Adds realm import functionality

Enables importing a Keycloak realm from a JSON file.

This feature allows users to pre-configure Keycloak instances
with specific realm settings, clients, and users, simplifying
the setup and configuration process.  A new test has been
added to verify the import functionality.

Author: VladislavAntonyuk

src/Testcontainers.Keycloak/KeycloakBuilder.cs

@@ -60,6 +60,17 @@ public KeycloakBuilder WithPassword(string password)
             .WithEnvironment("KEYCLOAK_ADMIN_PASSWORD", password);
     }
 
+    /// <summary>
+    /// Sets the Keycloak to Import Realm file.
+    /// </summary>
+    /// <param name="path">The path to realm-export.json</param>
+    /// <returns>A configured instance of <see cref="KeycloakBuilder" />.</returns>
+    public KeycloakBuilder WithRealm(string path)
+    {
+        return Clone(new ContainerConfiguration(command: new AppendEnumerable<string>(["--import-realm"])))
+            .WithBindMount(path, "/opt/keycloak/data/import/realm-export.json");
+    }
+
     /// <inheritdoc />
     public override KeycloakContainer Build()
     {

tests/Testcontainers.Keycloak.Tests/KeycloakContainerTest.cs

@@ -1,3 +1,6 @@
+using System.IO;
+using System.Linq;
+
 namespace Testcontainers.Keycloak;
 
 public abstract class KeycloakContainerTest : IAsyncLifetime
@@ -85,4 +88,28 @@ public KeycloakV26Configuration()
         {
         }
     }
+
+    [UsedImplicitly]
+    public sealed class KeycloakRealmConfiguration : KeycloakContainerTest
+    {
+        public KeycloakRealmConfiguration()
+            : base(new KeycloakBuilder().WithRealm(Path.GetFullPath("realm-export.json")).Build())
+        {
+        }
+
+        [Fact]
+        [Trait(nameof(DockerCli.DockerPlatform), nameof(DockerCli.DockerPlatform.Linux))]
+        public async Task RealmIsImported()
+        {
+            // Given
+            var keycloakClient = new KeycloakClient(_keycloakContainer.GetBaseAddress(), KeycloakBuilder.DefaultUsername, KeycloakBuilder.DefaultPassword);
+
+            // When
+            var realms = await keycloakClient.GetRealmsAsync("master", TestContext.Current.CancellationToken)
+                .ConfigureAwait(true);
+
+            // Then
+            Assert.True(realms.Count() == 2);
+        }
+    }
 }

tests/Testcontainers.Keycloak.Tests/Testcontainers.Keycloak.Tests.csproj

@@ -6,14 +6,19 @@
         <OutputType>Exe</OutputType>
     </PropertyGroup>
     <ItemGroup>
-        <PackageReference Include="Microsoft.NET.Test.Sdk"/>
-        <PackageReference Include="coverlet.collector"/>
-        <PackageReference Include="xunit.runner.visualstudio"/>
-        <PackageReference Include="xunit.v3"/>
-        <PackageReference Include="Keycloak.Net.Core"/>
+        <PackageReference Include="Microsoft.NET.Test.Sdk" />
+        <PackageReference Include="coverlet.collector" />
+        <PackageReference Include="xunit.runner.visualstudio" />
+        <PackageReference Include="xunit.v3" />
+        <PackageReference Include="Keycloak.Net.Core" />
     </ItemGroup>
     <ItemGroup>
-        <ProjectReference Include="../../src/Testcontainers.Keycloak/Testcontainers.Keycloak.csproj"/>
-        <ProjectReference Include="../Testcontainers.Commons/Testcontainers.Commons.csproj"/>
+        <ProjectReference Include="../../src/Testcontainers.Keycloak/Testcontainers.Keycloak.csproj" />
+        <ProjectReference Include="../Testcontainers.Commons/Testcontainers.Commons.csproj" />
+    </ItemGroup>
+    <ItemGroup>
+      <None Update="realm-export.json">
+        <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+      </None>
     </ItemGroup>
 </Project>

tests/Testcontainers.Keycloak.Tests/realm-export.json

@@ -0,0 +1,47 @@
+{
+  "realm": "test-realm",
+  "enabled": true,
+  "clients": [
+    {
+      "clientId": "test-client",
+      "secret": "secret",
+      "enabled": true,
+      "protocol": "openid-connect",
+      "publicClient": false,
+      "directAccessGrantsEnabled": true,
+      "serviceAccountsEnabled": true,
+      "name": "Test Client",
+      "attributes": {
+        "jwt.client.claims": "true"
+      },
+      "protocolMappers": [
+        {
+          "name": "audience",
+          "protocol": "openid-connect",
+          "protocolMapper": "oidc-audience-mapper",
+          "consentRequired": false,
+          "config": {
+            "included.client.audience": "test-client",
+            "id.token.claim": "true",
+            "access.token.claim": "true"
+          }
+        }
+      ]
+    }
+  ],
+  "users": [
+    {
+      "username": "admin",
+      "enabled": true,
+      "emailVerified": true,
+      "credentials": [
+        {
+          "type": "password",
+          "value": "admin",
+          "temporary": false
+        }
+      ],
+      "email": "admin@example.com"
+    }
+  ]
+}