Remove ML TransportVersionUtils

ML sometimes checks whether the a cluster is in the middle of an upgrade
by comparing the lowest versioned node to the current node version.
TransportVersionUtils exists to simplify that check, but comparing two
transport versions for equality is trivial. This commit updates the few
places checking for an in progress upgrade and removes
TransportVersionUtils.

Author: rjernst

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/ml/utils/TransportVersionUtils.java

@@ -14,6 +14,7 @@
 import org.elasticsearch.ElasticsearchStatusException;
 import org.elasticsearch.ResourceAlreadyExistsException;
 import org.elasticsearch.ResourceNotFoundException;
+import org.elasticsearch.TransportVersion;
 import org.elasticsearch.action.ActionListener;
 import org.elasticsearch.action.search.SearchResponse;
 import org.elasticsearch.action.support.ActionFilters;
@@ -64,7 +65,6 @@
 import org.elasticsearch.xpack.core.ml.inference.trainedmodel.IndexLocation;
 import org.elasticsearch.xpack.core.ml.job.messages.Messages;
 import org.elasticsearch.xpack.core.ml.utils.ExceptionsHelper;
-import org.elasticsearch.xpack.core.ml.utils.TransportVersionUtils;
 import org.elasticsearch.xpack.ml.MachineLearning;
 import org.elasticsearch.xpack.ml.inference.assignment.TrainedModelAssignmentService;
 import org.elasticsearch.xpack.ml.inference.persistence.TrainedModelDefinitionDoc;
@@ -148,7 +148,7 @@ protected void masterOperation(
             return;
         }
 
-        if (TransportVersionUtils.isMinTransportVersionSameAsCurrent(state) == false) {
+        if (state.getMinTransportVersion().equals(TransportVersion.current()) == false) {
             listener.onFailure(
                 new ElasticsearchStatusException(
                     "Cannot start model deployment [{}] while cluster upgrade is in progress.",

x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/action/TransportStartTrainedModelDeploymentAction.java

@@ -11,6 +11,7 @@
 import org.elasticsearch.ElasticsearchStatusException;
 import org.elasticsearch.ResourceAlreadyExistsException;
 import org.elasticsearch.ResourceNotFoundException;
+import org.elasticsearch.TransportVersion;
 import org.elasticsearch.action.ActionListener;
 import org.elasticsearch.action.support.ActionFilters;
 import org.elasticsearch.action.support.master.TransportMasterNodeAction;
@@ -47,7 +48,6 @@
 import org.elasticsearch.xpack.core.ml.job.results.Result;
 import org.elasticsearch.xpack.core.ml.job.snapshot.upgrade.SnapshotUpgradeTaskParams;
 import org.elasticsearch.xpack.core.ml.utils.ExceptionsHelper;
-import org.elasticsearch.xpack.core.ml.utils.TransportVersionUtils;
 import org.elasticsearch.xpack.ml.MachineLearning;
 import org.elasticsearch.xpack.ml.job.persistence.JobConfigProvider;
 import org.elasticsearch.xpack.ml.job.persistence.JobResultsProvider;
@@ -110,7 +110,7 @@ protected void masterOperation(Task task, Request request, ClusterState state, A
             return;
         }
 
-        if (TransportVersionUtils.isMinTransportVersionSameAsCurrent(state) == false) {
+        if (state.getMinTransportVersion().equals(TransportVersion.current()) == false) {
             listener.onFailure(
                 ExceptionsHelper.conflictStatusException(
                     "Cannot upgrade job [{}] snapshot [{}] while cluster upgrade is in progress.",

x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/action/TransportUpgradeJobModelSnapshotAction.java

@@ -11,6 +11,7 @@
 import org.apache.logging.log4j.Logger;
 import org.elasticsearch.ElasticsearchStatusException;
 import org.elasticsearch.ResourceNotFoundException;
+import org.elasticsearch.TransportVersion;
 import org.elasticsearch.action.ActionListener;
 import org.elasticsearch.action.support.ActionFilters;
 import org.elasticsearch.action.support.master.TransportMasterNodeAction;
@@ -29,7 +30,6 @@
 import org.elasticsearch.threadpool.ThreadPool;
 import org.elasticsearch.transport.TransportService;
 import org.elasticsearch.xpack.core.XPackSettings;
-import org.elasticsearch.xpack.core.ml.utils.TransportVersionUtils;
 import org.elasticsearch.xpack.core.security.SecurityContext;
 import org.elasticsearch.xpack.core.transform.TransformMetadata;
 import org.elasticsearch.xpack.core.transform.action.UpgradeTransformsAction;
@@ -107,7 +107,7 @@ protected void masterOperation(Task ignoredTask, Request request, ClusterState s
         }
 
         // do not allow in mixed clusters
-        if (TransportVersionUtils.isMinTransportVersionSameAsCurrent(state) == false) {
+        if (state.getMinTransportVersion().equals(TransportVersion.current()) == false) {
             listener.onFailure(
                 new ElasticsearchStatusException("Cannot upgrade transforms while cluster upgrade is in progress.", RestStatus.CONFLICT)
             );