Freckle.App.OpenTelemetry

Application tracing via https://opentelemetry.io/

data App = App
  { -- ...
  , appTracer :: Tracer
  }

instance HasTracer App where
  tracerL = lens appTracer $ x y -> x { appTracer = y }

loadApp f = do
  -- ...
  withTracerProvider $ tracerProvider -> do
    let appTracer = makeTracer tracerProvider "my-app" tracerOptions
    f App {..}

You may need to do this even if you don't plan to manually trace things, in order to satisfy the MonadTracer constraint required by functions like runDB. If you don't need this feature, and don't plan on running an otel-collector, set OTEL_TRACES_EXPORTER=none in the environment, which makes all tracing a no-op.

In the future, it should be possible to use OTEL_SDK_DISABLED for the same purpose. See https://github.com/iand675/hs-opentelemetry/issues/60.

Documentation

class HasTracer s where

A small utility lens for extracting a Tracer from a larger data type

This will generally be most useful as a means of implementing getTracer

Since: hs-opentelemetry-api-0.0.1.0

Methods

tracerL :: Lens' s Tracer

data Tracer

The Tracer is responsible for creating Spans.

Each Tracer should be associated with the library or application that it instruments.

Instances

Show Tracer

Defined in OpenTelemetry.Internal.Trace.Types

Methods

showsPrec :: Int -> Tracer -> ShowS

show :: Tracer -> String

showList :: [Tracer] -> ShowS

Effects

class Monad m => MonadTracer (m :: Type -> Type) where

This is generally scoped by Monad stack to do different things

Methods

getTracer :: m Tracer

Instances

HasTracer app => MonadTracer (AppExample app)

Defined in Freckle.App.Test

Methods

getTracer :: AppExample app Tracer

(Monad m, HasTracer app) => MonadTracer (AppT app m)

Defined in Freckle.App

Methods

getTracer :: AppT app m Tracer

MonadTracer m => MonadTracer (IdentityT m)

Defined in OpenTelemetry.Trace.Monad

Methods

getTracer :: IdentityT m Tracer

MonadTracer m => MonadTracer (ReaderT r m)

Defined in OpenTelemetry.Trace.Monad

Methods

getTracer :: ReaderT r m Tracer

inSpan :: (MonadUnliftIO m, MonadTracer m, HasCallStack) => Text -> SpanArguments -> m a -> m a

defaultSpanArguments :: SpanArguments

Smart constructor for SpanArguments providing reasonable values for most Spans created that are internal to an application.

Defaults:

• kind: Internal
• attributes: []
• links: []
• startTime: Nothing (getTimestamp will be called upon Span creation)

Querying

withTraceIdContext :: (MonadIO m, MonadMask m) => m a -> m a

getCurrentTraceId :: MonadIO m => m (Maybe TraceId)

getCurrentTraceIdAsDatadog :: MonadIO m => m (Maybe Word64)

getCurrentSpanContext :: MonadIO m => m (Maybe SpanContext)

Setup

withTracerProvider :: MonadUnliftIO m => (TracerProvider -> m a) -> m a

Tracer

makeTracer :: TracerProvider -> InstrumentationLibrary -> TracerOptions -> Tracer

tracerOptions :: TracerOptions

Default Tracer options