Build: allow building snapshot of release branches (elastic/x-pack-elasticsearch#1582)

This allows us to build both 5.5.0-SNAPSHOT and 5.4.1-SNAPSHOT
artifacts for backwards compatibility testing. It is a port of
elastic/elasticsearch:24870 to x-pack and will be super useful
when elastic/elasticsearch:24846 is ported to x-pack.

Original commit: elastic/x-pack-elasticsearch@0ea443f488

build.gradle

@@ -44,8 +44,18 @@ subprojects {
     additionalLicense 'ESCON', 'Elasticsearch Confidential', 'ELASTICSEARCH CONFIDENTIAL'
   }
   ext.projectSubstitutions += [ "org.elasticsearch.plugin:x-pack-api:${version}": ':x-pack-elasticsearch:plugin']
+
   if (wireCompatVersions[-1].snapshot) {
-    ext.projectSubstitutions += [
-      "org.elasticsearch.plugin:x-pack:${wireCompatVersions[-1]}": ':x-pack-elasticsearch:plugin:bwc-zip']
+    /* 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']
+    }
   }
 }

plugin/bwc-zip/build.gradle

@@ -1,121 +0,0 @@
-import java.util.regex.Matcher
-import org.elasticsearch.gradle.LoggedExec
-
-/**
- * This is a dummy project which does a local checkout of the previous
- * wire compat version's branch, and builds a snapshot. This allows backcompat
- * tests to test against the next unreleased version, closest to this version,
- * without relying on snapshots.
- */
-
-String bwcVersion = wireCompatVersions[-1]
-if (bwcVersion.endsWith('-SNAPSHOT')) {
-  apply plugin: 'distribution'
-
-  def (String major, String minor, String bugfix) = bwcVersion.split('\\.')
-  String bwcBranch = bugfix == '0-SNAPSHOT' ? "${major}.x" : "${major}.${minor}"
-
-  File esCheckoutDir = file("${buildDir}/bwc/checkout-es-${bwcBranch}")
-  File xpackCheckoutDir = file("${esCheckoutDir}-extra/x-pack-elasticsearch")
-  task createElasticsearchClone(type: LoggedExec) {
-    onlyIf { esCheckoutDir.exists() == false }
-    commandLine = ['git', 'clone', rootDir, esCheckoutDir]
-  }
-
-  task createXPackClone(type: LoggedExec) {
-    onlyIf { xpackCheckoutDir.exists() == false }
-    commandLine = ['git', 'clone', project(':x-pack-elasticsearch').projectDir, xpackCheckoutDir]
-  }
-
-  // we use regular Exec here to ensure we always get output, regardless of logging level
-  task findElasticsearchUpstream(type: Exec) {
-    dependsOn createElasticsearchClone
-    workingDir = esCheckoutDir
-    commandLine = ['git', 'remote', '-v']
-    ignoreExitValue = true
-    ByteArrayOutputStream output = new ByteArrayOutputStream()
-    standardOutput = output
-    doLast {
-      if (execResult.exitValue != 0) {
-        output.toString('UTF-8').eachLine { line -> logger.error(line) }
