Re-enable cross-repository blob mounts

jib-core/src/main/java/com/google/cloud/tools/jib/builder/steps/PushBlobStep.java

@@ -96,8 +96,16 @@ public BlobDescriptor call() throws IOException, RegistryException, ExecutionExc
         return blobDescriptor;
       }
 
-      // todo: leverage cross-repository mounts
-      registryClient.pushBlob(blobDescriptor.getDigest(), blob, null, throttledProgressReporter);
+      // If base and target images are in the same registry, then use mount/from to try mounting the
+      // BLOB from the base image repository to the target image repository and possibly avoid
+      // having to push the BLOB. See
+      // https://docs.docker.com/registry/spec/api/#cross-repository-blob-mount for details.
+      String baseRegistry = buildConfiguration.getBaseImageConfiguration().getImageRegistry();
+      String baseRepository = buildConfiguration.getBaseImageConfiguration().getImageRepository();
+      String targetRegistry = buildConfiguration.getTargetImageConfiguration().getImageRegistry();
+      String sourceRepository = targetRegistry.equals(baseRegistry) ? baseRepository : null;
+      registryClient.pushBlob(
+          blobDescriptor.getDigest(), blob, sourceRepository, throttledProgressReporter);
 
       return blobDescriptor;
     }

jib-core/src/main/java/com/google/cloud/tools/jib/configuration/BuildConfiguration.java

@@ -449,6 +449,18 @@ public RegistryClient.Factory newBaseImageRegistryClientFactory() {
    * @return a new {@link RegistryClient.Factory}
    */
   public RegistryClient.Factory newTargetImageRegistryClientFactory() {
+    // if base and target are on the same registry, try enabling cross-repository mounts
+    if (baseImageConfiguration
+        .getImageRegistry()
+        .equals(targetImageConfiguration.getImageRegistry())) {
+      return RegistryClient.factory(
+              getEventHandlers(),
+              targetImageConfiguration.getImageRegistry(),
+              targetImageConfiguration.getImageRepository(),
+              baseImageConfiguration.getImageRepository())
+          .setAllowInsecureRegistries(getAllowInsecureRegistries())
+          .setUserAgentSuffix(getToolName());
+    }
     return newRegistryClientFactory(targetImageConfiguration);
   }
 

jib-core/src/main/java/com/google/cloud/tools/jib/global/JibSystemProperties.java

@@ -25,6 +25,8 @@ public class JibSystemProperties {
 
   @VisibleForTesting public static final String HTTP_TIMEOUT = "jib.httpTimeout";
 
+  @VisibleForTesting static final String CROSS_REPOSITORY_BLOB_MOUNTS = "jib.blobMounts";
+
   @VisibleForTesting
   public static final String SEND_CREDENTIALS_OVER_HTTP = "sendCredentialsOverHttp";
 
@@ -46,6 +48,18 @@ public static int getHttpTimeout() {
     return Integer.getInteger(HTTP_TIMEOUT);
   }
 
+  /**
+   * Gets whether or not to use <em>cross-repository blob mounts</em> when uploading image layers
+   * ({@code mount/from}). This is defined by the {@code jib.blobMounts} system property.
+   *
+   * @return {@code true} if {@code mount/from} should be used, {@code false} if not, defaulting to
+   *     {@code true}
+   */
+  public static boolean useCrossRepositoryBlobMounts() {
+    return System.getProperty(CROSS_REPOSITORY_BLOB_MOUNTS) == null
+        || Boolean.getBoolean(CROSS_REPOSITORY_BLOB_MOUNTS);
+  }
+
   /**
    * Gets whether or not to serialize Jib's execution. This is defined by the {@code jibSerialize}
    * system property.

jib-core/src/main/java/com/google/cloud/tools/jib/http/Authorization.java

@@ -29,14 +29,6 @@
  */
 public class Authorization {
 
-  /**
-   * @param token the token
-   * @return an {@link Authorization} with a {@code Bearer} token
-   */
-  public static Authorization fromBearerToken(String token) {
-    return new Authorization("Bearer", token);
-  }
-
   /**
    * @param username the username
    * @param secret the secret
@@ -56,6 +48,14 @@ public static Authorization fromBasicToken(String token) {
     return new Authorization("Basic", token);
   }
 
+  /**
+   * @param token the token
+   * @return an {@link Authorization} with a {@code Bearer} token
+   */
+  public static Authorization fromBearerToken(String token) {
+    return new Authorization("Bearer", token);
+  }
+
   private final String scheme;
   private final String token;
 

jib-core/src/main/java/com/google/cloud/tools/jib/json/JsonTemplateMapper.java

@@ -104,6 +104,20 @@ public static <T extends JsonTemplate> T readJson(String jsonString, Class<T> te
     return objectMapper.readValue(jsonString, templateClass);
   }
 
+  /**
+   * Deserializes a JSON object from a JSON byte array.
+   *
+   * @param <T> child type of {@link JsonTemplate}
+   * @param jsonBytes a JSON byte array
+   * @param templateClass the template to deserialize the string to
+   * @return the template filled with the values parsed from {@code jsonBytes}
+   * @throws IOException if an error occurred during parsing the JSON
+   */
+  public static <T extends JsonTemplate> T readJson(byte[] jsonBytes, Class<T> templateClass)
+      throws IOException {
+    return objectMapper.readValue(jsonBytes, templateClass);
+  }
+
   /**
    * Deserializes a JSON object list from a JSON string.
    *

jib-core/src/main/java/com/google/cloud/tools/jib/registry/RegistryAuthenticator.java

