chore(examples): close the S14 follow-ups (breaker-reset polling, runtime comments, gRPC span check)

CLAUDE.md

@@ -202,6 +202,8 @@ Do not use `gh cache delete --all`: it also removes the entries the current poli
     (`spring.grpc.client.channel.<name>.target`). Never `ServerBuilder` or `ManagedChannelBuilder` by hand.
     The protobuf plugin stays xolstice 0.6.1: the Boot-managed `io.github.ascopes` plugin fails under the
     UBI image's packaged Maven. .NET callers use the gRPC client factory (`AddGrpcClient`).
+    Traces come from the OTel Java agent alone: do not add a Micrometer tracing bridge, or Spring gRPC's
+    observation interceptor adds a second span per call.
 
 ## House test tools (prefer these; don't introduce alternatives)
 

_plans/examples-plan.md

@@ -191,7 +191,7 @@ Build 20 runnable examples referenced by the tutorial site, each demonstrating p
   - Debezium (example 04)
   - flagd (example 27)
 
-### Minikube Stack (optional, added later in the modernization plan)
+### Minikube Stack (optional; S9 ran Example 05 on minikube, Appendix R, and S10 on OpenShift Local, Appendix S)
 - **Base**: Istio + KEDA + Strimzi + CloudNativePG + LGTM (covered by `lgtm-minikube-stack`)
 - **Opt-ins**:
   - Apicurio (example 09)

_plans/s14-resilience-plan.md

@@ -170,3 +170,14 @@ slack; Polly's breaker state lives per typed client, so `/breaker-state` must re
 SmallRye FT annotations need CDI-intercepted calls (not `this.` calls); Spring gRPC's port and health defaults
 versus the compose wiring; the OTel agent and Spring gRPC's own observation both instrumenting gRPC (double spans);
 Conan cache churn if C++ dependencies change (they should not).
+
+Outcome (2026-10-15): the breaker windows, half-open rules, Polly's per-client state, CDI interception and the Spring
+gRPC defaults were all settled by the 111/111 matrix. The two left open are closed:
+
+- Reset wait: `verify.sh` no longer sleeps a fixed 11 s. It waits the 10 s open period, then calls `/with-breaker`
+  once a second until `/breaker-state` reports closed (at most 20 s), so the slack no longer depends on one
+  library's timing. Verified on all six languages.
+- Double spans: none. In Example 11 (Spring Boot) a `POST /orders` trace holds one gRPC CLIENT span in
+  order-service and one SERVER span in inventory-service, both from the OTel agent (`io.opentelemetry.grpc-1.6`),
+  the server span parented on the client span. Spring gRPC's observation interceptor creates no spans because
+  Micrometer Tracing is not on the classpath; adding a Micrometer tracing bridge would bring the duplicates back.

examples/01-cloud-native-principles/verify.sh

@@ -7,12 +7,11 @@ BASE="${BASE:-http://localhost:8080}"
 CURL_OPTS="${CURL_OPTS:-}"
 
 # Container operations go through these helpers so the checks do not hard-code
-# an engine. RUNTIME=openshift is added later: a ctr_target function will map
-# a container name (cndp-kafka, cndp-postgres, ...) to its pod and each helper
-# will call `oc exec` / `oc logs` instead.
+# an engine. This example runs on Docker Compose only (RUNTIME=docker); Example 05's
+# verify.sh shows the RUNTIME=kubernetes variant used on minikube and OpenShift Local.
 case "$RUNTIME" in
     docker) ;;
-    *) echo "RUNTIME=$RUNTIME not supported yet" >&2; exit 1 ;;
+    *) echo "RUNTIME=$RUNTIME not supported (docker)" >&2; exit 1 ;;
 esac
 ctr_exec()    { docker exec "$@"; }
 ctr_logs()    { docker logs "$@"; }

examples/02-communications/verify.sh

@@ -7,12 +7,11 @@ BASE="${BASE:-http://localhost:8080}"
 CURL_OPTS="${CURL_OPTS:-}"
 
