bri.config

Two layers into one plain map: conf.edn → APP_* env. No config classes, no watchers, no remote sources.

(def cfg (config/load!))   ; reads a file (and the env), no more
(:port cfg)                ; a plain map — get/get-in like any other

This is the cfg you saw on the golden page in the tutorial: a top-level def that constructs a value, with no other I/O.

conf.edn and profiles

Profiles are a :profiles section, not a file family:

{:port 3000
 :db   {:host "localhost" :pool-size 5}
 :profiles
 {:dev  {}
  :test {:db {:host "test-db"}}}}

APP_PROFILE selects the overlay (default dev; cljgo dev sets dev, cljgo test sets test). The selected profile deep-merges over the base map.

Environment overlay

APP_* variables win over the file. The mapping is deterministic: __ (double underscore) separates path segments, single _ joins words —

APP_PORT=8080            → [:port]
APP_DB__POOL_SIZE=9      → [:db :pool-size]

Values coerce: all-digit → integer, true/false → boolean, else string. Durations and sizes are numbers (seconds, bytes) — no stringly-typed "5m".

Secrets are env-only

APP_SESSION_KEY and friends never belong in conf.edn. (APP_PROFILE and APP_SESSION_KEY are selectors/secrets, not config data — they don’t appear in the map.)

The schema (optional, enforced when present)

conf.schema.edn — generated minimal by cljgo new --template web, delete it to go schemaless:

{[:port] {:type :int :required true :default 3000}}

• :default is the lowest layer (file, profile, and env all beat it).
• :required missing from every layer → load! throws before any server/pool/worker starts, naming the key. Misconfigured deploys must not boot.
• :type (:int :number :string :boolean :keyword) mismatches name the key and the layer that supplied the bad value.

2 a.m. debugging

$ cljgo config
profile: dev
  [:db :host]       "localhost"  <- file
  [:db :pool-size]  9            <- env
  [:port]           3000         <- file

Every key, its effective value, and the layer that won (default < file < profile < env).

Where next

• Tutorial — the full 15-minute walkthrough where config/load! fits
• bri.http — the server that consumes (:port cfg) and APP_SESSION_KEY
• bri.html — pages and forms