A simple configuration API and functions for managing config files.
This module is deprecated, use the modules Config and Config.Reader from Elixir's standard library instead.
Most commonly, this module is used to define your own configuration:
use Mix.Config
config :root_key,
key1: "value1",
key2: "value2"
import_config "#{Mix.env()}.exs"
use Mix.Config will import the functions config/2, config/3 and import_config/1 to help you manage your configuration.
Once a configuration is written to a file, the functions in this module can be used to read and merge said configuration. The eval!/2 function allows you to evaluate a given configuration file and the merge/2 function allows you to deep merge the results of multiple configurations. Those functions should not be invoked by users writing configurations but rather by library authors.
The most common use of Mix.Config is to define application configuration so that Application.get_env/3 and other Application functions can be used to retrieve or further change them.
Application config files are typically placed in the config/ directory of your Mix projects. For example, the following config
# config/config.exs config :my_app, :key, "value"
will be automatically loaded by Mix and persisted into the :my_app's application environment, which can be accessed in its source code as follows:
"value" = Application.fetch_env!(:my_app, :key1)
Configures the given root_key.
Configures the given key for the given root_key.
Evaluates the given configuration file.
Imports configuration from the given file or files.
Merges two configurations.
Persists the given configuration by modifying the configured applications environment.
Reads the configuration file.
Configures the given root_key.
Keyword lists are always deep merged.
The given opts are merged into the existing configuration for the given root_key. Conflicting keys are overridden by the ones specified in opts. For example, the application configuration below
config :logger, level: :warn, backends: [:console] config :logger, level: :info, truncate: 1024
will have a final configuration for :logger of:
[level: :info, backends: [:console], truncate: 1024]
Configures the given key for the given root_key.
Keyword lists are always deep merged.
The given opts are merged into the existing values for key in the given root_key. Conflicting keys are overridden by the ones specified in opts. For example, the application configuration below
config :ecto, Repo, log_level: :warn, adapter: Ecto.Adapters.Postgres config :ecto, Repo, log_level: :info, pool_size: 10
will have a final value of the configuration for the Repo key in the :ecto application of:
[log_level: :info, pool_size: 10, adapter: Ecto.Adapters.Postgres]
Evaluates the given configuration file.
It accepts a list of imported_paths that should raise if attempted to be imported again (to avoid recursive imports).
It returns a tuple with the configuration and the imported paths.
Imports configuration from the given file or files.
If path_or_wildcard is a wildcard, then all the files matching that wildcard will be imported; if no file matches the wildcard, no errors are raised. If path_or_wildcard is not a wildcard but a path to a single file, then that file is imported; in case the file doesn't exist, an error is raised.
If path/wildcard is a relative path/wildcard, it will be expanded relatively to the directory the current configuration file is in.
This is often used to emulate configuration across environments:
import_config "#{Mix.env()}.exs"
Or to import files from children in umbrella projects:
import_config "../apps/*/config/config.exs"
Merges two configurations.
The configurations are merged together with the values in the second one having higher preference than the first in case of conflicts. In case both values are set to keyword lists, it deep merges them.
iex> Mix.Config.merge([app: [k: :v1]], [app: [k: :v2]]) [app: [k: :v2]] iex> Mix.Config.merge([app: [k: [v1: 1, v2: 2]]], [app: [k: [v2: :a, v3: :b]]]) [app: [k: [v1: 1, v2: :a, v3: :b]]] iex> Mix.Config.merge([app1: []], [app2: []]) [app1: [], app2: []]
Persists the given configuration by modifying the configured applications environment.
config should be a list of {app, app_config} tuples or a %{app => app_config} map where app are the applications to be configured and app_config are the configuration (as key-value pairs) for each of those applications.
Returns the configured applications.
Mix.Config.persist(logger: [level: :error], my_app: [my_config: 1]) #=> [:logger, :my_app]
read!(Path.t(), [Path.t()]) :: keyword()
Reads the configuration file.
The same as eval!/2 but only returns the configuration in the given file, without returning the imported paths.
It exists for convenience purposes. For example, you could invoke it inside your mix.exs to read some external data you decided to move to a configuration file:
subsystem: Mix.Config.read!("rel/subsystem.exs")
© 2012 Plataformatec
Licensed under the Apache License, Version 2.0.
https://hexdocs.pm/mix/1.11.2/Mix.Config.html