Add JVM/Kotlin example

jvm/kotlin/.gitignore

@@ -0,0 +1,6 @@
+.project
+.settings
+.classpath
+.idea/
+target/
+hello-world.iml

jvm/kotlin/README.md

@@ -0,0 +1,46 @@
+# Hello World in JVM/Kotlin on Fission
+
+The `io.fission.HelloWorld` class is a very simple fission function that implements `io.fission.Function` and says "Hello, World!".
+
+## Building locally and deploying with Fission
+
+You can build the jar file in one of the two ways below based on your setup:
+
+- You can use docker without the need to install JDK and Maven to build the jar file from source code:
+
+```shell script
+$ bash ./build.sh
+
+```
+- If you have JDK and Maven installed, you can directly (and much faster) build the JAR file using command:
+
+```shell script
+$ mvn clean package
+```
+
+Both of above steps will generate a target subdirectory which has the archive `target/hello-world-1.0-SNAPSHOT-jar-with-dependencies.jar` which will be used for creating function.
+
+- The archive created above will be used as a deploy package when creating the function.
+
+**Note:** The archive contains a Java 9 file, and the Fission environment currently only supports Java 8. To fix this,
+run the following command every time after building the archive:
+
+```shell script
+$ zip -d target/hello-world-1.0-SNAPSHOT-jar-with-dependencies.jar 'META-INF/versions/*'
+```
+
+```shell script
+$ fission env create --name jvm --image fission/jvm-env --version 2 --keeparchive=true
+$ fission fn create --name hello --deploy target/hello-world-1.0-SNAPSHOT-jar-with-dependencies.jar --env jvm --entrypoint io.fission.HelloWorld
+$ fission route create --function hello --url /hellop --method GET
+$ fission fn test --name hello
+Hello World! Greetings from function 'hello' delivered by Kotlin!
+```
+
+If you use Minikube for this, alternatively run the function using
+
+```shell script
+$ export FISSION=$(minikube ip):$(kubectl -n fission get svc router -o jsonpath='{...nodePort}')
+$ curl http://$FISSION/hellop
+Hello, World! Greetings from function 'hello' delivered by Kotlin!
+```

jvm/kotlin/build.sh

@@ -0,0 +1,5 @@
+#!/bin/bash
+# This script allows you to build the jar without needing Maven & JDK installed locally. 
+# You need docker, as it uses a Docker image to build source code
+set -eou pipefail
+docker run -it --rm  -v "$(pwd)":/usr/src/mymaven -w /usr/src/mymaven maven:3.5-jdk-8 mvn clean package

jvm/kotlin/pom.xml

@@ -0,0 +1,139 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+
+	<modelVersion>4.0.0</modelVersion>
+	<groupId>io.fission</groupId>
+	<artifactId>hello-world</artifactId>
+	<version>1.0-SNAPSHOT</version>
+	<packaging>jar</packaging>
+
+	<name>hello-world</name>
+	<url>http://maven.apache.org</url>
+
+	<properties>
+		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <java.version>1.8</java.version>
+        <maven.compiler.target>1.8</maven.compiler.target>
+        <maven.compiler.source>1.8</maven.compiler.source>
+        <kotlin.version>1.5.20</kotlin.version>
+        <maven.test.skip>true</maven.test.skip>
+	</properties>
+
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-web</artifactId>
+			<version>2.0.1.RELEASE</version>
+			<scope>provided</scope>
+		</dependency>
+		<dependency>
+			<groupId>io.fission</groupId>
+			<artifactId>fission-java-core</artifactId>
+			<version>0.0.2-SNAPSHOT</version>
+			<scope>provided</scope>
+		</dependency>
+        <dependency>
+            <groupId>org.jetbrains.kotlin</groupId>
+            <artifactId>kotlin-stdlib-jdk8</artifactId>
+            <version>${kotlin.version}</version>
+        </dependency>
+    </dependencies>
+
+	<build>
+        <sourceDirectory>${project.basedir}/src/main/kotlin</sourceDirectory>
+		<plugins>
+			<plugin>
+				<artifactId>maven-assembly-plugin</artifactId>
+				<configuration>
+					<descriptorRefs>
+						<descriptorRef>jar-with-dependencies</descriptorRef>
+					</descriptorRefs>
+				</configuration>
+				<executions>
+					<execution>
+						<id>make-assembly</id> <!-- this is used for inheritance merges -->
+						<phase>package</phase> <!-- bind to the packaging phase -->
+						<goals>
+							<goal>single</goal>
+						</goals>
+					</execution>
+				</executions>
+			</plugin>
+			<plugin>
+            			<groupId>org.apache.maven.plugins</groupId>
+            			<artifactId>maven-surefire-plugin</artifactId>
+            			<version>2.22.1</version>
+            			<configuration>
+                			<useSystemClassLoader>false</useSystemClassLoader>
+            			</configuration>
+        		</plugin>
+            <plugin>
+                <groupId>org.jetbrains.kotlin</groupId>
+                <artifactId>kotlin-maven-plugin</artifactId>
+                <version>${kotlin.version}</version>
+                <executions>
+                    <execution>
+                        <id>compile</id>
+                        <phase>compile</phase>
+                        <goals>
+                            <goal>compile</goal>
+                        </goals>
+                    </execution>
+                    <execution>
+                        <id>test-compile</id>
+                        <phase>test-compile</phase>
+                        <goals>
+                            <goal>test-compile</goal>
+                        </goals>
+                    </execution>
+                </executions>
+                <configuration>
+                    <jvmTarget>1.8</jvmTarget>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <id>default-compile</id>
+                        <phase>none</phase>
+                    </execution>
+                    <execution>
+                        <id>default-testCompile</id>
+                        <phase>none</phase>
+                    </execution>
+                    <execution>
+                        <id>compile</id>
+                        <phase>compile</phase>
+                        <goals>
+                            <goal>compile</goal>
+                        </goals>
+                    </execution>
+                    <execution>
+                        <id>testCompile</id>
+                        <phase>test-compile</phase>
+                        <goals>
+                            <goal>testCompile</goal>
+                        </goals>
+                    </execution>
+                </executions>
+                <configuration>
+                    <source>1.8</source>
+                    <target>1.8</target>
+                </configuration>
+            </plugin>
+        </plugins>
+	</build>
+
+	<!-- Adding Sonatype repository to pull snapshots -->
+	<repositories>
+		<repository>
+			<id>fission-java-core</id>
+			<name>fission-java-core-snapshot</name>
+			<url>https://oss.sonatype.org/content/repositories/snapshots/</url>
+		</repository>
+	</repositories>
+
+</project>

