Q:

How to read/receive Get/POST messages at the HTTPs Linux server?

how can I decrypt/read https Post/Get messages for testing purposes ? Just need to verify post/get messages are reaching https server.

A:

If you have access to the key file, some traffic analysis tools can use it to decrypt the network traffic. For example, here https://wiki.wireshark.org/SSL is info on doing so with Wire Shark. 
Another option might be turning the logging/debug level up in the server config and looking in the log files. 

