From f96f6faf2449e521014703ff3f84955630086328 Mon Sep 17 00:00:00 2001
From: Nicolas Vazquez <nicovazquez90@gmail.com>
Date: Thu, 17 Feb 2022 21:51:30 -0300
Subject: [PATCH] Improve messages on adding hosts errors (#5988)

* Improve messages on adding hosts errors

* Remove unreachable code

* Improve error logs

* Apply suggestions

* Improve error msg
---
 .../discoverer/LibvirtServerDiscoverer.java   | 20 ++++++++++++-------
 .../cloud/resource/ResourceManagerImpl.java   | 18 +++++++++++++----
 2 files changed, 27 insertions(+), 11 deletions(-)

diff --git a/server/src/main/java/com/cloud/hypervisor/kvm/discoverer/LibvirtServerDiscoverer.java b/server/src/main/java/com/cloud/hypervisor/kvm/discoverer/LibvirtServerDiscoverer.java
index 818c14f5b25..0b18ea90103 100644
--- a/server/src/main/java/com/cloud/hypervisor/kvm/discoverer/LibvirtServerDiscoverer.java
+++ b/server/src/main/java/com/cloud/hypervisor/kvm/discoverer/LibvirtServerDiscoverer.java
@@ -273,8 +273,11 @@ public abstract class LibvirtServerDiscoverer extends DiscovererBase implements
             }
 
             if (!SSHCmdHelper.sshExecuteCmd(sshConnection, "ls /dev/kvm")) {
-                s_logger.debug("It's not a KVM enabled machine");
-                return null;
+                String errorMsg = "This machine does not have KVM enabled.";
+                if (s_logger.isDebugEnabled()) {
+                    s_logger.debug(errorMsg);
+                }
+                throw new DiscoveredWithErrorException(errorMsg);
             }
 
             if (SSHCmdHelper.sshExecuteCmd(sshConnection, "rpm -qa | grep -i ovmf", 3)) {
@@ -335,9 +338,10 @@ public abstract class LibvirtServerDiscoverer extends DiscovererBase implements
                 setupAgentCommand = "sudo cloudstack-setup-agent ";
             }
             if (!SSHCmdHelper.sshExecuteCmd(sshConnection, setupAgentCommand + parameters)) {
-                s_logger.info("cloudstack agent setup command failed: "
-                        + setupAgentCommand + parameters);
-                return null;
+                String errorMsg = String.format("CloudStack Agent setup through command [%s] with parameters [%s] failed.",
+                        setupAgentCommand, parameters);
+                s_logger.info(errorMsg);
+                throw new DiscoveredWithErrorException(errorMsg);
             }
 
             KvmDummyResourceBase kvmResource = new KvmDummyResourceBase();
@@ -373,12 +377,14 @@ public abstract class LibvirtServerDiscoverer extends DiscovererBase implements
         } catch (Exception e) {
             String msg = " can't setup agent, due to " + e.toString() + " - " + e.getMessage();
             s_logger.warn(msg);
+            if (s_logger.isDebugEnabled()) {
+                s_logger.debug(msg, e);
+            }
+            throw new DiscoveredWithErrorException(msg, e);
         } finally {
             if (sshConnection != null)
                 sshConnection.close();
         }
-
-        return null;
     }
 
     private HostVO waitForHostConnect(long dcId, long podId, long clusterId, String guid) {
diff --git a/server/src/main/java/com/cloud/resource/ResourceManagerImpl.java b/server/src/main/java/com/cloud/resource/ResourceManagerImpl.java
index 70d205ade20..5dadd16ed02 100755
--- a/server/src/main/java/com/cloud/resource/ResourceManagerImpl.java
+++ b/server/src/main/java/com/cloud/resource/ResourceManagerImpl.java
@@ -807,9 +807,18 @@ public class ResourceManagerImpl extends ManagerBase implements ResourceManager,
             try {
                 resources = discoverer.find(dcId, podId, clusterId, uri, username, password, hostTags);
             } catch (final DiscoveryException e) {
-                throw e;
+                String errorMsg = String.format("Could not add host at [%s] with zone [%s], pod [%s] and cluster [%s] due to: [%s].",
+                        uri, dcId, podId, clusterId, e.getMessage());
+                if (s_logger.isDebugEnabled()) {
+                    s_logger.debug(errorMsg, e);
+                }
+                throw new DiscoveryException(errorMsg, e);
             } catch (final Exception e) {
-                s_logger.info("Exception in host discovery process with discoverer: " + discoverer.getName() + ", skip to another discoverer if there is any");
+                String err = "Exception in host discovery process with discoverer: " + discoverer.getName();
+                s_logger.info(err + ", skip to another discoverer if there is any");
+                if (s_logger.isDebugEnabled()) {
+                    s_logger.debug(err + ":" + e.getMessage(), e);
+                }
             }
             processResourceEvent(ResourceListener.EVENT_DISCOVER_AFTER, resources);
 
@@ -863,8 +872,9 @@ public class ResourceManagerImpl extends ManagerBase implements ResourceManager,
             s_logger.warn(msg);
             throw new DiscoveryException(msg);
         }
-        s_logger.warn("Unable to find the server resources at " + url);
-        throw new DiscoveryException("Unable to add the host");
+        String errorMsg = "Cannot find the server resources at " + url;
+        s_logger.warn(errorMsg);
+        throw new DiscoveryException("Unable to add the host: " + errorMsg);
     }
 
     @Override