Blog post about the native compilation of application using virtual t…

…hreads

_posts/2023-09-19-virtual-thread-1.adoc

@@ -358,7 +358,7 @@ Next, we will cover:
 - https://quarkus.io/blog/virtual-threads-2/[How to write a crud application using virtual threads]
 - https://quarkus.io/blog/virtual-threads-3/[How to test virtual threads applications]
 - https://quarkus.io/blog/virtual-threads-4/[How to process Kafka messages using virtual threads]
-- How to build a native executable when using virtual threads (_to be published_)
+- https://quarkus.io/blog/virtual-threads-5/[How to build a native executable when using virtual threads]
 - How to containerize an application using virtual threads (in JVM mode) (_to be published_)
 - How to containerize an application using virtual threads in native mode (_to be published_)
 - How to process Kafka messages using virtual threads (_to be published_)

_posts/2023-10-19-virtual-threads-5.adoc

@@ -0,0 +1,129 @@
+---
+layout: post
+title: 'Compiling virtual thread applications into native executables'
+date: 2023-10-19
+tags: virtual-threads native
+synopsis: 'Learn how to compile applications using virtual threads into native executable.'
+author: cescoffier
+---
+:imagesdir: /assets/images/posts/virtual-threads
+
+In https://quarkus.io/blog/virtual-threads-2/[another blog post], we have seen how you can implement a CRUD application with Quarkus to utilize virtual threads.
+This post will show how you can compile such an application into a native executable.
+
+== Installing GraalVM 21
+
+To compile a Quarkus application leveraging virtual threads into a native executable, you need a GraalVM version supporting Java 21.
+You can download it from https://github.com/graalvm/graalvm-ce-builds/releases/tag/jdk-21.0.0[GitHub].
+
+Alternatively, you can use the https://sdkman.io/[SDKMAN] tool to install it:
+
+[source, bash]
+----
+> sdk install java 21-graalce
+Downloading: java 21-graalce
+
+In progress...
+
+Repackaging Java 21-graalce...
+
+Done repackaging...
+Cleaning up residual files...
+
+Installing: java 21-graalce
+Done installing!
+
+Do you want java 21-graalce to be set as default? (Y/n): n
+----
+
+Once installed, make sure the `GRAALVM_HOME` environment variable points to the GraalVM installation directory:
+
+[source, bash]
+----
+> export GRAALVM_HOME=$HOME/.sdkman/candidates/java/21-graalce
+----
+
+== Compiling the application into a native executable
+
+We will reuse the CRUD application developed in a https://quarkus.io/blog/virtual-threads-2/[previous blog post].
+The source code is located in the https://github.com/quarkusio/virtual-threads-demos/tree/main/crud-example[virtual-threads-demos GitHub repository].
+Note that while we are using the CRUD application, the same approach can be used with any Quarkus application leveraging virtual threads, including the other demos from the repository.
+
+First make sure you use Java 21+ and that the `GRAALVM_HOME` environment variable points to the GraalVM installation directory.
+
+Then, in the `pom.xml` file, add the `native` profile:
+
+[source, xml]
+----
+<profiles>
+  <profile>
+    <id>native</id>
+      <activation>
+        <property>
+          <name>native</name>
+        </property>
+      </activation>
+      <properties>
+        <quarkus.package.type>native</quarkus.package.type>
+      </properties>
+  </profile>
+</profiles>
+----
+
+The `native` profile is activated when the `native` property is set.
+So, compile the application with:
+
+[source, bash]
+----
+> mvn clean package -Dnative
+----
+
+The compilation takes a few minutes.
+Once done, you can run the application:
+
+* 1) First, start the database:
+
+[source, bash]
+----
+> docker run --ulimit memlock=-1:-1 -d -it --rm=true --memory-swappiness=0 \
+    --name postgres-quarkus-demo -e POSTGRES_USER=restcrud \
+    -e POSTGRES_PASSWORD=restcrud -e POSTGRES_DB=rest-crud \
+    -p 5432:5432 postgres:15-bullseye
+----
+
+* 2) Then, start the application:
+
+[source, bash]
+----
+> ./target/crud-example-1.0.0-SNAPSHOT-runner
+----
+
+You get:
+
+[source, bash]
+----
+> ./target/crud-example-1.0.0-SNAPSHOT-runner
+__  ____  __  _____   ___  __ ____  ______
+ --/ __ \/ / / / _ | / _ \/ //_/ / / / __/
+ -/ /_/ / /_/ / __ |/ , _/ ,< / /_/ /\ \
+--\___\_\____/_/ |_/_/|_/_/|_|\____/___/
+2023-10-17 09:44:34,925 INFO  [io.quarkus] (main) crud-example 1.0.0-SNAPSHOT native (powered by Quarkus 3.4.1) started in 0.072s. Listening on: http://0.0.0.0:8080
+2023-10-17 09:44:34,925 INFO  [io.quarkus] (main) Profile prod activated.
+2023-10-17 09:44:34,925 INFO  [io.quarkus] (main) Installed features: [agroal, cdi, hibernate-orm, hibernate-orm-panache, hibernate-validator, jdbc-postgresql, narayana-jta, resteasy-reactive, resteasy-reactive-jackson, smallrye-context-propagation, vertx]
+----
+
+Then, open the application in a browser (http://localhost:8080) and start adding, updating, and completing tasks.
+You will see in the logs that the processing of these requests are executed on virtual threads:
+
+[source, text]
+----
+2023-10-17 10:15:09,992 INFO  [org.acm.cru.TodoResource] (quarkus-virtual-thread-0) Called on VirtualThread[#78,quarkus-virtual-thread-0]/runnable@ForkJoinPool-5-worker-1
+2023-10-17 10:15:13,136 INFO  [org.acm.cru.TodoResource] (quarkus-virtual-thread-1) Called on VirtualThread[#85,quarkus-virtual-thread-1]/runnable@ForkJoinPool-5-worker-1
+----
+
+== Summary
+
+This blog post explains how to compile a Quarkus application leveraging virtual threads into a native executable.
+First, make sure that you have a GraalVM installation supporting Java 21+.
+Then, add the `native` profile to the `pom.xml` file and compile the application using the `-Dnative` option.
+Finally, run it as any other native executable!