Archived
jschoubben
3954157555
Services are named under the machine they run on — postgres.novox.internal, plex.ace.internal. The first label is the service and the rest is the node, so what has to resolve is anything under a node's name. What routes it once it arrives is a proxy's concern and stays separate. A hosts file cannot do that. It answers exact names, and a wildcard there would mean writing down every service in advance — which is the enumeration the arrangement exists to avoid. novox/hq 08-connectivity named this exact case as the trigger for needing a resolver rather than a file, and it is the first thing to meet it. The mesh writes the data and runs no daemon. A resolver is third-party software, and third-party software runs on the mesh rather than being of it (ADR 0001): the mesh has no business shipping one, choosing which one, or knowing its configuration language. What only the mesh can know is which machines exist and where they are. A module that runs a resolver requires what this provides and reads one file, so swapping the daemon changes that module and nothing here. Separate from names rather than part of them: a machine with no container runtime can still have a hosts file, and folding them together would take exact names away from a machine that cannot run a daemon in order to give it a wildcard it cannot use either. A machine with no address is left out. A wildcard pointing at nothing is worse than no wildcard — every name under it resolves and then hangs, where an unresolvable name fails at once and says which name it was.