[etcd]: add etcd distributed tracing flags (#10666)

* [etcd]: add etcd distributed tracing flags

Signed-off-by: Ugur Ozturk <ugurozturk918@gmail.com>

* [etcd]: add etcd distributed tracing flags - fix

Signed-off-by: Ugur Ozturk <ugurozturk918@gmail.com>

* [etcd]: add etcd distributed tracing flags - fix

Signed-off-by: Ugur Ozturk <ugurozturk918@gmail.com>

---------

Signed-off-by: Ugur Ozturk <ugurozturk918@gmail.com>

inventory/sample/group_vars/etcd.yml

@@ -24,3 +24,12 @@
 ### ETCD: disable peer client cert authentication.
 # This affects ETCD_PEER_CLIENT_CERT_AUTH variable
 # etcd_peer_client_auth: true
+
+## Enable distributed tracing
+## To enable this experimental feature, set the etcd_experimental_enable_distributed_tracing: true, along with the
+## etcd_experimental_distributed_tracing_sample_rate to choose how many samples to collect per million spans,
+## the default sampling rate is 0 https://etcd.io/docs/v3.5/op-guide/monitoring/#distributed-tracing
+# etcd_experimental_enable_distributed_tracing: false
+# etcd_experimental_distributed_tracing_sample_rate: 100
+# etcd_experimental_distributed_tracing_address: "localhost:4317"
+# etcd_experimental_distributed_tracing_service_name: etcd

roles/etcd/defaults/main.yml

@@ -120,3 +120,10 @@ etcd_experimental_initial_corrupt_check: true
 # may contain some private data, so it is recommended to set it to false
 # in the production environment.
 unsafe_show_logs: false
+
+# Enable distributed tracing
+# https://etcd.io/docs/v3.5/op-guide/monitoring/#distributed-tracing
+etcd_experimental_enable_distributed_tracing: false
+etcd_experimental_distributed_tracing_sample_rate: 100
+etcd_experimental_distributed_tracing_address: "localhost:4317"
+etcd_experimental_distributed_tracing_service_name: etcd

roles/etcd/templates/etcd.env.j2

@@ -68,3 +68,11 @@ ETCDCTL_CERT={{ etcd_cert_dir }}/admin-{{ inventory_hostname }}.pem
 # ETCD 3.5.x issue
 # https://groups.google.com/a/kubernetes.io/g/dev/c/B7gJs88XtQc/m/rSgNOzV2BwAJ?utm_medium=email&utm_source=footer
 ETCD_EXPERIMENTAL_INITIAL_CORRUPT_CHECK={{ etcd_experimental_initial_corrupt_check }}
+
+{% if etcd_experimental_enable_distributed_tracing %}
+ETCD_EXPERIMENTAL_ENABLE_DISTRIBUTED_TRACING=true
+ETCD_EXPERIMENTAL_DISTRIBUTED_TRACING_SAMPLE_RATE={{ etcd_experimental_distributed_tracing_sample_rate }}
+ETCD_EXPERIMENTAL_DISTRIBUTED_TRACING_ADDRESS={{ etcd_experimental_distributed_tracing_address }}
+ETCD_EXPERIMENTAL_DISTRIBUTED_TRACING_SERVICE_NAME={{ etcd_experimental_distributed_tracing_service_name }}
+ETCD_EXPERIMENTAL_DISTRIBUTED_TRACING_INSTANCE_ID={{ etcd_member_name }}
+{% endif %}