fix: Adding ability to use kubernetes API proxy on Kubernetes

assembly/assembly-wsmaster-war/src/main/java/org/eclipse/che/api/deploy/WsMasterModule.java

@@ -445,9 +445,7 @@ private void configureMultiUserMode(
 
     bindConstant().annotatedWith(Names.named("che.agents.auth_enabled")).to(true);
 
-    if (OpenShiftInfrastructure.NAME.equals(infrastructure)) {
-      install(new InfraProxyModule());
-    }
+    install(new InfraProxyModule());
   }
 
   private void configureJwtProxySecureProvisioner(String infrastructure) {

assembly/assembly-wsmaster-war/src/main/webapp/WEB-INF/classes/che/che.properties

@@ -535,6 +535,13 @@ che.infra.kubernetes.trusted_ca.mount_path=/public-certs
 # See the `che.infra.kubernetes.trusted_ca.dest_configmap` property.
 che.infra.kubernetes.trusted_ca.dest_configmap_labels=
 
+# Enables the `/unsupported/k8s` endpoint to resolve calls on Kubernetes infrastructure.
+# Provides direct access to the underlying infrastructure REST API.
+# This results in huge privilege escalation.
+# It impacts only Kubernetes infrastructure. Therefore it implies no security risk on OpenShift with OAuth.
+# Do not enable this, unless you understand the risks.
+che.infra.kubernetes.enable_unsupported_k8s=false
+
 ### OpenShift Infra parameters
 
 # Comma separated list of labels to add to the CA certificates ConfigMap in user workspace.

infrastructures/kubernetes/src/main/java/org/eclipse/che/workspace/infrastructure/kubernetes/DirectKubernetesAPIAccessHelper.java

@@ -151,9 +151,11 @@ private static Headers toOkHttpHeaders(HttpHeaders headers) {
     if (headers != null) {
       for (Map.Entry<String, List<String>> e : headers.getRequestHeaders().entrySet()) {
         String name = e.getKey();
-        List<String> values = e.getValue();
-        for (String value : values) {
-          headersBuilder.add(name, value);
+        if (HttpHeaders.CONTENT_TYPE.equalsIgnoreCase(name)) {
+          List<String> values = e.getValue();
+          for (String value : values) {
+            headersBuilder.add(name, value);
+          }
         }
       }
     }

infrastructures/kubernetes/src/main/java/org/eclipse/che/workspace/infrastructure/kubernetes/KubernetesClientFactory.java

@@ -142,13 +142,16 @@ protected OkHttpClient getHttpClient() {
    * <p>Unlike {@link #getHttpClient()}, this method creates a new HTTP client instance each time it
    * is called.
    *
+   * <p>This is a workaround to allow direct k8s API access on Kubernetes infrastructure, since
+   * impersonating the current user is not supported in the Kubernetes Client. This is insecure and
+   * will only be called if permitted by enabling it in Che properties.
+   *
    * @return HTTP client with authorization set up
    * @throws InfrastructureException if it is not possible to build the client with authentication
    *     infromation
    */
   public OkHttpClient getAuthenticatedHttpClient() throws InfrastructureException {
-    throw new InfrastructureException(
-        "Impersonating the current user is not supported in the Kubernetes Client.");
+    return create(getDefaultConfig()).getHttpClient();
   }
 
   /**
@@ -216,7 +219,7 @@ protected Interceptor buildKubernetesInterceptor(Config config) {
    * authenticate with the credentials (user/password or Oauth token) contained in the {@code
    * config} parameter.
    */
-  private KubernetesClient create(Config config) {
+  private DefaultKubernetesClient create(Config config) {
     OkHttpClient clientHttpClient =
         httpClient.newBuilder().authenticator(Authenticator.NONE).build();
     OkHttpClient.Builder builder = clientHttpClient.newBuilder();

infrastructures/openshift/src/main/java/org/eclipse/che/workspace/infrastructure/openshift/OpenShiftClientFactory.java

@@ -129,7 +129,8 @@ public OkHttpClient getAuthenticatedHttpClient() throws InfrastructureException
       throw new InfrastructureException(
           "Not able to construct impersonating openshift API client.");
     }
-    return clientForConfig(buildConfig(getDefaultConfig(), null));
+    // Ensure to get OkHttpClient with all necessary interceptors.
+    return createOC(buildConfig(getDefaultConfig(), null)).getHttpClient();
   }
 
   @Override
@@ -222,7 +223,7 @@ protected Interceptor buildKubernetesInterceptor(Config config) {
     };
   }
 
-  private OpenShiftClient createOC(Config config) {
+  private DefaultOpenShiftClient createOC(Config config) {
     return new UnclosableOpenShiftClient(
         clientForConfig(config), config, this::initializeRequestTracing);
   }

wsmaster/che-core-api-infraproxy/src/main/java/org/eclipse/che/api/infraproxy/server/InfrastructureApiService.java

