goth v1.2.0 Goth.Config behaviour
Goth.Config is a GenServer that holds the current configuration.
This configuration is loaded from one of four places:
- a JSON string passed in via your application's config
- a ENV variable passed in via your application's config
- The Application Default Credentials, as defined by https://developers.google.com/identity/protocols/application-default-credentials
- an
init/1callback on a custom config module. This init function is passed the current config and must return an{:ok, config}tuple
The Goth.Config server exists mostly for other parts of your application
(or other libraries) to pull the current configuration state,
via Goth.Config.get/1. If necessary, you can also set config values via
Goth.Config.set/2
Link to this section Summary
Functions
Returns a specification to start this module under a supervisor
Retrieve a value from the config
Invoked when the server is started. start_link/3 or start/3 will
block until it returns
Set a value in the config
Callbacks
A callback executed when the Goth.Config server starts
Link to this section Functions
add_config(config)
child_spec(init_arg)
Returns a specification to start this module under a supervisor.
See Supervisor.
get(key)
Retrieve a value from the config.
get(account, key)
init(envs)
Invoked when the server is started. start_link/3 or start/3 will
block until it returns.
init_arg is the argument term (second argument) passed to start_link/3.
Returning {:ok, state} will cause start_link/3 to return
{:ok, pid} and the process to enter its loop.
Returning {:ok, state, timeout} is similar to {:ok, state}
except handle_info(:timeout, state) will be called after timeout
milliseconds if no messages are received within the timeout.
Returning {:ok, state, :hibernate} is similar to {:ok, state}
except the process is hibernated before entering the loop. See
c:handle_call/3 for more information on hibernation.
Returning {:ok, state, {:continue, continue}} is similar to
{:ok, state} except that immediately after entering the loop
the c:handle_continue/2 callback will be invoked with the value
continue as first argument.
Returning :ignore will cause start_link/3 to return :ignore and
the process will exit normally without entering the loop or calling
c:terminate/2. If used when part of a supervision tree the parent
supervisor will not fail to start nor immediately try to restart the
GenServer. The remainder of the supervision tree will be started
and so the GenServer should not be required by other processes.
It can be started later with Supervisor.restart_child/2 as the child
specification is saved in the parent supervisor. The main use cases for
this are:
- The
GenServeris disabled by configuration but might be enabled later. - An error occurred and it will be handled by a different mechanism than the
Supervisor. Likely this approach involves callingSupervisor.restart_child/2after a delay to attempt a restart.
Returning {:stop, reason} will cause start_link/3 to return
{:error, reason} and the process to exit with reason reason without
entering the loop or calling c:terminate/2.
Callback implementation for GenServer.init/1.
map_config(config)
set(key, value)
Set a value in the config.
set(account, key, value)
start_link(envs)
Link to this section Callbacks
init(config) (optional)
A callback executed when the Goth.Config server starts.
The sole argument is the :goth configuration as stored in the
application environment. It must return {:ok, keyword} with the updated
list of configuration.
To have your module's init/1 callback called at startup, add your module
as the :config_module in the application environment:
config :goth, config_module: MyConfig