Slightly evolved but not-yet-working OpenTelemetry

More usefully, including docker config for starting a CORS enabled
OTLP collector so we don't have to use zipkin.

config/otel_dev/docker-compose.yaml

@@ -0,0 +1,23 @@
+version: "2"
+services:
+ # Jaeger
+ jaeger-all-in-one:
+   image: jaegertracing/all-in-one:latest
+   ports:
+     - "16686:16686"
+     - "14268"
+     - "14250"
+ # Collector
+ collector-gateway:
+   image: otel/opentelemetry-collector:latest
+   volumes:
+     - ./collector-gateway.yaml:/etc/collector-gateway.yaml
+   command: [ "--config=/etc/collector-gateway.yaml" ]
+   ports:
+     - "1888:1888"   # pprof extension
+     - "13133:13133" # health_check extension
+     - "4317:4317"        # OTLP gRPC receiver
+     - "4318:4318"        # OTLP HTTP receiver
+     - "55670:55679" # zpages extension
+   depends_on:
+     - jaeger-all-in-one