To work around this, Istio has a variety of abstractions meant to make writing controllers easier.

## Clients

Istio offers a variety of increasingly high level abstractions on top of the common Kubernetes [`client-go`](https://github.com/kubernetes/client-go).

```mermaid
flowchart TD
    kcg["Kubernetes client-go"]
    ic["Istio kube.Client"]
    ikc["Istio kclient.Client"]
    ikrt["Istio krt.Collection"]

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.common.base.Function;
import com.google.common.base.Functions;
import com.google.common.base.Predicates;
import com.google.common.base.Supplier;
import com.google.common.collect.Maps.EntryTransformer;

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect.testing;

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.testing.features.CollectionSize;
import java.util.Collection;
import org.checkerframework.checker.nullness.qual.Nullable;

/**

 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */

package com.google.common.base;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import java.lang.ref.ReferenceQueue;
import java.lang.ref.WeakReference;
import javax.annotation.CheckForNull;

/**

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect;

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.TableCollectionTest.RowMapTests;
import java.util.Map;

@GwtCompatible
@ElementTypesAreNonnullByDefault

 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */

package com.google.common.base;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import java.lang.ref.ReferenceQueue;
import java.lang.ref.WeakReference;
import javax.annotation.CheckForNull;

/**

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package promotion

import common.VersionedSettingsBranch
import common.gradleWrapper
import common.pluginPortalUrlOverride
import jetbrains.buildServer.configs.kotlin.triggers.schedule
import jetbrains.buildServer.configs.kotlin.triggers.vcs
import vcsroots.gradlePromotionBranches

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect;

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;

 * the License.
 */

package com.google.common.collect;

import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkElementIndex;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.collect.BoundType.CLOSED;
import static java.util.Objects.requireNonNull;

import com.google.common.annotations.GwtCompatible;

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect;

import com.google.caliper.BeforeExperiment;
import com.google.caliper.Benchmark;
import com.google.caliper.Param;
import com.google.common.base.Function;
import java.math.BigInteger;
import java.util.Comparator;
import java.util.PriorityQueue;
import java.util.Queue;