Stream Docker image tarball to disk directly instead of in memory

I’m attempting to create a tarball of an existing Docker image via the https://docker-py.readthedocs.io/en/stable/images.html save example. When attempting to write the data to disk, I get MemoryError during the writing process.

The image is 1.516GB so I’m assuming we are running out of memory (this process is within a container).

Can the save be done directly to disk and avoid being pushed into memory?

[shin-]

We should provide a streaming option. You can try the following code excerpt in the meantime:

import docker

client = docker.from_env()
img = client.images.get('busybox:latest')
url = client.api._url('/images/{0}/get', img.id)
res = client.api._get(url, stream=True)
with open('/tmp/img.tar', 'w') as f:
  for chunk in res.iter_content(chunk_size=None):
    f.write(chunk)

[shin-]

Just wanted to say - I read the messages, and it’s on my radar - should be a simple fix. Thanks everyone for the reports.