how to setup percona pmm monitoring of percona 5.7 in docker container
Can you show us the command you used to launch the Percona Server for MySQL 5.7 container? You need to ensure you are allowing access to 3306/tcp.

Otherwise from PMM Server perspective there will be nothing unique to your use case of running Percona Server for MYSQL from docker or via yum/apt-get, the mysqld_exporter will connect to 3306/tcp and collect MySQL metrics as needed.

You will be missing collection of node_exporter data so you won't have anything on your Disk Performance, Disk Space, etc graphs.