Unable to set blob metadata

I am trying to set custom metadata on a blob. However, this does not work. I’m using the following script:

#!/usr/bin/env python3
import os

from gcloud import storage

client = storage.Client('super secret id')
bucket = client.get_bucket('super secret bucket')

blob = bucket.blob('kirby.png')
blob.metadata = dict(Color='Pink')
with open(os.path.expanduser('~/Pictures/kirby.png'), 'rb') as img_data:
    blob.upload_from_file(img_data)

When retrieving the blob or inspecing it in the developer console, the metadata is still unset.

[pdknsk]

I think this is a duplicate of #754. The use of metadata is a bit ambiguous as metadata refers to both the metadata of an object (such as Cache-Control) and the metadata property, meant for custom metadata.

Anyway, to the issue. Any update? The problem with patch is that the object is online briefly with wrong metadata, or less briefly in case of a connection failure between two requests. And, it increases metageneration.

>>> text = bucket.blob('file.txt')
>>> text.cache_control = 'no-cache'
>>> text.upload_from_string('text')
>>> text.reload()
>>> text.cache_control
>>> text.metageneration
1
>>> text.cache_control = 'no-cache'
>>> text.patch()
>>> text.reload()
>>> text.cache_control
u'no-cache'
>>> text.metageneration
2

[gjkemnitz]

You can work around this bug by creating a completely new dictionary, assigning it to blob.metadata, and doing blob.patch():

newdict={}
for x in blob.metadata:
    newdict[x] = blob.metadata[x]
    newdict['mynewproperty'] = 'awesome'
blob.metadata=newdict
blob.patch()

Your blob will now have the {‘mynewproperty’:‘awesome’} metadata property in its stored metadata list on GCS.