Day 2: Install Docker Desktop and Launch Your First Container in 5 Minutes

Day 1 covered the concepts; today we install Docker Desktop.

Docker Desktop can be installed on macOS either by downloading the installer from the official Docker documentation ( https://docs.docker.com/get-docker/) or via Homebrew with the command: brew install --cask docker After installation the Docker whale icon appears in Launchpad and a Docker icon shows in the menu bar; the first launch may prompt for a login (optional).

Verify the installation:

docker --version
# Docker version 29.4.0, build ...

docker compose version
# Docker Compose version v5.1.3

For faster image pulls in China, open Docker Desktop → Settings → Docker Engine and add a registry-mirrors array, for example:

{
  "registry-mirrors": [
    "https://docker.1ms.run",
    "https://docker.xuanyuan.me"
  ]
}

Click Apply & Restart to apply the mirrors.

Run Your First Container

docker run hello-world

The output shows:

Hello from Docker!
This message shows that your installation appears to be working correctly.

What happens: docker run checks whether the hello‑world image exists locally.

If not, Docker pulls the image from Docker Hub.

Docker creates a container from the image and runs it.

Interactive Containers

To start a container and get a shell inside it:

# Create a container and enter bash
docker run -it ubuntu bash

# Exit the container
exit

Flags: -i: keep STDIN open (interactive mode). -t: allocate a pseudo‑TTY.

Note: after exit the container stops; use -d to run it detached.

Run NGINX in the Background

# Start NGINX detached and map ports
docker run -d -p 8080:80 nginx

# Verify it is running
docker ps

# Open a browser at http://localhost:8080

Flags: -d: run container in detached (background) mode. -p 8080:80: map host port 8080 to container port 80.

Day 2 Summary

Docker Desktop is the standard development tool. docker run hello-world = pull image + create container + run. -it for interactive mode, -d for background, -p for port mapping.

Next up on Day 3: the three essential image commands – pull, images, and rm.