1 files changed, 0 insertions, 187 deletions
diff --git a/docker-api/src/main/java/com/yahoo/vespa/hosted/dockerapi/DockerImageGarbageCollector.java b/docker-api/src/main/java/com/yahoo/vespa/hosted/dockerapi/DockerImageGarbageCollector.java
deleted file mode 100644
index 242332ebd54..00000000000
--- a/docker-api/src/main/java/com/yahoo/vespa/hosted/dockerapi/DockerImageGarbageCollector.java
+++ /dev/null
@@ -1,187 +0,0 @@
-// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-package com.yahoo.vespa.hosted.dockerapi;
-
-import com.github.dockerjava.api.model.Container;
-import com.github.dockerjava.api.model.Image;
-import com.google.common.base.Strings;
-import com.yahoo.collections.Pair;
-import com.yahoo.config.provision.DockerImage;
-
-import java.time.Clock;
-import java.time.Duration;
-import java.time.Instant;
-import java.util.Collections;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Map;
-import java.util.Optional;
-import java.util.Set;
-import java.util.concurrent.ConcurrentHashMap;
-import java.util.function.Function;
-import java.util.logging.Logger;
-import java.util.stream.Collectors;
-import java.util.stream.Stream;
-
-/**
- * This class keeps track of downloaded docker images and helps delete images that have not been recently used
- *
- * <p>Definitions:
- * <ul>
- *   <li>Every image has exactly 1 id</li>
- *   <li>Every image has between 0..n tags, see
- *       <a href="https://docs.docker.com/engine/reference/commandline/tag/">docker tag</a> for more</li>
- *   <li>Every image has 0..1 parent ids</li>
- * </ul>
- *
- * <p>Limitations:
- * <ol>
- *   <li>Image that has more than 1 tag cannot be deleted by ID</li>
- *   <li>Deleting a tag of an image with multiple tags will only remove the tag, the image with the
- *       remaining tags will remain</li>
- *   <li>Deleting the last tag of an image will delete the entire image.</li>
- *   <li>Image cannot be deleted if:</li>
- *   <ol>
- *     <li>It has 1 or more children</li>
- *     <li>A container uses it</li>
- *   </ol>
- * </ol>
- *
- * @author freva
- */
-class DockerImageGarbageCollector {
-    private static final Logger logger = Logger.getLogger(DockerImageGarbageCollector.class.getName());
-
-    private final Map<String, Instant> lastTimeUsedByImageId = new ConcurrentHashMap<>();
-    private final DockerImpl docker;
-    private final Clock clock;
-
-    DockerImageGarbageCollector(DockerImpl docker) {
-        this(docker, Clock.systemUTC());
-    }
-
-    DockerImageGarbageCollector(DockerImpl docker, Clock clock) {
-        this.docker = docker;
-        this.clock = clock;
-    }
-
-    /**
-     * This method must be called frequently enough to see all containers to know which images are being used
-     *
-     * @param excludes List of images (by tag or id) that should not be deleted regardless of their used status
-     * @param minImageAgeToDelete Minimum duration after which an image can be removed if it has not been used
-     * @return true iff at least 1 image was deleted
-     */
-    boolean deleteUnusedDockerImages(List<DockerImage> excludes, Duration minImageAgeToDelete) {
-        List<Image> images = docker.listAllImages();
-        List<ContainerLite> containers = docker.listAllContainers();
-
-        Map<String, Image> imageByImageId = images.stream().collect(Collectors.toMap(Image::getId, Function.identity()));
-
-        // Find all the ancestors for every local image id, this includes the image id itself
-        Map<String, Set<String>> ancestorsByImageId = images.stream()
-                .map(Image::getId)
-                .collect(Collectors.toMap(
-                        Function.identity(),
-                        imageId -> {
-                            Set<String> ancestors = new HashSet<>();
-                            while (!Strings.isNullOrEmpty(imageId)) {
-                                ancestors.add(imageId);
-                                imageId = Optional.of(imageId).map(imageByImageId::get).map(Image::getParentId).orElse(null);
-                            }
-                            return ancestors;
-                        }
-                ));
-
-        // The set of images that we want to keep is:
-        // 1. The images that were recently used
-        // 2. The images that were explicitly excluded
-        // 3. All of the ancestors of from images in 1 & 2
-        Set<String> imagesToKeep = Stream
