docker-windows10-Home

spring boot app with mysql in two containers

Step 1 - install Docker on Windows 10 Home

Dictionary

Docker Machine - a CLI tool for installing Docker Engine on virtual hosts
Docker Engine - runs on top of the Linux Kernel; used for building and running containers
Docker Client - a CLI tool for issuing commands to Docker Engine via REST API
Docker Compose - a tool for defining and running multi-container applications

Initial Setup

• Install Git Bash This will be our primary terminal for running Docker commands.

• Install Chocolatey It will make the work of installing the rest of the programs easier.

• Install VirtualBox

C:\ choco install virtualbox

Docker Engine Setup

Install Docker Machine. You can execute this command inside an elevated PowerShell terminal:

C:\ choco install docker-machine

Using Git Bash terminal, use Docker Machine to install Docker Engine. This will download a Linux image containing the Docker Engine and have it run as a VM using VirtualBox.

$ docker-machine create --driver virtualbox default

Configure which ports are exposed when running Docker containers. To do this, you’ll need to launch Oracle VM VirtualBox from your start menu. Select default VM on the side menu. Next click on Settings > Network > Adapter 1 > Port Forwarding. You should find the ssh forwarding port already set up for you. You can add more like so:

Allow Docker to mount volumes located on your hard drive. In VirtualBox GUI select default VM and go to Settings > Shared Folders. Add a new one by clicking the plus symbol. Enter the fields like so. If there’s an option called Permanent, enable it.

To get rid of the invalid settings error as seen in the above screenshot, simply increase Video Memory under the Display tab in the settings option

Start the Linux VM\Give it some time for the boot process to complete. It shouldn’t take more than a minute. You’ll need to do this every time you boot your host OS:

$ docker-machine start vbox

Next, need to set up Docker environment variables
This is to allow the Docker client and Docker Compose to communicate with the Docker Engine running in the Linux VM, default.
in Git Bash:

• Print out docker machine instance settings

$ docker-machine env default

• Set environment variables using Linux 'export' command

$ eval $(docker-machine env default --shell linux)

You’ll need to set the environment variables every time you start a new Git Bash terminal. If you’d like to avoid this, you can copy eval output and save it in your .bashrc file. It should look something like this:

export DOCKER_TLS_VERIFY="1"
export DOCKER_HOST="tcp://192.168.99.101:2376"
export DOCKER_CERT_PATH="C:\***\default"
export DOCKER_MACHINE_NAME="default"
export COMPOSE_CONVERT_WINDOWS_PATHS="true"

Install Docker Client and Docker Compose

Docker Tools Setup
Using PowerShell in admin mode using Chocolatey:

C:\ choco install docker-cli
C:\ choco install docker-compose

Switch back to Git Bash terminal

• Start Docker VM

$ docker-machine start default

• Confirm Docker VM is running

$ docker-machine ls

• Configure Docker Envrionment to use Docker Vm

$ eval $(docker-machine env default --shell linux)

• Confirm Docker is connected. Should output Docker VM specs

$ docker info

• Run hello-world docker image. Should output "Hello from Docker"

$ docker run hello-world

Create Spring Boot + MYSQL Application

Create the schema-mysql.sql file and specify the initialization scripts-

CREATE TABLE IF NOT EXISTS employee (
  id VARCHAR(10) NOT NULL,
  firstName VARCHAR(100) NOT NULL,
  lastName VARCHAR(100) NOT NULL,
  age INT
);

In the application.properties file specify the datasource properties

spring.datasource.url=jdbc:mysql://localhost/project_db?useUnicode=true&serverTimezone=UTC
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.platform=mysql
spring.datasource.initialization-mode=always

Start the Spring Boot Application. Open POSTMAN and create a POST request to url -

localhost:8080/insert

Spring Boot Postman call
In the browser or in Postman again use

localhost:8080/employees

Deploying Spring Boot + MYSQL to Docker

Firstly create a network named employee-mysql

start docker
docker network create employee-mysql

Check that you created

docker network ls

Next step: write config data of your db

docker container run --name mysqldb --network employee-mysql -e MYSQL_ROOT_PASSWORD=root -e MYSQL_DATABASE=project_db -d mysql:5

And start it

docker container start mysqldb

Using the exec command we can inspect if the database named project_db is created successfully.

docker container exec -tty [name or id container] mysql -uroot -proot "show databases"

Next we will modify the application.properties in the Spring Boot application to make use of the mysql container name i.e.mysqldb instead of localhost

spring.datasource.url=jdbc:mysql://mysqldb/project_db
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.platform=mysql
spring.datasource.initialization-mode=always

The docker file for spring boot project will be as follows

From openjdk:8
copy ./target/spring-boot-docker-example-1.0-SNAPSHOT.jar spring-boot-docker-example-1.0-SNAPSHOT.jar
CMD ["java","-jar","spring-boot-docker-example-1.0-SNAPSHOT.jar"]

Build the docker image for the spring boot project

docker image build -t spring-boot-docker-example .

Next run this as a container. Also we are running the container on the employee-mysql network. docker container run --network employee-mysql --name employee-jdbc-container -p 8080:8080 -d spring-boot-docker-example

spring boot mysql docker container image run

docker container logs -f 34 

Insert data with POST request using curl

curl --header "Content-Type: application/json"   --request POST   --data '{"empId":"emp001","empName":"emp001"}'   http://localhost:8080/insertemployee