# Copyright The OpenTelemetry Authors
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import logging
import os
from urllib.parse import urlparse
from ddtrace.ext import SpanTypes as DatadogSpanTypes
from ddtrace.internal.writer import AgentWriter
from ddtrace.span import Span as DatadogSpan
import opentelemetry.trace as trace_api
from opentelemetry.sdk.trace import sampling
from opentelemetry.sdk.trace.export import SpanExporter, SpanExportResult
# pylint:disable=relative-beyond-top-level
from .constants import (
DD_ORIGIN,
ENV_KEY,
SAMPLE_RATE_METRIC_KEY,
SERVICE_NAME_TAG,
VERSION_KEY,
)
logger = logging.getLogger(__name__)
DEFAULT_AGENT_URL = "http://localhost:8126"
_INSTRUMENTATION_SPAN_TYPES = {
"opentelemetry.instrumentation.aiohttp-client": DatadogSpanTypes.HTTP,
"opentelemetry.instrumentation.asgi": DatadogSpanTypes.WEB,
"opentelemetry.instrumentation.dbapi": DatadogSpanTypes.SQL,
"opentelemetry.instrumentation.django": DatadogSpanTypes.WEB,
"opentelemetry.instrumentation.flask": DatadogSpanTypes.WEB,
"opentelemetry.instrumentation.grpc": DatadogSpanTypes.GRPC,
"opentelemetry.instrumentation.jinja2": DatadogSpanTypes.TEMPLATE,
"opentelemetry.instrumentation.mysql": DatadogSpanTypes.SQL,
"opentelemetry.instrumentation.psycopg2": DatadogSpanTypes.SQL,
"opentelemetry.instrumentation.pymemcache": DatadogSpanTypes.CACHE,
"opentelemetry.instrumentation.pymongo": DatadogSpanTypes.MONGODB,
"opentelemetry.instrumentation.pymysql": DatadogSpanTypes.SQL,
"opentelemetry.instrumentation.redis": DatadogSpanTypes.REDIS,
"opentelemetry.instrumentation.requests": DatadogSpanTypes.HTTP,
"opentelemetry.instrumentation.sqlalchemy": DatadogSpanTypes.SQL,
"opentelemetry.instrumentation.wsgi": DatadogSpanTypes.WEB,
}
[docs]class DatadogSpanExporter(SpanExporter):
"""Datadog span exporter for OpenTelemetry.
Args:
agent_url: The url of the Datadog Agent or use ``DD_TRACE_AGENT_URL`` environment variable
service: The service name to be used for the application or use ``DD_SERVICE`` environment variable
env: Set the application’s environment or use ``DD_ENV`` environment variable
version: Set the application’s version or use ``DD_VERSION`` environment variable
tags: A list of default tags to be added to every span or use ``DD_TAGS`` environment variable
"""
def __init__(
self, agent_url=None, service=None, env=None, version=None, tags=None
):
self.agent_url = (
agent_url
if agent_url
else os.environ.get("DD_TRACE_AGENT_URL", DEFAULT_AGENT_URL)
)
self.service = service or os.environ.get("DD_SERVICE")
self.env = env or os.environ.get("DD_ENV")
self.version = version or os.environ.get("DD_VERSION")
self.tags = _parse_tags_str(tags or os.environ.get("DD_TAGS"))
self._agent_writer = None
@property
def agent_writer(self):
if self._agent_writer is None:
url_parsed = urlparse(self.agent_url)
if url_parsed.scheme in ("http", "https"):
self._agent_writer = AgentWriter(
hostname=url_parsed.hostname,
port=url_parsed.port,
https=url_parsed.scheme == "https",
)
elif url_parsed.scheme == "unix":
self._agent_writer = AgentWriter(uds_path=url_parsed.path)
else:
raise ValueError(
"Unknown scheme `%s` for agent URL" % url_parsed.scheme
)
return self._agent_writer
[docs] def export(self, spans):
datadog_spans = self._translate_to_datadog(spans)
self.agent_writer.write(spans=datadog_spans)
return SpanExportResult.SUCCESS
[docs] def shutdown(self):
if self.agent_writer.started:
self.agent_writer.stop()
self.agent_writer.join(self.agent_writer.exit_timeout)
# pylint: disable=too-many-locals
def _translate_to_datadog(self, spans):
datadog_spans = []
for span in spans:
trace_id, parent_id, span_id = _get_trace_ids(span)
