tree -a
.
└── .devcontainer
    └── devcontainer.json
    └── Dockerfile

{
	"build": {
		"dockerfile": "Dockerfile",
	},
}

tree -a
.
├── .devcontainer
│   └── devcontainer.json
└── docker
    └── Dockerfile

{
	"build": {
		"dockerfile": "../docker/Dockerfile",
	},
}

docker pull openjdk:15-jdk-alpine

curl https://start.spring.io/starter.zip -d language=kotlin -d dependencies=web,mustache,jpa,h2,devtools -d packageName=com.example.blog -d name=Blog -o blog.zip -d type=gradle-project

$ tree -a
.
├── .devcontainer
│   └── devcontainer.json
└── docker
    ├── docker-compose.yml
    ├── mysql-confd
    │   └── default_authentication.cnf
    └── openjdk
        └── Dockerfile

{
	"name": "My Java/Kotlin Application",

	"dockerComposeFile": "../docker/docker-compose.yml",
	"service": "openjdk",
	"workspaceFolder": "/workspace",
	"settings": {
	},

	"extensions": [
		// Language: Java / Kotlin
		"vscjava.vscode-java-pack",
		"redhat.java",
		"vscjava.vscode-java-debug",

		// Spring Boot
		"vscjava.vscode-spring-initializr",
		"pivotal.vscode-spring-boot",
		"pivotal.vscode-boot-dev-pack",
		"vscjava.vscode-spring-boot-dashboard"
	],
}

version: '3'
services:
  openjdk:
    build: ./openjdk
    ports:
      - "8080:8080"
    command: /bin/sh -c "while :; do sleep 10; done"
    volumes:
      - ..:/workspace:cached

  mysql:
    image: mysql:5.7
    container_name: "dc-db-mysql"
    restart: always
    environment:
      MYSQL_DATABASE: mysqldb
      MYSQL_ROOT_PASSWORD: mysqldb
    ports: 
      - 13306:3306
    volumes:
      - ./mysql-confd:/etc/mysql/conf.d

ARG JDK_VERSION="15"
ARG ALPIN_VERSION="3.12"
FROM openjdk:${JDK_VERSION}-jdk-alpine${ALPIN_VERSION}

RUN apk update \
    && apk add git curl maven make mysql-client

[mysqld]
default_authentication_plugin= mysql_native_password

Unresolved reference: SpringBootApplicationkotlin(UNRESOLVED_REFERENCE)