add tcp_keepalive to Config object

[dlm6693]

This PR partially addresses #2249. We have chosen not to incorporate duration_seconds as it is a pretty niche, rarely used argument that also relies on others to be set in the same config object. Because tcp_keepalive is a setting that originates from an operating system, it can only ever be enabled not disabled. This means if set in a scoped config, but not the client config object, it will still be enabled.

[codecov-commenter]

Codecov Report

Base: 95.25% // Head: 95.25% // Increases project coverage by +0.00% 🎉

Coverage data is based on head (a79e9d0) compared to base (5aa876e).
Patch coverage: 100.00% of modified lines in pull request are covered.

Additional details and impacted files

@@           Coverage Diff            @@
##           develop    #2766   +/-   ##
========================================
  Coverage    95.25%   95.25%           
========================================
  Files           62       62           
  Lines        12899    12900    +1     
========================================
+ Hits         12287    12288    +1     
  Misses         612      612           

Impacted Files	Coverage Δ
botocore/config.py	100.00% <ø> (ø)
botocore/args.py	100.00% <100.00%> (ø)

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[jonemo]

This makes sense to me. I added a few small suggestions in the inline comments.

[jonemo]

LGTM, but can you double check what is causing the codecov to report a decrease in coverage? I can't figure out a way to see the affected files in their UI, so this might require generating two reports for before and after locally...

[miketheman]

Thanks for working on this! I spent some time to try and see how a client instance could expose the value back to the caller, but it seems like no matter what, it'll always return None:

import boto3
from botocore.config import Config

# No setting set in either config file or Config object
client = boto3.client("dynamodb")
print(client.meta.config.tcp_keepalive)
# None

# Pass in explicitly to enable
client = boto3.client("dynamodb", config=Config(tcp_keepalive=True))
print(client.meta.config.tcp_keepalive)
# None

Is there another way to access the property, or is that this value is not being persisted to the Config object returned?

botocore/botocore/args.py

Line 123 in 409b404

new_config = Config(**config_kwargs)

I can confirm (via interactive debugger) that the file loader still ends up on scoped_config and the code-side Config object ends up with the correct value in the client_config, so final_args has the right value, but I can't find a way to access it to print out.

[dlm6693]

@miketheman thanks for flagging this! I did a little bit of digging and this should be a one line fix. I'll touch base internally with my team about this just to make sure we want to expose this in the new config object that gets constructed in get_client_args. In the meantime, while you can't access the tcp_keepalive setting directly, you can infer it by examining your client's socket options:

import boto3
from botocore.config import Config
cfg = Config(tcp_keepalive=True)
client = boto3.client('s3', config=cfg)
print(client._endpoint.http_session._socket_options)
[(6, 1, 1), (65535, 8, 1)]

[miketheman]

Thanks @dlm6693 ! That is helpful, for sure. I opened #2771 - uncertain if that's the right solution or not.

[dlm6693]

@miketheman sweet! That's exactly the change I was thinking of thank you for working on it. I'll be speaking with my team this afternoon, but assuming we're set, I can approve it and we can get it merged ASAP.

[HayesData]

thanks @dlm6693 and @miketheman my team is dealing with this exact issue right now and getting an official fix in place would be mega helpful

[miketheman]

@HayesData Sorry to hear you're hitting this issue! An "official fix" is already in place with this change since version 1.27.84 - the change allows setting the desired configuration via Config instantiation, not an environment variable (yet).

Like @dlm6693 posted a little earlier, you can update your client creation to account for the configuration already, like so:

import boto3
from botocore.config import Config
cfg = Config(tcp_keepalive=True)  # here's the important bit!
s3_client = boto3.client('s3', config=cfg)
s3_client....