CODEWITHSUNDEEP
pythonfirebasegoogle-cloud-functionsgoogle-cloud-storagepython-imaging-library
et-hicks
et-hicks

Reputation: 21

How to get GCP Function generated image to be recognized as valid in GC Storage?

I am trying to create an image thumbnail creation function using python, running in a google cloud platform's function. The image is sent as a base64 string to the cloud function, manipulated and made smaller with Python's Pillow package. It is then uploaded as an image, going from a Pillow Image object, to a BytesIO object, then saved to google cloud storage. This is all done successfully.

The problem here is very strange: Google Cloud Storage does not recognize the image until an access token is created manually. Otherwise, the image is left in an infinite loop, never loading, and never being able to be used.

I have reviewed this SO post, which has a very similar problem to mine (the image here shows exactly my problem: an uploaded file cannot be loaded properly), but it differs in two imporant categories: 1) They are manipulating the image array directly, while my code never touches it and 2) they are working in Node.js, where the Firebase SDK is different than in Python.

The code to generate the image is as follows:

def thumbnailCreator(request):
    # Setting up the resourcse we are going to use
    storage_client = storage.Client()
    stor_bucket = storage_client.bucket(BUCKET_LINK)

    # Retriving the Data
    sent_data = request.get_json()['data']
    name = sent_data['name']
    userID = sent_data['userID']

    # Process to go between base64 string to bytes, to a file object 
    imageString = stor_bucket.blob(PATH_TO_FULL_SIZE_IMAGE).download_as_string()
    
    imageFile = BytesIO(imageString)
    image = Image.open(imageFile)

    # Resizing the image is the goal 
    image = image.resize(THUMBNAIL_SIZE)

    # Go between pillow Image object to a file
    imageFile = BytesIO()
    image.save(imageFile, format='PNG')
    imageBytes = imageFile.getvalue()
    image64 = base64.b64encode(imageBytes)
    imageFile.seek(0)


    # Uploading the Data 
    other_blob = stor_bucket.blob(PATH_FOR_THUMBNAIL_IMAGE)
    other_blob.upload_from_file(imageFile, content_type = 'image/png')

    return {'data': {'response': 'ok', 'status': 200}}

Again, this works. I have a feeling there is something wrong with the MIME type. I am a novice when it comes to this type of programming/networking/image manipulation, so I'm always looking for a better way to do this. Anyway, thanks for any and all help.

Upvotes: 1

Views: 574

Answers (1)

et-hicks
et-hicks

Reputation: 21

It appears that the premise of this question - that a access token must be made manually for the image to work - is not accurate. After further testing, the error came from other parts of the code base I was working in. The above python script does work for image manipulation. An access token to the image can be generated via code, and be provided client-side.

Leaving this up in case someone stumbles upon it in the future when they need to work with Pillow/PIL in the Google Cloud Platform.

Upvotes: 1

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