 # Container operations go through these helpers so the checks do not hard-code
-# an engine. RUNTIME=openshift is added later: a ctr_target function will map
-# a container name (cndp-kafka, cndp-postgres, ...) to its pod and each helper
-# will call `oc exec` / `oc logs` instead.
+# an engine. This example runs on Docker Compose only (RUNTIME=docker); Example 05's
+# verify.sh shows the RUNTIME=kubernetes variant used on minikube and OpenShift Local.
 case "$RUNTIME" in
     docker) ;;
-    *) echo "RUNTIME=$RUNTIME not supported yet" >&2; exit 1 ;;
+    *) echo "RUNTIME=$RUNTIME not supported (docker)" >&2; exit 1 ;;
 esac
 ctr_exec()    { docker exec "$@"; }
 ctr_logs()    { docker logs "$@"; }

examples/03-composition/verify.sh

@@ -7,12 +7,11 @@ BASE="${BASE:-http://localhost:8080}"
 CURL_OPTS="${CURL_OPTS:-}"
 
 # Container operations go through these helpers so the checks do not hard-code
-# an engine. RUNTIME=openshift is added later: a ctr_target function will map
-# a container name (cndp-kafka, cndp-postgres, ...) to its pod and each helper
-# will call `oc exec` / `oc logs` instead.
+# an engine. This example runs on Docker Compose only (RUNTIME=docker); Example 05's
+# verify.sh shows the RUNTIME=kubernetes variant used on minikube and OpenShift Local.
 case "$RUNTIME" in
     docker) ;;
-    *) echo "RUNTIME=$RUNTIME not supported yet" >&2; exit 1 ;;
+    *) echo "RUNTIME=$RUNTIME not supported (docker)" >&2; exit 1 ;;
 esac
 ctr_exec()    { docker exec "$@"; }
 ctr_logs()    { docker logs "$@"; }

examples/04-data/verify.sh

@@ -8,12 +8,11 @@ CONNECT="${CONNECT:-http://localhost:8083}"
 CURL_OPTS="${CURL_OPTS:-}"
 
 # Container operations go through these helpers so the checks do not hard-code
-# an engine. RUNTIME=openshift is added later: a ctr_target function will map
-# a container name (cndp-kafka, cndp-postgres, ...) to its pod and each helper
-# will call `oc exec` / `oc logs` instead.
+# an engine. This example runs on Docker Compose only (RUNTIME=docker); Example 05's
+# verify.sh shows the RUNTIME=kubernetes variant used on minikube and OpenShift Local.
 case "$RUNTIME" in
     docker) ;;
-    *) echo "RUNTIME=$RUNTIME not supported yet" >&2; exit 1 ;;
+    *) echo "RUNTIME=$RUNTIME not supported (docker)" >&2; exit 1 ;;
 esac
 ctr_exec()    { docker exec "$@"; }
 ctr_logs()    { docker logs "$@"; }

examples/06-stream-processing/verify.sh

@@ -7,12 +7,11 @@ BASE="${BASE:-http://localhost:8080}"
 CURL_OPTS="${CURL_OPTS:-}"
 
 # Container operations go through these helpers so the checks do not hard-code
-# an engine. RUNTIME=openshift is added later: a ctr_target function will map
-# a container name (cndp-kafka, cndp-postgres, ...) to its pod and each helper
-# will call `oc exec` / `oc logs` instead.
+# an engine. This example runs on Docker Compose only (RUNTIME=docker); Example 05's
+# verify.sh shows the RUNTIME=kubernetes variant used on minikube and OpenShift Local.
 case "$RUNTIME" in
     docker) ;;
-    *) echo "RUNTIME=$RUNTIME not supported yet" >&2; exit 1 ;;
+    *) echo "RUNTIME=$RUNTIME not supported (docker)" >&2; exit 1 ;;
 esac
 ctr_exec()    { docker exec "$@"; }
 ctr_logs()    { docker logs "$@"; }

examples/09-api-registry/verify.sh

@@ -8,12 +8,11 @@ REGISTRY="${REGISTRY:-$BASE/apis/registry/v3}"
 CURL_OPTS="${CURL_OPTS:-}"
 
