Add Jaeger exporter (#174)

This adds a Jeager exporter for OpenTelemetry.  This exporter is based
on https://github.com/census-instrumentation/opencensus-python/tree/master/contrib/opencensus-ext-jaeger.

The exporter uses thrift and can be configured to send data to the agent and
also to a remote collector.

There is a long discussion going on about how to include generated files
in the repo, so for now just put them here.

.flake8

@@ -1,2 +1,3 @@
 [flake8]
 ignore = E501,W503,E203
+exclude = .svn,CVS,.bzr,.hg,.git,__pycache__,.tox,ext/opentelemetry-ext-jaeger/src/opentelemetry/ext/jaeger/gen/,ext/opentelemetry-ext-jaeger/build/*

.isort.cfg

@@ -12,3 +12,4 @@ line_length=79
 ; )
 ; docs: https://github.com/timothycrosley/isort#multi-line-output-modes
 multi_line_output=3
+skip_glob=ext/opentelemetry-ext-jaeger/src/opentelemetry/ext/jaeger/gen/*

.pylintrc

@@ -7,7 +7,7 @@ extension-pkg-whitelist=
 
 # Add files or directories to the blacklist. They should be base names, not
 # paths.
-ignore=CVS
+ignore=CVS,gen
 
 # Add files or directories matching the regex patterns to the blacklist. The
 # regex matches against base names, not paths.

ext/opentelemetry-ext-jaeger/README.rst

@@ -0,0 +1,67 @@
+OpenTelemetry Jaeger Exporter
+=============================
+
+Installation
+------------
+
+::
+
+     pip install opentelemetry-ext-jaeger
+
+
+Usage
+-----
+
+The **OpenTelemetry Jaeger Exporter** allows to export `OpenTelemetry`_ traces to `Jaeger`_.
+This exporter always send traces to the configured agent using Thrift compact protocol over UDP.
+An optional collector can be configured, in this case Thrift binary protocol over HTTP is used.
+gRPC is still not supported by this implementation.
+
+
+.. _Jaeger: https://www.jaegertracing.io/
+.. _OpenTelemetry: https://github.com/opentelemetry/opentelemetry-python/
+
+.. code:: python
+
+    from opentelemetry import trace
+    from opentelemetry.ext import jaeger
+    from opentelemetry.sdk.trace import Tracer
+    from opentelemetry.sdk.trace.export import BatchExportSpanProcessor
+
+    trace.set_preferred_tracer_implementation(lambda T: Tracer())
+    tracer = trace.tracer()
+
+    # create a JaegerSpanExporter
+    jaeger_exporter = jaeger.JaegerSpanExporter(
+        service_name='my-helloworld-service',
+        # configure agent
+        agent_host_name='localhost',
+        agent_port=6831,
+        # optional: configure also collector
+        # collector_host_name='localhost',
+        # collector_port=14268,
+        # collector_endpoint='/api/traces?format=jaeger.thrift',
+        # username=xxxx, # optional
+        # password=xxxx, # optional
+    )
+
+    # Create a BatchExportSpanProcessor and add the exporter to it
+    span_processor = BatchExportSpanProcessor(jaeger_exporter)
+
+    # add to the tracer
+    tracer.add_span_processor(span_processor)
+
+    with tracer.start_span('foo'):
+        print('Hello world!')
+
+    # shutdown the span processor
+    # TODO: this has to be improved so user doesn't need to call it manually
+    span_processor.shutdown()
+
+The `examples <./examples>`_ folder contains more elaborated examples.
+
+References
+----------
+
+* `Jaeger <https://www.jaegertracing.io/>`_
+* `OpenTelemetry Project <https://opentelemetry.io/>`_

ext/opentelemetry-ext-jaeger/examples/jaeger_exporter_example.py

@@ -0,0 +1,51 @@
+import time
+
+from opentelemetry import trace
+from opentelemetry.ext import jaeger
+from opentelemetry.sdk.trace import Tracer
+from opentelemetry.sdk.trace.export import BatchExportSpanProcessor
+
+trace.set_preferred_tracer_implementation(lambda T: Tracer())
+tracer = trace.tracer()
+
+# create a JaegerSpanExporter
+jaeger_exporter = jaeger.JaegerSpanExporter(
+    service_name="my-helloworld-service",
+    # configure agent
+    agent_host_name="localhost",
+    agent_port=6831,
+    # optional: configure also collector
+    # collector_host_name="localhost",
+    # collector_port=14268,
+    # collector_endpoint="/api/traces?format=jaeger.thrift",
+    # username=xxxx, # optional
+    # password=xxxx, # optional
+)
+
+# create a BatchExportSpanProcessor and add the exporter to it
+span_processor = BatchExportSpanProcessor(jaeger_exporter)
+
+# add to the tracer
+tracer.add_span_processor(span_processor)
+
+# create some spans for testing
+with tracer.start_span("foo") as foo:
+    time.sleep(0.1)
+    foo.set_attribute("my_atribbute", True)
+    foo.add_event("event in foo", {"name": "foo1"})
+    with tracer.start_span("bar") as bar:
+        time.sleep(0.2)
+        bar.set_attribute("speed", 100.0)
+        bar.add_link(foo.get_context())
+
+        with tracer.start_span("baz") as baz:
+            time.sleep(0.3)
+            baz.set_attribute("name", "mauricio")
+
+        time.sleep(0.2)
+
+    time.sleep(0.1)
+
+# shutdown the span processor
+# TODO: this has to be improved so user doesn't need to call it manually
+span_processor.shutdown()

ext/opentelemetry-ext-jaeger/setup.cfg

@@ -0,0 +1,47 @@
+# Copyright 2019, 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.
+#
+[metadata]
+name = opentelemetry-ext-jaeger
+description = Jaeger Exporter for OpenTelemetry
+long_description = file: README.rst
+long_description_content_type = text/x-rst
+author = OpenTelemetry Authors
+author_email = cncf-opentelemetry-contributors@lists.cncf.io
+url = https://github.com/open-telemetry/opentelemetry-python/ext/opentelemetry-ext-jaeger
+platforms = any
+license = Apache-2.0
+classifiers =
+    Development Status :: 3 - Alpha
+    Intended Audience :: Developers
+    License :: OSI Approved :: Apache Software License
+    Programming Language :: Python
+    Programming Language :: Python :: 3
+    Programming Language :: Python :: 3.4
+    Programming Language :: Python :: 3.5
+    Programming Language :: Python :: 3.6
+    Programming Language :: Python :: 3.7
+
+[options]
+python_requires = >=3.4
+package_dir=
+    =src
+packages=find_namespace:
+install_requires =
+    thrift >= 0.10.0
+    opentelemetry-api
+    opentelemetry-sdk
+
+[options.packages.find]
+where = src

ext/opentelemetry-ext-jaeger/setup.py

@@ -0,0 +1,26 @@
+# Copyright 2019, 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 os
+
+import setuptools
+
+BASE_DIR = os.path.dirname(__file__)
+VERSION_FILENAME = os.path.join(
+    BASE_DIR, "src", "opentelemetry", "ext", "jaeger", "version.py"
+)
+PACKAGE_INFO = {}
+with open(VERSION_FILENAME) as f:
+    exec(f.read(), PACKAGE_INFO)
+
+setuptools.setup(version=PACKAGE_INFO["__version__"])