show node monitors on agent page (#8725)

* show node monitors on agent page

add an advanced button on the agent page. When clicking it will show the
node monitors for this agent including any warnings/errors

* fix style

core/src/main/java/hudson/model/Computer.java

@@ -90,6 +90,7 @@
 import java.util.Enumeration;
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -1161,6 +1162,17 @@ public String getSearchUrl() {
         return r;
     }
 
+    @Restricted(NoExternalUse.class)
+    public Map<NodeMonitor, Object> getMonitoringData() {
+        Map<NodeMonitor, Object> r = new LinkedHashMap<>();
+        for (NodeMonitor monitor : NodeMonitor.getAll()) {
+            if (monitor.getColumnCaption() != null) {
+                r.put(monitor, monitor.data(this));
+            }
+        }
+        return r;
+    }
+
     /**
      * Gets the system properties of the JVM on this computer.
      * If this is the master, it returns the system property of the master computer.

core/src/main/resources/hudson/model/Computer/index.jelly

@@ -69,7 +69,19 @@ THE SOFTWARE.
         <p>${%title.no_manual_launch(it.retentionStrategy.descriptor.displayName)}</p>
       </j:if>
 
-        <j:if test="${it.node.assignedLabels.size() gt 1}">
+      <f:advanced title="${%Monitoring Data}">
+        <table class="jenkins-table jenkins-table--small jenkins-table--auto-width">
+          <j:forEach var="m" items="${it.monitoringData}">
+            <tr>
+              <td>${m.key.columnCaption}</td>
+              <j:set var="data" value="${m.value}"/>
+              <st:include page="column.jelly" from="${m.key}" />
+            </tr>
+          </j:forEach>
+        </table>
+      </f:advanced>
+
+      <j:if test="${it.node.assignedLabels.size() gt 1}">
         <div class="jenkins-!-margin-bottom-3">
           <h2>${%Labels}</h2>
           <j:forEach var="entry" items="${it.node.labelCloud}">

war/src/main/scss/components/_table.scss

@@ -183,6 +183,10 @@
     }
   }
 
+  &--auto-width {
+    width: auto !important;
+  }
+
   &--small {
     --table-padding: 0.2rem;