 # Container operations go through these helpers so the checks do not hard-code
-# an engine. RUNTIME=openshift is added later: a ctr_target function will map
-# a container name (cndp-kafka, cndp-postgres, ...) to its pod and each helper
-# will call `oc exec` / `oc logs` instead.
+# an engine. This example runs on Docker Compose only (RUNTIME=docker); Example 05's
+# verify.sh shows the RUNTIME=kubernetes variant used on minikube and OpenShift Local.
 case "$RUNTIME" in
     docker) ;;
-    *) echo "RUNTIME=$RUNTIME not supported yet" >&2; exit 1 ;;
+    *) echo "RUNTIME=$RUNTIME not supported (docker)" >&2; exit 1 ;;
 esac
 ctr_exec()    { docker exec "$@"; }
 ctr_logs()    { docker logs "$@"; }

examples/11-observability/verify.sh

@@ -8,12 +8,11 @@ TEMPO="${TEMPO:-http://localhost:3200}"
 CURL_OPTS="${CURL_OPTS:-}"
 
 # Container operations go through these helpers so the checks do not hard-code
-# an engine. RUNTIME=openshift is added later: a ctr_target function will map
-# a container name (cndp-kafka, cndp-postgres, ...) to its pod and each helper
-# will call `oc exec` / `oc logs` instead.
+# an engine. This example runs on Docker Compose only (RUNTIME=docker); Example 05's
+# verify.sh shows the RUNTIME=kubernetes variant used on minikube and OpenShift Local.
 case "$RUNTIME" in
     docker) ;;
-    *) echo "RUNTIME=$RUNTIME not supported yet" >&2; exit 1 ;;
+    *) echo "RUNTIME=$RUNTIME not supported (docker)" >&2; exit 1 ;;
 esac
 ctr_exec()    { docker exec "$@"; }
 ctr_logs()    { docker logs "$@"; }

examples/12-security/verify.sh

@@ -7,12 +7,11 @@ BASE="${BASE:-http://localhost:8080}"
 CURL_OPTS="${CURL_OPTS:-}"
 
 # Container operations go through these helpers so the checks do not hard-code
-# an engine. RUNTIME=openshift is added later: a ctr_target function will map
-# a container name (cndp-kafka, cndp-postgres, ...) to its pod and each helper
-# will call `oc exec` / `oc logs` instead.
+# an engine. This example runs on Docker Compose only (RUNTIME=docker); Example 05's
+# verify.sh shows the RUNTIME=kubernetes variant used on minikube and OpenShift Local.
 case "$RUNTIME" in
     docker) ;;
-    *) echo "RUNTIME=$RUNTIME not supported yet" >&2; exit 1 ;;
+    *) echo "RUNTIME=$RUNTIME not supported (docker)" >&2; exit 1 ;;
 esac
 ctr_exec()    { docker exec "$@"; }
 ctr_logs()    { docker logs "$@"; }

examples/16-websockets/verify.sh

@@ -9,12 +9,11 @@ POD2="${POD2:-http://localhost:8082}"
 CURL_OPTS="${CURL_OPTS:-}"
 
 # Container operations go through these helpers so the checks do not hard-code
-# an engine. RUNTIME=openshift is added later: a ctr_target function will map
-# a container name (cndp-kafka, cndp-postgres, ...) to its pod and each helper
-# will call `oc exec` / `oc logs` instead.
+# an engine. This example runs on Docker Compose only (RUNTIME=docker); Example 05's
+# verify.sh shows the RUNTIME=kubernetes variant used on minikube and OpenShift Local.
 case "$RUNTIME" in
     docker) ;;
-    *) echo "RUNTIME=$RUNTIME not supported yet" >&2; exit 1 ;;
+    *) echo "RUNTIME=$RUNTIME not supported (docker)" >&2; exit 1 ;;
 esac
 ctr_exec()    { docker exec "$@"; }
 ctr_logs()    { docker logs "$@"; }

examples/17-sagas/verify.sh

@@ -7,12 +7,11 @@ BASE="${BASE:-http://localhost:8080}"
 CURL_OPTS="${CURL_OPTS:-}"
 
