With dev and prod open side by side in the same browser, the tabs were
indistinguishable. ENV is written into the title of every page unless it says
prod, so "dev · Foodster" picks itself out. The value is used verbatim, so
ENV=staging labels itself too, and prod and production both count as unmarked
so a stray capital cannot tag the real instance.
Environment variables lose their prefix: PASSWORD, DB, ENV, ADDR, HOST, REPO,
TAG. The container namespaces them already, and this matches how the other
services here are configured.
PUID/PGID are the exception rather than UID/GID. UID is read-only in bash, so
a value set in .env would be silently replaced by the invoking shell's own and
compose's user: would ignore what was asked for.
Breaking for a running instance: the deployed .env has to be rewritten in the
same deploy, or the app will refuse to start on an unset PASSWORD.
Esa Kataja
c6a8532569