fix: catch and display unknownhost exception (#757)

Signed-off-by: Andre Dietisheim <[email protected]>

Author: adietish

src/main/kotlin/com/redhat/devtools/intellij/kubernetes/model/client/ClientAdapter.kt

@@ -81,14 +81,22 @@ abstract class ClientAdapter<C : KubernetesClient>(private val fabric8Client: C)
                     setSslContext(builder, config, externalTrustManagerProvider)
                 }
                 .build()
-            return if (ClusterHelper.isOpenShift(kubeClient)) {
+            return if (isOpenShift(kubeClient)) {
                 val osClient = kubeClient.adapt(NamespacedOpenShiftClient::class.java)
                 OSClientAdapter(osClient, kubeClient)
             } else {
                 KubeClientAdapter(kubeClient)
             }
         }
 
+        private fun isOpenShift(client: KubernetesClient): Boolean {
+            return try {
+                ClusterHelper.isOpenShift(client)
+            } catch (e: Exception) {
+                false;
+            }
+        }
+
         private fun setSslContext(
             builder: HttpClient.Builder,
             config: Config,

src/main/kotlin/com/redhat/devtools/intellij/kubernetes/model/util/ExceptionUtils.kt

@@ -24,6 +24,7 @@ fun toTitle(e: Throwable?): String {
 
 fun toMessage(e: Throwable?): String {
     return noCurrentContextMessage(e)
+        ?: unknownHostMessage(e)
         ?: recursiveGetMessage(e)
         ?: "Unknown Error"
 }
@@ -48,3 +49,33 @@ fun noCurrentContextMessage(e: Throwable?): String? {
         null
     }
 }
+
+fun unknownHostMessage(e: Throwable?): String? {
+    val unknownHostException = recursiveGetThrowable(e) {
+        throwable -> throwable is UnknownHostException
+    }
+    return if (unknownHostException is UnknownHostException) {
+        "Unreachable cluster at ${getHost(unknownHostException)}."
+    } else {
+        null
+    }
+}
+
+private fun getHost(e: UnknownHostException): String? {
+    val portions = e.message?.split(':') ?: return e.message
+    return if (1 < portions.size) {
+        portions[1]
+    } else {
+        e.message
+    }
+}
+
+private fun recursiveGetThrowable(e: Throwable?, predicate: (e: Throwable?) -> Boolean): Throwable? {
+    return if (e == null
+        || e == e.cause
+        || predicate.invoke(e)) {
+        e
+    } else {
+        recursiveGetThrowable(e.cause, predicate)
+    }
+}

src/main/kotlin/com/redhat/devtools/intellij/kubernetes/tree/TreeStructure.kt

@@ -30,6 +30,7 @@ import com.redhat.devtools.intellij.kubernetes.model.util.hasDeletionTimestamp
 import com.redhat.devtools.intellij.kubernetes.model.util.isSameResource
 import com.redhat.devtools.intellij.kubernetes.model.util.isUnauthorized
 import com.redhat.devtools.intellij.kubernetes.model.util.isWillBeDeleted
+import com.redhat.devtools.intellij.kubernetes.model.util.unknownHostMessage
 import io.fabric8.kubernetes.api.model.HasMetadata
 import io.fabric8.kubernetes.client.KubernetesClientException
 import javax.swing.Icon
@@ -264,6 +265,10 @@ open class TreeStructure(
         }
 
         private fun getMessage(e: Exception?): String {
+            val unknownHostMessage = unknownHostMessage(e)
+            if (unknownHostMessage != null) {
+                return unknownHostMessage
+            }
             val causeMessage = e?.cause?.message
             return if (causeMessage == null) {
                 getMessageOrDefault(e)