 # Container operations go through these helpers so the checks do not hard-code
-# an engine. RUNTIME=openshift is added later: a ctr_target function will map
-# a container name (cndp-kafka, cndp-postgres, ...) to its pod and each helper
-# will call `oc exec` / `oc logs` instead.
+# an engine. This example runs on Docker Compose only (RUNTIME=docker); Example 05's
+# verify.sh shows the RUNTIME=kubernetes variant used on minikube and OpenShift Local.
 case "$RUNTIME" in
     docker) ;;
-    *) echo "RUNTIME=$RUNTIME not supported yet" >&2; exit 1 ;;
+    *) echo "RUNTIME=$RUNTIME not supported (docker)" >&2; exit 1 ;;
 esac
 ctr_exec()    { docker exec "$@"; }
 ctr_logs()    { docker logs "$@"; }

examples/18-errors/verify.sh

@@ -7,12 +7,11 @@ BASE="${BASE:-http://localhost:8080}"
 CURL_OPTS="${CURL_OPTS:-}"
 
 # Container operations go through these helpers so the checks do not hard-code
-# an engine. RUNTIME=openshift is added later: a ctr_target function will map
-# a container name (cndp-kafka, cndp-postgres, ...) to its pod and each helper
-# will call `oc exec` / `oc logs` instead.
+# an engine. This example runs on Docker Compose only (RUNTIME=docker); Example 05's
+# verify.sh shows the RUNTIME=kubernetes variant used on minikube and OpenShift Local.
 case "$RUNTIME" in
     docker) ;;
-    *) echo "RUNTIME=$RUNTIME not supported yet" >&2; exit 1 ;;
+    *) echo "RUNTIME=$RUNTIME not supported (docker)" >&2; exit 1 ;;
 esac
 ctr_exec()    { docker exec "$@"; }
 ctr_logs()    { docker logs "$@"; }

examples/19-ddd-hexagonal/verify.sh

@@ -7,12 +7,11 @@ BASE="${BASE:-http://localhost:8080}"
 CURL_OPTS="${CURL_OPTS:-}"
 
 # Container operations go through these helpers so the checks do not hard-code
-# an engine. RUNTIME=openshift is added later: a ctr_target function will map
-# a container name (cndp-kafka, cndp-postgres, ...) to its pod and each helper
-# will call `oc exec` / `oc logs` instead.
+# an engine. This example runs on Docker Compose only (RUNTIME=docker); Example 05's
+# verify.sh shows the RUNTIME=kubernetes variant used on minikube and OpenShift Local.
 case "$RUNTIME" in
     docker) ;;
-    *) echo "RUNTIME=$RUNTIME not supported yet" >&2; exit 1 ;;
+    *) echo "RUNTIME=$RUNTIME not supported (docker)" >&2; exit 1 ;;
 esac
 ctr_exec()    { docker exec "$@"; }
 ctr_logs()    { docker logs "$@"; }

examples/21-graceful-shutdown/verify.sh

@@ -7,12 +7,11 @@ BASE="${BASE:-http://localhost:8080}"
 CURL_OPTS="${CURL_OPTS:-}"
 
 # Container operations go through these helpers so the checks do not hard-code
-# an engine. RUNTIME=openshift is added later: a ctr_target function will map
-# a container name (cndp-kafka, cndp-postgres, ...) to its pod and each helper
-# will call `oc exec` / `oc logs` instead.
+# an engine. This example runs on Docker Compose only (RUNTIME=docker); Example 05's
+# verify.sh shows the RUNTIME=kubernetes variant used on minikube and OpenShift Local.
 case "$RUNTIME" in
     docker) ;;
-    *) echo "RUNTIME=$RUNTIME not supported yet" >&2; exit 1 ;;
+    *) echo "RUNTIME=$RUNTIME not supported (docker)" >&2; exit 1 ;;
 esac
 ctr_exec()    { docker exec "$@"; }
 ctr_logs()    { docker logs "$@"; }

examples/22-l7-routing/verify.sh

@@ -9,12 +9,11 @@ ROUTER="${ROUTER:-http://localhost:8090}"
 CURL_OPTS="${CURL_OPTS:-}"
 