-                .concat(
-                        getRecentlyUsedImageIds(images, containers, minImageAgeToDelete).stream(), // 1
-                        dockerImageToImageIds(excludes, images).stream()) // 2
-                .flatMap(imageId -> ancestorsByImageId.getOrDefault(imageId, Collections.emptySet()).stream()) // 3
-                .collect(Collectors.toSet());
-
-        // Now take all the images we have locally
-        return imageByImageId.keySet().stream()
-
-                // filter out images we want to keep
-                .filter(imageId -> !imagesToKeep.contains(imageId))
-
-                // Sort images in an order is safe to delete (children before parents)
-                .sorted((o1, o2) -> {
-                    // If image2 is parent of image1, image1 comes before image2
-                    if (imageIsDescendantOf(imageByImageId, o1, o2)) return -1;
-                    // If image1 is parent of image2, image2 comes before image1
-                    else if (imageIsDescendantOf(imageByImageId, o2, o1)) return 1;
-                    // Otherwise, sort lexicographically by image name (For testing)
-                    else return o1.compareTo(o2);
-                })
-
-                // Map back to image
-                .map(imageByImageId::get)
-
-                // Delete image, if successful also remove last usage time to prevent re-download being instantly deleted
-                .peek(image -> {
-                    // Deleting an image by image ID with multiple tags will fail -> delete by tags instead
-                    Optional.ofNullable(image.getRepoTags())
-                            .map(Stream::of)
-                            .orElse(Stream.of(image.getId()))
-                            .forEach(imageReference -> {
-                                logger.info("Deleting unused docker image " + imageReference);
-                                docker.deleteImage(DockerImage.fromString(imageReference));
-                            });
-
-                    lastTimeUsedByImageId.remove(image.getId());
-                })
-                .count() > 0;
-    }
-
-    private Set<String> getRecentlyUsedImageIds(List<Image> images, List<ContainerLite> containers, Duration minImageAgeToDelete) {
-        final Instant now = clock.instant();
-
-        // Add any already downloaded image to the list once
-        images.forEach(image -> lastTimeUsedByImageId.putIfAbsent(image.getId(), now));
-
-        // Update last used time for all current containers
-        containers.forEach(container -> lastTimeUsedByImageId.put(container.imageId(), now));
-
-        // Return list of images that have been used within minImageAgeToDelete
-        return lastTimeUsedByImageId.entrySet().stream()
-                .filter(entry -> Duration.between(entry.getValue(), now).minus(minImageAgeToDelete).isNegative())
-                .map(Map.Entry::getKey)
-                .collect(Collectors.toSet());
-    }
-
-    /**
-     * Attemps to make dockerImages which may be image tags or image ids to image ids. This only works
-     * if the given tag is actually present locally. This is fine, because if it isn't - we can't delete
-     * it, so no harm done.
-     */
-    private Set<String> dockerImageToImageIds(List<DockerImage> dockerImages, List<Image> images) {
-        Map<String, String> imageIdByImageTag = images.stream()
-                .flatMap(image -> Optional.ofNullable(image.getRepoTags())
-                        .map(Stream::of)
-                        .orElseGet(Stream::empty)
-                        .map(repoTag -> new Pair<>(repoTag, image.getId())))
-                .collect(Collectors.toMap(Pair::getFirst, Pair::getSecond));
-
-        return dockerImages.stream()
-                .map(DockerImage::asString)
-                .map(tag -> imageIdByImageTag.getOrDefault(tag, tag))
-                .collect(Collectors.toSet());
-    }
-
-    /**
-     * @return true if ancestor is a parent or grand-parent or grand-grand-parent, etc. of img
-     */
-    private boolean imageIsDescendantOf(Map<String, Image> imageIdToImage, String img, String ancestor) {
-        while (imageIdToImage.containsKey(img)) {
-            img = imageIdToImage.get(img).getParentId();
-            if (img == null) return false;
-            if (ancestor.equals(img)) return true;
-        }
-        return false;
-    }
-}