What is Docker
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Docker is one of container implementation. Others are Rocket,
Drawbridge, LXC.
Docker Inc. is the company that sells the commercial version of Docker. Docker is also available as open source.
Docker Daemon / dockerd? Manages Docker objects(Eg: Images, containers, networks, and volumes). dockerd also communicate with other daemons to manage Docker services.
Docker client / docker? Users interact with docker client.
User
$ docker run -----> [Docker Client] -----> [Docker Daemon/dockerd]
Docker vs Kubernets
| Docker (docker) | Kubernetes (kubectl)(Container Orchestration system) | |
|---|---|---|
| Unit you manage | A container | A Pod (1+ containers that share IP and volumes) |
| Scope | This machine only | Whole cluster (filtered by namespace) |
| What | Platform for building containers | Platform for managing multiple containers |
| Use case | Run containers on 1 host | Run containers on cluster of machines, providing scaling, self-healing, and rollback |
| Commands | docker run | helm |