Docker

• Docker is a container technology: A tool for creating and managing containers
• Container is a standardized piece of software.
• The container includes a package of code and dependencies to run that code.
• The same container will always yield the same application.
• Containers are self-contained and isolated
• One of the main goals of Docker is to have the same development and production environment.
• The second goal of Docker is to have the same environment within a development team.
• The third goal is to avoid problems with different versions between projects.
• The main problems with virtual machines are wasted space and performance issues.
• VM's contain their own OS, but containers don't.

  Docker is just a tool, the focus is on containers.
• Docker Desktop is just a tool that checks if Docker Engine is working correctly (daemon - a process which keeps running and checks Docker, docker's heart and includes CLI)
• We installed the docker engine which includes a VM that runs Linux which then runs Docker
• Every container has its own file system
• docker stop <name> to stop the container
• docker ps - to list all running container
• By default there isn't connection with our localhost and container port, we need to connect it with -p port:port option
• By default, container is isolated from other environment
• Docker ps -a is to list all processes
• Common practice is to build upon pre-existing images