Search code examples
dockerkubernetesdocker-compose

What's the difference between Docker Compose and Kubernetes?

While diving into Docker, Google Cloud and Kubernetes, and without clearly understanding all three of them yet, it seems to me these products are overlapping, yet they're not compatible.

For example, a docker-compose.yml file needs to be re-written so an app can be deployed to Kubernetes.

Could someone provide a high-level, rough description of where Docker, Docker Compose, Docker Cloud, and Kubernetes overlap and where one is dependent on the other?

Solution

  • Containers:

    • Containers are at the core of the other technologies listed here

    Docker:

    • Docker is a popular implementation of the technology that allows applications to be bundled into a container.
    • docker is a command-line tool to manage images, containers, volumes, and networks

    Docker Compose

    • Docker Compose is the declarative version of the docker cli
    • It can start one or more containers
    • It can create one or more networks and attach containers to them
    • It can create one or more volumes and configure containers to mount them
    • All of this is for use on a single host

    Docker Classic Swarm

    • Docker swarm has been abandoned by Docker Inc. and is not being actively maintained or supported.
    • Docker Swarm is for running and connecting containers on multiple hosts.
    • Docker Swarm is a container cluster management and orchestration tool.
    • It manages containers running on multiple hosts and does things like scaling, starting a new container when one crashes, networking containers ...
    • The Docker Swarm file named stack file is very similar to a Docker Compose file
    • The only comparison between Kubernetes and Compose is at the most trivial and unimportant level: they both run containers, but this says nothing to help one understand what the two tools are and where they are useful. They are both useful for different things

    Kubernetes

    • Kubernetes (K8S) is a distributed container orchestration tool initially created by Google
    • It was open-sourced in 2014 and handed over to the Cloud Native Computing Foundation (CNCF) the following year
    • The CNCF is an industry body with hundreds of members drawn from the majority of large cloud, software and hardware companies
    • At the time of writing (late 2021) there are nearly a thousand K8S related projects split into around twenty classes with a total of over $21 billion dollars in funding
    • Kubernetes (2021) is the most popular distributed system orchestrator in the world with 88% adoption
    • Because of its near ubiquity, K8S has become the most popular contemporary platform for innovative system development in 2021
    • Kubernetes is a competitor (more or less) to Docker swarm but does more stuff than docker swarm i.e a popular choice.