Merge pull request #1 from aiven/initial-checkout

Do initial code and README check-in

#1

Author: Ormod

.gitignore

@@ -1,23 +1,7 @@
-# Compiled class file
-*.class
+.idea
 
-# Log file
-*.log
+# Ignore Gradle project-specific cache directory
+.gradle
 
-# BlueJ files
-*.ctxt
-
-# Mobile Tools for Java (J2ME)
-.mtj.tmp/
-
-# Package Files #
-*.jar
-*.war
-*.nar
-*.ear
-*.zip
-*.tar.gz
-*.rar
-
-# virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
-hs_err_pid*
+# Ignore Gradle build output directory
+build

.travis.yml

@@ -0,0 +1,16 @@
+language: java
+
+git:
+  depth: 3
+
+jdk:
+  - openjdk8
+  - openjdk11
+
+before_cache:
+  - rm -f  $HOME/.gradle/caches/modules-2/modules-2.lock
+  - rm -fr $HOME/.gradle/caches/*/plugin-resolution/
+cache:
+  directories:
+    - $HOME/.gradle/caches/
+    - $HOME/.gradle/wrapper/

README.md

@@ -0,0 +1,35 @@
+# Aiven Kafka Connect Transformations
+
+[![Build Status](https://travis-ci.org/aiven/aiven-kafka-connect-transforms.svg?branch=master)](https://travis-ci.org/aiven/aiven-kafka-connect-transforms)
+
+This is a set of [Kafka Connect transformations](https://kafka.apache.org/documentation/#connect_transforms).
+
+## Transformations
+
+### `ExtractTopic`
+
+This transformation extracts a string value from the message and use it as the topic name.
+
+The transformation can use either the whole key or value (in this case, it must have `STRING` type) or a field in them (in this case, it must have `STRUCT` type and the field's value must be `STRING`).
+
+Exists in two variants:
+- `io.aiven.kafka.connect.transforms.ExtractTopic$Key` - works on keys;
+- `io.aiven.kafka.connect.transforms.ExtractTopic$Value` - works on values.
+
+The transformation defines the following configurations:
+
+- `field.name` - The name of the field which should be used as the topic name. If `null` or empty, the entire key or value is used (and assumed to be a string). By default is `null`.
+- `skip.missing.or.null` - In case the source of the new topic name is `null` or missing, should a record be silently passed without transformation. By default is `false`.
+
+Here's an example of this transformation configuration:
+
+```properties
+transforms=ExtractTopicFromValueField
+transforms.ExtractTopicFromValueField.field.name=inner_field_name
+```
+
+See [the Kafka documentation](https://kafka.apache.org/documentation/#connect_transforms) for more details about configuring transformations. 
+
+## License
+
+This project is licensed under the [Apache License, Version 2.0](LICENSE).

build.gradle

@@ -0,0 +1,81 @@
+/*
+ * Copyright 2019 Aiven Oy
+ *
+ * Licensed 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.
+ */
+
+plugins {
+    // https://docs.gradle.org/current/userguide/java_library_plugin.html
+    id 'java-library'
+
+    // https://docs.gradle.org/current/userguide/distribution_plugin.html
+    id 'distribution'
+
+    // https://docs.gradle.org/current/userguide/checkstyle_plugin.html
+    id 'checkstyle'
+}
+
+repositories {
+    jcenter()
+}
+
+sourceCompatibility = JavaVersion.VERSION_1_8
+targetCompatibility = JavaVersion.VERSION_1_8
+
+ext {
+    kafkaVersion = "2.0.1"
+}
+
+distributions {
+    main {
+        contents {
+            from jar
+            from configurations.runtimeClasspath
+        }
+    }
+}
+
+dependencies {
+    compileOnly "org.apache.kafka:connect-api:$kafkaVersion"
+
+    implementation "org.slf4j:slf4j-api:1.7.25"
+
+    testImplementation "org.junit.jupiter:junit-jupiter:5.5.1"
+    testImplementation "org.hamcrest:hamcrest:2.1"
+    testImplementation "org.apache.kafka:connect-api:$kafkaVersion"
+    testRuntime "org.apache.logging.log4j:log4j-slf4j-impl:2.12.1"
+}
+
+checkstyle {
+    toolVersion "8.21"
+}
+
+test {
+    useJUnitPlatform {
+        includeEngines 'junit-jupiter'
+    }
+}
+
+processResources {
+    filesMatching('aiven-kafka-connect-transforms-version.properties') {
+        expand(version: version)
+    }
+}
+
+jar {
+    manifest {
+        attributes(
+                'Version': "${getArchiveVersion()}"
+        )
+    }
+}