-        execResult.assertNormalExitValue()
-      }
-      project.ext.esUpstreamExists = false
-      output.toString('UTF-8').eachLine {
-        if (it.contains("upstream")) {
-          project.ext.esUpstreamExists = true
-        }
-      }
-    }
-  }
-
-  task findXPackUpstream(type: Exec) {
-    dependsOn createXPackClone
-    workingDir = xpackCheckoutDir
-    commandLine = ['git', 'remote', '-v']
-    ignoreExitValue = true
-    ByteArrayOutputStream output = new ByteArrayOutputStream()
-    standardOutput = output
-    doLast {
-      if (execResult.exitValue != 0) {
-        output.toString('UTF-8').eachLine { line -> logger.error(line) }
-        execResult.assertNormalExitValue()
-      }
-      project.ext.xpackUpstreamExists = false
-      output.toString('UTF-8').eachLine {
-        if (it.contains("upstream")) {
-          project.ext.xpackUpstreamExists = true
-        }
-      }
-    }
-  }
-
-  task addElasticsearchUpstream(type: LoggedExec) {
-    dependsOn findElasticsearchUpstream
-    onlyIf { project.ext.esUpstreamExists == false }
-    workingDir = esCheckoutDir
-    commandLine = ['git', 'remote', 'add', 'upstream', 'git@github.com:elastic/elasticsearch.git']
-  }
-
-  task addXPackUpstream(type: LoggedExec) {
-    dependsOn findXPackUpstream
-    onlyIf { project.ext.xpackUpstreamExists == false }
-    workingDir = xpackCheckoutDir
-    commandLine = ['git', 'remote', 'add', 'upstream', 'git@github.com:elastic/x-pack-elasticsearch.git']
-  }
-
-  task fetchElasticsearchLatest(type: LoggedExec) {
-    dependsOn addElasticsearchUpstream
-    workingDir = esCheckoutDir
-    commandLine = ['git', 'fetch', 'upstream']
-  }
-
-  task fetchXPackLatest(type: LoggedExec) {
-    dependsOn addXPackUpstream
-    workingDir = xpackCheckoutDir
-    commandLine = ['git', 'fetch', 'upstream']
-  }
-
-  task checkoutElasticsearchBwcBranch(type: LoggedExec) {
-    dependsOn fetchElasticsearchLatest
-    workingDir = esCheckoutDir
-    commandLine = ['git', 'checkout', "upstream/${bwcBranch}"]
-  }
-
-  task checkoutXPackBwcBranch(type: LoggedExec) {
-    dependsOn fetchXPackLatest
-    workingDir = xpackCheckoutDir
-    commandLine = ['git', 'checkout', "upstream/${bwcBranch}"]
-  }
-
-  File bwcZip = file("${xpackCheckoutDir}/plugin/build/distributions/x-pack-${bwcVersion}.zip")
-  task buildBwcVersion(type: GradleBuild) {
-    dependsOn checkoutXPackBwcBranch, checkoutElasticsearchBwcBranch
-    dir = xpackCheckoutDir
-    tasks = [':x-pack-elasticsearch:plugin:assemble']
-  }
-
-  artifacts {
-    'default' file: bwcZip, name: 'x-pack', type: 'zip', builtBy: buildBwcVersion
-  }
-}

