I once had a requirement to log bash commands and I checked many solutions like Snoopy, but none of them were proper for a production environment. So the below is the most simple method to add logging to bash in Linux.
Modify bash config
First step is to modify the configuration file for bash
Open /etc/bashrc with the following command
sudo vim /etc/bashrc
After that, add the following line to the end of the file
PROMPT_COMMAND='history -a >(tee -a ~/.bash_history | logger -p local6.info -t "$USER[$$] $SSH_CONNECTION")'
The above entry basically logs all the bash history (commands) to the local6.info log severity.
This will start working only after logging out and logging in again (Or you can manually source the new bashrc)
Modify Rsyslog config
Now to actually log the bash commands, the Rsyslog configuration must be edited to send all the local6.* logs to the /var/log/secure file
So open up Rsyslog config with the following command
sudo vim /etc/rsyslog.conf
And then change the existing secure log entry
After this, restart Rsyslog with the following command
sudo systemctl restart rsyslogd.service
This will enable bash logging but do note that this will enable only bash logging. If there is any other shell like sh or zsh, this method will not log the commands run using those shells.
Also anyone can put any commands in a script and run it and this will only log the name of the script and not the commands inside the script.