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)>

[lukin0110]

• azure-storage-blob:
• 12.5.0:
• Linux 39a68fd14e65 4.19.76-linuxkit First real commit to the Python Azure repository #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

[xiafu-msft]

Hi @lukin0110

So you also saw this warning when only executing this two lines?

client = BlobServiceClient.from_connection_string("<connection string here>").get_blob_client(container="<container name>", blob="<blob name>")
raw_data = client.download_blob().readall()

[lukin0110]

Hi @xiafu-msft

The correct way to reproduce is:

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()

[xiafu-msft]

Hi @lukin0110

Thanks for your code!
can you try this and see if you still get this warning:

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

[lukin0110]

Heh @xiafu-msft,

Using it as a context is still showing the warning.

[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.

[lukin0110]

Thanks for the quick follow up!

[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

[lukin0110]

@tadam-msft thanks for clarifying. I've applied your suggestion. The resource warning is not appearing anymore.

[tasherif-msft]

Hi @lukin0110! fantastic :)