Water heater leak troubleshooting for dummies

[forgop]

Never had a hot water tank issue before. Small stream of water coming from the bottom of the tank. I shut off the gas and the supply line. The supply line shows visible condensation, but no actual drips. When shutting off supply line, leak from bottom stops. Therefore, I've eliminated that it's a hole at the bottom, but somewhere in the supply to the tank. There's no physical evidence of a leak, so if the leak is actually concealed inside the tank enclosure, is it pretty much in need of replacement?

I've thought about going with tankless, so I don't know if this is my sign or what.