Elixir v1.11.0-dev Config.Reader View Source

API for reading config files defined with Config.

As a provider

Config.Reader can also be used as a Config.Provider. When used as a provider, it expects a single argument: the configuration path (as outlined in Config.Provider.config_path/0) for the file to be read and loaded during the system boot.

For example, if you expect the target system to have a config file in an absolute path, you can configure your mix release as:

config_providers: [{Config.Reader, "/etc/config.exs"}]

Or if you want to read a custom path inside the release:

config_provider: [{Config.Reader, {:system, "RELEASE_ROOT", "/config.exs"}}]

You can also pass a keyword list of options to the reader, where the :path is a required key:

config_providers: [
  {Config.Reader,
   path: "/etc/config.exs",
   env: :prod,
   imports: :disabled}
]

Note by default Mix releases supports runtime configuration via a config/runtime.exs. If a config/runtime.exs exists in your application, it is automatically copied inside the release and automatically set as a config provider.

Link to this section Summary

Functions

Evaluates the configuration contents for the given file.

Merges two configurations.

Reads the configuration file.

Reads the given configuration file and returns the configuration with its imports.

Link to this section Functions

Link to this function

eval!(file, contents, opts \\ [])

View Source (since 1.11.0)

Specs

eval!(Path.t(), binary(), keyword()) :: keyword()

Evaluates the configuration contents for the given file.

Accepts the same options as read!/2.

Link to this function

merge(config1, config2)

View Source (since 1.9.0)

Specs

merge(keyword(), keyword()) :: keyword()

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.

Examples

iex> Config.Reader.merge([app: [k: :v1]], [app: [k: :v2]])
[app: [k: :v2]]

iex> Config.Reader.merge([app: [k: [v1: 1, v2: 2]]], [app: [k: [v2: :a, v3: :b]]])
[app: [k: [v1: 1, v2: :a, v3: :b]]]

iex> Config.Reader.merge([app1: []], [app2: []])
[app1: [], app2: []]
Link to this function

read!(file, opts \\ [])

View Source (since 1.9.0)

Specs

read!(Path.t(), keyword()) :: keyword()

Reads the configuration file.

Options

  • :imports - a list of already imported paths or :disabled to disable imports

  • :env - the environment the configuration file runs on. See Config.config_env/0 for sample usage

  • :target - the target the configuration file runs on. See Config.config_target/0 for sample usage

Link to this function

read_imports!(file, opts \\ [])

View Source (since 1.9.0)

Specs

read_imports!(Path.t(), keyword()) :: {keyword(), [Path.t()]}

Reads the given configuration file and returns the configuration with its imports.

Accepts the same options as read!/2. Although note the :imports option cannot be disabled in read_imports!/2.