Diaries of a Spaceport Janitor

From the introduction:

Xabran’s Rock is a relatively insignificant planetoid by many standards. It is not large or particularly rich in minerals. There is no abundant plant life, deposits of gemstones, and it is the only planet bothering to orbit a dwarf yellow star only a few millions years away from burning through all of its hydrogen. Just about the only thing it does have is empty space. Situated right in the nexus of the trading routes for hundreds of alien species.