In "The Guest" by Albert Camus, what details are we given about Daru's life? Why are they important?

In "The Guest" by Albert Camus, Daru is a French-Algerian schoolmaster who has been charged with educating indigenous students according to colonial standards. The sparse details given about his isolated life are important because they serve as both the backdrop and motivation for his actions in the story.
Daru's Surroundings
Daru lives in a room attached to the schoolhouse where he works. Although his home is located in an area that is not particularly unforgiving, his students come from a nearby village that has been afflicted by a severe drought. The weather in this area is extreme, inflicting both drought and severe snowstorms at different times of the year. The harsh landscape is one of the most heavily detailed aspects of Daru's life, and it serves as a character in its own right. Like Daru, the schoolhouse is disconnected from the surrounding communities of the Algerians, the French military posts, and the nomadic tribes. It is this barren environment with which Daru forms a strange kinship, his only true emotional connection in the story.
Daru's Personality
Daru is a somber yet kind man who regularly distributes food rations to his students. He avoids commitment at nearly all costs and becomes resentful when Balducci conscripts him to escort an Arab prisoner to the authorities. Although Daru is French, he is not sympathetic to his government's efforts to colonize the region. He has long struggled to remain impartial in the conflict that surrounds him, but Balducci forces him to choose a side. Daru passes on this burden by allowing the prisoner to choose freedom or to turn himself in to the authorities. When the prisoner chooses to turn himself in, Daru watches in clear disappointment.
As the story progresses, we see that these details of Daru's life, in terms of his personality, his duty, and his surroundings, are reflections of themes presented in the overall narrative. Daru's circumstances are similar to those of the author, a French-Algerian man whose efforts to mediate between the Algerian separatists and the French government were met with frustration. All of the details in Daru's life serve to emphasize the fact that he is alone metaphorically and often physically. From his isolated home in the schoolhouse, Daru watches Balducci and the prisoner approach from the road with a sense of detachment that characterizes his actions throughout the tale. He does not feel any strong human bonds and, despite his altruism, he seems to have little stake in any aspect of life.