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...
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?
5 Answers
- Containers are at the core of the other technologies listed here
- Docker is a popular implementation of the technology that allows applications to be bundled into a container.
dockeris a command-line tool to manage images, containers, volumes, and networks
- 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 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 (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
In addition to @yamenk's answer, I'd like to add a few details here which might help people with their journey of understanding Kubernetes.
Short answer:
docker-compose: is a tool that takes a YAML file which describes your multi-container application and helps you create, start/stop, remove all those containers without having to type multipledocker ...commands for each container.Kubernetes: is a platform for managing containerized workloads and services, that facilitates both declarative configuration and automation. What? 🤔 Keep reading...
Docker Compose
(from the docs): Compose is a tool for defining and running multi-container Docker applications. With Compose, you use a YAML file to configure your application’s services. Then, with a single command, you create and start all the services from your configuration. Compose has commands for managing the whole lifecycle of your application:
- Start, stop, and rebuild services
- View the status of running services
- Stream the log output of running services
- Run a one-off command on a service
Kubernetes
(from Introduction to Kubernetes): Kubernetes is a container orchestrator like Docker Swarm, Mesos Marathon, Amazon ECS, Hashicorp Nomad. Container orchestrators are the tools which group hosts together to form a cluster, and help us make sure applications:
- are fault-tolerant,
- can scale, and do this on-demand
- use resources optimally
- can discover other applications automatically, and communicate with each other
- are accessible from the external world
- can update/rollback without any downtime.
Many people argue that Kubernetes is hard to learn. It's because it solves a series of problems and people try to understand without knowing all the prerequisites. This makes it complicated. Start putting the pieces of the puzzle together by reading about concepts/terms like the following. This process will help you understand the kind of problems Kubernetes tries to solve:
- 12-factor apps,
- Automatic binpacking,
- Self-healing mechanisms,
- Horizontal scaling,
- Service discovery and Load balancing,
- Automated rollouts and rollbacks,
- Blue-Green deployments / Canary deployments
- Secrets and configuration management,
- Storage orchestration
And because there are a lot of different things around containers and their management, keep an eye on the Cloud Native landscape:
Interactive version here:
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