docker run -d -p 9411:9411 openzipkin/zipkin

services:
  zipkin:
    image: openzipkin/zipkin
    ports:
      - 9411:9411

from opentelemetry import trace
from opentelemetry.sdk.trace import TracerProvider
from opentelemetry.sdk.trace.export import BatchSpanProcessor
from opentelemetry.exporter.zipkin.json import ZipkinExporter

provider = TracerProvider()
provider.add_span_processor(
    BatchSpanProcessor(ZipkinExporter(endpoint="http://localhost:9411/api/v2/spans"))
)
trace.set_tracer_provider(provider)

import requests, time
from opentelemetry import trace

def test_order_trace_in_zipkin():
    with use_tracer():
        create_order(items=[item])

    trace.get_tracer_provider().force_flush(timeout_millis=5000)
    time.sleep(0.5)

    resp = requests.get(
        "http://localhost:9411/api/v2/traces",
        params={"serviceName": "orders", "spanName": "order.create",
                "lookback": 60000, "limit": 1},
    )
    traces = resp.json()  # list of lists of spans
    assert len(traces) == 1
    spans = traces[0]
    create_span = next(s for s in spans if s["name"] == "order.create")
    assert create_span["tags"]["order.item_count"] == "1"  # tags are strings in Zipkin V2

b3: {TraceId}-{SpanId}-{SamplingState}-{ParentSpanId}

b3: 80f198ee56343ba864fe8b2a57d3eff7-e457b5a2e4d86bd1-1-05e3ac9a4f6e3b90

def test_b3_single_header_propagates():
    headers = {"b3": f"{trace_id}-{span_id}-1-{parent_id}"}
    resp = requests.get("http://localhost:8080/orders", headers=headers)

    # Verify downstream service preserved trace_id
    time.sleep(0.5)
    traces = requests.get(
        "http://localhost:9411/api/v2/trace/" + trace_id
    ).json()
    assert any(s["traceId"] == trace_id for s in traces)

def test_orders_calls_payments():
    # Exercise the cross-service flow
    create_order_with_payment()
    trace.get_tracer_provider().force_flush(5000)
    time.sleep(2.0)  # dependency aggregation can be lazy

    end_ts = int(time.time() * 1000)
    deps = requests.get(
        "http://localhost:9411/api/v2/dependencies",
        params={"endTs": end_ts, "lookback": 60000},
    ).json()

    pair = next(
        (d for d in deps if d["parent"] == "orders" and d["child"] == "payments"),
        None,
    )
    assert pair is not None
    assert pair["callCount"] >= 1

service_name = f"orders-test-{uuid4()}"
# ... use this service_name in SDK config + Zipkin queries ...