Several times in my life, though not at all recently, I’ve heard ‘How goes the war?’ used as a secondary greeting; as in: ‘Good morning, Bob. How goes the war?’
Where does the phrase originate? ‘How goes the night?’ is spoken in Macbeth, but that’s ‘night’, and not ‘war’.
From The Answer Bank, a possible ancestor.
‘How goes the battle?’ was a jocular greeting in Canada in the 1940s. ‘How’s battle?’ - without the ‘the’ - was used by some here from the mid-1930s to mean the battle of life. It’s just a variant of ‘How’s it going?’, really, the ‘it’ meaning life in general.