Docker vs Docker Compose

A common question is: what’s the difference between Docker and Docker Compose? If you’re deploying one container, the Docker CLI is enough. If you’re running an app stack (web + DB + cache), Docker Compose is usually the right tool.

Docker Compose vs Docker (the real difference)

• Docker = build and run individual containers (docker build, docker run, docker stop).
• Docker Compose = define and run multi-container applications in one YAML (docker compose up).

Feature	Docker CLI	Docker Compose
Scope	Single container	App stack (many containers)
Config	CLI flags	compose.yaml / docker-compose.yml
Network	manual	automatic default network
Volumes	manual	declared once, reused
Reproducibility	low	high (“config as code”)
Scaling	manual scripting	docker compose up --scale

What is Docker Compose?

Docker Compose is a tool that reads a YAML file and starts the services (containers), networks, and volumes your app needs—consistently, on any machine.

Minimal example (web + Postgres):

services:
  web:
    image: my-web-app
    ports: ["8080:8080"]
    depends_on: [db]
  db:
    image: postgres:16
    environment:
      POSTGRES_PASSWORD: secret

Run it:

docker compose up -d

“docker compose is not a docker command”

This usually happens when:

• you’re using an older Docker install where Compose v2 isn’t available, or
• you still have Compose v1 (docker-compose) but not v2.

Quick checks:

docker compose version
docker-compose version

On Linux, the simplest fix is installing/upgrading Docker and Compose (v2) via your distro packages or Docker’s official repo.

Dockerfile vs Docker Compose

• Dockerfile = how to build an image.
• Compose file = how to run images (ports, env, volumes, networks).

Docker Compose vs docker build

You still use docker build (or Compose build:) to create images. Compose then runs them.

Common Compose questions (quick answers)

docker compose down vs stop

• docker compose stop stops containers (keeps networks/volumes).
• docker compose down removes containers + default network. Add -v to remove volumes too.

docker compose remove container

Use:

docker compose rm -f

Or docker compose down to remove the whole stack.

docker compose scale

docker compose up -d --scale web=3

Works well for stateless services behind a load balancer.

docker compose privileged

privileged: true gives a container broad host access. Avoid unless you truly need it (e.g., low-level device access). Prefer specific capabilities (cap_add) and read-only mounts.

docker compose devices / device

For passing hardware through:

services:
  app:
    devices:
      - "/dev/ttyUSB0:/dev/ttyUSB0"

docker compose platform / docker compose platform amd64

Useful for cross-arch images (e.g., running amd64 images on arm64):

services:
  app:
    image: some/image:tag
    platform: linux/amd64

docker compose entrypoint vs command

• entrypoint replaces the image entrypoint.
• command replaces/extends the default CMD. Use command for simple overrides; only touch entrypoint when you must control the startup binary.

docker compose container alias

Compose supports network aliases:

services:
  api:
    networks:
      default:
        aliases: ["backend"]

Kubernetes vs Docker Compose

• Compose is great for local dev, small servers, and simple production stacks.
• Kubernetes is better for larger systems: scheduling across nodes, advanced rollout strategies, autoscaling, policies.

A common path: Compose → prove it works → Kubernetes when you outgrow it.

Portainer Docker Compose

Portainer can deploy Compose stacks via its UI, but the underlying concept is the same: a Compose file that defines services and how they connect.

Docker Compose alternatives

If you’re looking for a Docker Compose alternative:

• Kubernetes (bigger systems)
• Nomad (simpler cluster scheduling)
• Podman Compose / Quadlet (Podman-based workflows)

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Hostim supports Docker and Docker Compose

Hostim.dev can deploy a single Docker image or a full Docker Compose stack (apps + databases + volumes) without manual infrastructure work.

Deploy a Docker Compose Stack