Docker: Some Important Commands

Start Docker :

$ sudo systemctl start docker                                                                                             

List All the Available Docker Images :

  $ sudo docker images                              

Download a docker image from docker hub:

 $ sudo docker pull rabbitmq                     

Management Commands:

  config      Manage Docker configs

  container   Manage containers

  image       Manage images

  network     Manage networks

  node        Manage Swarm nodes

  plugin      Manage plugins

  secret      Manage Docker secrets

  service     Manage services

  stack       Manage Docker stacks

  swarm       Manage Swarm

  system      Manage Docker

  trust       Manage trust on Docker images

  volume      Manage volumes

Commands:

  attach      Attach local standard input, output, and error streams to a running container

  build       Build an image from a Dockerfile

  commit      Create a new image from a container's changes

  cp          Copy files/folders between a container and the local filesystem

  create      Create a new container

  deploy      Deploy a new stack or update an existing stack

  diff        Inspect changes to files or directories on a container's filesystem

  events      Get real time events from the server

  exec        Run a command in a running container

  export      Export a container's filesystem as a tar archive

  history     Show the history of an image

  images      List images

  import      Import the contents from a tarball to create a filesystem image

  info        Display system-wide information

  inspect     Return low-level information on Docker objects

  kill        Kill one or more running containers

  load        Load an image from a tar archive or STDIN

  login       Log in to a Docker registry

  logout      Log out from a Docker registry

  logs        Fetch the logs of a container

  pause       Pause all processes within one or more containers

  port        List port mappings or a specific mapping for the container

  ps          List containers

  pull        Pull an image or a repository from a registry

  push        Push an image or a repository to a registry

  rename      Rename a container

  restart     Restart one or more containers

  rm          Remove one or more containers

  rmi         Remove one or more images

  run         Run a command in a new container

  save        Save one or more images to a tar archive (streamed to STDOUT by default)

  search      Search the Docker Hub for images

  start       Start one or more stopped containers

  stats       Display a live stream of container(s) resource usage statistics

  stop        Stop one or more running containers

  tag         Create a tag TARGET_IMAGE that refers to SOURCE_IMAGE

  top         Display the running processes of a container

  unpause     Unpause all processes within one or more containers

  update      Update configuration of one or more containers

  version     Show the Docker version information

  wait        Block until one or more containers stop, then print their exit codes

How To Install and Use Docker on CentOS 7

Prerequisites

• 64-bit CentOS 7 
• Non-root user with sudo privileges. A CentOS 7 server set up using Initial Setup Guide for CentOS 7explains how to set this up.

Note: Docker requires a 64-bit version of CentOS 7 as well as a kernel version equal to or greater than 3.10. The default 64-bit CentOS 7 Droplet meets these requirements.

All the commands in this tutorial should be run as a non-root user. If root access is required for the command, it will be preceded by sudo. Initial Setup Guide for CentOS 7 explains how to add users and give them sudo access.

Docker Architecture:

Install using the repository

Before you install Docker CE for the first time on a new host machine, you need to set up the Docker repository. Afterward, you can install and update Docker from the repository.

SET UP THE REPOSITORY

1. Install required packages. yum-utils provides the yum-config-manager utility, and device-mapper-persistent-data and lvm2are required by the devicemapper storage driver.

   $ sudo yum install -y yum-utils \
     device-mapper-persistent-data \
     lvm2
   

2. Use the following command to set up the stable repository. You always need the stable repository, even if you want to install builds from the edge or test repositories as well.

   $ sudo yum-config-manager \
       --add-repo \
       https://download.docker.com/linux/centos/docker-ce.repo
   

3. Optional: Enable the edge and test repositories. These repositories are included in the docker.repo file above but are disabled by default. You can enable them alongside the stable repository.

   $ sudo yum-config-manager --enable docker-ce-edge
   

   $ sudo yum-config-manager --enable docker-ce-test
   

   You can disable the edge or test repository by running the yum-config-manager command with the --disable flag. To re-enable it, use the --enable flag. The following command disables the edge repository.

   $ sudo yum-config-manager --disable docker-ce-edge
   

   Note: Starting with Docker 17.06, stable releases are also pushed to the edge and test repositories.

   Learn about stable and edge builds.

INSTALL DOCKER CE

1. Install the latest version of Docker CE, or go to the next step to install a specific version:

   $ sudo yum install docker-ce
   

   If prompted to accept the GPG key, verify that the fingerprint matches 060A 61C5 1B55 8A7F 742B 77AA C52F EB6B 621E 9F35, and if so, accept it.

   Got multiple Docker repositories?

   If you have multiple Docker repositories enabled, installing or updating without specifying a version in the yum installor yum update command always installs the highest possible version, which may not be appropriate for your stability needs.

   Docker is installed but not started. The docker group is created, but no users are added to the group.
2. To install a specific version of Docker CE, list the available versions in the repo, then select and install:
   a. List and sort the versions available in your repo. This example sorts results by version number, highest to lowest, and is truncated:

   $ yum list docker-ce --showduplicates | sort -r
   
   docker-ce.x86_64            18.03.0.ce-1.el7.centos             docker-ce-stable
   

   The list returned depends on which repositories are enabled, and is specific to your version of CentOS (indicated by the .el7suffix in this example).
   b. Install a specific version by its fully qualified package name, which is the package name (docker-ce) plus the version string (2nd column) up to the first hyphen, separated by a hyphen (-), for example, docker-ce-18.03.0.ce.

   $ sudo yum install docker-ce-<VERSION STRING>
   

   Docker is installed but not started. The docker group is created, but no users are added to the group.
3. Start Docker.

   $ sudo systemctl start docker
   

4. Verify that docker is installed correctly by running the hello-world image.

   $ sudo docker run hello-world
   

   This command downloads a test image and runs it in a container. When the container runs, it prints an informational message and exits.

Docker CE is installed and running. You need to use sudo to run Docker commands. Continue to Linux postinstall to allow non-privileged users to run Docker commands and for other optional configuration steps.

Find Details here:

https://www.digitalocean.com/community/tutorials/how-to-install-and-use-docker-on-centos-7

https://docs.docker.com/install/linux/docker-ce/centos/