Module: Wurk::API::Flows

Defined in:
lib/wurk/api/flows.rb

Overview

One route: read a flow.

A producer that posted a graph needs to know how far it got, and a fid is the only thing it holds — so this answers by fid and nothing else. There is no listing: the flows index is a dashboard affordance for a human who lost an id, and paging a machine client through every flow in the deployment is not a question a producer has.

Nor is there a write. Abandonment is an operator decision made with the graph on screen (slice 11 decision 4), and the dashboard is where that screen is; a producer that could abandon its own flows over HTTP is one bad retry away from killing a run that was merely slow.

Reads through Flow::Status, the same view the dashboard uses, for the reason every other observe-plane route reads through an inspector: a second reader of the flow key schema is a second thing to keep in step with the completion scripts that write it.

Constant Summary collapse

TABLE = 
[
  [:get, '/flows/:fid', :read, :show]
].freeze

Class Method Summary collapse

Class Method Details

.draw(router) ⇒ Object 



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# File 'lib/wurk/api/flows.rb', line 34

def draw(router)
  TABLE.each do |verb, pattern, scope, handler|
    router.public_send(verb, pattern, scope: scope) do |request|
      public_send(handler, request)
    rescue Validation::Invalid => e
      Problem.from(e, instance: request.path)
    end
  end
end

.not_found(request, fid) ⇒ Object

Expiry is named because it is the likeliest answer for a producer whose fid used to work: a flow is kept on the batch clock and then goes, and a client that assumed otherwise is the one reading this.



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# File 'lib/wurk/api/flows.rb', line 55

def not_found(request, fid)
  Problem.render(
    Problem::FLOW_NOT_FOUND,
    status: 404,
    detail: "No flow has fid #{fid}; it was never created, or it has expired.",
    instance: request.path,
    fid: fid
  )
end

.show(request) ⇒ Object 



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# File 'lib/wurk/api/flows.rb', line 44

def show(request)
  fid = Validation.fid!(request.path_params[:fid])
  status = ::Wurk::Flow::Status.new(fid)
  return not_found(request, fid) unless status.exists?

  Response.json(200, Serializers.flow(status))
end