Routemaster Client v0.3.0 Routemaster.Director View Source

The Director module provides functions to interact with the Routemaster event bus REST API. It’s a client and each function will perform an authenticated HTTP request to the even bus server.

Link to this section Summary

Types

http_status()

Functions

all_subscribers()

Retrieves the subscribers currently known to the server and their metadata

all_topics()

Retrieves the current topics from the server and their metadata. It performs a GET /topics request

delete_topic(name)

Deletes an owned topic from the bus server

get_topic(name)

Returns a single topic, by name. It will fetch all topics over the network and filter them locally

subscribe(topics, options \\ [])

Creates a subscription on the bus server. Arguments

unsubscribe(topic_name)

Unsubscribes this consumer from the provided topic. Returns :ok on success and {:error, 404} if either the topic doesn’t exist or we are not subscribed to it

unsubscribe_all()

Unsubscribes this consumer from all current topics

Link to this section Types

http_status()

http_status() :: non_neg_integer()

Link to this section Functions

all_subscribers()

all_subscribers() :: {:ok, [map()]} | {:error, http_status()}

Retrieves the subscribers currently known to the server and their metadata.

all_topics()

all_topics() :: {:ok, [map()]} | {:error, http_status()}

Retrieves the current topics from the server and their metadata. It performs a GET /topics request.

Examples

case Director.all_topics() do
  {:ok, topics} ->
    "The bus is handling #{length topics} topics"
  {:error, status} ->
    "Couldn't get topics, HTTP error #{status}"
end

delete_topic(name)

delete_topic(binary()) :: :ok | {:error, http_status()}

Deletes an owned topic from the bus server.

get_topic(name)

get_topic(binary()) :: {:ok, map()} | {:error, http_status()}

Returns a single topic, by name. It will fetch all topics over the network and filter them locally.

subscribe(topics, options \\ [])

subscribe([binary()], Keyword.t()) :: :ok | {:error, http_status()}

Creates a subscription on the bus server. Arguments:

topics: a list of valid topic names. This must always be the complete set of topics this subscriber wants to receive, because any missing previously-submitted topics will see their subscriptions deleted.
options, an optional keyword list with:
- max: How many events can be batched together on delivery. The server will never deliver batches larger than this number. Default: 100.
- timeout: How long the server can wait before delivering the events (ms). Once this timeout is reached, a batch is delivered even if incomplete. This indirectly controls the max latency of event delivery. Default: 500ms.

Subscribe to two topics, and dispatch events within 2 seconds, in batches no larger than 300 events:

Director.subscribe(~w(users orders), max: 300, timeout: 2_000)

unsubscribe(topic_name)

unsubscribe(binary()) :: :ok | {:error, http_status()}

Unsubscribes this consumer from the provided topic. Returns :ok on success and {:error, 404} if either the topic doesn’t exist or we are not subscribed to it.

unsubscribe_all()

unsubscribe_all() :: :ok | {:error, http_status()}

Unsubscribes this consumer from all current topics.