 # Container operations go through these helpers so the checks do not hard-code
-# an engine. RUNTIME=openshift is added later: a ctr_target function will map
-# a container name (cndp-kafka, cndp-postgres, ...) to its pod and each helper
-# will call `oc exec` / `oc logs` instead.
+# an engine. This example runs on Docker Compose only (RUNTIME=docker); Example 05's
+# verify.sh shows the RUNTIME=kubernetes variant used on minikube and OpenShift Local.
 case "$RUNTIME" in
     docker) ;;
-    *) echo "RUNTIME=$RUNTIME not supported yet" >&2; exit 1 ;;
+    *) echo "RUNTIME=$RUNTIME not supported (docker)" >&2; exit 1 ;;
 esac
 ctr_exec()    { docker exec "$@"; }
 ctr_logs()    { docker logs "$@"; }

examples/24-monolith-to-microservices/verify.sh

@@ -9,12 +9,11 @@ DECORATOR="${DECORATOR:-http://localhost:8091}"
 CURL_OPTS="${CURL_OPTS:-}"
 
 # Container operations go through these helpers so the checks do not hard-code
-# an engine. RUNTIME=openshift is added later: a ctr_target function will map
-# a container name (cndp-kafka, cndp-postgres, ...) to its pod and each helper
-# will call `oc exec` / `oc logs` instead.
+# an engine. This example runs on Docker Compose only (RUNTIME=docker); Example 05's
+# verify.sh shows the RUNTIME=kubernetes variant used on minikube and OpenShift Local.
 case "$RUNTIME" in
     docker) ;;
-    *) echo "RUNTIME=$RUNTIME not supported yet" >&2; exit 1 ;;
+    *) echo "RUNTIME=$RUNTIME not supported (docker)" >&2; exit 1 ;;
 esac
 ctr_exec()    { docker exec "$@"; }
 ctr_logs()    { docker logs "$@"; }

examples/25-caching/verify.sh

@@ -7,12 +7,11 @@ BASE="${BASE:-http://localhost:8080}"
 CURL_OPTS="${CURL_OPTS:-}"
 
 # Container operations go through these helpers so the checks do not hard-code
-# an engine. RUNTIME=openshift is added later: a ctr_target function will map
-# a container name (cndp-kafka, cndp-postgres, ...) to its pod and each helper
-# will call `oc exec` / `oc logs` instead.
+# an engine. This example runs on Docker Compose only (RUNTIME=docker); Example 05's
+# verify.sh shows the RUNTIME=kubernetes variant used on minikube and OpenShift Local.
 case "$RUNTIME" in
     docker) ;;
-    *) echo "RUNTIME=$RUNTIME not supported yet" >&2; exit 1 ;;
+    *) echo "RUNTIME=$RUNTIME not supported (docker)" >&2; exit 1 ;;
 esac
 ctr_exec()    { docker exec "$@"; }
 ctr_logs()    { docker logs "$@"; }

examples/26-failure-modes/verify.sh

@@ -9,12 +9,11 @@ BACKEND="${BACKEND:-http://localhost:8081}"
 CURL_OPTS="${CURL_OPTS:-}"
 
 # Container operations go through these helpers so the checks do not hard-code
-# an engine. RUNTIME=openshift is added later: a ctr_target function will map
-# a container name (cndp-kafka, cndp-postgres, ...) to its pod and each helper
-# will call `oc exec` / `oc logs` instead.
+# an engine. This example runs on Docker Compose only (RUNTIME=docker); Example 05's
+# verify.sh shows the RUNTIME=kubernetes variant used on minikube and OpenShift Local.
 case "$RUNTIME" in
     docker) ;;
-    *) echo "RUNTIME=$RUNTIME not supported yet" >&2; exit 1 ;;
+    *) echo "RUNTIME=$RUNTIME not supported (docker)" >&2; exit 1 ;;
 esac
 ctr_exec()    { docker exec "$@"; }
 ctr_logs()    { docker logs "$@"; }
@@ -177,15 +176,19 @@ else
 fi
 
 # --- Breaker recovery ---
-printf '  \xe2\x86\x92 restoring backend and waiting for breaker reset (11s)...\n'
+printf '  \xe2\x86\x92 restoring backend; the breaker stays open 10s, then trial calls close it...\n'
 curl $CURL_OPTS -s -X POST -H 'Content-Type: application/json' \
     -d '{"mode":"healthy"}' "$BACKEND/mode" >/dev/null
-sleep 11
+sleep 10
 
