrDefault();
+            return !string.IsNullOrEmpty(value) ? int.Parse(value) : null;
+        }, null);
+    }
+
+    public int GetIntValue(string name, int defaultValue)
     {
         return GetValue(name, values =>
         {

src/WireMock.Net/Settings/WireMockServerSettings.cs

@@ -22,6 +22,8 @@ namespace WireMock.Settings;
 /// </summary>
 public class WireMockServerSettings
 {
+    internal const int DefaultStartTimeout = 10000;
+
     /// <summary>
     /// Gets or sets the http port.
     /// </summary>
@@ -81,7 +83,7 @@ public class WireMockServerSettings
     /// StartTimeout
     /// </summary>
     [PublicAPI]
-    public int StartTimeout { get; set; } = 10000;
+    public int StartTimeout { get; set; } = DefaultStartTimeout;
 
     /// <summary>
     /// Allow Partial Mapping (default set to false).

src/WireMock.Net/Settings/WireMockServerSettingsParser.cs

@@ -1,3 +1,4 @@
+using System.Collections;
 using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 using System.Linq;
@@ -18,16 +19,16 @@ public static class WireMockServerSettingsParser
     /// Parse commandline arguments into WireMockServerSettings.
     /// </summary>
     /// <param name="args">The commandline arguments</param>
+    /// <param name="environment">The environment settings (optional)</param>
     /// <param name="logger">The logger (optional, can be null)</param>
     /// <param name="settings">The parsed settings</param>
     [PublicAPI]
-    public static bool TryParseArguments(string[] args, [NotNullWhen(true)] out WireMockServerSettings? settings,
-        IWireMockLogger? logger = null)
+    public static bool TryParseArguments(string[] args, IDictionary? environment, [NotNullWhen(true)] out WireMockServerSettings? settings, IWireMockLogger? logger = null)
     {
         Guard.HasNoNulls(args);
 
-        var parser = new SimpleCommandLineParser();
-        parser.Parse(args);
+        var parser = new SimpleSettingsParser();
+        parser.Parse(args, environment);
 
         if (parser.GetBoolSwitchValue("help"))
         {
@@ -55,6 +56,7 @@ public static class WireMockServerSettingsParser
             RequestLogExpirationDuration = parser.GetIntValue("RequestLogExpirationDuration"),
             SaveUnmatchedRequests = parser.GetBoolValue(nameof(WireMockServerSettings.SaveUnmatchedRequests)),
             StartAdminInterface = parser.GetBoolValue("StartAdminInterface", true),
+            StartTimeout = parser.GetIntValue(nameof(WireMockServerSettings.StartTimeout), WireMockServerSettings.DefaultStartTimeout),
             ThrowExceptionWhenMatcherFails = parser.GetBoolValue("ThrowExceptionWhenMatcherFails"),
             UseRegexExtended = parser.GetBoolValue(nameof(WireMockServerSettings.UseRegexExtended), true),
             WatchStaticMappings = parser.GetBoolValue("WatchStaticMappings"),
@@ -79,8 +81,7 @@ public static class WireMockServerSettingsParser
         return true;
     }
 
-    private static void ParseLoggerSettings(WireMockServerSettings settings, IWireMockLogger? logger,
-        SimpleCommandLineParser parser)
+    private static void ParseLoggerSettings(WireMockServerSettings settings, IWireMockLogger? logger, SimpleSettingsParser parser)
     {
         var loggerType = parser.GetStringValue("WireMockLogger");
         switch (loggerType)
@@ -103,7 +104,7 @@ public static class WireMockServerSettingsParser
         }
     }
 
-    private static void ParseProxyAndRecordSettings(WireMockServerSettings settings, SimpleCommandLineParser parser)
+    private static void ParseProxyAndRecordSettings(WireMockServerSettings settings, SimpleSettingsParser parser)
     {
         var proxyUrl = parser.GetStringValue("ProxyURL") ?? parser.GetStringValue("ProxyUrl");
         if (!string.IsNullOrEmpty(proxyUrl))
@@ -135,7 +136,7 @@ public static class WireMockServerSettingsParser
         }
     }
 
-    private static void ParsePortSettings(WireMockServerSettings settings, SimpleCommandLineParser parser)
+    private static void ParsePortSettings(WireMockServerSettings settings, SimpleSettingsParser parser)
     {
         if (parser.Contains(nameof(WireMockServerSettings.Port)))
         {
@@ -147,7 +148,7 @@ public static class WireMockServerSettingsParser
         }
     }
 
-    private static void ParseCertificateSettings(WireMockServerSettings settings, SimpleCommandLineParser parser)
+    private static void ParseCertificateSettings(WireMockServerSettings settings, SimpleSettingsParser parser)
     {
         var certificateSettings = new WireMockCertificateSettings
         {
@@ -163,7 +164,7 @@ public static class WireMockServerSettingsParser
         }
     }
 
-    private static void ParseWebProxyAddressSettings(ProxyAndRecordSettings settings, SimpleCommandLineParser parser)
+    private static void ParseWebProxyAddressSettings(ProxyAndRecordSettings settings, SimpleSettingsParser parser)
     {
         string? proxyAddress = parser.GetStringValue("WebProxyAddress");
         if (!string.IsNullOrEmpty(proxyAddress))
@@ -177,7 +178,7 @@ public static class WireMockServerSettingsParser
         }
     }
 
-    private static void ParseProxyUrlReplaceSettings(ProxyAndRecordSettings settings, SimpleCommandLineParser parser)
+    private static void ParseProxyUrlReplaceSettings(ProxyAndRecordSettings settings, SimpleSettingsParser parser)
     {
         var proxyUrlReplaceOldValue = parser.GetStringValue("ProxyUrlReplaceOldValue");
         var proxyUrlReplaceNewValue = parser.GetStringValue("ProxyUrlReplaceNewValue");