Ajeet Singh RainaDocker Desktop 4.18 is an exciting release with a lot of great new features that will make it easier for developers to work with Docker.
One of the most exciting features is the new Learning Center, which is designed to help users get started with Docker. This new area provides a wealth of resources and tutorials to help beginners get up to speed quickly.
Another new feature is Docker init, which is currently in beta. This feature generates Docker assets for projects, making it easier to create Docker images and containers. This is a great addition for developers who want to quickly create and manage Docker assets without having to manually configure everything.
docker init
The Container File Explorer is now generally available, allowing users to explore the contents of Docker containers with ease.
Additionally, the Images tab now includes an Artifactory view, which allows users to view and analyze images from Artifactory registries.
Another interesting addition is the Docker Scout CLI, which provides security update recommendations in the CLI. This is a handy tool for developers who want to ensure that their Docker assets are up to date and secure.
The experimental Docker Compose watch command is also included in this release. This command updates running Compose services as you edit and save your code, making it easier to make changes on the fly.
Finally, the new Adminless Mac Install is a new installation flow that doesn't require admin privileges. This makes it easier for developers to get started with Docker on their Macs without having to worry about administrative restrictions.
Introducing the docker init CLI
Docker init is a CLI command that was introduced in Docker Desktop 4.18 to simplify the process of initializing a new project to run in a Docker container. When you run the docker init command in your project directory, it will guide you through the creation of the necessary files for your project with sensible defaults. These files include:
- .dockerignore
- Dockerfile
- docker-compose.yaml
The docker init command also allows you to choose the application platform that your project uses and the relative directory of your main package. Additionally, it can generate Docker assets for your project using the Docker Scout CLI and provides an adminless Mac install flow that does not require admin privileges.
Getting Started
Step 1. Initialize
docker init
Welcome to the Docker Init CLI!
This utility will walk you through creating the following files with sensible defaults for your project:
- .dockerignore
- Dockerfile
- compose.yaml
Let's get started!
? What application platform does your project use? [Use arrows to move, type to filter]
> Node - (detected) suitable for a Node server application
Go - suitable for a Go server application
Python - suitable for a Python server application
Other - general purpose starting point for containerizing your application
Don't see something you need? Let us know!
Quit
Step 2. Choose your preferred language
For this demo, I will choose Go and 1.20 as Go version.
Step 3. Choosing the relative directory
Before you choose relative directory of your main package, let's open a new terminal and create a simple Go program that exposes a "Hello, World!" app over HTTP.
package main
import (
"fmt"
"net/http"
)
func main() {
http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
fmt.Fprintf(w, "Hello, World!")
})
fmt.Println("Listening on port 8080...")
err := http.ListenAndServe(":8080", nil)
if err != nil {
panic(err)
}
}
This program listens for incoming HTTP requests on port 8080 and responds with the text "Hello, World!" for any incoming request. You can run this program using the go run command and then visit http://localhost:8080 in your web browser to see the output.
go run main.go
The output should show Listening on port 8080.... Then, visit http://localhost:8080 in your web browser to see the "Hello, World!" message.
Ensure that you have the go.sum file with the following content. The go.sum file is created automatically by the Go module system whenever new dependencies are added or removed from a module. When a new dependency is added to a module, the Go module system fetches the dependency and computes its checksum, which is then added to the go.sum file. If the dependency is already present in the go.sum file, the Go module system verifies that its checksum matches the expected value.:
cat go.sum
github.com/google/uuid v1.3.0 h1:t6JiXgmwXMjEs8VusXIJk2BXHsn+wx8BZdTaoZ5fu7I=
github.com/google/uuid v1.3.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
Open the original terminal and just press "." so that it picks up the default directory where our main.go file is located. It will show the following results:
? What's the relative directory (with a leading .) of your main package? .
? What port does your server listen on? 8080
CREATED: .dockerignore
CREATED: Dockerfile
CREATED: docker-compose.yaml
✔ Your Docker files are ready!
Take a moment to review them and tailor them to your application.
When you're ready, start your application by running: docker compose up --build -d
Your application will be available at http://localhost:8080
To stop your application, run: docker compose down
Step 4. Visualising the Project Directory
This is how the project directory structure look like:
tree
.
├── Dockerfile
├── docker-compose.yaml
├── go.sum
└── main.go
1 directory, 4 files
Go mod is a command-line tool that is built into the Go programming language. It is used to manage dependencies in Go projects. Go mod provides a way to declare and manage dependencies, versioning, and modules, which are collections of related Go packages.The Go mod CLI is the command-line interface for Go mod. It is used to run commands to manage modules, dependencies, and versions in Go projects.
Let's initializes a new Go module in the current directory.
go mod init helloworld
tree
.
├── Dockerfile
├── docker-compose.yaml
├── go.mod
├── go.sum
└── main.go
1 directory, 5 files
Step 5. Building the container
% docker compose up --build -d
Step 6. Listing the services
docker compose ps
NAME IMAGE COMMAND SERVICE CREATED STATUS PORTS
sample_app-server-1 sample_app-server "/bin/server" server 6 seconds ago Up 5 seconds 0.0.0.0:8080->8080/tcp
Step 7. Accessing the App
% curl localhost:8080
Hello from Docker!
