Contents
Does Docker container have OS?
Docker does not has an OS in its containers. In simple terms, a docker container image just has a kind of filesystem snapshot of the linux-image the container image is dependent on.
What OS do Docker containers use?
The Docker platform runs natively on Linux (on x86-64, ARM and many other CPU architectures) and on Windows (x86-64). Docker Inc. builds products that let you build and run containers on Linux, Windows and macOS.
Do containers run their own OS?
Yes, they do. Every container is based on an OS image, e.g. Alpine, CentOS or Ubuntu. They just share the host kernel, but run every user-space process in a separate name space specific for that container.
Are Docker containers OS independent?
What is Docker? According to Docker, a container is ” a lightweight, stand-alone, executable package of a piece of software that includes everything needed to run it.” And since containers are platform-independent, Docker can run across both Windows- and Linux-based platforms.
Can a Docker image run on any OS?
No, Docker containers can’t run on all operating systems directly, and there are reasons behind that. Let me explain in detail why Docker containers won’t run on all operating systems. Docker container engine was powered by the core Linux container library (LXC) during the initial releases.
What is Docker not good for?
You risk running Docker containers with incomplete isolation. Any malicious code can get access to your computer memory. There is a popular practice to run a lot of containers in a single environment. Any processes that break out of Docker container will have the same privileges on the host as it did in the container.
Can a docker container be based on an OS image?
Yes, they do. Every container is based on an OS image, e.g. Alpine, CentOS or Ubuntu. They just share the host kernel, but run every user-space process in a separate name space specific for that container. Look into a dockerfile example (adapted by me) to understand this:
Which is the host OS for Docker in Linux?
The Host OS is Ubuntu. The Docker Client and the Docker Daemon (together called the Docker Engine) are running on the Host OS. Each container shares the Host OS kernel. CentOS and BusyBox are Linux Base OS images. The “No OS” container demonstrates that you do not NEED a base OS to run a container in Linux.
Why do Docker containers run on Docker engine?
Docker containers that run on Docker Engine: Standard: Docker created the industry standard for containers, so they could be portable anywhere Lightweight: Containers share the machine’s OS system kernel and therefore do not require an OS per application, driving higher server efficiencies and reducing server and licensing costs
Is the host OS the same as the container OS?
In the case of Linux and non-Hyper-V containers, the Host OS shares its kernel with running Docker containers. For Hyper-V each container has its own Hyper-V kernel. Container OS: Also called the Base OS.