CNCF OpenTelemetry Passthrough
All the application code here is available from the docs git repository.
This example is the simplest possible configuration of tremor with support for CNCF OpenTelemetry interception and distribution. It shows the very basic building blocks:
- CNCF OpenTelemetry Onramp
- CNCF OpenTelemetry Offramp
- Deployment configuration file
External open telemetry clients can use port
4316 to send OpenTelemetry logs, traces and metrics
through tremor. Tremor prints the json mapping to standard out and forwards the events to the
The onramp we use is the
otel CNCF OpenTeletry onramp listening on
a non-standard CNCF OpenTelemetry port
4316, it receives protocol buffer messages over gRPC on this
port. The log, metric and trace events received are converted to tremor's value system and passed through
a passthrough pipeline to the CNCF OpenTelemetry sink. The sink will try to connect to a downstream CNCF
OpenTelemetry endpoint. In this workshop we will use the well known OpenTelemetry port of
4317 for our
sink and run the standard OpenTelemetry collector on this port using a collector configuration.
- id: otlp
type: otel # Use the OpenTelemetry gRPC listener source
codec: json # Json is the only supported value
port: 4316 # The TCP port to listen on
host: "0.0.0.0" # The IP address to bind on ( all interfaces in this case )
It connects to a passthrough pipeline. This pipeline forwards any received observability events downstream unchanged.
select event from in into out;
We connect the passthrough output events into an OpenTelemetry sink which distributes them to a downstream OpenTelemetry service.
- id: otlp
codec: json # Jsn is the only supported value
The binding expresses these relations and gives deployment connectivity graph.
- id: example
Finally the mapping instanciates the binding with the given name and instance variable to activate the elements of the binding.
select event from in into out
Command line testing during logic development
Use any compliant OpenTelemetry instrumented application and configure the
server to our source on port
4316 instead of the default
For convenience, use the provided docker-compose.yaml to start and stop tremor and the opentelemetry collector as follows:
$ docker compose up
$ docker compose stop