Add defaults maxconn

[kenichi-mashiyama]

Summary

This PR adds support for configuring the maxconn parameter within the defaults section of HAProxy configurations.

Motivation

HAProxy allows setting a maximum number of concurrent connections per process using the maxconn parameter. While this is configurable at the frontend level, there are scenarios where operators need to define a global or default maxconn limit across all proxies that do not explicitly override it. By introducing the maxconn field to the DefaultsConfiguration struct, users can now specify a default maximum connection limit directly via the Instance CRD.

Changes

• Added the Maxconn (*int64) field to the DefaultsConfiguration struct in apis/proxy/v1alpha1/instance_types.go.
• Updated the Model() method in apis/proxy/v1alpha1/instance_types.go to map this new field to the native HAProxy model (defaults.Maxconn = d.Maxconn).
• Added unit tests (TestDefaultsConfigurationModelWithMaxconn and TestDefaultsConfigurationAddToParserWithMaxconn) in apis/proxy/v1alpha1/instance_types_test.go to verify the correct mapping and generation of the maxconn configuration line.
• Regenerated CRDs, DeepCopyInto methods, and API documentation to reflect the new maxconn field.

Checklist

• Code changes implemented
• Unit tests added/updated
• Generated CRDs and API docs updated

[xosk31]

Thanks for your contribution!