opencensus_absinthe

v0.1.0

opencensus_absinthe v0.1.0 Opencensus.Absinthe

Extends Absinthe to automatically create opencensus spans. Designed to work with whatever is producing spans upstream, e.g. Opencensus.Plug.

Installation

Assuming you're using Absinthe.Plug:

Add opencensus_absinthe to your deps in mix.exs, using a tighter version constraint than:

{:absinthe_plug, ">= 0.0.0"},
{:opencensus_absinthe, ">= 0.0.0"},

Add a :pipeline to your Absinthe.Plug.opts/0 to have it call Opencensus.Absinthe.Plug.traced_pipeline/2. If you're using Phoenix.Router.forward/4, for example:

forward(
  path,
  Absinthe.Plug,
  # ... existing config ...
  pipeline: {Opencensus.Absinthe.Plug, :traced_pipeline}
)

If you already have a pipeline, you can define your own and call both to insert their phases. To work with ApolloTracing, for example:

def your_custom_pipeline(config, pipeline_opts \ []) do
  config
  |> Absinthe.Plug.default_pipeline(pipeline_opts)
  |> ApolloTracing.Pipeline.add_phases()
  |> Opencensus.Absinthe.add_phases()
end

Worst case, you'll need to copy the code from the current pipeline target and add a call to Opencensus.Absinthe.add_phases/1 as above.

Link to this section Summary

Functions

add_phases(pipeline)

Add tracing phases to an existing pipeline for blueprint resolution.

middleware(middleware, field, object)

Add tracing middleware for field resolution.

Link to this section Functions

Link to this function

add_phases(pipeline) 
add_phases(Absinthe.Pipeline.t()) :: Absinthe.Pipeline.t()

Add tracing phases to an existing pipeline for blueprint resolution.

pipeline =
  Absinthe.Pipeline.for_document(schema, pipeline_opts)
  |> Opencensus.Absinthe.add_phases()
Link to this function

middleware(middleware, field, object) 
middleware(
  [Absinthe.Middleware.spec(), ...],
  Absinthe.Type.Field.t(),
  Absinthe.Type.Object.t()
) :: [Absinthe.Middleware.spec(), ...]

Add tracing middleware for field resolution.

Specifically, prepends Opencensus.Absinthe.Middleware to the middleware chain if the field has trace or absinthe_telemetry set in its metadata, e.g.:

  field :users, list_of(:user), meta: [trace: true] do
    middleware(Middleware.Authorize, "superadmin")
    resolve(&Resolvers.Account.all_users/2)
  end