Fix containerd tracing with containerd 2.x (#13630)

* fix(containerd): pass tracing settings as OpenTelemetry environment variables

* fix(containerd): address review on tracing

* fix(containerd): drop tracing comments

roles/container-engine/containerd/templates/config.toml.j2

@@ -91,15 +91,3 @@ oom_score = {{ containerd_oom_score }}
 
   [plugins."io.containerd.nri.v1.nri"]
     disable = {{ 'false' if nri_enabled else 'true' }}
-
-{% if containerd_tracing_enabled %}
-  [plugins."io.containerd.tracing.processor.v1.otlp"]
-    endpoint = "{{ containerd_tracing_endpoint }}"
-    protocol = "{{ containerd_tracing_protocol }}"
-{% if containerd_tracing_protocol == "grpc" %}
-    insecure = false
-{% endif %}
-  [plugins."io.containerd.internal.v1.tracing"]
-    sampling_ratio = {{ containerd_tracing_sampling_ratio }}
-    service_name = "{{ containerd_tracing_service_name }}"
-{% endif %}

roles/container-engine/containerd/templates/containerd.service.j2

@@ -40,6 +40,13 @@ OOMScoreAdjust=-999
 {% if kube_reserved is defined and kube_reserved|bool %}
 Slice={{ kube_reserved_cgroups_for_service_slice }}
 {% endif %}
+{% if containerd_tracing_enabled and containerd_version is version('2.0.0', '>=') %}
+Environment="OTEL_EXPORTER_OTLP_ENDPOINT={{ containerd_tracing_endpoint }}"
+Environment="OTEL_EXPORTER_OTLP_PROTOCOL={{ containerd_tracing_protocol }}"
+Environment="OTEL_SERVICE_NAME={{ containerd_tracing_service_name }}"
+Environment="OTEL_TRACES_SAMPLER=parentbased_traceidratio"
+Environment="OTEL_TRACES_SAMPLER_ARG={{ containerd_tracing_sampling_ratio }}"
+{% endif %}
 
 [Install]
 WantedBy=multi-user.target