Docker install and first Dockerfile

preface

This article only explains the installation of Docker and the creation of Dockerfile. Dockerfile is composed of different commands in different requirements, which can be understood as a configuration file. However, only a demo is shown here to show the basic usage of Docker

Server environment

linux centos 7.6

install

• step 1

If you have installed an older version of docker, you need to uninstall it first

sudo yum remove docker \
                  docker-client \
                  docker-client-latest \
                  docker-common \
                  docker-latest \
                  docker-latest-logrotate \
                  docker-logrotate \
                  docker-selinux \
                  docker-engine-selinux \
                  docker-engine

• step 2

install dependencies

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

• step 3

set stable Repository

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

• step 4

install docker

sudo yum install docker-ce docker-ce-cli containerd.io

• step 5

start docker service

sudo systemctl start docker

• step 6

Run a demo to see if the installation was successful
: The hello-world image is not in your local, but when you run the command, docker will pulls the helloworld image from the remote repository

sudo docker run hello-world

create a demo

• step 1

create dockerfile
Choose any directory and create a dockerfile.
It is suggested to name ‘Dockerfile’, because by default docker will run the file called ‘Dockerfile’ in the current directory. If you give it a different name, add the -f parameter and the path of the dockerfile

vim Dockerfile

FROM nginx
MAINTAINER author <email>
RUN echo '<h1>Hello, Docker!</h1>' > /usr/share/nginx/html/index.html


:wq

• step 2

build image

docker build -t test/hello-world: .

-t is to set the repository and image
test is repository name
hello-world as the image name

• step 3

run image

docker run --name hello -d -p 8080:80   test/hello

• step 4

Browser input http://localhost:8080/

final

This is a simple example of using Dockerfile to build the image and run the container!