Add API specs for voting config exclusions (#55760)

Closes #48131

Author: zacharymorn

client/rest-high-level/src/test/java/org/elasticsearch/client/RestHighLevelClientTests.java

@@ -869,6 +869,8 @@ public void testApiNamingConventions() throws Exception {
             "cluster.reroute",
             "cluster.state",
             "cluster.stats",
+            "cluster.post_voting_config_exclusions",
+            "cluster.delete_voting_config_exclusions",
             "indices.shard_stores",
             "indices.upgrade",
             "indices.recovery",

rest-api-spec/src/main/resources/rest-api-spec/api/cluster.delete_voting_config_exclusions.json

@@ -0,0 +1,26 @@
+{
+  "cluster.delete_voting_config_exclusions":{
+    "documentation":{
+      "url":"https://www.elastic.co/guide/en/elasticsearch/reference/master/voting-config-exclusions.html",
+      "description":"Clears cluster voting config exclusions."
+    },
+    "stability":"stable",
+    "url":{
+      "paths":[
+        {
+          "path":"/_cluster/voting_config_exclusions",
+          "methods":[
+            "DELETE"
+          ]
+        }
+      ]
+    },
+    "params":{
+      "wait_for_removal": {
+        "type":"boolean",
+        "description":"Specifies whether to wait for all excluded nodes to be removed from the cluster before clearing the voting configuration exclusions list.",
+        "default":true
+      }
+    }
+  }
+}

rest-api-spec/src/main/resources/rest-api-spec/api/cluster.post_voting_config_exclusions.json

@@ -0,0 +1,34 @@
+{
+  "cluster.post_voting_config_exclusions":{
+    "documentation":{
+      "url":"https://www.elastic.co/guide/en/elasticsearch/reference/master/voting-config-exclusions.html",
+      "description":"Updates the cluster voting config exclusions by node ids or node names."
+    },
+    "stability":"stable",
+    "url":{
+      "paths":[
+        {
+          "path":"/_cluster/voting_config_exclusions",
+          "methods":[
+            "POST"
+          ]
+        }
+      ]
+    },
+    "params":{
+      "node_ids":{
+        "type":"string",
+        "description":"A comma-separated list of the persistent ids of the nodes to exclude from the voting configuration. If specified, you may not also specify ?node_names."
+      },
+      "node_names":{
+        "type":"string",
+        "description":"A comma-separated list of the names of the nodes to exclude from the voting configuration. If specified, you may not also specify ?node_ids."
+      },
+      "timeout":{
+        "type":"time",
+        "description":"Explicit operation timeout",
+        "default":"30s"
+      }
+    }
+  }
+}

rest-api-spec/src/main/resources/rest-api-spec/test/cluster.voting_config_exclusions/10_basic.yml

@@ -0,0 +1,85 @@
+teardown:
+  - do:
+      cluster.delete_voting_config_exclusions: {}
+
+---
+"Get cluster state without voting config exclusions":
+  - do:
+      cluster.state: {}
+
+  - length: { metadata.cluster_coordination.voting_config_exclusions: 0 }
+
+---
+"Add voting config exclusion by unknown node Id":
+  - do:
+      cluster.post_voting_config_exclusions:
+        node_ids: nodeId
+
+  - do:
+      cluster.state: {}
+
+  - length: { metadata.cluster_coordination.voting_config_exclusions: 1 }
+  - match: { metadata.cluster_coordination.voting_config_exclusions.0.node_id: "nodeId" }
+  - match: { metadata.cluster_coordination.voting_config_exclusions.0.node_name: "_absent_" }
+
+---
+"Add voting config exclusion by unknown node Ids":
+  - skip:
+        reason: "contains is a newly added assertion"
+        features: contains
+
+  - do:
+      cluster.post_voting_config_exclusions:
+        node_ids: nodeId1,nodeId2
+
+  - do:
+      cluster.state: {}
+
+  - length: { metadata.cluster_coordination.voting_config_exclusions: 2 }
+  - contains : { metadata.cluster_coordination.voting_config_exclusions: {node_id: "nodeId1", node_name: "_absent_"} }
+  - contains : { metadata.cluster_coordination.voting_config_exclusions: {node_id: "nodeId2", node_name: "_absent_"} }
+
+---
+"Add voting config exclusion by unknown node name":
+  - do:
+      cluster.post_voting_config_exclusions:
+        node_names: nodeName
+
+  - do:
+      cluster.state: {}
+
+  - length: { metadata.cluster_coordination.voting_config_exclusions: 1 }
+  - match: { metadata.cluster_coordination.voting_config_exclusions.0.node_id: "_absent_" }
+  - match: { metadata.cluster_coordination.voting_config_exclusions.0.node_name: "nodeName" }
+
+---
+"Add voting config exclusion by unknown node names":
+  - skip:
+      reason: "contains is a newly added assertion"
+      features: contains
+
+  - do:
+      cluster.post_voting_config_exclusions:
+        node_names: nodeName1,nodeName2
+
+  - do:
+      cluster.state: {}
+
+  - length: { metadata.cluster_coordination.voting_config_exclusions: 2 }
+  - contains : { metadata.cluster_coordination.voting_config_exclusions: {node_id: "_absent_", node_name: "nodeName1"} }
+  - contains : { metadata.cluster_coordination.voting_config_exclusions: {node_id: "_absent_", node_name: "nodeName2"} }
+
+---
+"Throw exception when adding voting config exclusion without specifying nodes":
+  - do:
+      catch: /You must set \[node_names\] or \[node_ids\] but not both/
+      cluster.post_voting_config_exclusions: {}
+
+---
+"Throw exception when adding voting config exclusion and specifying both node_ids and node_names":
+  - do:
+      catch: /You must set \[node_names\] or \[node_ids\] but not both/
+      cluster.post_voting_config_exclusions:
+        node_ids: nodeId
+        node_names: nodeName
+