Add workload tracing to Mimir (#84)

* workload traces

* fix syntax

* remove git

* better desc

metadata.yaml

@@ -56,11 +56,17 @@ requires:
     description: |
       Certificate and key files for securing Mimir communications with TLS.
 
-  tracing:
+  charm-tracing:
     interface: tracing
     limit: 1
     description: |
-      Enables sending traces to the tracing backend.
+      Enables sending charm traces to a distributed tracing backend such as Tempo.
+
+  workload-tracing:
+    interface: tracing
+    limit: 1
+    description: |
+      Enables sending workload traces to a distributed tracing backend such as Tempo.
 
 provides:
   mimir-cluster:

requirements.txt

@@ -1,5 +1,5 @@
 ops
-cosl
+cosl>=0.0.43
 pydantic
 # crossplane is a package from nginxinc to interact with the Nginx config
 crossplane

src/charm.py

@@ -15,14 +15,15 @@
 import os
 import shutil
 import socket
-from typing import Any, Optional
+from typing import Any
 from urllib.parse import urlparse
 
 import cosl.coordinated_workers.nginx
 import ops
 from charms.grafana_k8s.v0.grafana_source import GrafanaSourceProvider
 from charms.prometheus_k8s.v1.prometheus_remote_write import PrometheusRemoteWriteProvider
 from charms.tempo_coordinator_k8s.v0.charm_tracing import trace_charm
+from charms.tempo_coordinator_k8s.v0.tracing import charm_tracing_config
 from charms.traefik_k8s.v2.ingress import IngressPerAppReadyEvent, IngressPerAppRequirer
 from cosl.coordinated_workers.coordinator import Coordinator
 from ops.model import ModelError
@@ -39,8 +40,8 @@
 
 
 @trace_charm(
-    tracing_endpoint="tempo_endpoint",
-    server_cert="server_cert_path",
+    tracing_endpoint="charm_tracing_endpoint",
+    server_cert="server_ca_cert",
     extra_types=[
         Coordinator,
     ],
@@ -71,11 +72,17 @@ def __init__(self, *args: Any):
                 "grafana-dashboards": "grafana-dashboards-provider",
                 "logging": "logging-consumer",
                 "metrics": "self-metrics-endpoint",
-                "tracing": "tracing",
+                "charm-tracing": "charm-tracing",
+                "workload-tracing": "workload-tracing",
                 "s3": "s3",
             },
             nginx_config=NginxConfig().config,
             workers_config=MimirConfig().config,
+            workload_tracing_protocols=["jaeger_thrift_http"],
+        )
+
+        self.charm_tracing_endpoint, self.server_ca_cert = charm_tracing_config(
+            self.coordinator.charm_tracing, cosl.coordinated_workers.nginx.CA_CERT_PATH
         )
 
         if port := urlparse(self.internal_url).port:
@@ -134,19 +141,6 @@ def hostname(self) -> str:
         """Unit's hostname."""
         return socket.getfqdn()
 
-    @property
-    def tempo_endpoint(self) -> Optional[str]:
-        """Tempo endpoint for charm tracing."""
-        if self.coordinator.tracing.is_ready():
-            return self.coordinator.tracing.get_endpoint(protocol="otlp_http")
-        else:
-            return None
-
-    @property
-    def server_cert_path(self) -> Optional[str]:
-        """Server certificate path for tls tracing."""
-        return cosl.coordinated_workers.nginx.CERT_PATH
-
     @property
     def internal_url(self) -> str:
         """Returns workload's FQDN. Used for ingress."""