DockerTutorials

Download and Install Docker Desktop for Mac

2022-06-06T00:21:48-05:00

Docker is the most popular platform for building, shipping and running applications in isolated environment called container. To get started with Docker, you need to have Docker software installed on your computer, which is called Docker Desktop on Windows/Mac environment.

In this article, I’d like to guide you how to download and install Docker Desktop for Mac, on macOS operating system.

1. What is Docker Desktop?

You know, Docker Desktop is a suite of software applications that enable you to build and share containerized applications and microservices on Windows or Mac environment. It is free for small business that have under 250 employees.

When you install Docker Desktop, you get the following programs and tools installed:

- Docker daemon: is the Docker engine that powers containerized apps

- Docker Client: is the command-line client which you can use to connect to Docker engine

- Docker Compose: is used to build and run multi-container apps

- Docker Content Trust: is used to digitally sign and verify Docker images

- Kubernetes: is the container orchestration system

- Credential Helper: is used to safely store Docker credentials in native stores

Note that on macOS operating system, the Docker daemon runs in a LinuxKit virtual machine, which runs on the Hypervisor framework provided by Apple’s OS. That means Docker is not running natively on Mac - it requires a virtualized Linux OS to operate.

2. Download Docker Desktop for Mac

In order to install Docker Desktop for Mac, your macOS must be version 10.15 or newer. That means you can install Docker Desktop on macOS Catalina, Big Sur, Monterey or newer.

Click this link to head over to the Docker Desktop’s official download page. You’ll see the following download options:

Click the button Mac with Intel Chip if your Mac running on Intel’s CPU (amd64 architecture); or click the button Mac with Apple Chip if your Mac running on Apple’s CPU (arm64 architecture) such as Apple M1.

The result is you have the Docker.dmg file gets downloaded on to your computer.

3. Install Docker Desktop on macOS

Install Docker Desktop for Mac is pretty easy. Firstly, double click the Docker.img file to launch the installer. Then you will see the following dialog:

Drag the Docker’s whale icon into the Applications folder. And wait for a moment while it is copying the data files:

Then you will see the Docker icon appears in the Launchpad. Double click it to start Docker Desktop for Mac. For the first time you need to provide administrator’s password to get Docker Helper installed:

Then the following screen appears:

Check the option I accept the terms, and click Accept to proceed. Wait for a while, then you will see Docker Desktop started as below:

That’s done! You have successfully installed Docker Desktop for Mac on macOS. It’s time to explore and have fun containerizing your applications.

You can also watch the following video to see the installation in action:

https://www.youtube.com/watch?v=tlr18csEwdc

Create Docker Image for Spring Boot Application

2022-05-05T16:49:01-05:00

Docker is widely-used open platform for developing, shipping and running applications. In this article, I’d like to share with you guys, about how to create and build Docker image for a Spring Boot application, i.e. containerizing your Spring Boot application.

You’ll also learn how to run the created Docker image, and share your Docker image on Docker Hub. I suppose that you have the following things ready on your computer:

Docker Desktop (for Windows or macOS) or Docker Engine for Linux
An account on Docker Hub
An existing Spring Boot project without database server (I’ll share how to create Docker image for Spring boot app with database in a separate article). Also you need to have JDK and Maven installed.

1. What is Docker?

Let’s understand briefly about Docker. You know, Docker enables you to separate your applications from infrastructure so you can deliver software quickly. It provides the ability to package and run application in a container - a loosely isolated Linux environment.

Compared to virtual machines, containers are more lightweight and faster as they share the same operating system. Whereas each virtual machine needs to run on its own OS. Docker engine is the software that manages containers running on a computer.

You can use Docker for the following purposes (not limited to):

Deploy your application as a container
Share your app as a Docker image so everyone can get the same container that works in the same way
Test different versions of your app in separate containers, without affecting development and production environment
Streamline development with Continuous Integration and Continuous Delivery (CI/CD) workflows.

