dockerの基本

## まずはイメージ取得する

```
 [root@centos8_1 ~]# docker image pull centos
Emulate Docker CLI using podman. Create /etc/containers/nodocker to quiet msg.
Resolved "centos" as an alias (/etc/containers/registries.conf.d/000-shortnames.conf)
Trying to pull quay.io/centos/centos:latest...
Getting image source signatures
Copying blob 7a0437f04f83 done
Copying config 300e315adb done
Writing manifest to image destination
Storing signatures
300e315adb2f96afe5f0b2780b87f28ae95231fe3bdd1e16b9ba606307728f55
[root@centos8_1 ~]#
```


## イメージを取得できたことを確認する
```
[root@centos8_1 ~]# docker image list
Emulate Docker CLI using podman. Create /etc/containers/nodocker to quiet msg.
REPOSITORY               TAG         IMAGE ID      CREATED       SIZE
quay.io/centos/centos    latest      300e315adb2f  3 years ago   217 MB
[root@centos8_1 ~]#
```

### イメージ(centos)からコンテナを起動する　
### 名前をtestos1にしています。

```
[root@centos8_1 ~]# docker run -it --name testos1 centos /bin/bash
Emulate Docker CLI using podman. Create /etc/containers/nodocker to quiet msg.
[root@2269307d2760 /]#
```

### コンテナを停止せずに画面からログアウト？する方法
```
ctrl ＋P ＋ Q

```

### 停止していないことを確認する
```
[root@centos8_1 ~]# docker ps -a
Emulate Docker CLI using podman. Create /etc/containers/nodocker to quiet msg.
CONTAINER ID  IMAGE                         COMMAND     CREATED        STATUS                 PORTS       NAMES
2269307d2760  quay.io/centos/centos:latest  /bin/bash   2 minutes ago  Up About a minute ago              testos1
```


### コンテナを停止する

```
[root@centos8_1 ~]# docker stop testos1
Emulate Docker CLI using podman. Create /etc/containers/nodocker to quiet msg.
testos1

[root@centos8_1 ~]# docker ps -a
Emulate Docker CLI using podman. Create /etc/containers/nodocker to quiet msg.
CONTAINER ID  IMAGE       COMMAND     CREATED     STATUS      PORTS       NAMES
[root@centos8_1 ~]#

```

### コンテナを起動する
オプションの説明

https://qiita.com/kooohei/items/f0352f408056861a8f74



```
[root@centos8_1 ~]# docker start -ai testos1
Emulate Docker CLI using podman. Create /etc/containers/nodocker to quiet msg.
testos1
[root@centos8_1 ~]#
[root@centos8_1 ~]#
[root@centos8_1 ~]# docker ps -a
Emulate Docker CLI using podman. Create /etc/containers/nodocker to quiet msg.
CONTAINER ID  IMAGE                         COMMAND     CREATED         STATUS            PORTS       NAMES
2269307d2760  quay.io/centos/centos:latest  /bin/bash   10 minutes ago  Up 7 seconds ago              testos1
[root@centos8_1 ~]#

```

### 起動後のログイン方法

```
[root@centos8_1 ~]# docker attach testos1
Emulate Docker CLI using podman. Create /etc/containers/nodocker to quiet msg.
[root@2269307d2760 /]#
[root@2269307d2760 /]#
[root@2269307d2760 /]#
[root@2269307d2760 /]#
```

## イメージ一覧を検索したい場合

```
[root@docker163 ~]# docker search centos
NAME                           DESCRIPTION                                      STARS     OFFICIAL   AUTOMATED
centos                         DEPRECATED; The official build of CentOS.        7751      [OK]
centos/postgresql-10-centos7   PostgreSQL is an advanced Object-Relational …   20
centos/systemd                 systemd enabled base container.                  115                  [OK]
centos/postgresql-96-centos7   PostgreSQL is an advanced Object-Relational …   45
centos/redis-5-centos8                                                          0
centos/postgresql-10-centos8                                                    0
centos/httpd-24-centos8                                                         3
centos/mariadb-103-centos8                                                      2
centos/postgresql-12-centos8                                                    0
centos/mysql-56-centos7        MySQL 5.6 SQL database server                    23
centos/mongodb-36-centos7      MongoDB NoSQL database server                    12
centos/mariadb-101-centos7     MariaDB 10.1 SQL database server                 13
centos/mysql-80-centos8                                                         0
centos/nginx-112-centos7       Platform for running nginx 1.12 or building …   16
centos/ruby-25-centos7         Platform for building and running Ruby 2.5 a…   3
centos/redis-32-centos7        Redis in-memory data structure store, used a…   6
centos/mysql-57-centos7        MySQL 5.7 SQL database server                    95
centos/mariadb-102-centos7     MariaDB 10.2 SQL database server                 6
centos/httpd-24-centos7        Platform for running Apache httpd 2.4 or bui…   46
centos/php-56-centos7          Platform for building and running PHP 5.6 ap…   34
centos/python-27-centos7       Platform for building and running Python 2.7…   17
centos/nginx-116-centos7       Platform for running nginx 1.16 or building …   3
centos/nginx-18-centos7        Platform for running nginx 1.8 or building n…   14
centos/redis-5-centos7         Redis in-memory data structure store, used a…   0
centos/postgresql-12-centos7   PostgreSQL is an advanced Object-Relational …   5
```

https://qiita.com/t-yotsu/items/559731aca6300eef78ec


## 続編
https://qiita.com/XKYUXSOX/items/b7926439b3e06303d193


## 参考
https://qiita.com/tifa2chan/items/e9aa408244687a63a0ae