Distillery's REPLACE_OS_VARS is cool, but it can provide only binary values.
This tiny script will cast your runtime, ENV-based configuration to
proper values (atoms, integers, booleans).
Have you ever wanted to set the logger level in runtime?
# config/prod.exs
config :logger, level: "${LOG_LEVEL}"
# LOG_LEVEL=warn
iex([email protected])3> Logger.warn "hello"
** (FunctionClauseError) no function clause matching in Logger.level_to_number/1
The following arguments were given to Logger.level_to_number/1:
# 1
"warn"
Now you can!
# config/prod.exs
config :logger, level: {:atom, "${LOG_LEVEL}"}
# LOG_LEVEL=warn
iex([email protected])3> Logger.warn "hello"
13:22:25.461 [warn] hello
All you need to do is copy a single file, add one line to release config and adjust the prod configuration.
# config/prod.exs
use Mix.Config
config :hello,
str_var: "${STR_VAR}",
int_var: {:integer, "${INT_VAR}"},
bool_var: {:boolean, "${BOOL_VAR}"}2. Copy typonf.sh into rel/hooks/typonf.sh
# this code snippet is here so you don't miss it
mkdir -p rel/hooks
vim rel/hooks/typonf.sh# rel/config.exs
environment :prod do
# ...
set post_configure_hook: "rel/hooks/typonf.sh"
end# build release
mix release
# see it working
STR_VAR=hi INT_VAR=123 BOOL_VAR=true REPLACE_OS_VARS=true _build/prod/rel/hello/bin/hello console
iex([email protected])1> Application.get_env(:hello, :str_var)
"hi"
iex([email protected])2> Application.get_env(:hello, :int_var)
123
iex([email protected])3> Application.get_env(:hello, :bool_var)
true