unit docker.service not found

This error message usually indicates that Docker is not installed or is not running on the system. To resolve this issue, you can try the following steps:

1. Install Docker on your system. You can find installation instructions for your specific operating system on the Docker website.

2. Once Docker is installed, start the Docker service by running the following command in your terminal:

   sudo systemctl start docker

3. Verify that the Docker service is running by running the following command:

   sudo systemctl status docker

If the service is running, you should see a message indicating that the service is active and running.

4. If the service is not running, try restarting the service by running the following command:

   sudo systemctl restart docker

This should start the Docker service and resolve the issue.