// .devcontainer/devcontainer.json
  // Default Ubuntu-based DevContainer Template.
  // For more customization options, see https://containers.dev/implementors/json_reference
  {
-   name: "Default",
+   name: "spring-boot-demo",
    image: "ubuntu:latest",

    customizations : {
      // Configure JetBrains IDE-specific properties
      jetbrains : {
        backend : "IntelliJ",
        settings : {
          // IDE settings can be added via “Show context actions”|“Add currently modified settings from IDE”.
          // A complete list of supported settings is also available through auto-completion
        },
        plugins: [
          // A set of plugin IDs.
          // Plugin ID can be found on the corresponding plugin’s page at https://plugins.jetbrains.com.
        ]
      }
    },
    features: {
      "ghcr.io/devcontainers/features/git" : {},
      // Add additional features to your project using auto-completion.
+     "ghcr.io/devcontainers/features/docker-outside-of-docker:1": {},
+     "ghcr.io/devcontainers/features/java:1": {
+       "version": "23.1.8.r21",
+       "jdkDistro": "nik"
+     }
    },

    // Comment out to connect as the root user.
    remoteUser: "ubuntu"
  }

  // .devcontainer/devcontainer.env
+ POSTGRES_PASSWORD=postgres
+ POSTGRES_USER=postgres
+ POSTGRES_DB=postgres
+ POSTGRES_HOSTNAME=host.docker.internal
+

  # .devcontainer/compose.yaml
+ services:
+   app:
+     container_name: javadev
+     image: ubuntu:latest
+     env_file: devcontainer.env
+     # NOTE: POSTGRES_DB/USER/PASSWORD should match values in db container
+
+     volumes:
+       - ../..:/workspaces:cached
+
+     # Overrides default command so things don't shut down after the process ends.
+     command: sleep infinity
+
+   db:
+     container_name: postgresdb
+     image: postgres:latest
+     restart: unless-stopped
+     volumes:
+       - postgres-data:/var/lib/postgresql/data
+     env_file: devcontainer.env
+     # NOTE: POSTGRES_DB/USER/PASSWORD should match values in app container
+
+     # Runs db on the same network as the app container, allows "forwardPorts" in devcontainer.json function.
+     network_mode: service:app
+
+     # Use "forwardPorts" in **devcontainer.json** to forward an app port locally. 
+     # (Adding the "ports" property to this file will not forward from a Codespace.)
+
+ volumes:
+   postgres-data:
+

  // .devcontainer/devcontainer.json
  // Default Ubuntu-based DevContainer Template.
  // For more customization options, see https://containers.dev/implementors/json_reference
  {
    name: "spring-boot-demo",
-   image: "ubuntu:latest",
+   dockerComposeFile: "compose.yaml",
+   service: "app",
+
+   // Use 'forwardPorts' to make a list of ports inside the container available locally.
+   // This can be used to network with other containers or with the host.
+   "forwardPorts": [5432],

  ...

  // ./src/main/kotlin/com/example/demo/controller/HelloController.kt
+ package com.example.demo.controller
+ 
+ import org.springframework.web.bind.annotation.GetMapping
+ import org.springframework.web.bind.annotation.RestController
+
+ @RestController
+ class HelloController {
+
+     @GetMapping("/hello")
+     fun handle() = "Hello WebFlux"
+ }
+