Adding network capabilities

.gitignore

@@ -1,4 +1,5 @@
 .vscode
 .vs
 **/bin
-**/obj
+**/obj
+src/KubewardenPolicySDK/.gitmessage.txt

src/KubewardenPolicySDK/KubewardenPolicySDK.csproj

@@ -13,13 +13,17 @@
     <EnableTrimAnalyzer>true</EnableTrimAnalyzer>
   </PropertyGroup>
 
-  <PropertyGroup Condition= " '$(Configuration)' == 'Debug' ">
+  <PropertyGroup Condition=" '$(Configuration)' == 'Debug' ">
     <DocumentationFile>bin\Debug\net7.0\KubewardenPolicySDK.xml</DocumentationFile>
   </PropertyGroup>
 
   <ItemGroup>
     <!-- Add README.md to nuget gallery -->
-    <None Include="README.md" Pack="true" PackagePath="\"/>
+    <None Include="README.md" Pack="true" PackagePath="\" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="wapcGuest" Version="0.1.1" />
   </ItemGroup>
 
   <Target Name="PackTaskDependencies" BeforeTargets="GenerateNuspec">

src/KubewardenPolicySDK/host_capabilities/Host.cs

@@ -0,0 +1,8 @@
+namespace Capabilities;
+/// <summary>
+/// Host makes possible to interact with the policy host from inside of a policy.
+/// </summary>
+public class Host
+{
+    public IWapcClient Client { get; set; }
+}

src/KubewardenPolicySDK/host_capabilities/HostFactory.cs

@@ -0,0 +1,11 @@
+namespace Capabilities;
+public static class HostFactory
+{
+    /// <summary>
+    /// Creates a new Host with a WapcClient
+    /// </summary>
+    public static Host NewHost()
+    {
+        return new Host { Client = new WapcClient() };
+    }
+}

src/KubewardenPolicySDK/host_capabilities/IWapcClinet.cs

@@ -0,0 +1,6 @@
+namespace Capabilities;
+
+public interface IWapcClient
+{
+    byte[] HostCall(string binding, string nameSpace, string operation, byte[] payload);
+}

src/KubewardenPolicySDK/host_capabilities/WapcClient.cs

@@ -0,0 +1,17 @@
+using WapcGuest;
+
+namespace Capabilities;
+/// <summary>
+/// Default implementation of the WapcClient interface
+/// </summary>
+public class WapcClient : IWapcClient
+{
+    /// <summary>
+    /// Implementation of the HostCall method using wapc
+    /// </summary>
+    public byte[] HostCall(string binding, string nameSpace, string operation, byte[] payload)
+    {
+        // This would use the actual wapc library to make the host call
+        return Wapc.HostCall(binding, nameSpace, operation, payload);
+    }
+}

src/KubewardenPolicySDK/host_capabilities/net/INetworkOperations.cs

@@ -0,0 +1,7 @@
+using Capabilities;
+namespace Net;
+
+public interface INetworkOperations
+{
+    List<string> LookupHost(Host host, string hostname);
+}

src/KubewardenPolicySDK/host_capabilities/net/LookupHostResponse.cs

@@ -0,0 +1,17 @@
+using System;
+using System.Collections.Generic;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using Capabilities;
+
+namespace Net;
+
+/// <summary>
+/// Response object for DNS lookup operations
+/// </summary>
+public class LookupHostResponse
+{
+    [JsonPropertyName("ips")]
+   public List<string> Ips { get; set; } = new List<string>();
+}
+

src/KubewardenPolicySDK/host_capabilities/net/NetJsonContext.cs

@@ -0,0 +1,13 @@
+
+using System.Text.Json.Serialization;
+namespace Net;
+
+
+/// <summary>
+/// A JSON serialization context for handling types like string and LookupHostResponse.
+/// </summary>
+[JsonSerializable(typeof(string))]
+[JsonSerializable(typeof(LookupHostResponse))]
+public partial class NetJsonContext : JsonSerializerContext
+{
+}

src/KubewardenPolicySDK/host_capabilities/net/NetworkOperations.cs

@@ -0,0 +1,67 @@
+using System;
+using System.Collections.Generic;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using Capabilities;
+
+namespace Net;
+
+/// <summary>
+/// Network capabilities using the Kubewarden host
+/// </summary>
+public class NetworkOperations : INetworkOperations
+{
+    /// <summary>
+    /// Looks up the addresses for a given hostname via DNS.
+    /// </summary>
+    /// <param name="host">The host object with WapcClient capabilities</param>
+    /// <param name="hostname">The hostname to look up</param>
+    /// <returns>List of IP addresses associated with the hostname</returns>
+    public List<string> LookupHost(Host host, string hostname)
+    {
+        if (host == null || host.Client == null)
+        {
+            throw new ArgumentNullException(nameof(host), "Host or Host.Client cannot be null");
+        }
+
+        if (string.IsNullOrEmpty(hostname))
+        {
+            throw new ArgumentNullException(nameof(hostname), "Hostname cannot be null or empty");
+        }
+
+        // Build request payload - serialize the hostname to JSON using JsonContext
+        byte[] payload;
+        try
+        {
+            payload = JsonSerializer.SerializeToUtf8Bytes(hostname, NetJsonContext.Default.String);
+        }
+        catch (Exception ex)
+        {
+            throw new Exception($"Cannot serialize host to JSON: {ex.Message}");
+        }
+
+        // Perform host callback
+        byte[] responsePayload;
+        try
+        {
+            responsePayload = host.Client.HostCall("kubewarden", "net", "v1/dns_lookup_host", payload);
+        }
+        catch (Exception ex)
+        {
+            throw new Exception($"Host call failed: {ex.Message}");
+        }
+
+        // Deserialize the response using JsonContext
+        try
+        {
+            var response = JsonSerializer.Deserialize(responsePayload, NetJsonContext.Default.LookupHostResponse);
+
+            // Ensure we don't return null
+            return response?.Ips ?? new List<string>();
+        }
+        catch (Exception ex)
+        {
+            throw new Exception($"Cannot deserialize response: {ex.Message}");
+        }
+    }
+}