feat(otel): export traces to Tempo, add memory_limiter

compose.yml

@@ -643,7 +643,7 @@ services:
     volumes:
       - ./infra/otel/otel-collector.yml:/etc/otelcol-contrib/config.yaml:ro
     depends_on:
-      - jaeger
+      - tempo
       - loki
     healthcheck:
       test:

infra/otel/otel-collector.yml

@@ -1,5 +1,5 @@
 # OpenTelemetry Collector configuration
-# Fan-out: traces → Jaeger, metrics → Prometheus scrape, logs → Loki
+# Fan-out: traces → Tempo, metrics → Prometheus scrape, logs → Loki
 
 receivers:
   otlp:
@@ -14,6 +14,11 @@ processors:
     timeout: 5s
     send_batch_size: 1024
 
+  memory_limiter:
+    check_interval: 5s
+    limit_mib: 256
+    spike_limit_mib: 64
+
   resource:
     attributes:
       - key: deployment.environment
@@ -21,8 +26,8 @@ processors:
         action: upsert
 
 exporters:
-  otlp_grpc/jaeger:
-    endpoint: jaeger:4317
+  otlp_http/tempo:
+    endpoint: http://tempo:4318
     tls:
       insecure: true
 
@@ -44,13 +49,13 @@ service:
   pipelines:
     traces:
       receivers: [otlp]
-      processors: [batch, resource]
-      exporters: [otlp_grpc/jaeger]
+      processors: [memory_limiter, batch, resource]
+      exporters: [otlp_http/tempo]
     metrics:
       receivers: [otlp]
-      processors: [batch]
+      processors: [memory_limiter, batch]
       exporters: [prometheus]
     logs:
       receivers: [otlp]
-      processors: [batch, resource]
+      processors: [memory_limiter, batch, resource]
       exporters: [otlp_http/loki]

tests/test_observability.py

@@ -127,3 +127,15 @@ class TestPerServiceStages:
         for container, label in self.EXPECTED.items():
             assert f'container="{container}"' in text, f"no match stage for {container}"
             assert label in text, f"no {label} extraction for {container}"
+
+
+class TestOtelTempo:
+    def test_otel_exports_traces_to_tempo(self):
+        cfg = yaml.safe_load((ROOT / "infra/otel/otel-collector.yml").read_text())
+        exporters = cfg["exporters"]
+        assert "otlp_http/tempo" in exporters
+        assert exporters["otlp_http/tempo"]["endpoint"] == "http://tempo:4318"
+        assert "otlp_grpc/jaeger" not in exporters
+        traces = cfg["service"]["pipelines"]["traces"]
+        assert "otlp_http/tempo" in traces["exporters"]
+        assert "memory_limiter" in traces["processors"]