Script for remote connection and facility automation and configurations

I need a script to remotely connect to another linux server and perform installation of some services and make some configuration settings. The script have to connect via ssh and need to make a series of installations and configurations. NOTE: These are installation and configuration linux servers to protect and optimize shared environment. The script should be divided into parts He must have specific fields (at the beginning of the script) to put information for access. NOTE: The connection needs to have an option to connect via login / password and some other form safest "for example RSA KEY" The script needs to have a separate part just to test the connection and record log that the connection was successful. After the connection to the remote server, the script needs to do installations of applications and change settings on linux server. Each step of scritpt should be recorded in a log for reading progress.