Overwrite S3 endpoint using Boto3 configuration file

You cannot set host in config file, however you can override it from your code with boto3.

import boto3

session = boto3.session.Session()

s3_client = session.client(
    service_name='s3',
    aws_access_key_id='aaa',
    aws_secret_access_key='bbb',
    endpoint_url='http://localhost',
)

Then you can interact as usual.

print(s3_client.list_buckets())

boto3 only reads the signature version for s3 from that config file. You may want to open a feature request, but for now here is how you can address a custom endpoint:

import boto3
from botocore.utils import fix_s3_host
resource = boto3.resource(service_name='s3', endpoint_url='http://localhost')
resource.meta.client.meta.events.unregister('before-sign.s3', fix_s3_host)

That bit about the meta is important because boto3 automatically changes the endpoint to your_bucket_name.s3.amazonaws.com when it sees fit 1. If you'll be working with both your own host and s3, you may wish to override the functionality rather than removing it altogether.

using boto3 resource:

import boto3

# use third party object storage
s3 = boto3.resource('s3', endpoint_url='https://URL:443',
  aws_access_key_id = 'AccessKey',
  aws_secret_access_key = 'SecertKey')

# Print out bucket names
for bucket in s3.buckets.all():
 print(bucket.name)