Spring Boot§

To run apps based on the Spring Boot frameworks using Unit:

1. Install Unit with a Java language module.

2. Create your Spring Boot project; we’ll use the quickstart example, creating it at https://start.spring.io:

   

   Note

   Choose the same Java version that your Unit language module has.

   Download and extract the project files where you need them:

   $ unzip demo.zip -d /path/to/app/
   

   This creates a directory named /path/to/app/demo/ for you to add your app code to; in our example, it’s a single file called /path/to/app/demo/src/main/java/com/example/demo/DemoApplication.java:

   package com.example.demo;
   
   import org.springframework.boot.SpringApplication;
   import org.springframework.boot.autoconfigure.SpringBootApplication;
   import org.springframework.web.bind.annotation.GetMapping;
   import org.springframework.web.bind.annotation.RequestParam;
   import org.springframework.web.bind.annotation.RestController;
   
   @SpringBootApplication
   @RestController
   public class DemoApplication {
   
     public static void main(String[] args) {
       SpringApplication.run(DemoApplication.class, args);
     }
   
     @GetMapping("/hello")
     public String hello(@RequestParam(value = "name", defaultValue = "World") String name) {
       return String.format("Hello, %s!", name);
     }
   }
   

   Finally, assemble a .war file.

   If you chose Gradle as the build tool:

   $ cd /path/to/app/demo/
   

   $ ./gradlew bootWar
   

   If you chose Maven:

   $ cd /path/to/app/demo/
   

   $ ./mvnw package
   

   Note

   By default, Gradle puts the .war file in the build/libs/ subdirectory, while Maven uses target/; note your path for later use in Unit configuration.

3. Run the following command so Unit can access the application directory:

   # chown -R unit:unit /path/to/app/
   

   Note

   The unit:unit user-group pair is available only with official packages, Docker images, and some third-party repos. Otherwise, account names may differ; run the ps aux | grep unitd command to be sure.

   For further details, including permissions, see the security checklist.

4. Next, put together the Spring Boot configuration (use a real value for working_directory):

   {
       "listeners": {
           "*:80": {
               "pass": "applications/bootdemo"
           }
       },
   
       "applications": {
           "bootdemo": {
               "type": "java",
               "webapp": "gradle-or-maven-build-dir/demo.war",
               "working_directory": "/path/to/app/demo/"
           }
       }
   }
   

5. Upload the updated configuration. Assuming the JSON above was added to config.json:

   # curl -X PUT --data-binary @config.json --unix-socket \
          /path/to/control.unit.sock http://localhost/config/
   

   Note

   The control socket path may vary; run unitd -h or see Startup and Shutdown for details.

   After a successful update, your app should be available on the listener’s IP address and port:

   $ curl http://localhost/hello?name=Unit
   
         Hello, Unit!