[FEATURE] - Not actually require postfix, or a way to override that

[dkowis]

User Story

As a homelab server runner, I want to not be required to install postfix, because I'm using a different sendmail provider.

I've got msmtp installed, which relays to my node that runs actual postfix to do heavier SMTP bits. having postfix installed also conflicts with this, and doesn't need to be there.

Basic info

• Distro: Ubuntu 20.04
• Game: Valheim (in this case, but it'd apply to anything I think)
• Command: check-update
• LinuxGSM version: v21.2.3

Further Information

It'd be nice if it would detect that it's got a sendmail command to do the sending with, and not explicitly require postfix. I think it's completely fine to suggest/require postfix if nothing is installed, because that makes it easy, but I've provided a sendmail command via another package, and I think my chef even removes postfix in favor of the msmtp package, and it's kinda frustrating :)

Further Reading

I could link to msmtp documentation I guess: https://marlam.de/msmtp/

[dgibbs64]

Dependency checking needs a refactor. So this should be part of that

[dgibbs64]

The code exists but doesnt quite work for your case. I will rework this to improve email detection

	# Adds postfix to required dependencies if email alert is enabled.
	if [ "${emailalert}" == "on" ]; then
		if [ -f /usr/bin/mailx ]; then
			if [ -d /etc/exim4 ]; then
				array_deps_required+=( exim4 )
			elif [ -d /etc/sendmail ]; then
				array_deps_required+=( sendmail )
			elif [ "$(command -v dpkg-query 2>/dev/null)" ]; then
				array_deps_required+=( mailutils postfix )
			elif [ "$(command -v rpm 2>/dev/null)" ]; then
				array_deps_required+=( mailx postfix )
			fi
		else
			if [ "$(command -v dpkg-query 2>/dev/null)" ]; then
				array_deps_required+=( mailutils postfix )
			elif [ "$(command -v rpm 2>/dev/null)" ]; then
				array_deps_required+=( mailx postfix )
			fi
		fi
	fi
}```