Technology Docker containers (lower)

Technology Docker containers (lower)

A, Dockerfile basic commands

1.1.FROM - based on the reference mirror

• FROM centos # make reference image (based on centos)

• FROM scratch # does not rely on any reference mirror base image

• FROM tomcat:9.022-jdk8-openjdk

• Try to use the official Base Image

1.2.LABEL & MAINTAINER - descriptive information

• MAINTAINER xxx.com
• LABEL version = "1.0"
• LABEL description = "xxx what role"

1.3.WORKDIR - set the working directory

• WORKDIR /usr/local
• WORKDIR / usr / local / newdir # created automatically
• Try using an absolute path

1.4.ADD & COPY - Copy files

• ADD hello / #f copied to the root path
• ADD test.tar.gz / # add the root directory and extract
• ADD In addition to copying, but also have the added functionality of remote files, + website, similar to wget

1.5.ENV - Setting constant environment

• ENV JAVA_HOME /usr/local/openjdk8
• RUN ${JAVA_HOME}/bin/java -jar test.jar
• Try to use environment constants can improve maintenance procedures

Two, Dockerfile execution instruction

RUN&CMD&ENTRYPOINT

• RUN: Build to build upon the implementation of the equivalent of implementation of the shell
• ENTRYPOINT: start the implementation of the container
• CMD: CMD performed after the container has started [ "ps", "ef"] is equivalent to implementation of exec

Implementation modalities

RUN yum install -y vim #shell命令格式
RUN ["yum","install","-y","vim"] #Exec命令格式

Why should we offer two different ways to perform it?

• shell execution

Use Shell executed, the current shell is the parent process, generate a child process

Executed in sub-shell script, the script is finished, exit the sub-shell, back to the current shell

• exec run

The current process execution

Real

FROM centos
RUN ["echo","image building!!!"]//执行在子进程了
CMD ["echo","container starting..."]//只有这句能看到的

Note: CMD if increased, will replace CMD command, CMD command may not execute

ENTRYPOINT will perform

Third, the image constructed Redis

• Redis is a NoSQL database
• 2010.3.15 start, Redis development, chaired by VMWare

Writing Dockerfile

FROM centos
RUN ["yum","install","-y","gcc","gcc-c++","net-tools","make"]
WORKDIR /usr/local
ADD redis-4.0.14.tar.gz .   //会自动解压
WORKDIR /usr/local/redis-4.0.14/src
RUN make && make install
WORKDIR /usr/local/redis-4.0.14
ADD redis-7000.conf .
EXPOSE 7000 //暴露7000端口
CMD ["redis-server","redis-7000.conf"]

After performing mirrored building on the line

docker build -t xxx/docker-redis:1.0 .
docker run -p 7000:7000 xxx/docker-redis:1.0

Dockerfile here just about writing, practical work, mirroring can be used directly redis

Fourth, one-way communication between the container Link

• After the container is created, there is a virtual IP

Container-way access

Principle: Although virtual IP, container communicate, we do not use IP communications, the use of container for messaging

We used to specify the name --name

docker run -d --name web tomcat
docker run -d --name database -it centos /bin/bash

View Virtual IP

docker inspect [containerID]

We use ping

ping 172.17.0.3 是可以ping通的
但是我们ping名称是ping不通的

So we create a second tomcat when linked to a database

docker run --name web --link database tomcat

This time we enter the tomcat, and then ping, can naturally Unicom

ping database 可以自动ping通

Five, two-way communication based Bridge Bridge

Bridge two-way communication theory

To do: Binding and database tomcat

docker run -d --name web tomcat
docker run -d --name database centos /bin/bash
docker network ls
docker network create -d bridge my-bridge
docker network connect my-bridge web
docker network connect my-bridge database

June and share data container Volume

Unused volume container

Volume container principle

method:

1. By providing host directory mount -v

• format:
• docker run --name container -v host name path: the path within the vessel mounted mirror name
• Example:
• docker run --name t1 -v /usr/webapps:/usr/local/tomcat/webapps tomcat

2. By sharing container

• format:
• docker create --name webpage -v /webapps:/tomcat/webapps tomcat /bin/true
• Share vessel mount point
• docker run --volumes-from webpage --name t1 -d tomcat

七、Docker Compose

Multi-vessel deployment will encounter a lot of trouble, so we came out of Docker compose

Case

• Docker Compose single multi-container deployment tools
• By yml file defines how to deploy multi-vessel
• WIN / MAC provided by default Docker Compose, Linux will need to install

installation steps:

1. Obtain automatically installed

pip install -U docker-compose==1.23.2

2. Execute permission

sudo chmod +x /usr/local/bin/docker-compose

Install WordPress

1. Create a directory wordpress

mkdir wordpress

2.vim docker-compose.yml

复制官网上的

3.build the project

docker-compose up -d

八、Docker-compose应用实战

案例、两个SpringBoot项目构建docker-compose

SpringBoot打包

文件 applicaion-dev.yml application.yml bsbdj.jar

vim Dockerfile

FROM openjdk:8u222-jre
WORKDIR /usr/local/bsbdj   //上述肯定没有这个目录，所以会创建
ADD bdbdj.jar    //加入jar
ADD application.yml .
ADD application-dev.yml .
EXPOSE 80        //暴露端口80
CMD ["java","-jar","bsbdj.jar"] 

docker build -t msb.com/bsbdj-app .
docker run msb.com/bsbdj-app

数据库打包

vim Dockerfile

FROM mysql:5.7
WORKDIR /docker-entrypoint-initdb.d
ADD init-db.sql .

docker build -t msb.com/bsbdj-db .
docker run -e -d MYSQL_ROOT_PASSWORD=root msb.com/bsbdj-db

docker exec -it aae73fa77d75 /bin/bash

Docker-Compose进行关联和发布

vim docker-compose.yml

version: '3.3'
services: 
    db:
        build: ./bsbdj-db/
        restart: always  //容错，自动重启
        environment:
            MYSQL_ROOT_PASSWORD: root
    app:
        build: ./bsbdj-app/
        depends_on:
            - db
        ports:
            - "80:80"
        restart: always
        
        
docker-compose up
docker-compose up -d 
docker-compose logs
docker-compose down

我们连接数据库，那么yml中jdbc:mysql://db:3306/xxx即可