Prepend the minified static file header using a custom Storage class

(imported from commit 2b67a6d94de1693bdb8a91f455b92375692f4c41)

humbug/settings.py

@@ -222,8 +222,9 @@ STATICFILES_FINDERS = (
 if DEBUG:
     STATICFILES_STORAGE = 'pipeline.storage.PipelineStorage'
 else:
-    STATICFILES_STORAGE = 'pipeline.storage.PipelineCachedStorage'
+    STATICFILES_STORAGE = 'zephyr.storage.HumbugStorage'
 
+STATIC_HEADER_FILE = 'zephyr/static_header.txt'
 STATIC_ROOT = 'prod-static/collected'
 
 # This is the default behavior from Pipeline, but we set it

tools/update-prod-static

@@ -4,11 +4,6 @@
 
 cd "$(dirname "$0")"/..
 
-if ! which sponge >/dev/null; then
-    echo 'Install the moreutils package.' >&2
-    exit 1
-fi
-
 # Redirect output to a log file (most recent run only)
 exec >update-prod-static.log
 
@@ -32,11 +27,6 @@ rm -rf prod-static/serve-new
 mkdir -p prod-static/serve-new
 cp -r prod-static/collected/{favicon.ico,robots.txt,html,images,third,min,audio} prod-static/serve-new/
 
-# Prepend the third-party code notice to JavaScript and CSS files.
-for f in prod-static/serve-new/min/*.{js,css}; do
-    cat zephyr/static/header.txt $f | sponge $f
-done
-
 # Sync the new directory to the one nginx actually serves.
 # Hopefully this doesn't race too badly for clients loading
 # right as a deploy happens.

zephyr/storage.py

@@ -0,0 +1,59 @@
+from django.conf import settings
+from django.contrib.staticfiles.storage import CachedFilesMixin, StaticFilesStorage
+from pipeline.storage import PipelineMixin
+import os.path
+
+class AddHeaderMixin(object):
+    def post_process(self, paths, dry_run=False, **kwargs):
+        if dry_run:
+            return
+
+        with open(settings.STATIC_HEADER_FILE) as header_file:
+            header = header_file.read().decode(settings.FILE_CHARSET)
+
+        # A dictionary of path to tuples of (old_path, new_path,
+        # processed).  The return value of this method is the values
+        # of this dictionary
+        ret_dict = {}
+
+        for name in paths:
+            storage, path = paths[name]
+
+            # Find the top-level directory for the file
+            head, _ = os.path.split(path)
+            top_dir = head
+            while head != '':
+                top_dir = head
+                head, _ = os.path.split(head)
+
+            if top_dir != 'min':
+                ret_dict[path] = (path, path, False)
+                continue
+
+            # Prepend the header
+            with storage.open(path) as orig_file:
+                orig_contents = orig_file.read().decode(settings.FILE_CHARSET)
+
+            storage.delete(path)
+
+            with storage.open(path, 'w') as new_file:
+                new_file.write(header + orig_contents)
+
+            ret_dict[path] = (path, path, True)
+
+        super_class = super(AddHeaderMixin, self)
+        if hasattr(super_class, 'post_process'):
+            super_ret = super_class.post_process(paths, dry_run, **kwargs)
+        else:
+            super_ret = []
+
+        # Merge super class's return value with ours
+        for val in super_ret:
+            old_path, new_path, processed = val
+            if processed:
+                ret_dict[old_path] = val
+
+        return ret_dict.itervalues()
+
+class HumbugStorage(PipelineMixin, AddHeaderMixin, CachedFilesMixin, StaticFilesStorage):
+    pass