OciIndexTemplate.java

/*
 * Copyright 2019 Google LLC.
 *
 * 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 com.google.cloud.tools.jib.image.json;

import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
import com.google.cloud.tools.jib.api.DescriptorDigest;
import com.google.cloud.tools.jib.blob.BlobDescriptor;
import com.google.cloud.tools.jib.json.JsonTemplate;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.collect.ImmutableMap;
import java.util.ArrayList;
import java.util.List;
import java.util.Objects;
import java.util.stream.Collectors;
import javax.annotation.Nullable;

/**
 * JSON template for OCI archive "index.json" file.
 *
 * <p>Example manifest JSON:
 *
 * <pre>{@code
 * {
 *   "schemaVersion": 2,
 *   "mediaType": "application/vnd.oci.image.index.v1+json",
 *   "manifests": [
 *     {
 *       "mediaType": "application/vnd.oci.image.manifest.v1+json",
 *       "digest": "sha256:e684b1dceef404268f17d4adf7f755fd9912b8ae64864b3954a83ebb8aa628b3",
 *       "size": 1132,
 *       "platform": {
 *         "architecture": "ppc64le",
 *         "os": "linux"
 *       },
 *       "annotations": {
 *         "org.opencontainers.image.ref.name": "gcr.io/project/image:tag"
 *       }
 *     }
 *   ]
 * }
 * }</pre>
 *
 * @see <a href="https://github.com/opencontainers/image-spec/blob/master/image-index.md">OCI Image
 *     Index Specification</a>
 */
public class OciIndexTemplate implements ManifestListTemplate {

  /** The OCI Index media type. */
  public static final String MEDIA_TYPE = "application/vnd.oci.image.index.v1+json";

  private final int schemaVersion = 2;
  private final String mediaType = MEDIA_TYPE;

  private final List<ManifestDescriptorTemplate> manifests = new ArrayList<>();

  @Override
  public int getSchemaVersion() {
    return schemaVersion;
  }

  @Override
  public String getManifestMediaType() {
    return mediaType;
  }

  /**
   * Adds a manifest reference with the given {@link BlobDescriptor}.
   *
   * @param descriptor the manifest blob descriptor
   * @param imageReferenceName the image reference name
   */
  public void addManifest(BlobDescriptor descriptor, String imageReferenceName) {
    ManifestDescriptorTemplate contentDescriptorTemplate =
        new ManifestDescriptorTemplate(
            OciManifestTemplate.MANIFEST_MEDIA_TYPE, descriptor.getSize(), descriptor.getDigest());
    contentDescriptorTemplate.setAnnotations(
        ImmutableMap.of("org.opencontainers.image.ref.name", imageReferenceName));
    manifests.add(contentDescriptorTemplate);
  }

  @VisibleForTesting
  public List<ManifestDescriptorTemplate> getManifests() {
    return manifests;
  }

  @Override
  public List<String> getDigestsForPlatform(String architecture, String os) {
    return getManifests().stream()
        .filter(
            manifest ->
                manifest.platform != null
                    && os.equals(manifest.platform.os)
                    && architecture.equals(manifest.platform.architecture))
        .map(ManifestDescriptorTemplate::getDigest)
        .filter(Objects::nonNull)
        .map(DescriptorDigest::toString)
        .collect(Collectors.toList());
  }

  /**
   * Template for inner JSON object representing a single platform specific manifest. See <a
   * href="https://github.com/opencontainers/image-spec/blob/main/image-index.md">OCI Image Index
   * Specification</a>
   */
  public static class ManifestDescriptorTemplate
      extends BuildableManifestTemplate.ContentDescriptorTemplate {

    ManifestDescriptorTemplate(String mediaType, long size, DescriptorDigest digest) {
      super(mediaType, size, digest);
    }

    /** Necessary for Jackson to create from JSON. */
    @SuppressWarnings("unused")
    private ManifestDescriptorTemplate() {
      super();
    }

    @JsonIgnoreProperties(ignoreUnknown = true)
    public static class Platform implements JsonTemplate {
      @Nullable private String architecture;
      @Nullable private String os;

      @Nullable
      public String getArchitecture() {
        return architecture;
      }

      @Nullable
      public String getOs() {
        return os;
      }
    }

    @Nullable private OciIndexTemplate.ManifestDescriptorTemplate.Platform platform;

    /**
     * Sets a platform.
     *
     * @param architecture the manifest architecture
     * @param os the manifest os
     */
    public void setPlatform(String architecture, String os) {
      platform = new OciIndexTemplate.ManifestDescriptorTemplate.Platform();
      platform.architecture = architecture;
      platform.os = os;
    }

    @Nullable
    public OciIndexTemplate.ManifestDescriptorTemplate.Platform getPlatform() {
      return platform;
    }
  }
}