Specs

setup(specs :: specs()) :: {list(), list(), list()}

Set up pipeline infrastructure based on a list of queue/topic/subscription specs. A spec looks like this:

{Action, [{OtherAction, [filters]}, ...]}

An action with no subscriptions can simply be specified as

Action

For example, let's say you have 4 actions – A (do some things), B & C (do some things; depend on A's success), and D (handles all errors). The spec for this would be:

[
  :A,
  B: [A: [status: :ok]],
  C: [A: [status: :ok]],
  D: [A: [status: :error], B: [status: :error], C: [status: :error]]
]

The above spec will create:

• 4 SQS queues (sequins-a, sequins-c, sequins-c, sequins-d)
• 4 SNS topics (sequins-a, sequins-c, sequins-c, sequins-d)
• 5 SNS subscriptions
  • sequins-a -> sequins-b ({"status": "ok"})
  • sequins-a -> sequins-c ({"status": "ok"})
  • sequins-a -> sequins-d ({"status": "error"})
  • sequins-b -> sequins-d ({"status": "error"})
  • sequins-c -> sequins-d ({"status": "error"})

The default prefix for created resources is sequins, but can be changed by configuring the :sequins application's :prefix attribute. The options passed to the supervisor on startup can be specified by setting the :supervisor_opts attribute to a keyword list of valid Supervisor options.

In addition to :status, subscriptions can filter on any attribute added to the attrs hash by the Sequins.Pipeline.Action.process/2 callback.