Docker 事始め Vagrant On rocky8

etc docker

docker install

参考

[root@docker ~]# docker -v
Docker version 20.10.15, build fd82621

docker-compose install

curl -L https://github.com/docker/compose/releases/download/v2.5.0/docker-compose-linux-x86_64 -o /usr/local/bin/docker-compose

chmod +x /usr/local/bin/docker-compose
[root@docker vagrant]# docker-compose --version
Docker Compose version v2.5.0

Docker cmd list

URL

# 強制削除
docker rm -f getting-started-docs-1

httpd

# Docker image pull
docker pull httpd
# Docker httpd start
docker run -d --name my-apache -p 8080:80 -v "$PWD":/usr/local/apache2/htdocs/ httpd
# 確認
curl http://localhost:8080
## FROM HOST
http://192.168.56.10:8080/

docker run -d -p 80:80 docker/getting-started
# localhost
http://192.168.56.10/tutorial/

docker stop 0c57b84663b8
docker rm reverent_vaughan

docker container kill -s KILL jolly_wing
docker container kill -s KILL my-apache
docker container prune

docker images --filter "dangling=true"

docker rmi $(docker images -f "dangling=true" -q)

Terminal

docker run --name test -it debian

サンプル・アプリケーション

Docker公式

sudo su -
cd /share/vagrant/01.sample/
## git 無かったのでHOST側で
git clone https://github.com/docker/getting-started.git
cd getting-started/app
docker build -t getting-started .
# => REPOSITORY = getting-started
docker run -dp 3000:3000 --rm --name gs getting-started  

docker container ls
CONTAINER ID   IMAGE             COMMAND                  CREATED          STATUS          PORTS                            NAMES
3799de15aa65   getting-started   "docker-entrypoint.s…"   18 seconds ago   Up 17 seconds   0.0.0.0:3000->3000/tcp   gs

docker container exec -it gs ls /bin/
docker container exec -it gs /bin/ash

http://192.168.56.10:3000
curl http://localhost:3000

DB の保持

docker volume create todo-db
docker run -dp 3000:3000 --rm --name gs -v todo-db:/etc/todos getting-started

docker container exec -it gs /bin/ash

docker volume inspect todo-db
ll /var/lib/docker/volumes/todo-db/_data/
total 8
-rw-r--r-- 1 root root 8192 May  9 21:39 todo.db

# Docker\01.sample\getting-started\app\src\persistence\sqlite.js
 1 const sqlite3 = require('sqlite3').verbose();
 2 const fs = require('fs');
 3 const location = process.env.SQLITE_DB_LOCATION || '/etc/todos/todo.db';

バインド マウント の使用

*vagrant の共有フォルダでは volume 上手く行かない

mkdir -p /share/work
cp -R /share/vagrant/01.sample/getting-started/app /share/work/.
cd /share/work/app
docker run -dp 3000:3000 --name sample \
-w /app -v "$(pwd):/app" \
node:12-alpine \
sh -c "yarn install && yarn run dev"

docker logs -f sample

vim /share/work/app/src/static/js/app.js

# 109 行目
-  {submitting ? 'Adding...' : 'Add Item'}
+  {submitting ? 'Adding...' : 'Add'}

結果

docker logs -f sample

[nodemon] 2.0.13
[nodemon] to restart at any time, enter `rs`
[nodemon] watching path(s): *.*
[nodemon] watching extensions: js,mjs,json
[nodemon] starting `node src/index.js`
Using sqlite database at /etc/todos/todo.db
Listening on port 3000
[nodemon] restarting due to changes...        # 変更を検知して再起動してくれる。
[nodemon] starting `node src/index.js`
Using sqlite database at /etc/todos/todo.db
Listening on port 3000

複数コンテナのアプリ

# pwd
/share/work/app
docker network create todo-app

• MySQL コンテナを起動

docker run -d --name mysql --rm \
--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

• db 確認

docker exec -it mysql mysql -u root -p'secret'

• network 確認

docker run -it --network todo-app --name net_tools nicolaka/netshoot

;; ANSWER SECTION:
mysql.                  600     IN      A       172.19.0.2

• app 確認

docker run -dp 3000:3000 --name sample --rm \
  -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"

docker logs -f sample

[nodemon] watching extensions: js,mjs,json
[nodemon] starting `node src/index.js`
Waiting for mysql:3306.
Connected!
Connected to mysql db at host mysql
Listening on port 3000

Docker Compose を使う

URL

[vagrant@docker ~]$ docker --version
Docker version 20.10.15, build fd82621
[vagrant@docker ~]$ docker-compose --version
Docker Compose version v2.5.0

cp /share/vagrant/01.sample/docker-compose/docker-compose.yml /share/work/app/docker-compose.yml
cd /share/work/app

[root@docker ap]# docker-compose up -d
[+] Running 4/4
 ⠿ Network docker-compose_default           Created   0.1s 
 ⠿ Volume "docker-compose_todo-mysql-data"  Created   0.0s
 ⠿ Container docker-compose-mysql-1         Started   1.9s 
 ⠿ Container docker-compose-app-1           Started   1.9s

[root@docker app]# docker ps -a                                                                                                                      
CONTAINER ID   IMAGE            COMMAND                  CREATED         STATUS        PORTS                    NAMES
4fdc0b024710   node:12-alpine   "docker-entrypoint.s…"   3 seconds ago   Up 1 second   0.0.0.0:3000->3000/tcp   app-app-1
5e3945cc7a4b   mysql:5.7        "docker-entrypoint.s…"   3 seconds ago   Up 1 second   3306/tcp, 33060/tcp      app-mysql-1

 app という名前のグループが見えます。
 これは Docker Compose による「プロジェクト名」で、同じグループのコンテナに対して使われます。
 デフォルトでは、プロジェクト名はシンプルに docker-compose.yaml が置かれているディレクトリ名(app)です。

docker-compose logs -f app
docker-compose down

ll /var/lib/docker/volumes
total 24
drwx-----x  3 root root     19 May 10 22:08 app_todo-mysql-data
brw-------  1 root root 253, 0 May 10 21:54 backingFsBlockDev
drwx-----x  3 root root     19 May 10 22:02 docker-compose_todo-mysql-data
-rw-------. 1 root root  32768 May 10 22:08 metadata.db
drwx-----x  3 root root     19 May  9 21:34 todo-db
drwx-----x  3 root root     19 May  9 22:38 todo-mysql-data