Consolidate version numbering semantics (elastic/x-pack-elasticsearch#3078)

Fixes to the build system, particularly around BWC testing, and to make future
version bumps less painful.

Original commit: elastic/x-pack-elasticsearch@a1d456f30a

build.gradle

@@ -1,6 +1,8 @@
 import org.elasticsearch.gradle.BuildPlugin
+import org.elasticsearch.gradle.Version
 import org.elasticsearch.gradle.VersionProperties
 import org.elasticsearch.gradle.precommit.LicenseHeadersTask
+import sun.reflect.generics.reflectiveObjects.NotImplementedException
 
 if (project.projectDir.name != 'x-pack-elasticsearch') {
   throw new GradleException('You must checkout x-pack-elasticsearch in the following directory: <path to Elasticsearch checkout>/../elasticsearch-extra/x-pack-elasticsearch')
@@ -52,17 +54,11 @@ subprojects {
   ext.projectSubstitutions += [ "org.elasticsearch.plugin:x-pack-api:${version}": ':x-pack-elasticsearch:plugin']
   ext.projectSubstitutions += [ "org.elasticsearch:x-pack-client-api-objects:${version}": ':x-pack-elasticsearch:client:client-api-objects']
 
-  if (wireCompatVersions[-1].snapshot) {
-    /* The last and second to last versions can be snapshots. Rather than use
-     * snapshots built by CI we connect these versions to projects that build
-     * those versions from the HEAD of the appropriate branch. */
-    if (indexCompatVersions[-1].bugfix == 0) {
-      ext.projectSubstitutions += [
-        "org.elasticsearch.plugin:x-pack:${indexCompatVersions[-1]}": ':x-pack-elasticsearch:plugin:bwc:stable-snapshot',
-        "org.elasticsearch.plugin:x-pack:${indexCompatVersions[-2]}": ':x-pack-elasticsearch:plugin:bwc:release-snapshot']
-    } else {
-      ext.projectSubstitutions += [
-        "org.elasticsearch.plugin:x-pack:${indexCompatVersions[-1]}": ':x-pack-elasticsearch:plugin:bwc:release-snapshot']
+  for (final Version version : versionCollection.versionsIndexCompatibleWithCurrent) {
+    if (version.branch != null) {
+      final String snapshotProject = ":x-pack-elasticsearch:plugin:bwc-snapshot-dummy-projects:bwc-snapshot-${version.branch}"
+      project(snapshotProject).ext.bwcVersion = version
+      ext.projectSubstitutions["org.elasticsearch.plugin:x-pack:${version}"] = snapshotProject
     }
   }
 }

plugin/bwc-snapshot-dummy-projects/build.gradle

@@ -1,3 +1,5 @@
+import org.elasticsearch.gradle.Version
+
 import java.util.regex.Matcher
 import org.elasticsearch.gradle.LoggedExec
 
@@ -9,41 +11,20 @@ import org.elasticsearch.gradle.LoggedExec
  */
 
 subprojects {
-  String bwcVersion
-  boolean enabled = true
-  if (project.name == 'stable-snapshot') {
-    /* bwc-stable is only used if the last version is on a stable branch instead
-     * of a release branch */
-    enabled = indexCompatVersions[-1].bugfix == 0
-    bwcVersion = indexCompatVersions[-1]
-  } else if (project.name == 'release-snapshot') {
-    if (indexCompatVersions[-1].bugfix == 0) {
-      /* The last version is on a stable branch so it is handled by the bwc-stable
-       * project. This project will instead handle the version before that which
-       * *should* be on a release branch. */
-      bwcVersion = indexCompatVersions[-2]
-    } else {
-      // The last version is on a release branch so it is handled by this project
-      bwcVersion = indexCompatVersions[-1]
-    }
-  } else {
+  final Matcher match = project.name =~ /bwc-snapshot-(\d+\.(\d+|x))/
+  if (!match.matches()) {
     throw new InvalidUserDataException("Unsupport project name ${project.name}")
   }
-  if (enabled) {
+  String bwcBranch = match.group(1)
+
+  if (project.hasProperty('bwcVersion')) {
+    Version bwcVersion = project.ext.bwcVersion
+
     apply plugin: 'distribution'
     // Not published so no need to assemble
     tasks.remove(assemble)
     build.dependsOn.remove('assemble')
 
-    def (String major, String minor, String bugfix) = bwcVersion.split('\\.')
-    def (String currentMajor, String currentMinor, String currentBugfix) = version.split('\\.')
-    String bwcBranch
-    if (project.name == 'stable-snapshot' && major != currentMajor) {
-      bwcBranch = "${major}.x"
-    } else {
-      bwcBranch = "${major}.${minor}"
-    }
-
     File esCheckoutDir = file("${buildDir}/bwc/checkout-es-${bwcBranch}")
     File xpackCheckoutDir = file("${esCheckoutDir}-extra/x-pack-elasticsearch")
 

qa/full-cluster-restart/build.gradle

@@ -118,7 +118,7 @@ subprojects {
     into outputDir
   }
 
-  for (Version version : indexCompatVersions) {
+  for (Version version : versionCollection.versionsIndexCompatibleWithCurrent) {
     String baseName = "v${version}"
 
     Task oldClusterTest = tasks.create(name: "${baseName}#oldClusterTest", type: RestIntegTestTask) {
@@ -227,7 +227,11 @@ subprojects {
   // basic integ tests includes testing bwc against the most recent version
   task integTest {
     if (project.bwc_tests_enabled) {
-      dependsOn = ["v${wireCompatVersions[-1]}#bwcTest"]
+      if (project.bwc_tests_enabled) {
+        for (final def version : versionCollection.basicIntegrationTestVersions) {
+          dependsOn "v${version}#bwcTest"
+        }
+      }
     }
   }
 

qa/rolling-upgrade/build.gradle

@@ -103,7 +103,7 @@ subprojects {
     into outputDir
   }
 
-  for (Version version : wireCompatVersions) {
+  for (Version version : versionCollection.versionsWireCompatibleWithCurrent) {
     String baseName = "v${version}"
 
     Task oldClusterTest = tasks.create(name: "${baseName}#oldClusterTest", type: RestIntegTestTask) {
@@ -256,7 +256,11 @@ subprojects {
   // basic integ tests includes testing bwc against the most recent version
   task integTest {
     if (project.bwc_tests_enabled) {
-      dependsOn = ["v${wireCompatVersions[-1]}#bwcTest"]
+      if (project.bwc_tests_enabled) {
+        for (final def version : versionCollection.basicIntegrationTestVersions) {
+          dependsOn "v${version}#bwcTest"
+        }
+      }
     }
   }
   check.dependsOn(integTest)