Add support for configuring and testing tracing

This adds support for configuring tracing in Zuul along with
basic documentation of the configuration.

It also adds test infrastructure that runs a gRPC-based collector
so that we can test tracing end-to-end, and exercises a simple
test span.

Change-Id: I4744dc2416460a2981f2c90eb3e48ac93ec94964

1 files changed, 12 insertions, 0 deletions

diff --git a/tests/base.py b/tests/base.py
index cebcf2e1f..317d9d175 100644
--- a/tests/base.py
+++ b/tests/base.py
@@ -125,6 +125,8 @@ from zuul.lib.logutil import get_annotated_logger
 
 import tests.fakegithub
 import tests.fakegitlab
+from tests.otlp_fixture import OTLPFixture
+import opentelemetry.sdk.trace.export
 
 FIXTURE_DIR = os.path.join(os.path.dirname(__file__), 'fixtures')
 
@@ -4911,6 +4913,15 @@ class ZuulTestCase(BaseTestCase):
         if 'database' in config.sections():
             _setup_fixture(config, 'database')
 
+        if 'tracing' in config.sections():
+            self.otlp = OTLPFixture()
+            self.useFixture(self.otlp)
+            self.useFixture(fixtures.MonkeyPatch(
+                'zuul.lib.tracing.Tracing.processor_class',
+                opentelemetry.sdk.trace.export.SimpleSpanProcessor))
+            config.set('tracing', 'endpoint',
+                       f'http://localhost:{self.otlp.port}')
+
         if not self.setupSimpleLayout(config):
             tenant_config = None
             for cfg_attr in ('tenant_config', 'tenant_config_script'):
@@ -5197,6 +5208,7 @@ class ZuulTestCase(BaseTestCase):
                    and not t.name.startswith('Dummy-')
                    and not t.name.startswith('pydevd.')
                    and not t.name.startswith('ptvsd.')
+                   and not t.name.startswith('OTLPFixture_')
                    ]
         if len(threads) > 1:
             thread_map = dict(map(lambda x: (x.ident, x.name),