jvm/kotlin/specs/README

@@ -0,0 +1,42 @@
+
+Fission Specs
+=============
+
+This is a set of specifications for a Fission app.  This includes functions,
+environments, and triggers; we collectively call these things "resources".
+
+How to use these specs
+----------------------
+
+These specs are handled with the 'fission spec' command.  See 'fission spec --help'.
+
+'fission spec apply' will "apply" all resources specified in this directory to your
+cluster.  That means it checks what resources exist on your cluster, what resources are
+specified in the specs directory, and reconciles the difference by creating, updating or
+deleting resources on the cluster.
+
+'fission spec apply' will also package up your source code (or compiled binaries) and
+upload the archives to the cluster if needed.  It uses 'ArchiveUploadSpec' resources in
+this directory to figure out which files to archive.
+
+You can use 'fission spec apply --watch' to watch for file changes and continuously keep
+the cluster updated.
+
+You can add YAMLs to this directory by writing them manually, but it's easier to generate
+them.  Use 'fission function create --spec' to generate a function spec,
+'fission environment create --spec' to generate an environment spec, and so on.
+
+You can edit any of the files in this directory, except 'fission-deployment-config.yaml',
+which contains a UID that you should never change.  To apply your changes simply use
+'fission spec apply'.
+
+fission-deployment-config.yaml
+------------------------------
+
+fission-deployment-config.yaml contains a UID.  This UID is what fission uses to correlate
+resources on the cluster to resources in this directory.
+
+All resources created by 'fission spec apply' are annotated with this UID.  Resources on
+the cluster that are _not_ annotated with this UID are never modified or deleted by
+fission.
+

jvm/kotlin/specs/env-java.yaml

@@ -0,0 +1,17 @@
+apiVersion: fission.io/v1
+kind: Environment
+metadata:
+  creationTimestamp: null
+  name: java
+  namespace: default
+spec:
+  builder:
+    command: build
+    image: fission/jvm-builder:1.7.1
+  imagepullsecret: ""
+  keeparchive: true
+  poolsize: 3
+  resources: {}
+  runtime:
+    image: fission/jvm-env:1.7.1
+  version: 2

jvm/kotlin/specs/fission-deployment-config.yaml

@@ -0,0 +1,7 @@
+# This file is generated by the 'fission spec init' command.
+# See the README in this directory for background and usage information.
+# Do not edit the UID below: that will break 'fission spec apply'
+apiVersion: fission.io/v1
+kind: DeploymentConfig
+name: java
+uid: 908a303a-bf23-4bae-a22c-b1db9a1f71a9

jvm/kotlin/specs/function-hello.yaml

@@ -0,0 +1,27 @@
+apiVersion: fission.io/v1
+kind: Function
+metadata:
+  creationTimestamp: null
+  name: hello
+  namespace: default
+spec:
+  InvokeStrategy:
+    ExecutionStrategy:
+      ExecutorType: poolmgr
+      MaxScale: 0
+      MinScale: 0
+      SpecializationTimeout: 120
+      TargetCPUPercent: 0
+    StrategyType: execution
+  configmaps: null
+  environment:
+    name: java
+    namespace: default
+  functionTimeout: 60
+  package:
+    functionName: io.fission.HelloWorld
+    packageref:
+      name: hellojava
+      namespace: default
+  resources: {}
+  secrets: null

jvm/kotlin/specs/package-hellojava.yaml

@@ -0,0 +1,26 @@
+include:
+- src
+- pom.xml
+kind: ArchiveUploadSpec
+name: src-URlE
+
+---
+apiVersion: fission.io/v1
+kind: Package
+metadata:
+  creationTimestamp: null
+  name: hellojava
+  namespace: default
+spec:
+  deployment:
+    checksum: {}
+  environment:
+    name: java
+    namespace: default
+  source:
+    checksum: {}
+    type: url
+    url: archive://src-URlE
+status:
+  buildstatus: pending
+  lastUpdateTimestamp: "2020-01-29T09:43:56Z"

jvm/kotlin/src/main/kotlin/io/fission/HelloWorld.kt

@@ -0,0 +1,11 @@
+package io.fission
+
+import org.springframework.http.RequestEntity
+import org.springframework.http.ResponseEntity
+
+internal class HelloWorld : Function<Any?, Any?> {
+    override fun call(req: RequestEntity<*>, context: Context?): ResponseEntity<*> {
+        val functionName = req.headers["x-fission-function-name"]?.first() ?: "I do not know who I are?!?"
+        return ResponseEntity.ok("Hello, World! Greetings from function '$functionName' delivered by Kotlin!")
+    }
+}