How to measure containerized performance tests

Suppose I run my performance tests in docker, How can i see the report that gatling provides?

You should already know where Gatling writes its reports when run in local.
And you can configure the directory prefix with gatling.core.outputDirectoryBaseName as stated in the gatling.conf documentation.

So you may mount a volume there.
About mounting volume in docker, you should go and read the docker documentation.