plugin/bwc/build.gradle

@@ -0,0 +1,144 @@
+import java.util.regex.Matcher
+import org.elasticsearch.gradle.LoggedExec
+
+/**
+ * Subdirectories of this project are dummy projects which does a local
+ * checkout of the appropriate version's branch, and builds a snapshot. This
+ * allows backcompat tests to test against the next unreleased versions
+ * without relying on snapshots.
+ */
+
+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 {
+    throw new InvalidUserDataException("Unsupport project name ${project.name}")
+  }
+  if (enabled) {
+    apply plugin: 'distribution'
+
+    def (String major, String minor, String bugfix) = bwcVersion.split('\\.')
+    String bwcBranch =
+      project.name == 'stable-snapshot' ? "${major}.x" : "${major}.${minor}"
+
+    File esCheckoutDir = file("${buildDir}/bwc/checkout-es-${bwcBranch}")
+    File xpackCheckoutDir = file("${esCheckoutDir}-extra/x-pack-elasticsearch")
+
+    task createElasticsearchClone(type: LoggedExec) {
+      onlyIf { esCheckoutDir.exists() == false }
+      commandLine = ['git', 'clone', rootDir, esCheckoutDir]
+    }
+
+    task createXPackClone(type: LoggedExec) {
+      onlyIf { xpackCheckoutDir.exists() == false }
+      commandLine = ['git', 'clone', project(':x-pack-elasticsearch').projectDir, xpackCheckoutDir]
+    }
+
+    // we use regular Exec here to ensure we always get output, regardless of logging level
+    task findElasticsearchUpstream(type: Exec) {
+      dependsOn createElasticsearchClone
+      workingDir = esCheckoutDir
+      commandLine = ['git', 'remote', '-v']
+      ignoreExitValue = true
+      ByteArrayOutputStream output = new ByteArrayOutputStream()
+      standardOutput = output
+      doLast {
+        if (execResult.exitValue != 0) {
+          output.toString('UTF-8').eachLine { line -> logger.error(line) }
+          execResult.assertNormalExitValue()
+        }
+        project.ext.esUpstreamExists = false
+        output.toString('UTF-8').eachLine {
+          if (it.contains("upstream")) {
+            project.ext.esUpstreamExists = true
+          }
+        }
+      }
+    }
+
+    task findXPackUpstream(type: Exec) {
+      dependsOn createXPackClone
+      workingDir = xpackCheckoutDir
+      commandLine = ['git', 'remote', '-v']
+      ignoreExitValue = true
+      ByteArrayOutputStream output = new ByteArrayOutputStream()
+      standardOutput = output
+      doLast {
+        if (execResult.exitValue != 0) {
+          output.toString('UTF-8').eachLine { line -> logger.error(line) }
+          execResult.assertNormalExitValue()
+        }
+        project.ext.xpackUpstreamExists = false
+        output.toString('UTF-8').eachLine {
+          if (it.contains("upstream")) {
+            project.ext.xpackUpstreamExists = true
+          }
+        }
+      }
+    }
+
+    task addElasticsearchUpstream(type: LoggedExec) {
+      dependsOn findElasticsearchUpstream
+      onlyIf { project.ext.esUpstreamExists == false }
+      workingDir = esCheckoutDir
+      commandLine = ['git', 'remote', 'add', 'upstream', 'git@github.com:elastic/elasticsearch.git']
+    }
+
+    task addXPackUpstream(type: LoggedExec) {
+      dependsOn findXPackUpstream
+      onlyIf { project.ext.xpackUpstreamExists == false }
+      workingDir = xpackCheckoutDir
+      commandLine = ['git', 'remote', 'add', 'upstream', 'git@github.com:elastic/x-pack-elasticsearch.git']
+    }
+
+    task fetchElasticsearchLatest(type: LoggedExec) {
+      dependsOn addElasticsearchUpstream
+      workingDir = esCheckoutDir
+      commandLine = ['git', 'fetch', 'upstream']
+    }
+
+    task fetchXPackLatest(type: LoggedExec) {
+      dependsOn addXPackUpstream
+      workingDir = xpackCheckoutDir
+      commandLine = ['git', 'fetch', 'upstream']
+    }
+
+    task checkoutElasticsearchBwcBranch(type: LoggedExec) {
+      dependsOn fetchElasticsearchLatest
+      workingDir = esCheckoutDir
+      commandLine = ['git', 'checkout', "upstream/${bwcBranch}"]
+    }
+
+    task checkoutXPackBwcBranch(type: LoggedExec) {
+      dependsOn fetchXPackLatest
+      workingDir = xpackCheckoutDir
+      commandLine = ['git', 'checkout', "upstream/${bwcBranch}"]
+    }
+
+    File bwcZip = file("${xpackCheckoutDir}/plugin/build/distributions/x-pack-${bwcVersion}.zip")
+    task buildBwcVersion(type: GradleBuild) {
+      dependsOn checkoutXPackBwcBranch, checkoutElasticsearchBwcBranch
+      dir = xpackCheckoutDir
+      tasks = [':x-pack-elasticsearch:plugin:assemble']
+    }
+
+    artifacts {
+      'default' file: bwcZip, name: 'x-pack', type: 'zip', builtBy: buildBwcVersion
+    }
+  }
+}