Ignore mirroring related shutdown errors (#1740)

RabbitMQ 4.0 doesn't include the mirroring-specific command `rabbitmq-upgrade await_online_synchronized_mirror`.
Therefore, the preStop hook would fail on 4.0, leading to the
maintenance mode not getting enabled at all (the moment a command fails
in preStop, the shutdown process continues as if preStop completed).

This approach should make the Operator compatible with 3.x and 4.x.

internal/resource/statefulset.go

@@ -614,7 +614,7 @@ func (builder *StatefulSetBuilder) podTemplateSpec(previousPodAnnotations map[st
 								Command: []string{"/bin/bash", "-c",
 									fmt.Sprintf("if [ ! -z \"$(cat /etc/pod-info/%s)\" ]; then exit 0; fi;", DeletionMarker) +
 										fmt.Sprintf(" rabbitmq-upgrade await_online_quorum_plus_one -t %d &&"+
-											" rabbitmq-upgrade await_online_synchronized_mirror -t %d &&"+
+											" rabbitmq-upgrade await_online_synchronized_mirror -t %d || true &&"+
 											" rabbitmq-upgrade drain -t %d",
 											*builder.Instance.Spec.TerminationGracePeriodSeconds,
 											*builder.Instance.Spec.TerminationGracePeriodSeconds,

internal/resource/statefulset_test.go

@@ -1447,15 +1447,15 @@ default_pass = {{ .Data.data.password }}
 			Expect(gracePeriodSeconds).To(Equal(ptr.To(int64(10))))
 
 			// TerminationGracePeriodSeconds is used to set commands timeouts in the preStop hook
-			expectedPreStopCommand := []string{"/bin/bash", "-c", "if [ ! -z \"$(cat /etc/pod-info/skipPreStopChecks)\" ]; then exit 0; fi; rabbitmq-upgrade await_online_quorum_plus_one -t 10 && rabbitmq-upgrade await_online_synchronized_mirror -t 10 && rabbitmq-upgrade drain -t 10"}
+			expectedPreStopCommand := []string{"/bin/bash", "-c", "if [ ! -z \"$(cat /etc/pod-info/skipPreStopChecks)\" ]; then exit 0; fi; rabbitmq-upgrade await_online_quorum_plus_one -t 10 && rabbitmq-upgrade await_online_synchronized_mirror -t 10 || true && rabbitmq-upgrade drain -t 10"}
 			Expect(statefulSet.Spec.Template.Spec.Containers[0].Lifecycle.PreStop.Exec.Command).To(Equal(expectedPreStopCommand))
 		})
 
 		It("checks mirror and quorum queue status in preStop hook", func() {
 			stsBuilder := builder.StatefulSet()
 			Expect(stsBuilder.Update(statefulSet)).To(Succeed())
 
-			expectedPreStopCommand := []string{"/bin/bash", "-c", "if [ ! -z \"$(cat /etc/pod-info/skipPreStopChecks)\" ]; then exit 0; fi; rabbitmq-upgrade await_online_quorum_plus_one -t 604800 && rabbitmq-upgrade await_online_synchronized_mirror -t 604800 && rabbitmq-upgrade drain -t 604800"}
+			expectedPreStopCommand := []string{"/bin/bash", "-c", "if [ ! -z \"$(cat /etc/pod-info/skipPreStopChecks)\" ]; then exit 0; fi; rabbitmq-upgrade await_online_quorum_plus_one -t 604800 && rabbitmq-upgrade await_online_synchronized_mirror -t 604800 || true && rabbitmq-upgrade drain -t 604800"}
 
 			Expect(statefulSet.Spec.Template.Spec.Containers[0].Lifecycle.PreStop.Exec.Command).To(Equal(expectedPreStopCommand))
 		})