@@ -56,24 +56,35 @@ public class InfrastructureApiService extends Service {
 
   @Context private MediaType mediaType;
 
-  private static boolean determineAllowed(String infra, String identityProvider) {
-    return "openshift".equals(infra)
-        && identityProvider != null
-        && identityProvider.startsWith("openshift");
+  private static boolean determineAllowed(
+      String infra, String identityProvider, boolean allowedForKubernetes) {
+    if ("openshift".equals(infra)) {
+      return identityProvider != null && identityProvider.startsWith("openshift");
+    }
+    return allowedForKubernetes;
   }
 
   @Inject
   public InfrastructureApiService(
       @Nullable @Named("che.infra.openshift.oauth_identity_provider") String identityProvider,
+      @Named("che.infra.kubernetes.enable_unsupported_k8s") boolean allowedForKubernetes,
       RuntimeInfrastructure runtimeInfrastructure) {
-    this(System.getenv("CHE_INFRASTRUCTURE_ACTIVE"), identityProvider, runtimeInfrastructure);
+    this(
+        System.getenv("CHE_INFRASTRUCTURE_ACTIVE"),
+        allowedForKubernetes,
+        identityProvider,
+        runtimeInfrastructure);
   }
 
   @VisibleForTesting
-  InfrastructureApiService(String infraName, String identityProvider, RuntimeInfrastructure infra) {
+  InfrastructureApiService(
+      String infraName,
+      boolean allowedForKubernetes,
+      String identityProvider,
+      RuntimeInfrastructure infra) {
     this.runtimeInfrastructure = infra;
     this.mapper = new ObjectMapper();
-    this.allowed = determineAllowed(infraName, identityProvider);
+    this.allowed = determineAllowed(infraName, identityProvider, allowedForKubernetes);
   }
 
   @GET

wsmaster/che-core-api-infraproxy/src/test/java/org/eclipse/che/api/infraproxy/server/InfrastructureApiServiceTest.java

@@ -37,13 +37,15 @@ public class InfrastructureApiServiceTest {
 
   @BeforeMethod
   public void setup() throws Exception {
-    apiService = new InfrastructureApiService("openshift", "openshift-identityProvider", infra);
+    apiService =
+        new InfrastructureApiService("openshift", false, "openshift-identityProvider", infra);
   }
 
   @Test
-  public void testFailsAuthWhenNotOnOpenShift() throws Exception {
+  public void testFailsAuthWhenNotAllowedForKubernetesAndNotOnOpenShift() throws Exception {
     // given
-    apiService = new InfrastructureApiService("not-openshift", "openshift-identityProvider", infra);
+    apiService =
+        new InfrastructureApiService("not-openshift", false, "openshift-identityProvider", infra);
 
     // when
     Response response =
@@ -59,7 +61,49 @@ public void testFailsAuthWhenNotOnOpenShift() throws Exception {
   @Test
   public void testFailsAuthWhenNotUsingOpenShiftIdentityProvider() throws Exception {
     // given
-    apiService = new InfrastructureApiService("openshift", "not-openshift-identityProvider", infra);
+    apiService =
+        new InfrastructureApiService("openshift", false, "not-openshift-identityProvider", infra);
+
+    // when
+    Response response =
+        given()
+            .contentType("application/json; charset=utf-8")
+            .when()
+            .get("/unsupported/k8s/nazdar/");
+
+    // then
+    assertEquals(response.getStatusCode(), 403);
+  }
+
+  @Test
+  public void testResolvesCallWhenAllowedForKubernetesOnKubernetes() throws Exception {
+    // given
+    apiService =
+        new InfrastructureApiService("kubernetes", true, "not-openshift-identityProvider", infra);
+    when(infra.sendDirectInfrastructureRequest(any(), any(), any(), any()))
+        .thenReturn(
+            javax.ws.rs.core.Response.ok()
+                .header("Content-Type", "application/json; charset=utf-8")
+                .build());
+
+    // when
+    Response response =
+        given()
+            .contentType("application/json; charset=utf-8")
+            .when()
+            .get("/unsupported/k8s/nazdar/");
+
+    // then
+    assertEquals(response.getStatusCode(), 200);
+    assertEquals(response.getContentType(), "application/json;charset=utf-8");
+  }
+
+  @Test
+  public void testFailsAuthWhenAllowedForKubernetesOnOpenshiftWithNonOpenshiftIdentityProvider()
+      throws Exception {
+    // given
+    apiService =
+        new InfrastructureApiService("openshift", true, "not-openshift-identityProvider", infra);
 
     // when
     Response response =