2. Package Spring Boot Project

Open a new command prompt (Windows) or terminal (macOS/Linux). Change the current directory to the project’s root directory. For example:

cd SpringBootFormExample

Then type the following commands to clean and package the project:

mvn clean

mvn package

Depending on the packaging type specified in the project’s pom.xml file, a WAR or JAR file will be created under the target directory. As you can see in the Maven’s ouput:

[INFO] Processing war project
[INFO] Copying webapp resources [f:\SpringBoot\SpringBootFormExample\src\main\webapp]
[INFO] Webapp assembled in [303 msecs]
[INFO] Building war: f:\SpringBoot\SpringBootFormExample\target\SpringBootFormExample-1.0.war

Basically, you can use the java -jar filename command to run a Spring Boot application packaged in a WAR or JAR file.

3. Create Dockerfile

To create a Docker image for the Spring Boot application packaged in the previous step, you need to create a text file called Dockerfile under the project’s root (Note: no extension, just Dockerfile). And specify the following content:

FROM openjdk:11
COPY target/SpringBootFormExample-1.0.war SpringBootFormExample-1.0.war
ENTRYPOINT ["java", "-jar", "/SpringBootFormExample-1.0.war"]

The first line uses the command FROM that specifies an image name which can be found on Docker Hub registry. The image name openjdk:11 is an official image created by Docker. It contains a Linux operating system with OpenJDK version 11 installed.

The second line (COPY) copies the WAR file from the project’s target directory to the root directory of the operating system in the created image.

The third line (ENTRYPOINT) specifies the command that will launch the Spring Boot application when a container started from the image.

4. Build Docker Image for Spring Boot Application

Next, type the following command to build a Docker image for the current Spring Boot project:

docker build -t form-example .

Note that there is a dot (.) at the end, denoting the current directory. You’ll see the following output:

You can see it pulls the image openjdk:11 from registry-1.docker.io, copies the WAR file and creates the image. Then type docker images to verify:

You can see the image created with the name form-example with the size is about 681MB.

5. Run Spring Boot Application as a Docker Container

With the Docker image built in the previous step, you can now run it as a container. Docker allows you to run a container in either detached mode or attached mode.

Run Docker image in attached mode:

In attached mode, the Docker command-line client’s console is attached to the output of the application running in the container. Type the following command to run the image form-example:

docker run -p 8080:8080 form-example

Here, the -p flag specifies port bind between the port number on the host OS with the port number in the container. You’ll the familiar startup logs of a Spring Boot application:

If you see this, it means the Spring Boot application is running inside a Docker container, ready to accept incoming requests via port 8080. You can now type http://localhost:8080 in your browser to access the Spring Boot application deployed as a Docker container.

Note that the current command prompt/terminal is attached to the application’s output. So open a new command prompt and type docker ps to see a list of running containers:

You see, there’s one container running from the image form-example. And the container is assigned a random, friendly name brave_lamport.

To stop the container, type docker stop command as below:

You can specify the container’s assigned name or container ID as seen by the docker ps command.

Run Docker image in detached mode:

Type the following command to run a container from the image form-example in detached mode:

docker run -dp 80:8080 form-example

Here, the -d flag is for detached mode. The command starts a new container and returns immediately, resulting the container running in background. That means you won’t see the output of your Spring Boot application:

Now, type docker ps command, you’ll see another container created and running:

You see, this time it binds the port 80 in host machine with the port 8080 in the container, which means you should access your Spring Boot application via URL http://localhost.

6. Share Docker Image on Docker Hub

You can share your Docker image on Docker Hub (a public registry managed by Docker) so everyone can get the same container that works in the same way.

Sign in to https://hub.docker.com and click Create Repository button to create a new repository (choose the visibility is public). For example, I created the repository namhm/form-example.

Then in the command line, type the following command to update tag name of the image according to the repository name:

docker tag form-example namhm/form-example

Then type the following command to log into Docker Hub in command line:

docker login -u your_user_name

You need to provide password. Then type this command to share the image:

docker push namhm/form-example

Done. Wait a while for the image being uploaded to Docker registry. Then you can switch to your Docker Hub account to verify the image pushed successfully.

