Docker Useful Commands

Docker is a platform for developers and sysadmins to develop, ship, and run applications. Docker lets you quickly assemble applications from components and eliminates the friction that can come when shipping code. Docker lets you get your code tested and deployed into production as fast as possible.

With Docker, developers can build any app in any language using any toolchain. “Dockerized” apps are completely portable and can run anywhere - colleagues’ macOS and Windows laptops, QA servers running Ubuntu in the cloud, and production data center VMs running Red Hat.

Docker for Mac

Docker for Mac is the current release of Docker for macOS.

Installation

Docker for Mac can be downloaded here.

Quick Start

For quick start find the newly installed Docker Quickstart Terminal and double-click to launch it. Then you can start the Hello World container using:

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$ docker run hello-world

You can find more about Docker in the documentation.

Useful Docker Commands

Here follows a list of useful Docker commands with useful flags for each
command.

Table of Contents

  1. docker build
  2. docker exec
  3. docker images
  4. docker inspect
  5. docker logs
  6. docker ps
  7. docker rmi
  8. docker run
  9. Learn More

docker build

Build an image from a Dockerfile.

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docker build [DOCKERFILE PATH]

Example

Build an image tagged my-org/my-image where the Dockerfile can be found at
/tmp/Dockerfile.

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docker build -t my-org:my-image -f /tmp/Dockerfile

Useful flags

  • --file -f Path where to find the Dockerfile
  • --force-rm Always remove intermediate containers
  • --no-cache Do not use cache when building the image
  • --rm Remove intermediate containers after a successful build (this is
    true) by default
  • --tag -t Name and optionally a tag in the ‘name:tag’ format

docker exec

Execute a command inside a running container.

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docker exec [CONTAINER ID]

Example

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docker exec [CONTAINER ID] touch /tmp/exec_works

Useful flags

  • --detach -d Detached mode: run command in the background
  • -it This will not make the container you started shut down immediately, as
    it will create a pseudo-TTY session (-t) and keep STDIN open (-i)

docker images

List all downloaded/created images.

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docker images

Useful flags

  • -q Only show numeric IDs

docker inspect

Shows all the info of a container.

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docker inspect [CONTAINER ID]

docker logs

Gets logs from container.

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docker logs [CONTAINER ID]

Useful flags

  • --details Log extra details
  • --follow -f Follow log output. Do not stop when end of file is reached, but
    rather wait for additional data to be appended to the input.
  • --timestamps -t Show timestamps

docker ps

Shows information about all running containers.

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docker ps

Useful flags

  • --all -a Show all containers (default shows just running)
  • --filter -f Filter output based on conditions provided, docker ps -f="name="example"
  • --quiet -q Only display numeric IDs

docker rmi

Remove one or more images.

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docker rmi [IMAGE ID]

Useful flags

  • --force -f Force removal of the image

docker run

Creates and starts a container in one operation. Could be used to execute a
single command as well as start a long-running container.

Example:

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docker run -it ubuntu:latest /bin/bash

This will start a ubuntu container with the entrypoint /bin/bash. Note that
if you do not have the ubuntu image downloaded it will download it before
running it.

Useful flags

  • -it This will not make the container you started shut down immediately, as
    it will create a pseudo-TTY session (-t) and keep STDIN open (-i)
  • --rm Automatically remove the container when it exit. Otherwise it will be
    stored and visible running docker ps -a.
  • --detach -d Run container in background and print container ID
  • --volume -v Bind mount a volume. Useful for accessing folders on your local
    disk inside your docker container, like configuration files or storage that
    should be persisted (database, logs etc.).

Learn More

A list of more useful Docker commands can be found in the
docker-cheat-sheet.

Docker Tips and Tricks

A collection of useful tips and tricks for Docker.

Delete all containers

NOTE: This will remove ALL your containers.

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docker rm $(docker ps -a -q)

Delete all untagged containers

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docker rmi $(docker images | grep '^<none>' | awk '{print $3}')

See all space Docker take up

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docker system df

Get IP address of running container

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docker inspect [CONTAINER ID] | grep -wm1 IPAddress | cut -d '"' -f 4

Kill all running containers

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docker kill $(docker ps -q)
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