Add ability to provide custom client configuration

[maciejwalkowiak]

📢 Type of change

• Bugfix
• New feature
• Enhancement
• Refactoring

📜 Description

One common request is to add simple way to provide custom ClientConfiguration for different integrations. This change enables users to define a bean of name com.amazonaws.ClientConfiguration.BEAN_NAME that would be by default set on all AWS clients and in addition to that, define ClientConfiguration per client.

Client-specific beans must have specific name, for example - SQS ClientConfiguration bean must be named - sqsClientConfiguration.

💡 Motivation and Context

Common request:

• Custom client configuration NOT considered when using SQS #412
• clientconfiguration information when connecting through proxy #63

💚 How did you test it?

Integration tests.

📝 Checklist

• I reviewed submitted code
• I added tests to verify changes
• I updated reference documentation to reflect the change
• All tests passing
• No breaking changes

🔮 Next steps

• Add support for modules once PRs are merged:
  • Parameter Store (Add aws-parameterstore: prefix config import #723)
  • Secrets Manager (Add aws-secretsmanager: prefix config import #721)
  • SES (Add ses module #669)
• Update reference docs

[eddumelendez]

Currently, we have our own SpringCloudClientConfiguration which add a suffix to the user agent. By doing an injection of ClientConfiguration we will lose this. I think we can do something like RestTemplateBuilder and RestTemplateCustomizer and not lose this.

[maciejwalkowiak]

@eddumelendez suffix is still added: https://github.com/spring-cloud/spring-cloud-aws/pull/725/files#diff-06d076e20794983d503af739eef415c367243d9e21195c978fc8730d70209722L97

[gauravbrills]

@maciejwalkowiakis is there a plan to also add this to aws-paramstore as currently there isn't a way to customize this (specially in the case w need to pass custom proxy ) . Also even marking beans as primary still uses beans from the default configuration AwsParamStoreBootstrapConfiguration we have observed for ssmClient .