如何从 App Engine 将图像上传到 Google Cloud Storage

Question

我正在尝试获取 base64 编码的 PNG，对其进行解码，然后将其上传到 Google Cloud Storage 并获取其公共 URL。

我可以通过将 PNG 保存到文件然后使用 blob.upload_from_file('picture.png') 上传它来在本地执行此操作，但 App Engine 不允许对其文件结构进行写访问。

此代码在本地有效，但在 Google App Engine 中无效，在 with open(... 失败

import base64
from google.cloud import storage

def handler(request):

    pic = request.POST.get('photograph') #Object like 'data:image/png;base64,iVBORw0KGgoAAAAN…'
    data = pic[22:]                
    png = base64.b64decode(data)     
    filename = "pic.png" 
    with open(filename, "wb") as f:
        f.write(png)
    client = storage.Client.from_service_account_json(os.path.abspath('credentials.json'))
    bucket = client.get_bucket('mybucket')
    blob = bucket.blob(filename)        #create destination uri in bucket
    blob.upload_from_file(filename)       

    image_url = "https://storage.googleapis.com/mybucket/" + filename

GCS 文档告诉Use the Blob.upload_from_file(), Blob.upload_from_filename(), or Blob.upload_from_string() method to upload an object.

但是，这些方法都不适用于这种情况，因为没有文件，只有一个编码的 PNG 对象。如何将其上传到 gcloud 存储？

我肯定遗漏了一些明显的东西。任何想法将不胜感激。

Answer 1

根据 David 的建议，这是行之有效的。我只是在文件名之前添加了/tmp/，App Engine 允许我保存它。

import base64
from google.cloud import storage

def handler(request):
    pic = request.POST.get('photograph') 
    data = pic[22:]                
    png = base64.b64decode(data)     
    filename = "pic.png"

    temp_location = '/tmp/' + filename          #here
    with open(temp_location, "wb") as f:        
        f.write(png)

    client = storage.Client.from_service_account_json(os.path.abspath('credentials.json'))
    bucket = client.get_bucket('mybucket')
    blob = bucket.blob(filename)        
    blob.upload_from_file(temp_location)       

    image_url = "https://storage.googleapis.com/mybucket/" + filename

Answer 2

import base64
from google.cloud import storage 
#The post_image_base64 is base64 string
base64_img_bytes = post_image_base64.encode('utf-8')

#this for localhost if you want to upload it to gcloud storage then you have to add this path /tmp/ 

"""
with open('/tmp/'+'decoded_image.png', 'wb') as file_to_save:
   decoded_image_data = base64.decodebytes(base64_img_bytes)
"""
with open('decoded_image.png', 'wb') as file_to_save:
   decoded_image_data = base64.decodebytes(base64_img_bytes)
   ##Save file 
   #file_to_save.write(decoded_image_data)


gcs=storage.Client.from_service_account_json(os.path.abspath('credentials.json'))  
bucket = gcs.get_bucket("bucket_name")
blob = bucket.blob("image_name.png")

#for upload to gcloud storage you also need to add /tmp/ path in here
#blob.upload_from_string("/tmp/"+decoded_image_data)

blob.upload_from_string(decoded_image_data)

#and then make it public use this
blob = bucket.get_blob('image_name.png')
blob_url = blob.make_public()            
print(blob.public_url);