Integrate catadog image as proxy service between agent and library

.env

@@ -1,8 +1,8 @@
 SKIP_SIMPLECOV=1
-DD_AGENT_HOST=testagent
+DD_AGENT_HOST=catadog
 DD_API_KEY=00000000000000000000000000000000
 DD_METRIC_AGENT_PORT=8125
-DD_TRACE_AGENT_PORT=9126
+DD_TRACE_AGENT_PORT=8128
 
 # Values are used for proxying from APM Test Agent to real Datadog Agent
 DD_REAL_AGENT_HOST=ddagent

docker-compose.yml

@@ -13,11 +13,12 @@ services:
       - presto
       - redis
       - testagent
+      - catadog
     env_file: ./.env
     environment: &common-environment
       BUNDLE_GEMFILE: /app/Gemfile-2.5
-      DD_AGENT_HOST: testagent
-      DD_TRACE_AGENT_PORT: 9126
+      DD_AGENT_HOST: catadog
+      DD_TRACE_AGENT_PORT: 8128
       TEST_DATADOG_INTEGRATION: 1
       TEST_ELASTICSEARCH_HOST: elasticsearch
       TEST_MEMCACHED_HOST: memcached
@@ -201,23 +202,30 @@ services:
       - "127.0.0.1:${DD_REAL_AGENT_PORT}:8126"
     volumes:
       - ddagent_var_run:/var/run/datadog
-
   testagent:
     image: ghcr.io/datadog/dd-apm-test-agent/ddapm-test-agent:v1.12.0
     ports:
-        - "127.0.0.1:${DD_TRACE_AGENT_PORT}:9126"
+      - "127.0.0.1:9126:9126"
     depends_on:
       - ddagent
     env_file: ./.env
     environment:
-        - LOG_LEVEL=DEBUG
-        - TRACE_LANGUAGE=ruby
-        - DD_TRACE_AGENT_URL=http://${DD_REAL_AGENT_HOST}:${DD_REAL_AGENT_PORT}
-        - PORT=${DD_TRACE_AGENT_PORT}
-        - DD_POOL_TRACE_CHECK_FAILURES=true
-        - DD_DISABLE_ERROR_RESPONSES=true
-        - ENABLED_CHECKS=trace_content_length,trace_stall,meta_tracer_version_header,trace_count_header,trace_peer_service,trace_dd_service
-
+      - LOG_LEVEL=DEBUG
+      - TRACE_LANGUAGE=ruby
+      - DD_TRACE_AGENT_URL=http://${DD_REAL_AGENT_HOST}:${DD_REAL_AGENT_PORT}
+      - PORT=9126
+      - DD_POOL_TRACE_CHECK_FAILURES=true
+      - DD_DISABLE_ERROR_RESPONSES=true
+      - ENABLED_CHECKS=trace_content_length,trace_stall,meta_tracer_version_header,trace_count_header,trace_peer_service,trace_dd_service
+  catadog:
+    image: ghcr.io/datadog/catadog:latest
+    command: --agent-host testagent --agent-port 9126
+    ports:
+      - "127.0.0.1:${DD_TRACE_AGENT_PORT}:8128"
+    depends_on:
+      - testagent
+    environment:
+      - PORT=${DD_TRACE_AGENT_PORT}
   elasticsearch:
     image: elasticsearch:8.1.3
     expose:

docs/DevelopmentGuide.md

@@ -179,10 +179,23 @@ The actionable in this case would be to ensure that the thread created in `worke
 
 Depending on the situation, the thread in question might need to be forced to terminate. It's recommended to have a mechanism in place to terminate it (a shared variable that changes value when the thread should exit), but as a last resort, `Thread#terminate` forces the thread to finish. Keep in mind that regardless of the termination method, `Thread#join` must be called to ensure that the thread has completely finished its shutdown process.
 
+**Catadog**
+
+The catadog Docker image is a composable and extensible tool for development, testing, and diagnosis. The catadog container
+runs alongside the Ruby tracer and forwards trace information to the APM Test Agent.
+
+Catadog also emits helpful logging, which can be viewed in local testing or in CircleCI as a job step for tracer and contrib
+tests. Locally, to get catadog logs:
+
+    $ docker-compose logs -f catadog
+
+Read more about catadog:
+https://github.com/datadog/catadog#readme
+
 **The APM Test Agent**
 
 The APM test agent emulates the APM endpoints of the Datadog Agent. The Test Agent container
-runs alongside the Ruby tracer locally and in CI, handles all traces during test runs and performs a number
+runs alongside catadog and in CI, handles all traces during test runs and performs a number
 of 'Trace Checks'. For more information on these checks, see:
 https://github.com/DataDog/dd-apm-test-agent#trace-invariant-checks