Docker

concept

Docker Images (Images)

Docker images are templates used to create Docker containers

Docker Container

A container is one or a group of applications that run independently and is called a container after an image is started

Docker Client

Clients use Docker from the command line or other tools

Docker Host

A physical or virtual machine used to execute the Docker daemon and container

Docker Repository (Registry)

Docker repository is used to store images, which can be understood as a code-controlled code repository. Docker Hub provides a huge set of images for use

Using the process, the machine installs the Docker application, and then goes to the repository to download the image. After the image is downloaded, the image is started and the container is generated

Common operations

Mirror operation:

Container operation:

docker run [OPTIONS]

The OPTIONS:

• -a stdin: Specifies the standard input and output types. The options are STDIN, STDOUT, or STDERR.
• -d: Runs the container in the background and returns the container ID.
• -i: Runs the container in interactive mode, usually with-tSimultaneous use;
• -t: Reassigns a pseudo-input terminal to the container, usually with-iSimultaneous use;
• -P: random port mapping. Ports in a container are randomly mapped to ports on the host
• -p: Specifies the port mapping. The format is: Host port: container port
• --name="nginx-lb": Specifies a name for the container.
• --dns 8.8.8.8: Specifies the DNS server used by the container. The default DNS server is the same as the host server.
• --dns-search example.com: Specifies the container DNS search domain name, which is the same as the host by default.
• -h "mars": Specifies the hostname of the container.
• -e username="ritchie": Sets environment variables.
• --env-file=[]: reads environment variables from the specified file;
• --cpuset="0-2" or --cpuset="0,1,2": binds the container to a specified CPU to run.
• -m: Sets the maximum memory used by the container.
• --net="bridge"Specifies the network connection type, container support bridge/host/none/container: four types;
• --link=[]: Adds a link to another container
• --expose=[]: Open a port or group of ports;
• --volume.-v: Binds a volume
• --net=hostPort mapping is not required when starting with host-p)
• --restart=always: Starts with docker
• --privileged=true: The container root user has the rights of the root user on the host

Build Docker environment from 0

Docker installation

• Check the centos version Docker requires a centos kernel version later than 3.10uname -rCommand to see
• (Optional) If the kernel is smaller than 3.10, useyum updateupgrade
• Install the docker:yum install docker
• Start the docker:systemctl start docker
• Check:docker -vChecking the Version number
• Docker is set to boot automatically after startup:systemctl enable docker
• Stop the docker:systemctl stop docker

Docker installation image

Search for Docker images

Take MySql as an example:

Docker hub search docker image:

docker search mysql
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The installation image

Docker pull Image name: version number

Docker pull mysql: 5.7.31Copy the code

Start the MySql

Docker run -d --net=host --restart=always --privileged=true --name mysql -e MYSQL_ROOT_PASSWORD=123456 mysql:5.7.31 --lower_case_table_names=1Copy the code

Parameter Description:

• -d: Background startup
• –net=host: does not need to do port mapping
• –restart=always: start with docker
• — Privileged =true: The container root user has the privileges of the host root user
• -e MYSQL_ROOT_PASSWORD=root: Sets the password of user root
• –lower_case_table_names=1: Sets the table name and parameter names to ignore case

Start the Redis

Ordinary start

docker run -d --net=host --restart=always --name redis redis --requirepass "123456" --tcp-keepalive 10
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Parameter Description:

• -d: Background startup
• –net=host: does not need to do port mapping
• –restart=always: start with docker
• –requirepass “123456” : specifies the login password
• — TCP-Keepalive 10: resolves the reIDS delay error

Start from the configuration file

Configuration file download: download from the official website

The configuration file needs to be modified:

bind 127.0.0.1 # comment out this section, this restricts redis to local access only

protected-mode No # Default yes, enable protected mode, restrict local access

daemonize No # Default no, change to yes means to start in daemon mode, can run in background, except kill process, change to yes will cause configuration file mode to fail to start Redis

databases 16 # Number of databases (optional), I changed this just to see if it works.

dir  / # Enter the local redis database folder (optional).

appendonly Yes #redis persistence (optional)
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Start command:

docker run -d --net=host --restart=always --name redis redis --requirepass "123456" -v /redis/conf/redis.conf:/etc/redis/redis.conf -v /redis/data:/data --appendonly yes
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Parameter Description:

