Docker container technology

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ps :

I. Overview

• Docker is an open source engine, you can easily create a lightweight for any application, portable, self-contained container. Developers in a notebook compiled by the test container can batch deployed in a production environment

II: Core Concepts

• Host : A host machine docker program installed (Cocker mounted directly on the operating system)
• Client : Connecting the host operating docker
• Registry : To save all kinds of packaged software image
• Images : Packaged software mirroring, on the docker warehouse
• Container : An example of the image starts is called a container, the container is a stand-alone application or a group of

Three: Installation docker

(A) check the linux kernel version

• Must be 3.10 or above

uname -r

(B) mounting docker

yum install docker

• Enter yConfirm Installation

(C) start docker

# 启动docker
systemctl start docker
# 查看版本号
docker -v

(Iv) boot configuration

systemctl enable docker

(E) stop docker

systemctl stop docker

Four: Common Commands

(A) the mirroring

operating	command	Explanation
Seek	docker search 关键字	Search Mirror, also in dockerhub search for detailed information on
Pull	docker pull 镜像名:tag	:tagIs optional, tagrepresents a label, usually version, the default islatest
List	docker images	View all local mirror
delete	docker rmi image-id	Delete the specified local mirror

(B) operating the vessel

1. Search Mirror

docker search tomcat

2. Pull the mirror

docker pull tomcat

3. The image starting container

docker run --name mytomcat -d tomcat:latest

• --name : Assign a name to the container
• -d : --detach,Run container in background and print container ID

4. Check the operation of the vessel

docker ps

The container is stopped in operation

docker stop container-id

6. Check all containers

docker ps -a

7. Start container

docker start container-id

8. Remove the container

docker rm container-id

9. Port Mapping

docker run -d -p 8888:8080 tomcat

• -d : Background process
• -p: --publish list, The Publish apos Container Port A (S) The Host to (default []), will be released to the host port of the container port (host port: the port of the container)

10. The open port 8888

firewall-cmd --zone=public --add-port=8888/tcp --permanent

• --zone : Scope
• --add-port=8888/tcp : Add the port in the format: port / protocol
• --permanent : Permanent

11. Log

docker logs container-name/container-id

(C) install mysql

1. Pull mirror

docker pull mysql

2. Start

docker run --name mysql01 -d -p 3306:3306 mysql

• Rom found !!!

3. View Log

docker logs mysql01

error: database is uninitialized and password option is not specified 
  You need to specify one of MYSQL_ROOT_PASSWORD, MYSQL_ALLOW_EMPTY_PASSWORD and MYSQL_RANDOM_ROOT_PASSWORD

• Database is not initialized, the cryptographic operation is not described
• You need to describe one of these three variables

4. Start the specified variable

docker run --name mysql02 -d -p 3306:3306 -e MYSQL_ROOT_PASSWORD=123456 mysql

• -e : --env list,Set environment variables (default [])

The client connection

1) into the mirror

docker exec -ti 2cbb0f246353 /bin/bash

2) Log

mysql -uroot -p123456

3) modify the root login address

ALTER USER 'root'@'%' IDENTIFIED WITH mysql_native_password BY '123456';

Five: the use of summary docker step

1. Installation Docker
2. Docker warehouse to find the software corresponding to the image;
3. Docker run using this image, this image will generate a Docker containers;
4. Start to stop the vessel is to start the software stops;

Reproduced in: https: //www.jianshu.com/p/52c59cabf2b7