Changeset 4364

Timestamp:

11/15/2016 11:51:56 PM (8 years ago)

Author:

iandunn

Message:

CampTix Badge Generator: Retry failed download attempts to avoid ruining batch

File:

• sites/trunk/wordcamp.org/public_html/wp-content/plugins/camptix-badge-generator/includes/indesign-badges.php (modified) (2 diffs)

sites/trunk/wordcamp.org/public_html/wp-content/plugins/camptix-badge-generator/includes/indesign-badges.php

@@ -73 +73 @@
         }
 
-        $request_url = str_replace( '=blank', '=404', $attendee->avatar_url );
-        $response    = wp_remote_get( $request_url );
-        $image       = wp_remote_retrieve_body( $response );
-        $status_code = wp_remote_retrieve_response_code( $response );
-
-        if ( 404 == $status_code ) {
+        $request_url    = str_replace( '=blank', '=404', $attendee->avatar_url );
+        $gravatar_image = download_single_gravatar( $request_url );
+
+        if ( ! $gravatar_image ) {
             continue;
-        }
-
-        if ( ! $image || 200 != $status_code ) {
-            Logger\log( 'request_failed', compact( 'attendee', 'request_url', 'response' ) );
-            throw new \Exception( __( "Couldn't download all Gravatars.", 'wordcamporg' ) );
         }
 
@@ -90 +83 @@
         $gravatar_file = fopen( $gravatar_folder . '/' . $filename, 'w' );
 
-        fwrite( $gravatar_file, $image );
+        if ( ! $gravatar_file ) {
+            Logger\log( 'gravatar_open_failed', compact( 'attendee', 'gravatar_folder', 'filename' ) );
+            throw new \Exception( __( "Couldn't save all Gravatars.", 'wordcamporg' ) );
+        }
+
+        fwrite( $gravatar_file, $gravatar_image );
         fclose( $gravatar_file );
+    }
+}
+
+/**
+ * Download a Gravatar
+ *
+ * Sometimes the HTTP request times out, or Varnish returns a `503` error, but the batch will be ruined if even a
+ * single existing Gravatar cannot be downloaded successfully. In order to mitigate that, we retry the download
+ * multiple times.
+ *
+ * @param string $request_url
+ *
+ * @return bool|string `false` when the user does not have a Gravatar, `string` of image binary data when the
+ *                      image was successfully retrieved.
+ *
+ * @throws \Exception when the HTTP failed even after multiple attempts
+ */
+function download_single_gravatar( $request_url ) {
+    $attempt_count = 1;
+
+    while ( true ) {
+        $response    = wp_remote_get( $request_url );
+        $status_code = wp_remote_retrieve_response_code( $response );
+        $image       = wp_remote_retrieve_body( $response );
+        $retry_after = wp_remote_retrieve_header( $response, 'retry-after' ) ?: 5;
+        $retry_after = min( $retry_after * $attempt_count, 30 );
+
+        // A 404 is expected when the attendee doesn't have a Gravatar setup, so don't retry them
+        if ( 404 == $status_code ) {
+            return false;
+        }
+
+        if ( ! is_wp_error( $response ) && $image ) {
+            return $image;
+        }
+
+        $response['body'] = '[redacted]'; // Avoid cluttering the logs with a ton of binary data
+
+        if ( $attempt_count < 3 ) {
+            Logger\log( 'request_failed_temporarily', compact( 'attendee', 'request_url', 'response', 'attempt_count', 'retry_after' ) );
+            sleep( $retry_after );
+        } else {
+            Logger\log( 'request_failed_permenantly', compact( 'attendee', 'request_url', 'response' ) );
+            throw new \Exception( __( "Couldn't download all Gravatars.", 'wordcamporg' ) );
+        }
+
+        $attempt_count++;
     }
 }