RefInspector v1.3.0 RefInspector.Config View Source

Module to simplify access to configuration values with default values.

There should be no configuration required to start using :ref_inspector if you rely on the default values:

config :ref_inspector,
  database_files: ["referers.yml"],
  database_path: Application.app_dir(:ref_inspector, "priv"),
  http_opts: [],
  remote_urls: [{"referers.yml", "https://s3-eu-west-1.amazonaws.com/snowplow-hosted-assets/third-party/referer-parser/referers-latest.yml"}],
  startup_silent: false,
  startup_sync: false,
  yaml_file_reader: {:yamerl_constr, :file, [[:str_node_as_binary]]}

The default :database_path is evaluated at runtime and not compiled into a release!

How to Configure

There are two ways to change the configuration values with the preferred way depending on your environment and personal taste.

Static Configuration

If you can ensure the configuration are static and not dependent on i.e. the server your application is running on, you can use a static approach by modifying your config.exs file:

config :ref_inspector,
  database_files: ["referers_search.yml", "referers_social.yml"],
  database_path: "/path/to/ref_inspector/database_files"

Dynamic Configuration

If a compile time configuration is not possible or does not match the usual approach taken in your application you can use a runtime approach.

This is done by defining an initializer module that will automatically be called by RefInspector.Supervisor upon startup/restart. The configuration is expected to consist of a {mod, fun} or {mod, fun, args} tuple:

# {mod, fun}
config :ref_inspector,
  init: {MyInitModule, :my_init_mf}

# {mod, fun, args}
config :ref_inspector,
  init: {MyInitModule, :my_init_mfa, [:foo, :bar]}

defmodule MyInitModule do
  @spec my_init_mf() :: :ok
  def my_init_mf(), do: my_init_mfa(:foo, :bar)

  @spec my_init_mfa(atom, atom) :: :ok
  def my_init_mfa(:foo, :bar) do
    priv_dir = Application.app_dir(:my_app, "priv")

    Application.put_env(:ref_inspector, :database_path, priv_dir)
  end
end

The function is required to always return :ok.

Startup Behaviour

Databases are loaded asynchronously when starting the application using a :reload cast. This default behaviour can lead to the first parsing calls to work with an empty database and therefore not return the results you expect.

You can change this behaviour to have the application force a synchronous database loading during the initial startup:

config :ref_inspector,
  startup_sync: true

Starting Silently

When starting the application you will receive warnings if the database is not available. If you want to hide these messages you can configure the startup the be completely silent:

config :ref_inspector,
  startup_silent: true

This will automatically be set when calling the mix download task.

Database Configuration

Configuring the database to use can be done using three related values:

  • :database_files
  • :database_path
  • :remote_urls

The :database_path is the directory to look for when loading the databases. It is also the place where RefInspector.Downloader stores a copy of the configured files.

For the actual files loaded there is :database_files, a list of filenames to load in the order specified. All files are expected to be inside the configured database path.

When downloading the databases through RefInspector.Downloader the value :remote_urls is of utmost importance. It defines where each file is located.

config :ref_inspector,
  remote_urls: [
    "http://example.com/database.yml"
    {"database_local.yml", "http://example.com/database_remote.yml"}
  ]

To configure a remote database name you can either define a plain URL. It will be stored locally under the filename that is extracted from the url. In above example that would be "database.yml".

If the remote and local names match you can configure a {local, remote} tuple to deactivate the automatic name extraction.

Download Configuration

Using the default configuration all download requests for your database files are done using :hackney. To pass custom configuration values to hackney you can use the key :http_opts:

config :ref_inspector,
  http_opts: [proxy: "http://mycompanyproxy.com"]

Please see :hackney.request/5 for a complete list of available options.

If you want to change the library used to download the databases you can configure a module implementing the RefInspector.Downloader.Adapter behaviour:

config :ref_inspector,
  downloader_adapter: MyDownloaderAdapter

YAML File Reader Configuration

By default the library :yamerl will be used to read and decode the yaml database files. You can configure this reader to be a custom module:

config :ref_inspector,
  yaml_file_reader: {module, function}

config :ref_inspector,
  yaml_file_reader: {module, function, extra_args}

The configured module will receive the file to read as the first argument with any optionally configured extra arguments after that.

Link to this section Summary

Functions

Returns the list of configured database files.

Returns the configured database path.

Returns the default list of database files.

Returns whether the remote database matches the default.

Returns the default list of database urls.

Returns the configured downloader adapter module.

Provides access to configuration values with optional environment lookup.

Calls the optionally configured init method.

Returns the {mod, fun, extra_args} to be used when reading a yaml file.

Returns the remote urls of the database file.

Link to this section Functions

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database_files()

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database_files() :: list()

Returns the list of configured database files.

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database_path()

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database_path() :: String.t()

Returns the configured database path.

If the path is not defined the priv dir of :ref_inspector as returned by Application.app_dir(:ref_inspector, "priv") will be used.

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default_files()

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default_files() :: [binary()]

Returns the default list of database files.

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default_remote_database?()

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default_remote_database?() :: boolean()

Returns whether the remote database matches the default.

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default_urls()

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default_urls() :: [{binary(), binary()}]

Returns the default list of database urls.

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downloader_adapter()

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downloader_adapter() :: module()

Returns the configured downloader adapter module.

The modules is expected to adhere to the behaviour defined in RefInspector.Downloader.Adapter.

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get(key, default \\ nil)

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get(atom(), term()) :: term()

Provides access to configuration values with optional environment lookup.

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init_env()

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init_env() :: :ok

Calls the optionally configured init method.

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yaml_file_reader()

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yaml_file_reader() :: {module(), atom(), [term()]}

Returns the {mod, fun, extra_args} to be used when reading a yaml file.

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yaml_urls()

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yaml_urls() :: [String.t() | {String.t(), String.t()}]

Returns the remote urls of the database file.