Eumaios is Ithakan swineherd who takes Odysseus in when he returns home in the guise of a beggar, and he shows us that it's not just kings who can be hospitable—even swineherds know how to treat a guest right.
When Odysseus first shows up, Eumaios has no idea who he is. In fact, he simply calls him "old man of many sorrows" (14.386)—which actually sounds about right. He doesn't believe Odysseus' tale, but he'll give him a meal anyway: "It is not for [your lying words] that I will entertain and befriend you, but for fear of Zeus, the god of guests, and for my own pity" (14.388-89).
When it's time to eat, he puts his chine where his mouth is. Homer actually spends a while describing just how fair he is:
The swineherd stood up to divide the portions, for he was fair minded, and separated all the meat into seven portions. One he set aside, with a prayer, for the nymphs and Hermes, the son of Maia, and the rest he distributed to each man, but gave Odysseus in honor the long cuts of the chine's portion of the white-toothed pig, and so exalted the heart of his master. (14.432-438)
Everyone—he, Odysseus, and the other swineherds—gets a fair portion, but, as the guest, Odysseus gets the good stuff. And it "exalts" the heart of his master. It seems like Eumaios' hospitality doesn't just reflect well on him; it also reflects well on Odysseus.
That's not the only way Eumaios proves what a good servant he is. When he's talking to the disguised Odysseus, he says that he misses Odysseus so much that he "feel[s] some modesty about naming him … So I call him my master, though he is absent" (14.144-147). Even though Odysseus has been gone for 20 years and is in all likelihood at the bottom of the Mediterranean somewhere, Eumaios still thinks of him as his master. Really, he's almost as loyal as Penelope.
Like Penelope, he makes sure that things are taken care of in his master's absence. He even sleeps outside with his pigs—and "Odysseus was happy that his livelihood was so well cared for while he was absent" (14.527). You have to be careful in Ancient Greece: you never know when your master or a god is going to be checking up on you, so you'd better make sure that you're behaving. Just like Santa Claus.
But it's not all sleeping with pigs and dividing meat fairly. Check out how he welcomes Telemachos, when the boy comes back from his adventure:
He came up to meet his master, and kissed his head, and kissed too his beautiful shining eyes, and both his hands, and the swelling tear fell from him. And as a father, with heart full of love, welcomes his only and grown son, for whose sake he has undergone many hardships when he comes back in the tenth year from a distant country, so now the noble swineherd, clinging fast to godlike Telemachos, kissed him even as if he had escaped dying […].' (16.14-21)
Eumaios feels so much loyalty to Telemachos that he treats the boy like a son. But is it really all that surprising that the perfect master (Odysseus) and the perfect mistress (Penelope) also have the perfect servant?