# datadog Span is initialized with a reference to the tracer which is
# used to record the span when it is finished. We can skip ignore this
# because we are not calling the finish method and explictly set the
# duration.
tracer = None
# extract resource attributes to be used as tags as well as potential service name
[
resource_tags,
resource_service_name,
] = _extract_tags_from_resource(span.resource)
datadog_span = DatadogSpan(
tracer,
_get_span_name(span),
service=resource_service_name or self.service,
resource=_get_resource(span),
span_type=_get_span_type(span),
trace_id=trace_id,
span_id=span_id,
parent_id=parent_id,
)
datadog_span.start_ns = span.start_time
datadog_span.duration_ns = span.end_time - span.start_time
if not span.status.is_ok:
datadog_span.error = 1
if span.status.description:
exc_type, exc_val = _get_exc_info(span)
# no mapping for error.stack since traceback not recorded
datadog_span.set_tag("error.msg", exc_val)
datadog_span.set_tag("error.type", exc_type)
# combine resource attributes and span attributes, don't modify existing span attributes
combined_span_tags = {}
combined_span_tags.update(resource_tags)
combined_span_tags.update(span.attributes)
datadog_span.set_tags(combined_span_tags)
# add configured env tag
if self.env is not None:
datadog_span.set_tag(ENV_KEY, self.env)
# add configured application version tag to only root span
if self.version is not None and parent_id == 0:
datadog_span.set_tag(VERSION_KEY, self.version)
# add configured global tags
datadog_span.set_tags(self.tags)
# add origin to root span
origin = _get_origin(span)
if origin and parent_id == 0:
datadog_span.set_tag(DD_ORIGIN, origin)
sampling_rate = _get_sampling_rate(span)
if sampling_rate is not None:
datadog_span.set_metric(SAMPLE_RATE_METRIC_KEY, sampling_rate)
# span events and span links are not supported
datadog_spans.append(datadog_span)
return datadog_spans
def _get_trace_ids(span):
"""Extract tracer ids from span"""
ctx = span.get_span_context()
trace_id = ctx.trace_id
span_id = ctx.span_id
if isinstance(span.parent, trace_api.Span):
parent_id = span.parent.get_span_context().span_id
elif isinstance(span.parent, trace_api.SpanContext):
parent_id = span.parent.span_id
else:
parent_id = 0
trace_id = _convert_trace_id_uint64(trace_id)
return trace_id, parent_id, span_id
def _convert_trace_id_uint64(otel_id):
"""Convert 128-bit int used for trace_id to 64-bit unsigned int"""
return otel_id & 0xFFFFFFFFFFFFFFFF
def _get_span_name(span):
"""Get span name by using instrumentation and kind while backing off to
span.name
"""
instrumentation_name = (
span.instrumentation_info.name if span.instrumentation_info else None
)
span_kind_name = span.kind.name if span.kind else None
name = (
"{}.{}".format(instrumentation_name, span_kind_name)
if instrumentation_name and span_kind_name
else span.name
)
return name
def _get_resource(span):
"""Get resource name for span"""
if "http.method" in span.attributes:
route = span.attributes.get("http.route")
return (
span.attributes["http.method"] + " " + route
if route
else span.attributes["http.method"]
)
return span.name
def _get_span_type(span):
"""Get Datadog span type"""
instrumentation_name = (
span.instrumentation_info.name if span.instrumentation_info else None
)
span_type = _INSTRUMENTATION_SPAN_TYPES.get(instrumentation_name)
return span_type
def _get_exc_info(span):
"""Parse span status description for exception type and value"""
exc_type, exc_val = span.status.description.split(":", 1)
return exc_type, exc_val.strip()
def _get_origin(span):
ctx = span.get_span_context()
origin = ctx.trace_state.get(DD_ORIGIN)
return origin
def _get_sampling_rate(span):
ctx = span.get_span_context()
return (
span.sampler.rate
if ctx.trace_flags.sampled
and isinstance(span.sampler, sampling.TraceIdRatioBased)
else None
)
def _parse_tags_str(tags_str):
"""Parse a string of tags typically provided via environment variables.
The expected string is of the form::
"key1:value1,key2:value2"
:param tags_str: A string of the above form to parse tags from.
:return: A dict containing the tags that were parsed.
"""
parsed_tags = {}
if not tags_str:
return parsed_tags
for tag in tags_str.split(","):
try:
key, value = tag.split(":", 1)
# Validate the tag
if key == "" or value == "" or value.endswith(":"):
raise ValueError
except ValueError:
logger.error(
"Malformed tag in tag pair '%s' from tag string '%s'.",
tag,
tags_str,
)
else:
parsed_tags[key] = value
return parsed_tags
def _extract_tags_from_resource(resource):
"""Parse tags from resource.attributes, except service.name which
has special significance within datadog"""
tags = {}
service_name = None
if not (resource and getattr(resource, "attributes", None)):
return [tags, service_name]
for attribute_key, attribute_value in resource.attributes.items():
if attribute_key == SERVICE_NAME_TAG:
service_name = attribute_value
else:
tags[attribute_key] = attribute_value
return [tags, service_name]