new S3_FILEPATH_HEADERS setting, to set custom headers only if the filepath matches certain configured regular expressions.

docs/index.rst

@@ -214,9 +214,16 @@ uploading assets to S3.
                             specified by `flask.url_for`.
 `S3_HEADERS`                Sets custom headers to be sent with each file to S3.
                             **Default:** `{}`
+`S3_FILEPATH_HEADERS`       Sets custom headers for files whose filepath matches
+                            certain regular expressions. E.g. to add CORS
+                            headers for font files, set this to:
+                            `{r'\.(ttf|woff|woff2|svg|eot)$':`
+                            `    {'Access-Control-Allow-Origin': '*'}`
+                            `}`
+                            **Default:** `{}`
 `S3_ONLY_MODIFIED`          Only upload files that have been modified since last
                             upload to S3. SHA-1 file hashes are used to compute
-                            file changes. You can delete `.file-hashes` from 
+                            file changes. You can delete `.file-hashes` from
                             your S3 bucket to force all files to upload again.
 `S3_CACHE_CONTROL`          **Deprecated**. Please use `S3_HEADERS` instead.
 `S3_USE_CACHE_CONTROL`      **Deprecated**. Please use `S3_HEADERS` instead.

flask_s3.py

@@ -146,9 +146,20 @@ def _write_files(app, static_url_loc, static_folder, files, bucket,
             logger.debug("%s excluded from upload" % key_name)
         else:
             k = Key(bucket=bucket, name=key_name)
+
             # Set custom headers
             for header, value in app.config['S3_HEADERS'].iteritems():
                 k.set_metadata(header, value)
+
+            # Set more custom headers if the filepath matches certain
+            # configured regular expressions.
+            filepath_headers = app.config['S3_FILEPATH_HEADERS']
+            if filepath_headers:
+                for filepath_regex, headers in filepath_headers.iteritems():
+                    if re.search(filepath_regex, file_path):
+                        for header, value in headers.iteritems():
+                            k.set_metadata(header, value)
+
             k.set_contents_from_filename(file_path)
             k.make_public()
 
@@ -298,6 +309,7 @@ class FlaskS3(object):
                     ('S3_CDN_DOMAIN', ''),
                     ('S3_USE_CACHE_CONTROL', False),
                     ('S3_HEADERS', {}),
+                    ('S3_FILEPATH_HEADERS', {}),
                     ('S3_ONLY_MODIFIED', False),
                     ('S3_URL_STYLE', 'host')]