Pass commit authorship information to Buildkite

Summary:
Fixes T12251. Ref T13189. See PHI610. The difficulty here is that we don't want to disclose Phabricator account information to Buildkite. We're comfortable disclosing information from `git`, etc.

  - For commits, use the Identity to provide authorship information from Git.
  - For revisions, use the local commit information on the Diff to provide the Git/Mercurial/etc author of the HEAD commit.

Test Plan:
  - Built commits and revisions in Buildkite via Harbormaster.
  - I can't actually figure out how to see author information on the Buildkite side, but the values look sane when dumped locally.

Reviewers: amckinley

Subscribers: PHID-OPKG-gm6ozazyms6q6i22gyam

Maniphest Tasks: T13189, T12251

Differential Revision: https://secure.phabricator.com/D19614

src/applications/differential/harbormaster/DifferentialBuildableEngine.php

@@ -54,4 +54,28 @@ final class DifferentialBuildableEngine
     $this->applyTransactions(array($xaction));
   }
 
+  public function getAuthorIdentity() {
+    $object = $this->getObject();
+
+    if ($object instanceof DifferentialRevision) {
+      $object = $object->loadActiveDiff();
+    }
+
+    $authorship = $object->getDiffAuthorshipDict();
+    if (!isset($authorship['authorName'])) {
+      return null;
+    }
+
+    $name = $authorship['authorName'];
+    $address = idx($authorship, 'authorEmail');
+
+    $full = id(new PhutilEmailAddress())
+      ->setDisplayName($name)
+      ->setAddress($address);
+
+    return id(new PhabricatorRepositoryIdentity())
+      ->setIdentityName((string)$full)
+      ->makeEphemeral();
+  }
+
 }

src/applications/diffusion/harbormaster/DiffusionBuildableEngine.php

@@ -34,4 +34,10 @@ final class DiffusionBuildableEngine
     $this->applyTransactions(array($xaction));
   }
 
+  public function getAuthorIdentity() {
+    return $this->getObject()
+      ->loadIdentities($this->getViewer())
+      ->getAuthorIdentity();
+  }
+
 }

src/applications/harbormaster/engine/HarbormasterBuildableEngine.php

@@ -101,5 +101,8 @@ abstract class HarbormasterBuildableEngine
       $xactions);
   }
 
+  public function getAuthorIdentity() {
+    return null;
+  }
 
 }

src/applications/harbormaster/step/HarbormasterBuildkiteBuildStepImplementation.php

@@ -117,6 +117,20 @@ EOTEXT
       ),
     );
 
+    $engine = HarbormasterBuildableEngine::newForObject(
+      $object,
+      $viewer);
+
+    $author_identity = $engine->getAuthorIdentity();
+    if ($author_identity) {
+      $data_structure += array(
+        'author' => array(
+          'name' => $author_identity->getIdentityDisplayName(),
+          'email' => $author_identity->getIdentityEmailAddress(),
+        ),
+      );
+    }
+
     $json_data = phutil_json_encode($data_structure);
 
     $credential_phid = $this->getSetting('token');

src/applications/repository/storage/PhabricatorRepositoryCommit.php

@@ -200,6 +200,8 @@ final class PhabricatorRepositoryCommit
 
     $this->authorIdentity = $author;
     $this->committerIdentity = $committer;
+
+    return $this;
   }
 
   public function getAuthorIdentity() {
@@ -485,6 +487,23 @@ final class PhabricatorRepositoryCommit
     return null;
   }
 
+  public function loadIdentities(PhabricatorUser $viewer) {
+    if ($this->authorIdentity !== self::ATTACHABLE) {
+      return $this;
+    }
+
+    $commit = id(new DiffusionCommitQuery())
+      ->setViewer($viewer)
+      ->withIDs(array($this->getID()))
+      ->needIdentities(true)
+      ->executeOne();
+
+    $author_identity = $commit->getAuthorIdentity();
+    $committer_identity = $commit->getCommitterIdentity();
+
+    return $this->attachIdentities($author_identity, $committer_identity);
+  }
+
   public function hasCommitterIdentity() {
     return ($this->getCommitterIdentity() !== null);
   }

src/applications/repository/storage/PhabricatorRepositoryIdentity.php

@@ -65,6 +65,16 @@ final class PhabricatorRepositoryIdentity
       $this->getIdentityNameEncoding());
   }
 
+  public function getIdentityEmailAddress() {
+    $address = new PhutilEmailAddress($this->getIdentityName());
+    return $address->getAddress();
+  }
+
+  public function getIdentityDisplayName() {
+    $address = new PhutilEmailAddress($this->getIdentityName());
+    return $address->getDisplayName();
+  }
+
   public function getIdentityShortName() {
     // TODO
     return $this->getIdentityName();