Neo4j integration (#2692)

* Neo4j integration

bom/pom.xml

@@ -909,6 +909,22 @@
                 <artifactId>helidon-logging-log4j</artifactId>
                 <version>${helidon.version}</version>
             </dependency>
+            <!-- Neo4j -->
+            <dependency>
+                <groupId>io.helidon.integrations.neo4j</groupId>
+                <artifactId>helidon-integrations-neo4j</artifactId>
+                <version>${helidon.version}</version>
+            </dependency>
+            <dependency>
+                <groupId>io.helidon.integrations.neo4j</groupId>
+                <artifactId>helidon-integrations-neo4j-health</artifactId>
+                <version>${helidon.version}</version>
+            </dependency>
+            <dependency>
+                <groupId>io.helidon.integrations.neo4j</groupId>
+                <artifactId>helidon-integrations-neo4j-metrics</artifactId>
+                <version>${helidon.version}</version>
+            </dependency>
         </dependencies>
     </dependencyManagement>
 </project>

common/common/src/main/java/io/helidon/common/FeatureCatalog.java

@@ -499,6 +499,23 @@ final class FeatureCatalog {
             "Zipkin",
             "Zipkin tracer integration",
             "Tracing", "Zipkin");
+        add("io.helidon.integrations.neo4j",
+                FeatureDescriptor.builder()
+                        .name("Neo4j integration")
+                        .description("Integration with Neo4j driver")
+                        .path("Neo4j")
+                        .experimental(true)
+                        .nativeSupported(true));
+        add("io.helidon.integrations.neo4j.health",
+                FeatureDescriptor.builder()
+                        .name("Neo4j Health")
+                        .description("Health check for Neo4j integration")
+                        .path("Neo4j", "Health"));
+        add("io.helidon.integrations.neo4j.metrics",
+                FeatureDescriptor.builder()
+                        .name("Neo4j Metrics")
+                        .description("Metrics for Neo4j integration")
+                        .path("Neo4j", "Metrics"));
         add("io.helidon.webclient",
             FeatureDescriptor.builder()
                     .name("Web Client")

dependencies/pom.xml

@@ -106,6 +106,7 @@
         <version.lib.mockito>2.23.4</version.lib.mockito>
         <version.lib.mongodb.reactivestreams>1.11.0</version.lib.mongodb.reactivestreams>
         <version.lib.mssql-jdbc>8.4.1.jre8</version.lib.mssql-jdbc>
+        <version.lib.neo4j>4.2.0</version.lib.neo4j>
         <version.lib.mysql-connector-java>8.0.22</version.lib.mysql-connector-java>
         <version.lib.narayana>5.9.3.Final</version.lib.narayana>
         <version.lib.netty>4.1.59.Final</version.lib.netty>
@@ -1014,6 +1015,12 @@
                 <artifactId>micronaut-aop</artifactId>
                 <version>${version.lib.micronaut}</version>
             </dependency>
+            <!-- Neo4j -->
+            <dependency>
+                <groupId>org.neo4j.driver</groupId>
+                <artifactId>neo4j-java-driver</artifactId>
+                <version>${version.lib.neo4j}</version>
+            </dependency>
             <!-- END OF Section 1: direct third party dependencies -->
 
             <!-- Section 2: third party dependencies used by examples -->

examples/integrations/neo4j/neo4j-mp/.dockerignore

@@ -0,0 +1 @@
+target/*

examples/integrations/neo4j/neo4j-mp/Dockerfile

@@ -0,0 +1,44 @@
+#
+# Copyright (c) 2021 Oracle and/or its affiliates.
+#
+# 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.
+#
+
+# 1st stage, build the app
+FROM maven:3.6-jdk-11 as build
+
+WORKDIR /helidon
+
+# Create a first layer to cache the "Maven World" in the local repository.
+# Incremental docker builds will always resume after that, unless you update
+# the pom
+ADD pom.xml .
+RUN mvn package -Dmaven.test.skip -Declipselink.weave.skip
+
+# Do the Maven build!
+# Incremental docker builds will resume here when you change sources
+ADD src src
+RUN mvn package -DskipTests
+RUN echo "done!"
+
+# 2nd stage, build the runtime image
+FROM openjdk:11-jre-slim
+WORKDIR /helidon
+
+# Copy the binary built in the 1st stage
+COPY --from=build /helidon/target/helidon-examples-integration-neo4j-mp.jar ./
+COPY --from=build /helidon/target/libs ./libs
+
+CMD ["java", "-jar", "helidon-examples-integration-neo4j-mp.jar"]
+
+EXPOSE 8080

examples/integrations/neo4j/neo4j-mp/Dockerfile.jlink

@@ -0,0 +1,40 @@
+#
+# Copyright (c) 2021 Oracle and/or its affiliates.
+#
+# 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.
+#
+
+# 1st stage, build the app
+FROM maven:3.6.3-jdk-11-slim as build
+
+WORKDIR /helidon
+
+# Create a first layer to cache the "Maven World" in the local repository.
+# Incremental docker builds will always resume after that, unless you update
+# the pom
+ADD pom.xml .
+RUN mvn package -Dmaven.test.skip -Declipselink.weave.skip
+
+# Do the Maven build to create the custom Java Runtime Image
+# Incremental docker builds will resume here when you change sources
+ADD src src
+RUN mvn -Ddocker.build=true package -Pjlink-image -DskipTests
+RUN echo "done!"
+
+# 2nd stage, build the final image with the JRI built in the 1st stage
+
+FROM debian:stretch-slim
+WORKDIR /helidon
+COPY --from=build /helidon/target/helidon-examples-integration-neo4j-mp-jri ./
+ENTRYPOINT ["/bin/bash", "/helidon/bin/start"]
+EXPOSE 8080

