2.Docker Quickstart 2

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• 1.Docker Quick Start
• 2.Docker Quickstart 2
• 3.Docker Quickstart 3
• 4.Docker Quick Start

Multi-container application

In general, we refer to multiple services such as mysql, front-end services, Nginx, back-end services, queue services, Redis, etc. We recommend multiple containers for these services because:

1. It may be necessary to extend the API and the front end in a different way than the database
2. Individual containers can be independently updated to the version
3. While you can use a container for your database locally, you might want to use managed services for your database in a production environment. We don’t want to ship the database engine with the application, nor do we need to
4. Running multiple processes will require a process manager (the container starts only one process), which increases the complexity of container start/close

start

1. Multiple containers to access each other need to be created on the same network (non-local network/LAN, where each container has its own IP address)dockernetwork

docker network create todo-app
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2. Start a MySQL container and attach it to the network,--network-alias mysqlSpecifies a network alias, useful later

docker run -d \
    --network todo-app --network-alias mysql \
    -v todo-mysql-data:/var/lib/mysql \
    -e MYSQL_ROOT_PASSWORD=secret \
    -e MYSQL_DATABASE=todos \
    mysql:5.7
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If you use PowerShell

docker run -d ` --network todo-app --network-alias mysql ` -v todo-mysql-data:/var/lib/mysql ` -e MYSQL_ROOT_PASSWORD=secret '-e MYSQL_DATABASE=todos' mysql:5.7Copy the code

Note: Volumes are automatically created for todo-mysql-data

3. Test connection to mysql

docker exec -it <mysql-container-id> mysql -p
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4. Enter the password to view the database:SHOW DATABASES;

mysql> SHOW DATABASES;+--------------------+ | Database | +--------------------+ | information_schema | | mysql | | performance_schema | | sys | | todos | + -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- + 5 rows in the set (0.00 SEC)Copy the code

The toDOS database was created successfully

Connect to MySQL

1. usenicolaka/netshootImage starts a new container, making sure it is connected to the same network

docker run -it --network todo-app nicolaka/netshoot
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2. Find hostnamemysqltheIPaddress

dig mysql

; <<>> DiG 9.16.16 <<>> mysql
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 52110
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;mysql.				IN	A

;; ANSWER SECTION:
mysql.			600	IN	A	172.18.0.2

;; Query time: 3 msec
;; SERVER: 127.0.0.11#53(127.0.0.11)
;; WHEN: Wed Jun 23 06:11:23 UTC 2021
;; MSG SIZE  rcvd: 44
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!!!!!!!!! Mysql = 172.18.0.2; mysql = 172.18.0.2; mysql = 172.18.0.2

Using mysql

1. The specifiedmysqlEnvironment variable, switch toappDirectory, view1.Docker Quick Start

cd xx/app
ls
Dockerfile      node_modules    package.json    spec            src             yarn.lock
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Create a container

docker run -dp 3000:3000 \ -w /app -v "$(pwd):/app" \ --network todo-app \ -e MYSQL_HOST=mysql \ -e MYSQL_USER=root \ -e  MYSQL_PASSWORD=secret \ -e MYSQL_DB=todos \ node:12-alpine \ sh -c "yarn install && yarn run dev"Copy the code

If you use PowerShell

docker run -dp 3000:3000 ` -w /app -v "$(pwd):/app" ` --network todo-app ` -e MYSQL_HOST=mysql ` -e MYSQL_USER=root ` -e  MYSQL_PASSWORD=secret ` -e MYSQL_DB=todos ` node:12-alpine ` sh -c "yarn install && yarn run dev"Copy the code

Check log, connect to mysql

Yarn install V1.22.5 [1/4] Resolving Packages... Success Already up-to-date. Done in 0.59s. yarn run V1.22.5$ nodemon src/index.js
[nodemon] 1.19.2
[nodemon] to restart at any time, enter `rs`
[nodemon] watching dir(s): *.*
[nodemon] starting `node src/index.js`
Waiting for mysql:3306.
Connected!
Connected to mysql db at host mysql
Listening on port 3000
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The connection to mysql was successful

2. Go to http://localhost:3000/ to add a few
3. Check whether the mysql database exists

docker exec -it <mysql-container-id> mysql -p todos
Enter password: 

mysql> select * from todo_items;+--------------------------------------+---------+-----------+ | id | name | completed | +--------------------------------------+---------+-----------+ | 987d2be8-49fa-4fef-a0c1-4faf2fcb003e | a s d f | 0 | | bdd05e38-76b8-47c9-b408-22fa1b00b58b | 111 | 0 | +--------------------------------------+---------+-----------+ 2 rows In the set (0.00 SEC)Copy the code

Up to this point, we’ve managed to create a network that includes both mysql and Node services, and the code is hot.

Quick query of common commands

View image: docker image ls View container: docker ps Monitor logs: docker logs-f < container-id >