$ echo 'NOTE: assumes exactly 3 schedulable worker nodes (replicas must equal node count for the deadlock condition -- adjust replicas to match this cluster'\''s actual node count before applying)'
NOTE: assumes exactly 3 schedulable worker nodes (replicas must equal node count for the deadlock condition -- adjust replicas to match this cluster's actual node count before applying)

$ kubectl get nodes --no-headers | wc -l
3

$ kubectl apply -f client-only.yaml -f deadlock-fixtures.yaml && kubectl -n istio-vt-t82 wait --for=condition=available deploy/deadlock-echo --timeout=90s
the path "client-only.yaml" does not exist
the path "deadlock-fixtures.yaml" does not exist

[NOTE] spec references client-only.yaml/deadlock-fixtures.yaml as separate files; this run uses the single combined manifest.yaml saved per harness instructions (same resources). Re-running equivalent apply+wait below.

$ kubectl apply -f manifest.yaml && kubectl -n istio-vt-t82 wait --for=condition=available deploy/deadlock-echo --timeout=90s
pod/client configured
deployment.apps/deadlock-echo unchanged
deployment.apps/deadlock-echo condition met

$ kubectl -n istio-vt-t82 patch deployment deadlock-echo -p '{"spec":{"template":{"metadata":{"annotations":{"force-rollout":"1"}}}}}'
deployment.apps/deadlock-echo patched

$ sleep 20

$ kubectl -n istio-vt-t82 rollout status deploy/deadlock-echo --timeout=30s || echo 'rollout did NOT complete within 30s (as expected if deadlocked)'
Waiting for deployment "deadlock-echo" rollout to finish: 1 out of 3 new replicas have been updated...
error: timed out waiting for the condition
rollout did NOT complete within 30s (as expected if deadlocked)

$ kubectl -n istio-vt-t82 get pods -l app=deadlock-echo -o wide
NAME                             READY   STATUS    RESTARTS   AGE   IP               NODE          NOMINATED NODE   READINESS GATES
deadlock-echo-577dcdbc88-rttsh   2/2     Running   0          94s   10.255.159.136   k8s-master1   <none>           <none>
deadlock-echo-577dcdbc88-t224f   2/2     Running   0          94s   10.255.126.45    k8s-worker2   <none>           <none>
deadlock-echo-577dcdbc88-wcfc6   2/2     Running   0          94s   10.255.194.117   k8s-worker1   <none>           <none>
deadlock-echo-69b5c5bc9d-r9tgn   0/2     Pending   0          56s   <none>           <none>        <none>           <none>

$ kubectl -n istio-vt-t82 get pods -l app=deadlock-echo --field-selector=status.phase=Pending -o jsonpath='{range .items[*]}{.metadata.name}{" "}{.status.conditions[?(@.type=="PodScheduled")].message}{"
"}{end}'
deadlock-echo-69b5c5bc9d-r9tgn 0/3 nodes are available: 3 node(s) didn't match pod anti-affinity rules. preemption: 0/3 nodes are available: 3 No preemption victims found for incoming pod.

[EXTRA VERIFICATION - not in spec commands, added for confirmation]
$ kubectl -n istio-vt-t82 get deploy deadlock-echo -o jsonpath='replicas={.status.replicas} updated={.status.updatedReplicas} available={.status.availableReplicas} unavailable={.status.unavailableReplicas}{"
"}'
replicas=4 updated=1 available=3 unavailable=1

$ kubectl -n istio-vt-t82 describe pod deadlock-echo-69b5c5bc9d-r9tgn | tail -20
    Optional:  false
  istio-ca-crl:
    Type:      ConfigMap (a volume populated by a ConfigMap)
    Name:      istio-ca-crl
    Optional:  true
  kube-api-access-6kqxs:
    Type:                    Projected (a volume that contains injected data from multiple sources)
    TokenExpirationSeconds:  3607
    ConfigMapName:           kube-root-ca.crt
    Optional:                false
    DownwardAPI:             true
QoS Class:                   Burstable
Node-Selectors:              <none>
Tolerations:                 node.kubernetes.io/not-ready:NoExecute op=Exists for 300s
                             node.kubernetes.io/unreachable:NoExecute op=Exists for 300s
Events:
  Type     Reason            Age   From               Message
  ----     ------            ----  ----               -------
  Warning  FailedScheduling  65s   default-scheduler  0/3 nodes are available: 3 node(s) didn't match pod anti-affinity rules. preemption: 0/3 nodes are available: 3 No preemption victims found for incoming pod.
  Warning  FailedScheduling  1s    default-scheduler  0/3 nodes are available: 3 node(s) didn't match pod anti-affinity rules. preemption: 0/3 nodes are available: 3 No preemption victims found for incoming pod.