Make the clean up of ServiceMonitors optional when Operator is starting

Starting Theodolite (in Operator mode) fails if ServiceMonitors are not registered by the Kubernetes API. But, this may be the case when developing or running Theodolite in a cluster without support for service monitors.

theodolite/src/main/kotlin/theodolite/execution/operator/ClusterSetup.kt

 package theodolite.execution.operator
 
+import io.fabric8.kubernetes.client.KubernetesClientException
 import io.fabric8.kubernetes.client.NamespacedKubernetesClient
 import io.fabric8.kubernetes.client.dsl.MixedOperation
 import io.fabric8.kubernetes.client.dsl.Resource
+import mu.KotlinLogging
 import theodolite.execution.Shutdown
 import theodolite.k8s.K8sContextFactory
 import theodolite.k8s.ResourceByLabelHandler
 import theodolite.model.crd.*
 
+private val logger = KotlinLogging.logger {}
+
 class ClusterSetup(
     private val executionCRDClient: MixedOperation<ExecutionCRD, BenchmarkExecutionList, Resource<ExecutionCRD>>,
     private val benchmarkCRDClient: MixedOperation<BenchmarkCRD, KubernetesBenchmarkList, Resource<BenchmarkCRD>>,
@@ -75,10 +79,15 @@ class ClusterSetup(
             labelName = "app.kubernetes.io/created-by",
             labelValue = "theodolite"
         )
-        resourceRemover.removeCR(
-            labelName = "app.kubernetes.io/created-by",
-            labelValue = "theodolite",
-            context = serviceMonitorContext
-        )
+        try {
+            resourceRemover.removeCR(
+                labelName = "app.kubernetes.io/created-by",
+                labelValue = "theodolite",
+                context = serviceMonitorContext
+            )
+        } catch (e: KubernetesClientException) {
+            logger.warn { "Service monitors could not be cleaned up. It may be that service monitors are not registered by the Kubernetes API."}
+            logger.debug { "Error is: ${e.message}" }
+        }
     }
 }
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