Prevent partial application of Envoy extensions
Ensure that non-required extensions do not change xDS resources before
exiting on failure by cloning proto messages prior to applying each
extension.
To support this change, also move `CanApply` checks up a layer and make
them prior to attempting extension application, s.t. we avoid
unnecessary copies where extensions can't be applied.
Last, ensure that we do not allow panics from `CanApply` or `Extend`
checks to escape the attempted extension application.
Ensure nothing in the troubleshoot go module depends on consul's top level module. This is so we can import troubleshoot into consul-k8s and not import all of consul.
* turns troubleshoot into a go module [authored by @curtbushko]
* gets the envoy protos into the troubleshoot module [authored by @curtbushko]
* adds a new go module `envoyextensions` which has xdscommon and extensioncommon folders that both the xds package and the troubleshoot package can import
* adds testing and linting for the new go modules
* moves the unit tests in `troubleshoot/validateupstream` that depend on proxycfg/xds into the xds package, with a comment describing why those tests cannot be in the troubleshoot package
* fixes all the imports everywhere as a result of these changes
Co-authored-by: Curt Bushko <cbushko@gmail.com>
Michael Zalimeni
cui fliter
Ronald
Nitya Dhanushkodi