-# First call after reset should trigger half-open → trial
-curl $CURL_OPTS -sf "$EDGE/with-breaker" >/dev/null 2>&1
-curl $CURL_OPTS -sf "$EDGE/with-breaker" >/dev/null 2>&1
-curl $CURL_OPTS -sf "$EDGE/with-breaker" >/dev/null 2>&1
+# Poll rather than wait a fixed time: the libraries end the open period at slightly different moments, and the
+# first call after it is the half-open trial (Polly closes after one success, the others after two). A call made
+# while the breaker is still open only gets the fallback, so polling is harmless. Give up after 20 s.
+for _ in $(seq 1 20); do
+    curl $CURL_OPTS -sf "$EDGE/with-breaker" >/dev/null 2>&1
+    curl $CURL_OPTS -sf "$EDGE/breaker-state" 2>/dev/null | grep -q '"state":"closed"' && break
+    sleep 1
+done
 
 check "breaker recovered to closed after successful trials" \
     "curl $CURL_OPTS -sf $EDGE/breaker-state" \

examples/27-feature-flags/verify.sh

@@ -7,12 +7,11 @@ BASE="${BASE:-http://localhost:8080}"
 CURL_OPTS="${CURL_OPTS:-}"
 
 # Container operations go through these helpers so the checks do not hard-code
-# an engine. RUNTIME=openshift is added later: a ctr_target function will map
-# a container name (cndp-kafka, cndp-postgres, ...) to its pod and each helper
-# will call `oc exec` / `oc logs` instead.
+# an engine. This example runs on Docker Compose only (RUNTIME=docker); Example 05's
+# verify.sh shows the RUNTIME=kubernetes variant used on minikube and OpenShift Local.
 case "$RUNTIME" in
     docker) ;;
-    *) echo "RUNTIME=$RUNTIME not supported yet" >&2; exit 1 ;;
+    *) echo "RUNTIME=$RUNTIME not supported (docker)" >&2; exit 1 ;;
 esac
 ctr_exec()    { docker exec "$@"; }
 ctr_logs()    { docker logs "$@"; }

examples/28-newman/verify.sh

@@ -7,12 +7,11 @@ BASE="${BASE:-http://localhost:8080}"
 CURL_OPTS="${CURL_OPTS:-}"
 
 # Container operations go through these helpers so the checks do not hard-code
-# an engine. RUNTIME=openshift is added later: a ctr_target function will map
-# a container name (cndp-kafka, cndp-postgres, ...) to its pod and each helper
-# will call `oc exec` / `oc logs` instead.
+# an engine. This example runs on Docker Compose only (RUNTIME=docker); Example 05's
+# verify.sh shows the RUNTIME=kubernetes variant used on minikube and OpenShift Local.
 case "$RUNTIME" in
     docker) ;;
-    *) echo "RUNTIME=$RUNTIME not supported yet" >&2; exit 1 ;;
+    *) echo "RUNTIME=$RUNTIME not supported (docker)" >&2; exit 1 ;;
 esac
 ctr_exec()    { docker exec "$@"; }
 ctr_logs()    { docker logs "$@"; }

examples/30-blazor-signalr/verify.sh

@@ -8,12 +8,11 @@ BASE2="${BASE2:-http://localhost:8081}"  # second dashboard instance, same Redis
 CURL_OPTS="${CURL_OPTS:-}"
 
 # Container operations go through these helpers so the checks do not hard-code
-# an engine. RUNTIME=openshift is added later: a ctr_target function will map
-# a container name (cndp-kafka, cndp-postgres, ...) to its pod and each helper
-# will call `oc exec` / `oc logs` instead.
+# an engine. This example runs on Docker Compose only (RUNTIME=docker); Example 05's
+# verify.sh shows the RUNTIME=kubernetes variant used on minikube and OpenShift Local.
 case "$RUNTIME" in
     docker) ;;
-    *) echo "RUNTIME=$RUNTIME not supported yet" >&2; exit 1 ;;
+    *) echo "RUNTIME=$RUNTIME not supported (docker)" >&2; exit 1 ;;
 esac
 ctr_exec()    { docker exec "$@"; }
 ctr_logs()    { docker logs "$@"; }