@@ -30,13 +30,16 @@
 import com.google.cloud.tools.jib.json.JsonTemplateMapper;
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Verify;
+import com.google.common.collect.ImmutableMap;
 import com.google.common.io.CharStreams;
 import com.google.common.net.MediaType;
 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.nio.charset.StandardCharsets;
+import java.util.Map;
+import java.util.Map.Entry;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 import javax.annotation.Nullable;
@@ -180,26 +183,30 @@ public Authorization authenticatePush(@Nullable Credential credential)
   }
 
   @VisibleForTesting
-  String getServiceScopeRequestParameters(String scope) {
-    return "service="
-        + service
-        + "&scope=repository:"
-        + registryEndpointRequestProperties.getImageName()
-        + ":"
-        + scope;
+  String getServiceScopeRequestParameters(Map<String, String> repositoryScopes) {
+    StringBuilder parameters = new StringBuilder("service=").append(service);
+    for (Entry<String, String> pair : repositoryScopes.entrySet()) {
+      parameters
+          .append("&scope=repository:")
+          .append(pair.getKey())
+          .append(":")
+          .append(pair.getValue());
+    }
+    return parameters.toString();
   }
 
   @VisibleForTesting
-  URL getAuthenticationUrl(@Nullable Credential credential, String scope)
+  URL getAuthenticationUrl(@Nullable Credential credential, Map<String, String> repositoryScopes)
       throws MalformedURLException {
     return isOAuth2Auth(credential)
         ? new URL(realm) // Required parameters will be sent via POST .
-        : new URL(realm + "?" + getServiceScopeRequestParameters(scope));
+        : new URL(realm + "?" + getServiceScopeRequestParameters(repositoryScopes));
   }
 
   @VisibleForTesting
-  String getAuthRequestParameters(@Nullable Credential credential, String scope) {
-    String serviceScope = getServiceScopeRequestParameters(scope);
+  String getAuthRequestParameters(
+      @Nullable Credential credential, Map<String, String> repositoryScopes) {
+    String serviceScope = getServiceScopeRequestParameters(repositoryScopes);
     return isOAuth2Auth(credential)
         ? serviceScope
             // https://github.com/GoogleContainerTools/jib/pull/1545
@@ -227,15 +234,43 @@ boolean isOAuth2Auth(@Nullable Credential credential) {
    */
   private Authorization authenticate(@Nullable Credential credential, String scope)
       throws RegistryAuthenticationFailedException {
+    // try authorizing against both the main repository and the source repository too
+    // to enable cross-repository mounts on pushes
+    if (registryEndpointRequestProperties.getSourceImageName() != null) {
+      try {
+        Map<String, String> scopes =
+            ImmutableMap.of(
+                registryEndpointRequestProperties.getImageName(),
+                scope,
+                registryEndpointRequestProperties.getSourceImageName(),
+                "pull");
+        Authorization auth = authenticate(credential, scopes);
+        if (auth != null) {
+          return auth;
+        }
+      } catch (RegistryAuthenticationFailedException ex) {
+        // Unable to obtain authorization with source image: fallthrough and try without
+      }
+    }
+    Map<String, String> repositoryScopes =
+        ImmutableMap.of(registryEndpointRequestProperties.getImageName(), scope);
+    Authorization auth = authenticate(credential, repositoryScopes);
+    return auth;
+  }
+
+  private Authorization authenticate(
+      @Nullable Credential credential, Map<String, String> repositoryScopes)
+      throws RegistryAuthenticationFailedException {
     try (Connection connection =
-        Connection.getConnectionFactory().apply(getAuthenticationUrl(credential, scope))) {
+        Connection.getConnectionFactory()
+            .apply(getAuthenticationUrl(credential, repositoryScopes))) {
       Request.Builder requestBuilder =
           Request.builder()
               .setHttpTimeout(JibSystemProperties.getHttpTimeout())
               .setUserAgent(userAgent);
 
       if (isOAuth2Auth(credential)) {
-        String parameters = getAuthRequestParameters(credential, scope);
+        String parameters = getAuthRequestParameters(credential, repositoryScopes);
         requestBuilder.setBody(
             new BlobHttpContent(Blobs.from(parameters), MediaType.FORM_DATA.toString()));
       } else if (credential != null) {
@@ -257,9 +292,9 @@ private Authorization authenticate(@Nullable Credential credential, String scope
             registryEndpointRequestProperties.getServerUrl(),
             registryEndpointRequestProperties.getImageName(),
             "Did not get token in authentication response from "
-                + getAuthenticationUrl(credential, scope)
+                + getAuthenticationUrl(credential, repositoryScopes)
                 + "; parameters: "
-                + getAuthRequestParameters(credential, scope));
+                + getAuthRequestParameters(credential, repositoryScopes));
       }
       return Authorization.fromBearerToken(responseJson.getToken());