• – v/redis/conf/redis. Conf: / etc/redis/redis conf: mount persistence configuration

• /redis/conf/redis

  • /etc/redis/redis.conf: path to the redis.conf file in the container, which is automatically mapped to the redis.conf file of the previous host when the container is started. This way you don’t have to go inside the container to modify the redis.conf file

• -v /redis/data:/data: mounts persistent files

• /redis/data: is the location of persistent files in the host machine

• /data: is the location of the persistent file in the container

• –appendonly yes: Enable persistence

Start the Nginx

The configuration file

Create a mount directory on the host

mkdir -p /nginx/{conf,html,logs}
#-p is short for --parents which creates the entire directory tree up to a given directory.
#{conf, HTML,logs} three parallel folders
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Copy of the containernginx.conf 和 default.confTo the host

Docker ps check the container ID

docker cp ef:/etc/nginx/nginx.conf /nginx/conf 
dokcer cp ef:/etc/nginx/conf.d/default.conf /nginx/conf/conf.d
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Parameter Description:

• Cp: indicates replication
• Ef: is the ID of our nginx container
• /etc/nginx/nginx.conf: is the internal nginx.conf path of the container

Modify the nginx.conf file

Include /etc/nginx/conf.d/*.conf;

Example:

user  nginx;
worker_processes  1;

error_log  /var/log/nginx/error.log warn;
pid        /var/run/nginx.pid;

events {
    worker_connections  1024;
}

http {
    include       /etc/nginx/mime.types;
    default_type  application/octet-stream;

    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';

    access_log  /var/log/nginx/access.log  main;

    sendfile        on;
    #tcp_nopush on;

    keepalive_timeout  65;

    #gzip on;
	Check to see if the property exists and if the path is correct
    include /etc/nginx/conf.d/*.conf;
}
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Modify the default.conf file

upstream xxxserver{
	#ip_hash;
	server 192.168.1.101:8182 backup;
	server 192.168.1.102:8182;
}
server {
	listen       80;
	server_name  192.168.1.101;
	charset utf-8;
	location / {
		alias /home/ec2-user/hibate/ROOT/;
	}
	location /service/ {
		proxy_pass        http://xxxserver/;
		proxy_set_header    Host $host;
		proxy_set_header  X-Real-IP  $remote_addr;
		proxy_set_header    X-Forwarded-For $proxy_add_x_forwarded_for;
		client_max_body_size  100m;
	}
	location /admin {
		alias /home/ec2-user/hibate/admin/;
		try_files $uri $uri/ /admin/index.html;
    }
	location /merchant {
		alias /home/ec2-user/hibate/merchant/;
		try_files $uri $uri/ /merchant/index.html;
	}
	location /source {
		alias /home/ec2-user/hibate/source/;
	}
	error_page   500 502 503 504  /50x.html;
	location = /50x.html {
		root/usr/share/nginx/html; }}Copy the code

Start the command

docker run -d --name mynginx --net=host --rm --privileged=true -v /nginx/conf/nginx.conf:/etc/nginx/nginx.conf -v /nginx/conf/conf.d:/etc/nginx/conf.d -v /nginx/logs:/var/log/nginx -v /home/ec2-user/hibate/ROOT/:/home/ec2-user/hibate/ROOT/ -v /home/ec2-user/hibate/admin/:/home/ec2-user/hibate/admin/ -v /home/ec2-user/hibate/merchant/:/home/ec2-user/hibate/merchant/ -v /home/ec2-user/hibate/source/:/home/ec2-user/hibate/source/ -v /home/ec2-user/hibate/web/:/home/ec2-user/hibate/web/ nginx
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Parameter Description:

• -d: background running
• – name: name
• –net=host: The container can directly access all network information on the host
• –restart=always: restarts with the system
• –rm: deletes containers automatically after stop. This container is mutually exclusive with –restart-always. Only one container can exist
• — Privileged =true: The container root user has the privileges of the host root user
• -v: mounts files (folders). Format: Local path: container path Each path involved in the default.conf file needs to be mapped to -v

Start the RabbitMQ

docker run -d --name rabbitmq --net=host rabbitmq
#Get docker idDocker ps docker exec -it Container ID/container name sh#Start the plugin
#Only browser 15672 can access username and password are guest
rabbitmq-plugins enable rabbitmq_management
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