ResourceWarning: unclosed <ssl.SSLSocket fd=20, family=AddressFamily.AF_INET, type=SocketKind.SOCK_STREAM, proto=6, laddr=('10.1.0.62', 52098), raddr=('52.239.140.10', 443)>

• azure-storage-blob:
• 12.5.0:
• Linux 39a68fd14e65 4.19.76-linuxkit #1 SMP Tue May 26 11:42:35 UTC 2020 x86_64 GNU/Linux:
• Python 3.8.3:

Describe the bug We’ve enabled a few warning filters in our application with warning.simplefilter and we’re seeing a python warning when we download a file from the blob storage. ResourceWarning: unclosed <ssl.SSLSocket fd=20, family=AddressFamily.AF_INET, type=SocketKind.SOCK_STREAM, proto=6, laddr=('10.1.0.62', 52098), raddr=('52.239.140.10', 443)>

To Reproduce

client = BlobServiceClient.from_connection_string("<connection string here>").get_blob_client(container="<container name>", blob="<blob name>")
raw_data = client.download_blob().readall()
with gzip.open(BytesIO(raw_data), "rb") as fh:
    data = pickle.load(fh)  # noqa: S301

Expected behavior No warning or a proper way to close the stream.

Screenshots NA

Additional context NA

[tasherif-msft]

Hi @lukin0110, this is actually intended behavior. When you run

import warnings
from azure.storage.blob import BlobServiceClient

warnings.simplefilter("default", ResourceWarning)

CONNECTION = "<connection string here>"
CONTAINER = "<container name here>"
BLOB_NAME = "<blob name here>"

client = BlobServiceClient.from_connection_string(CONNECTION).get_blob_client(container=CONTAINER, blob=BLOB_NAME)
raw_data = client.download_blob().readall()

You’re creating a blob client from your BlobServiceClient and not closing any sessions. If you want to ensure all sessions are closed, you must close your parent client. You can achieve this by doing:

BlobServiceClient.from_connection_string(CONNECTION) as bsc:
    bc = bsc.get_blob_client(container="test", blob="blob.txt")
    raw_data = bc.download_blob().readall()

This ensures that the socket is closed since the child class is inheriting the same session.

You can also do:

bsc = BlobServiceClient.from_connection_string(CONNECTION)
bc = bsc.get_blob_client(container="test", blob="blob.txt")
raw_data = bc.download_blob().readall()
bsc.close()

Hope this helps! Let me know if there anything else needed

[xiafu-msft]

Hi @lukin0110

Thanks for reporting this issue. I was able to reproduce. The problem is we created a session and didn’t close it https://github.com/Azure/azure-sdk-for-python/blame/master/sdk/core/azure-core/azure/core/pipeline/transport/_requests_basic.py#L244

@xiangyan99 could you please find people to confirm we want to close the session before return.