examples/integrations/neo4j/neo4j-mp/Dockerfile.native

@@ -0,0 +1,44 @@
+#
+# Copyright (c) 2021 Oracle and/or its affiliates.
+#
+# 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.
+#
+
+# 1st stage, build the app
+FROM helidon/jdk11-graalvm-maven:20.2.0 as build
+
+WORKDIR /helidon
+
+# Create a first layer to cache the "Maven World" in the local repository.
+# Incremental docker builds will always resume after that, unless you update
+# the pom
+ADD pom.xml .
+RUN mvn package -Pnative-image -Dnative.image.skip -Dmaven.test.skip -Declipselink.weave.skip
+
+# Do the Maven build!
+# Incremental docker builds will resume here when you change sources
+ADD src src
+RUN mvn package -Pnative-image -Dnative.image.buildStatic -DskipTests
+
+RUN echo "done!"
+
+# 2nd stage, build the runtime image
+FROM scratch
+WORKDIR /helidon
+
+# Copy the binary built in the 1st stage
+COPY --from=build /helidon/target/helidon-examples-integration-neo4j-mp .
+
+ENTRYPOINT ["./helidon-examples-integration-neo4j-mp"]
+
+EXPOSE 8080

examples/integrations/neo4j/neo4j-mp/README.md

@@ -0,0 +1,167 @@
+# Helidon Quickstart MP Example
+
+This example implements a simple Neo4j REST service using MicroProfile.
+
+## Build and run
+
+Bring up a Neo4j instance via Docker
+
+```bash
+docker run --publish=7474:7474 --publish=7687:7687 -e 'NEO4J_AUTH=neo4j/secret'  neo4j:4.0
+```
+
+Goto the Neo4j browser and play the first step of the movies graph: [`:play movies`](http://localhost:7474/browser/?cmd=play&arg=movies).
+
+
+Then build with JDK11+
+```bash
+mvn package
+java -jar target/helidon-integrations-neo4j-mp.jar
+```
+
+## Exercise the application
+
+```
+curl -X GET http://localhost:8080/movies
+
+```
+
+## Try health and metrics
+
+```
+curl -s -X GET http://localhost:8080/health
+{"outcome":"UP",...
+. . .
+
+# Prometheus Format
+curl -s -X GET http://localhost:8080/metrics
+# TYPE base:gc_g1_young_generation_count gauge
+. . .
+
+# JSON Format
+curl -H 'Accept: application/json' -X GET http://localhost:8080/metrics
+{"base":...
+. . .
+
+```
+
+## Build the Docker Image
+
+```
+docker build -t helidon-integrations-neo4j-mp .
+```
+
+## Start the application with Docker
+
+```
+docker run --rm -p 8080:8080 helidon-integrations-neo4j-mp:latest
+```
+
+Exercise the application as described above
+
+## Deploy the application to Kubernetes
+
+```
+kubectl cluster-info                                # Verify which cluster
+kubectl get pods                                    # Verify connectivity to cluster
+kubectl create -f app.yaml                          # Deploy application
+kubectl get service helidon-integrations-neo4j-mp   # Verify deployed service
+```
+
+## Build a native image with GraalVM
+
+GraalVM allows you to compile your programs ahead-of-time into a native
+ executable. See https://www.graalvm.org/docs/reference-manual/aot-compilation/
+ for more information.
+
+You can build a native executable in 2 different ways:
+* With a local installation of GraalVM
+* Using Docker
+
+### Local build
+
+Download Graal VM at https://www.graalvm.org/downloads. We recommend
+version `20.1.0` or later.
+
+```
+# Setup the environment
+export GRAALVM_HOME=/path
+# build the native executable
+mvn package -Pnative-image
+```
+
+You can also put the Graal VM `bin` directory in your PATH, or pass
+ `-DgraalVMHome=/path` to the Maven command.
+
+See https://github.com/oracle/helidon-build-tools/tree/master/helidon-maven-plugin#goal-native-image
+ for more information.
+
+Start the application:
+
+```
+./target/helidon-quickstart-mp
+```
+
+### Multi-stage Docker build
+
+Build the "native" Docker Image
+
+```
+docker build -t helidon-integrations-neo4j-mp-native -f Dockerfile.native .
+```
+
+Start the application:
+
+```
+docker run --rm -p 8080:8080 helidon-integrations-neo4j-mp-native:latest
+```
+
+
+## Build a Java Runtime Image using jlink
+
+You can build a custom Java Runtime Image (JRI) containing the application jars and the JDK modules 
+on which they depend. This image also:
+
+* Enables Class Data Sharing by default to reduce startup time. 
+* Contains a customized `start` script to simplify CDS usage and support debug and test modes. 
+
+You can build a custom JRI in two different ways:
+* Local
+* Using Docker
+
+
+### Local build
+
+```
+# build the JRI
+mvn package -Pjlink-image
+```
+
+See https://github.com/oracle/helidon-build-tools/tree/master/helidon-maven-plugin#goal-jlink-image
+ for more information.
+
+Start the application:
+
+```
+./target/helidon-integrations-neo4j-mp-jri/bin/start
+```
+
+### Multi-stage Docker build
+
+Build the JRI as a Docker Image
+
+```
+docker build -t helidon-integrations-neo4j-mp-jri -f Dockerfile.jlink .
+```
+
+Start the application:
+
+```
+docker run --rm -p 8080:8080 helidon-integrations-neo4j-mp-jri:latest
+```
+
+See the start script help:
+
+```
+docker run --rm helidon-integrations-neo4j-mp-jri:latest --help
+```