1 files changed, 85 insertions, 0 deletions
diff --git a/wrapper.gradle b/wrapper.gradle
new file mode 100644
index 0000000000..2dfca19e74
--- /dev/null
+++ b/wrapper.gradle
@@ -0,0 +1,85 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+// This file contains tasks for the gradle wrapper generation.
+
+// Ensure the wrapper script is generated based on the version defined in the project
+// and not the version installed on the machine running the task.
+// Read more about the wrapper here: https://docs.gradle.org/current/userguide/gradle_wrapper.html
+wrapper {
+    gradleVersion = project.gradleVersion
+    distributionType = Wrapper.DistributionType.ALL
+}
+
+// Custom task to inject support for downloading the gradle wrapper jar if it doesn't exist.
+// This allows us to avoid checking in the jar to our repository.
+// Additionally adds a license header to the wrapper while editing the file contents.
+task bootstrapWrapper() {
+    // In the doLast block so this runs when the task is called and not during project configuration.
+    doLast {
+        def wrapperBasePath = "\$APP_HOME/gradle/wrapper"
+        def wrapperJarPath = wrapperBasePath + "/gradle-wrapper.jar"
+
+        // Add a trailing zero to the version if needed.
+        def fullVersion = project.gradleVersion.count(".") == 1 ? "${project.gradleVersion}.0" : versions.gradle
+        // Leverages the wrapper jar checked into the gradle project on github because the jar isn't
+        // available elsewhere. Using raw.githubusercontent.com instead of github.com because
+        // github.com servers deprecated TLSv1/TLSv1.1 support some time ago, so older versions
+        // of curl (built against OpenSSL library that doesn't support TLSv1.2) would fail to
+        // fetch the jar.
+        def wrapperBaseUrl = "https://raw.githubusercontent.com/gradle/gradle/v$fullVersion/gradle/wrapper"
+        def wrapperJarUrl = wrapperBaseUrl + "/gradle-wrapper.jar"
+
+        def bootstrapString = """
+      # Loop in case we encounter an error.
+      for attempt in 1 2 3; do
+        if [ ! -e "$wrapperJarPath" ]; then
+          if ! curl -s -S --retry 3 -L -o "$wrapperJarPath" "$wrapperJarUrl"; then
+            rm -f "$wrapperJarPath"
+            # Pause for a bit before looping in case the server throttled us.
+            sleep 5
+            continue
+          fi
+        fi
+      done
+      """.stripIndent()
+
+        def wrapperScript = wrapper.scriptFile
+        def wrapperLines = wrapperScript.readLines()
+        wrapperScript.withPrintWriter { out ->
+            def bootstrapWritten = false
+            wrapperLines.each { line ->
+                // Print the wrapper bootstrap before the first usage of the wrapper jar.
+                if (!bootstrapWritten && line.contains("gradle-wrapper.jar")) {
+                    out.println(bootstrapString)
+                    bootstrapWritten = true
+                }
+                out.print(line)
+                out.println()
+            }
+        }
+    }
+}
+wrapper.finalizedBy bootstrapWrapper
+
+// Remove the generated batch file since we don't test building in the Windows environment.
+task removeWindowsScript(type: Delete) {
+    delete "$rootDir/gradlew.bat"
+}
+wrapper.finalizedBy removeWindowsScript