That’s my tutorial about Creating Docker image for Spring Boot application. You also learn how to run Docker image and share the image on Docker Hub. To see the steps in action, I recommend you watch the following video:

https://www.youtube.com/watch?v=T8LqONZzMQI

Reference Links:

Download and Install Docker Desktop for Windows

You might be also interested in these articles:

Download and Install Docker Desktop for Windows

2022-06-02T05:56:22-05:00

In this article, I’d like to guide you how to download and install Docker Desktop for Windows, on Windows 10 operating system.

1. What is Docker Desktop?

When you install Docker Desktop, you get the following programs and tools installed:

- Docker daemon: is the Docker engine that powers containerized apps

- Docker Client: is the command-line client which you can use to connect to Docker engine

- Docker Compose: is used to build and run multi-container apps

- Docker Content Trust: is used to digitally sign and verify Docker images

- Kubernetes: is the container orchestration system

- Credential Helper: is used to safely store Docker credentials in native stores

2. Download Docker Desktop for Windows

Visit the official download page of Docker Desktop to download Docker Desktop for Windows installer program. Or click this link to download the installer directly.

You’ll get the Docker Desktop Installer.exe file downloaded on to your computer (around 480 MB).

3. Installation Requirement

Docker is based on Linux technology so it can’t run natively on Windows. The Docker Desktop for Windows requires Hyper-V or WSL (Windows Subsystem for Linux) that provides virtualized Linux kernel. The latest version of Docker Desktop for Windows works best with WSL 2, so make sure your Windows 10 operating system meets the following requirement: Home or Pro 2004 (build 19041) or higher, or Enterprise or Education 1909 (build 18363) or higher.

Open a new command prompt and you should see the version and build number of your Windows operating system:

If you don’t meet the requirement mentioned above, you should upgrade your OS before installation of Docker Desktop for Windows.

4. Install Docker Desktop on Windows

Double click the Docker Desktop Installer.exe file to launch Docker Desktop installer. You will see the following dialog appears:

By default, WSL 2 is checked. Click OK to proceed. Just wait for a while and you will end up this screen:

Close this dialog. Then double click the Docker Desktop icon on desktop to launch Docker Desktop application. The following screen appears:

Check I accept the terms, and click Accept to proceed. Then you will see the massage Docker Desktop stopping… appears few times. Don’t worry, it’s because WSL has not been installed, as shown in the next dialog:

Click the link presented in the warning dialog (https://aka.ms/wsl2kernel) to complete the installation of WSL 2. You’ll be directed to the step 4 of WSL 2 Manual Installation guide on Microsoft’s website:

On this page, click the link WSL2 Linux kernel update package for x64 machines, you will be asked to download the wsl_update_x64.msi file. Download and run this file to launch Windows Subsystem for Linux Update Setup, as shown below:

Click Next to install. And when it’s done, return to the warning dialog, and click Restart:

Wait for a while for Docker Desktop restarting. Finally, you should see the following screen:

Congratulations! You have successfully installed Docker on your Windows operating system. It’s time to explore and have fun with containerized applications. To see the installation in action, watch the following video:

https://www.youtube.com/watch?v=C3w59EHoxC0

DockerTutorials

Download and Install Docker Desktop for Mac

1. What is Docker Desktop?

2. Download Docker Desktop for Mac

3. Install Docker Desktop on macOS

Related Articles:

Create Docker Image for Spring Boot Application

1. What is Docker?

2. Package Spring Boot Project

3. Create Dockerfile

4. Build Docker Image for Spring Boot Application

5. Run Spring Boot Application as a Docker Container

Run Docker image in attached mode:

Run Docker image in detached mode:

6. Share Docker Image on Docker Hub

Related Articles:

Download and Install Docker Desktop for Windows

1. What is Docker Desktop?

2. Download Docker Desktop for Windows

3. Installation Requirement

4. Install Docker Desktop on Windows

Related Articles: