io.fabric8.kubernetes.client.dsl.internal.RollingUpdater.java Source code

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/**
 * Copyright (C) 2015 Red Hat, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *         http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package io.fabric8.kubernetes.client.dsl.internal;

import com.fasterxml.jackson.core.JsonProcessingException;
import okhttp3.OkHttpClient;
import io.fabric8.kubernetes.api.model.Doneable;
import io.fabric8.kubernetes.api.model.DoneablePod;
import io.fabric8.kubernetes.api.model.HasMetadata;
import io.fabric8.kubernetes.api.model.Pod;
import io.fabric8.kubernetes.api.model.PodCondition;
import io.fabric8.kubernetes.api.model.PodList;
import io.fabric8.kubernetes.client.Config;
import io.fabric8.kubernetes.client.KubernetesClientException;
import io.fabric8.kubernetes.client.dsl.ClientOperation;
import io.fabric8.kubernetes.client.dsl.ClientPodResource;
import io.fabric8.kubernetes.client.dsl.ClientRollableScallableResource;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.math.BigInteger;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.List;
import java.util.Objects;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;

import static io.fabric8.kubernetes.client.internal.SerializationUtils.dumpWithoutRuntimeStateAsYaml;

abstract class RollingUpdater<T extends HasMetadata, L, D extends Doneable<T>> {
    static final String DEPLOYMENT_KEY = "deployment";

    private static final Long DEFAULT_ROLLING_TIMEOUT = 15 * 60 * 1000L; // 15 mins

    private static final Long DEFAULT_SERVER_GC_WAIT_TIMEOUT = 60 * 1000L; // 60 seconds

    private static final transient Logger LOG = LoggerFactory.getLogger(RollingUpdater.class);

    protected final OkHttpClient client;
    protected final Config config;
    protected final String namespace;
    private final long rollingTimeoutMillis;
    private final long loggingIntervalMillis;

    RollingUpdater(OkHttpClient client, Config config, String namespace) {
        this(client, config, namespace, DEFAULT_ROLLING_TIMEOUT, Config.DEFAULT_LOGGING_INTERVAL);
    }

    RollingUpdater(OkHttpClient client, Config config, String namespace, long rollingTimeoutMillis,
            long loggingIntervalMillis) {
        this.client = client;
        this.config = config;
        this.namespace = namespace;
        this.rollingTimeoutMillis = rollingTimeoutMillis;
        this.loggingIntervalMillis = loggingIntervalMillis;
    }

    protected abstract T createClone(T obj, String newName, String newDeploymentHash);

    protected abstract PodList listSelectedPods(T obj);

    protected abstract void updateDeploymentKey(D obj, String hash);

    protected abstract void removeDeploymentKey(D obj);

    protected abstract int getReplicas(T obj);

    protected abstract T setReplicas(T obj, int replicas);

    T rollUpdate(T oldObj, T newObj) {
        try {
            // Get what namespace we're working in
            String namespace = oldObj.getMetadata().getNamespace();
            // And the old RC name
            String oldName = oldObj.getMetadata().getName();

            // Update the old to ensure there's no overlap between the new & old selectors
            String oldDeploymentHash = md5sum(oldObj);

            //Before we update the resource though we need to add the labels to the existing managed pods
            PodList oldPods = listSelectedPods(oldObj);

            for (Pod pod : oldPods.getItems()) {
                try {
                    pods().inNamespace(namespace).withName(pod.getMetadata().getName()).edit().editMetadata()
                            .addToLabels(DEPLOYMENT_KEY, oldDeploymentHash).and().done();
                } catch (KubernetesClientException e) {
                    LOG.warn("Unable to add deployment key to pod: {}", e.getMessage());
                }
            }

            // Now we can update the old object with the new selector
            D editable = resources().inNamespace(namespace).withName(oldName).cascading(false).edit();
            updateDeploymentKey(editable, oldDeploymentHash);
            oldObj = editable.done();

            // Get a hash of the new RC for
            String newDeploymentHash = md5sum(newObj);

            // And a name for the cloned object
            String newName = newObj.getMetadata().getName();
            if (newName == null || newName.equals(oldName)) {
                newName = newName + "-" + newDeploymentHash;
            }

            // Create a clone of the requested RC ready for the rolling update:
            //   - Set the new RC replicas to 0 before we do anything so we can scale up ourselves.
            //   - Set the new RC name to contain the hash if matches old RC name.
            //   - Add selector containing deployment hash.
            //   - Ensure it looks like a new RC by resetting resource version.
            T clonedObj = createClone(newObj, newName, newDeploymentHash);
            T createdObj = resources().inNamespace(namespace).create(clonedObj);

            // Now do the scale up/scale down dance
            int oldReplicas = getReplicas(oldObj);
            while (getReplicas(createdObj) < getReplicas(newObj)) {
                int newReplicas = getReplicas(createdObj) + 1;
                resources().inNamespace(namespace).withName(createdObj.getMetadata().getName()).scale(newReplicas,
                        true);
                waitUntilPodsAreReady(createdObj, namespace, newReplicas);
                createdObj = setReplicas(createdObj, newReplicas);

                if (oldReplicas > 0) {
                    resources().inNamespace(namespace).withName(oldName).scale(--oldReplicas, true);
                    waitUntilPodsAreReady(oldObj, namespace, oldReplicas);
                }
            }

            // Now delete all existing remaining resources, ensure to cascade
            resources().inNamespace(namespace).withName(oldName).delete();

            // Check if we need to rename it back to the original RC name
            if (Objects.equals(oldName, newObj.getMetadata().getName())) {
                // first delete the resource and orphan its pods.
                resources().inNamespace(namespace).withName(newName).cascading(false).delete();

                waitUntilDeleted(namespace, newName);

                createdObj.getMetadata().setResourceVersion(null);
                createdObj.getMetadata().setName(oldName);

                createdObj = resources().inNamespace(namespace).create(createdObj);

                editable = resources().inNamespace(namespace).withName(createdObj.getMetadata().getName())
                        .cascading(false).edit();
                removeDeploymentKey(editable);
                createdObj = editable.done();
            }

            return createdObj;
        } catch (NoSuchAlgorithmException | JsonProcessingException e) {
            throw new KubernetesClientException("Could not calculate MD5 of RC", e);
        }
    }

    /**
     * Lets wait until there are enough Ready pods of the given RC
     */
    private void waitUntilPodsAreReady(final T obj, final String namespace, final int requiredPodCount) {
        final CountDownLatch countDownLatch = new CountDownLatch(1);
        final AtomicInteger podCount = new AtomicInteger(0);

        final Runnable readyPodsPoller = new Runnable() {
            public void run() {
                PodList podList = listSelectedPods(obj);
                int count = 0;
                List<Pod> items = podList.getItems();
                for (Pod item : items) {
                    for (PodCondition c : item.getStatus().getConditions()) {
                        if (c.getType().equals("Ready") && c.getStatus().equals("True")) {
                            count++;
                        }
                    }
                }
                podCount.set(count);
                if (count == requiredPodCount) {
                    countDownLatch.countDown();
                }
            }
        };

        ScheduledExecutorService executor = Executors.newSingleThreadScheduledExecutor();
        ScheduledFuture poller = executor.scheduleWithFixedDelay(readyPodsPoller, 0, 1, TimeUnit.SECONDS);
        ScheduledFuture logger = executor.scheduleWithFixedDelay(new Runnable() {
            @Override
            public void run() {
                LOG.debug("Only {}/{} pod(s) ready for {}: {} in namespace: {} seconds so waiting...",
                        podCount.get(), requiredPodCount, obj.getKind(), obj.getMetadata().getName(), namespace);
            }
        }, 0, loggingIntervalMillis, TimeUnit.MILLISECONDS);
        try {
            countDownLatch.await(rollingTimeoutMillis, TimeUnit.MILLISECONDS);
            executor.shutdown();
        } catch (InterruptedException e) {
            poller.cancel(true);
            logger.cancel(true);
            executor.shutdown();
            LOG.warn(
                    "Only {}/{} pod(s) ready for {}: {} in namespace: {}  after waiting for {} seconds so giving up",
                    podCount.get(), requiredPodCount, obj.getKind(), obj.getMetadata().getName(), namespace,
                    TimeUnit.MILLISECONDS.toSeconds(rollingTimeoutMillis));
        }
    }

    /**
     * Since k8s v1.4.x, rc/rs deletes are asynchronous.
     * Lets wait until the resource is actually deleted in the server
     */
    private void waitUntilDeleted(final String namespace, final String name) {
        final CountDownLatch countDownLatch = new CountDownLatch(1);

        final Runnable waitTillDeletedPoller = new Runnable() {
            public void run() {
                try {
                    T res = resources().inNamespace(namespace).withName(name).get();
                    if (res == null) {
                        countDownLatch.countDown();
                    }
                } catch (KubernetesClientException e) {
                    if (e.getCode() == 404) {
                        countDownLatch.countDown();
                    }
                }
            }
        };

        ScheduledExecutorService executor = Executors.newSingleThreadScheduledExecutor();
        ScheduledFuture poller = executor.scheduleWithFixedDelay(waitTillDeletedPoller, 0, 5, TimeUnit.SECONDS);
        ScheduledFuture logger = executor.scheduleWithFixedDelay(new Runnable() {
            @Override
            public void run() {
                LOG.debug("Found resource {}/{} not yet deleted on server, so waiting...", namespace, name);
            }
        }, 0, loggingIntervalMillis, TimeUnit.MILLISECONDS);
        try {
            countDownLatch.await(DEFAULT_SERVER_GC_WAIT_TIMEOUT, TimeUnit.MILLISECONDS);
            executor.shutdown();
        } catch (InterruptedException e) {
            poller.cancel(true);
            logger.cancel(true);
            executor.shutdown();
            LOG.warn("Still found deleted resource {} in namespace: {}  after waiting for {} seconds so giving up",
                    name, namespace, TimeUnit.MILLISECONDS.toSeconds(DEFAULT_SERVER_GC_WAIT_TIMEOUT));
        }
    }

    private String md5sum(HasMetadata obj) throws NoSuchAlgorithmException, JsonProcessingException {
        byte[] digest = MessageDigest.getInstance("MD5").digest(dumpWithoutRuntimeStateAsYaml(obj).getBytes());
        BigInteger i = new BigInteger(1, digest);
        return String.format("%1$032x", i);
    }

    protected abstract ClientOperation<T, L, D, ClientRollableScallableResource<T, D>> resources();

    protected ClientOperation<Pod, PodList, DoneablePod, ClientPodResource<Pod, DoneablePod>> pods() {
        return new PodOperationsImpl(client, config, namespace);
    }

}