The mesh assigns the machine-side port and a module does not choose one (ADR
0038). For a container that is invisible: the mesh rewrites ports into
assigned:wanted, the software binds the number it always bound, and the machine
publishes another.
A process has no such layer. It runs on the machine, there is nothing to rewrite,
and it binds whatever its configuration says. So every process bound the number
written in its own config, two modules declaring the same one would collide, and
the mesh's whole reason for assigning ports was defeated by the resource kind
that most needs it — introduced, by me, three commits ago.
So a module asks. ${port:8080} is "the machine-side port you gave me for the 8080
I said I listen on", written into its own configuration exactly as an address it
was bound to is.
Asking about a port it never declared is refused, and the refusal says what it
did declare: the module is asking about something the mesh has no opinion on, and
answering would put a guess into a configuration file as a port number. With
nothing assigned yet it is told what it asked for, so a mesh that has made no
assignment still composes something coherent rather than writing a zero.
Claude-Session: https://claude.ai/code/session_01D6qtiYU3P9jk3pnAXyAFyx
jschoubben
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