Ever wanted to read Configurations.jl from environment variables? Here you go 🙂
using Configurations
@option struct Opt1
a::Bool
b::Union{Nothing, Int} = nothing
end
@option struct Opt2
a::Opt1
b::String
end
using ConfigurationsENV
# without an explicit `env` argument to `from_env`, the global `ENV` is used
env = Dict(
"PREFIX_A_A" => "true",
"PREFIX_A_B" => "",
"PREFIX_B" => "hello world",
)
config = from_env(Opt2, env, prefix="PREFIX_", separator="_")
# Opt2(Opt1(true, nothing), "hello world")
to_env(config, prefix=">") # separator defaults to "__", prefix to ""
# OrderedCollections.OrderedDict{String, Any} with 3 entries:
# ">A__A" => true
# ">A__B" => nothing
# ">B" => "hello world"In case you just want to parse a subset of the options fields from environment variables, use return_dict=true.
env = Dict("PREFIX__A__A" => "true")
nested_dict = from_env(Opt2, env, prefix="PREFIX__", return_dict=true)
# DataStructures.DefaultDict{String, Any, typeof(ConfigurationsENV.RecursiveDict)} with 1 entry:
# "a" => DefaultDict{String, Any, typeof(RecursiveDict)}("a"=>true)This dict can then be merged with other sources of parameters like TOML files or dicts.
from_dict(Opt2, merge(nested_dict, Dict("b" => "works")))
# Opt2(Opt1(true, nothing), "works")