Add alternate location for upper bounds in serverless (elastic#134418)

In serverless new transport versions are based on the greater of the
largest serverless transport version, or the largest in server. This
commit adds configuration to the generate task which allows specifying
the upper bound file from server to consule when generating a new
transport version.

Author: rjernst

build-conventions/src/main/java/org/elasticsearch/gradle/internal/conventions/VersionPropertiesBuildService.java

@@ -22,7 +22,7 @@
 import java.util.Properties;
 import javax.inject.Inject;
 
-abstract class VersionPropertiesBuildService implements BuildService<VersionPropertiesBuildService.Params>, AutoCloseable {
+public abstract class VersionPropertiesBuildService implements BuildService<VersionPropertiesBuildService.Params>, AutoCloseable {
 
     private final Properties properties;
 

build-tools-internal/src/integTest/groovy/org/elasticsearch/gradle/internal/transport/TransportVersionGenerationFuncTest.groovy

@@ -443,4 +443,46 @@ class TransportVersionGenerationFuncTest extends AbstractTransportVersionFuncTes
         assertUpperBound("9.2", "new_tv,8124000")
         assertReferableDefinition("new_tv", "8124000")
     }
+
+    def "alternate upper bound larger"() {
+        given:
+        referencedTransportVersion("new_tv")
+        file("myserver/alt_upper_bound.csv").text = "some_tv,8126000"
+        file("myserver/build.gradle") << """
+            tasks.named('generateTransportVersionDefinition') {
+                alternateUpperBoundFile = project.file("alt_upper_bound.csv")
+            }
+            tasks.named('validateTransportVersionResources') {
+                shouldValidateDensity = false
+            }
+        """
+
+        when:
+        def result = runGenerateAndValidateTask().build()
+        then:
+        assertGenerateAndValidateSuccess(result)
+        assertUpperBound("9.2", "new_tv,8127000")
+        assertReferableDefinition("new_tv", "8127000")
+    }
+
+    def "alternate upper bound less"() {
+        given:
+        referencedTransportVersion("new_tv")
+        file("myserver/alt_upper_bound.csv").text = "some_tv,8122100"
+        file("myserver/build.gradle") << """
+            tasks.named('generateTransportVersionDefinition') {
+                alternateUpperBoundFile = project.file("alt_upper_bound.csv")
+            }
+            tasks.named('validateTransportVersionResources') {
+                shouldValidateDensity = false
+            }
+        """
+
+        when:
+        def result = runGenerateAndValidateTask().build()
+        then:
+        assertGenerateAndValidateSuccess(result)
+        assertUpperBound("9.2", "new_tv,8124000")
+        assertReferableDefinition("new_tv", "8124000")
+    }
 }

build-tools-internal/src/main/java/org/elasticsearch/gradle/internal/transport/GenerateTransportVersionDefinitionTask.java

@@ -11,9 +11,11 @@
 
 import org.gradle.api.DefaultTask;
 import org.gradle.api.file.ConfigurableFileCollection;
+import org.gradle.api.file.RegularFileProperty;
 import org.gradle.api.provider.Property;
 import org.gradle.api.services.ServiceReference;
 import org.gradle.api.tasks.Input;
+import org.gradle.api.tasks.InputFile;
 import org.gradle.api.tasks.InputFiles;
 import org.gradle.api.tasks.Optional;
 import org.gradle.api.tasks.PathSensitive;
@@ -22,6 +24,9 @@
 import org.gradle.api.tasks.options.Option;
 
 import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashSet;
@@ -74,6 +79,14 @@ public abstract class GenerateTransportVersionDefinitionTask extends DefaultTask
     @Input
     public abstract Property<String> getCurrentUpperBoundName();
 
+    /**
+     * An additional upper bound file that will be consulted when generating a transport version.
+     * The larger of this and the current upper bound will be used to create the new primary id.
+     */
+    @InputFile
+    @Optional
+    public abstract RegularFileProperty getAlternateUpperBoundFile();
+
     @TaskAction
     public void run() throws IOException {
         TransportVersionResourcesService resources = getResourceService().get();
@@ -119,7 +132,7 @@ private List<TransportVersionId> updateUpperBounds(
                 if (targetId == null) {
                     // Case: an id doesn't yet exist for this upper bound, so create one
                     int targetIncrement = upperBoundName.equals(currentUpperBoundName) ? increment : 1;
-                    targetId = TransportVersionId.fromInt(existingUpperBound.definitionId().complete() + targetIncrement);
+                    targetId = createTargetId(existingUpperBound, targetIncrement);
                     var newUpperBound = new TransportVersionUpperBound(upperBoundName, definitionName, targetId);
                     resources.writeUpperBound(newUpperBound);
                 }
@@ -237,4 +250,21 @@ private TransportVersionId maybeGetExistingId(
         return null; // no existing id for this upper bound
     }
 
+    private TransportVersionId createTargetId(TransportVersionUpperBound existingUpperBound, int increment) throws IOException {
+        int currentId = existingUpperBound.definitionId().complete();
+
+        // allow for an alternate upper bound file to be consulted. This supports Serverless basing its
+        // own transport version ids on the greater of server or serverless
+        if (getAlternateUpperBoundFile().isPresent()) {
+            Path altUpperBoundPath = getAlternateUpperBoundFile().get().getAsFile().toPath();
+            String contents = Files.readString(altUpperBoundPath, StandardCharsets.UTF_8);
+            var altUpperBound = TransportVersionUpperBound.fromString(altUpperBoundPath, contents);
+            if (altUpperBound.definitionId().complete() > currentId) {
+                currentId = altUpperBound.definitionId().complete();
+            }
+        }
+
+        return TransportVersionId.fromInt(currentId + increment);
+    }
+
 }