Target group helpers

[rdickey-r7]

Description

Adds the ability, suggested by @erran-r7 to specify target_group_attributes and matcher for an elbv2 target group.

Motivation and Context

Usage Examples

Old way:

    matcher do
      http_code 200
    end
    target_group_attribute do
      key 'deregistration_delay.timeout_seconds'
      value 300
    end

New way:

    matcher 200
    target_group_attribute 'deregistration_delay.timeout_seconds', 300

Testing Steps

Post-merge Steps

[bcall-r7]

Ship it