Expand `/_cat/nodes` to return information about hard drive (#21775)

Expand `/_cat/nodes` with already present information about available disk space `diskAvail` (alias: `d`, `disk`) by:

    * `diskTotal` (alias `dt`): total disk space
    * `diskUsed` (alias `du`): used disk space (`diskTotal - diskAvail`)
    * `diskUsedPercent` (alias `dup`): used disk space percentage

Note: The available disk space is the number of bytes available to the node's Java virtual machine. The size might be smaller than the real one. That means the used disk space (percentage) is larger.

Closes #21679

core/src/main/java/org/elasticsearch/rest/action/cat/RestNodesAction.java

@@ -35,6 +35,7 @@ import org.elasticsearch.common.Table;
 import org.elasticsearch.common.network.NetworkAddress;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.transport.TransportAddress;
+import org.elasticsearch.common.unit.ByteSizeValue;
 import org.elasticsearch.http.HttpInfo;
 import org.elasticsearch.index.cache.query.QueryCacheStats;
 import org.elasticsearch.index.cache.request.RequestCacheStats;
@@ -124,7 +125,10 @@ public class RestNodesAction extends AbstractCatAction {
         table.addCell("version", "default:false;alias:v;desc:es version");
         table.addCell("build", "default:false;alias:b;desc:es build hash");
         table.addCell("jdk", "default:false;alias:j;desc:jdk version");
-        table.addCell("disk.avail", "default:false;alias:d,disk,diskAvail;text-align:right;desc:available disk space");
+        table.addCell("disk.total", "default:false;alias:dt,diskTotal;text-align:right;desc:total disk space");
+        table.addCell("disk.used", "default:false;alias:du,diskUsed;text-align:right;desc:used disk space");
+        table.addCell("disk.avail", "default:false;alias:d,da,disk,diskAvail;text-align:right;desc:available disk space");
+        table.addCell("disk.used_percent", "default:false;alias:dup,diskUsedPercent;text-align:right;desc:used disk space percentage");
         table.addCell("heap.current", "default:false;alias:hc,heapCurrent;text-align:right;desc:used heap");
         table.addCell("heap.percent", "alias:hp,heapPercent;text-align:right;desc:used heap ratio");
         table.addCell("heap.max", "default:false;alias:hm,heapMax;text-align:right;desc:max configured heap");
@@ -267,7 +271,15 @@ public class RestNodesAction extends AbstractCatAction {
             table.addCell(node.getVersion().toString());
             table.addCell(info == null ? null : info.getBuild().shortHash());
             table.addCell(jvmInfo == null ? null : jvmInfo.version());
+            
+            long diskTotal = fsInfo.getTotal().getTotal().getBytes();
+            long diskUsed = diskTotal - fsInfo.getTotal().getAvailable().getBytes();
+            double diskUsedRatio = diskTotal == 0 ? 1.0 : (double) diskUsed / diskTotal;
+            table.addCell(fsInfo == null ? null : fsInfo.getTotal().getTotal());
+            table.addCell(fsInfo == null ? null : new ByteSizeValue(diskUsed));
             table.addCell(fsInfo == null ? null : fsInfo.getTotal().getAvailable());
+            table.addCell(fsInfo == null ? null : String.format(Locale.ROOT, "%.2f", 100.0 * diskUsedRatio));
+            
             table.addCell(jvmStats == null ? null : jvmStats.getMem().getHeapUsed());
             table.addCell(jvmStats == null ? null : jvmStats.getMem().getHeapUsedPercent());
             table.addCell(jvmInfo == null ? null : jvmInfo.getMem().getHeapMax());

docs/reference/cat/nodes.asciidoc

@@ -71,7 +71,10 @@ veJR 127.0.0.1 59938 {version} *
 |`version` |`v` |No |Elasticsearch version |{version}
 |`build` |`b` |No |Elasticsearch Build hash |5c03844
 |`jdk` |`j` |No |Running Java version |1.8.0
-|`disk.avail` |`d`, `disk`, `diskAvail` |No |Available disk space |1.8gb
+|`disk.total` |`dt`, `diskTotal` |No |Total disk space| 458.3gb
+|`disk.used` |`du`, `diskUsed` |No |Used disk space| 259.8gb
+|`disk.avail` |`d`, `disk`, `diskAvail` |No |Available disk space |198.4gb
+|`disk.used_percent` |`dup`, `diskUsedPercent` |No |Used disk space percentage |56.71
 |`heap.current` |`hc`, `heapCurrent` |No |Used heap |311.2mb
 |`heap.percent` |`hp`, `heapPercent` |Yes |Used heap percentage |7
 |`heap.max` |`hm`, `heapMax` |No |Maximum configured heap |1015.6mb

rest-api-spec/src/main/resources/rest-api-spec/test/cat.nodes/10_basic.yml

@@ -58,6 +58,38 @@
       $body: |
                /^      http \n ((\d{1,3}\.){3}\d{1,3}:\d{1,5}\n)+  $/
 
+---
+"Additional disk information":
+  - skip:
+      version: " - 5.5.99"
+      reason:  additional disk info added in 5.6.0
+
+  - do:
+      cat.nodes:
+          h: diskAvail,diskTotal,diskUsed,diskUsedPercent
+          v: true
+
+  - match:
+      # leading whitespace on columns and optional whitespace on values is necessary
+      # because `diskAvail` is right aligned and text representation of disk size might be
+      # longer so it's padded with leading whitespace
+      $body: |
+               /^  \s* diskAvail            \s+ diskTotal            \s+ diskUsed            \s+ diskUsedPercent            \n
+                  (\s* \d+(\.\d+)?[ptgmk]?b \s+ \d+(\.\d+)?[ptgmk]?b \s+ \d+(\.\d+)?[ptgmk]?b\s+ (100\.00 | \d{1,2}\.\d{2}) \n)+  $/
+
+  - do:
+      cat.nodes:
+          h: disk,dt,du,dup
+          v: true
+
+  - match:
+      # leading whitespace on columns and optional whitespace on values is necessary
+      # because `disk` is right aligned and text representation of disk size might be
+      # longer so it's padded with leading whitespace
+      $body: |
+               /^  \s* disk                 \s+ dt                   \s+ du                  \s+ dup                        \n
+                  (\s* \d+(\.\d+)?[ptgmk]?b \s+ \d+(\.\d+)?[ptgmk]?b \s+ \d+(\.\d+)?[ptgmk]?b\s+ (100\.00 | \d{1,2}\.\d{2}) \n)+  $/
+
 ---
 "Test cat nodes output with full_id set":
   - skip: