How can you tell if Docker has started?

You can check if Docker is running by using the following methods:

1. Check the status of the Docker service using the command line tool. Run the following command in the terminal:

sudo systemctl status docker

If Docker is already running, it will display the active status and process ID.

1. Check if the Docker process is running using a command line tool. Run the following command in the terminal:

ps aux | grep docker

If Docker is running, one or more Docker processes will be displayed.

1. Try executing a Docker command in the terminal, such as running the following command to view the Docker version:

docker version

If Docker is already running, it will display the version information of Docker.

1. Connect to the Docker daemon using the Docker client tool. For example, run the following command to list all running containers:

docker ps

If Docker is already running, a list of running containers will be displayed.

Please note that the commands in the methods above may need to be run in administrator or superuser mode, depending on your operating system and installation configuration.