[Docker学习笔记] 创建容器常见选项

1）docker container run，-i 交互式，-t 创建一个伪终端，-d 后台运行

[root@localhost ~]# docker container run -itd --name bs busybox
6cfa0a43ba1b393d2f5f086ad59f662e0b6bb293d80c3a3d6bdf8d1d2ff7255c
[root@localhost ~]# docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
6cfa0a43ba1b        busybox             "sh"                4 seconds ago       Up 2 seconds                            bs
[root@localhost ~]#

2）docker container attach 进入容器再退出容器会停；按 Ctrl+p+q 退出则会继续运行。

使用 docker container exec -it <container id | container name> 进入容器终端再退出，不会停止运行。

[root@localhost ~]# docker container attach 6cfa0a43ba1b
/ # ls
bin   dev   etc   home  proc  root  sys   tmp   usr   var
/ # exit
[root@localhost ~]# docker container attach bs
You cannot attach to a stopped container, start it first
[root@localhost ~]# docker container start bs
bs
[root@localhost ~]# ls
anaconda-ks.cfg
[root@localhost ~]# docker container attach bs
/ # ls
bin   dev   etc   home  proc  root  sys   tmp   usr   var
/ # read escape sequence
[root@localhost ~]# docker container exec -it bs sh
/ # exit
[root@localhost ~]# docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
6cfa0a43ba1b        busybox             "sh"                About an hour ago   Up About a minute                       bs
[root@localhost ~]#

3）容器和宿主机的一些联系

第一，关于IP地址

[root@localhost ~]# ip addr
...(skipped)...
3: docker0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default
    link/ether 02:42:ba:15:f7:99 brd ff:ff:ff:ff:ff:ff
    inet 172.17.0.1/16 brd 172.17.255.255 scope global docker0
       valid_lft forever preferred_lft forever
    inet6 fe80::42:baff:fe15:f799/64 scope link
       valid_lft forever preferred_lft forever
...(skipped)...
[root@localhost ~]#
[root@localhost ~]# docker container attach 6cfa0a43ba1b
/ # ls
bin   dev   etc   home  proc  root  sys   tmp   usr   var
/ # ifconfig
eth0      Link encap:Ethernet  HWaddr 02:42:AC:11:00:02
          inet addr:172.17.0.2  Bcast:172.17.255.255  Mask:255.255.0.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:16 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:1312 (1.2 KiB)  TX bytes:0 (0.0 B)

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

第二，每次重启容器，会重新挂载以下三个文件

[root@localhost ~]# docker container attach bs
/ # mount
rootfs on / type rootfs (rw)
overlay on / type overlay 
...(skipped)...
/dev/mapper/centos-root on /etc/resolv.conf type xfs (rw,seclabel,relatime,attr2,inode64,noquota)
/dev/mapper/centos-root on /etc/hostname type xfs (rw,seclabel,relatime,attr2,inode64,noquota)
/dev/mapper/centos-root on /etc/hosts type xfs (rw,seclabel,relatime,attr2,inode64,noquota)
...(skipped)...
/ # cat /etc/resolv.conf
# Generated by NetworkManager
nameserver 114.114.114.114
/ # cat /etc/hostname
6cfa0a43ba1b
/ # cat /etc/hosts
127.0.0.1       localhost
::1     localhost ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
172.17.0.2      6cfa0a43ba1b
/ #

4）docker container run，-e 起容器的时候传入变量

[root@localhost ~]# docker container run -itd -e a=666 --name bs1 busybox
d8758dd0bd0d18047616680decedb25021037430ddb312e707e3bae5f7dad442
[root@localhost ~]# docker exec -it bs1 sh
/ # echo $a
666

5）docker container run，-p 起容器的时候做端口映射，例如将容器的80端口转到宿主机的8080端口

[root@localhost ~]# docker container run -itd -p 8080:80 --name nginx01 nginx
b83f2dc64a57b045ae8397bcafd5a9308f4e0c4d3a982e69b630b3d44f84743d
[root@localhost ~]# docker ps | egrep 'CONTAINER|nginx01'
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                  NAMES
b83f2dc64a57        nginx               "nginx -g 'daemon of…"   36 seconds ago      Up 35 seconds       0.0.0.0:8080->80/tcp   nginx01
[root@localhost ~]#

打开浏览器，url输入 <宿主机地址>:8080，会进入如下页面

6）docker logs <container name | container ID> 查看容器控制台输出；输出也会存储到宿主机的 /var/lib/docker/containers/<容器完整ID> 下的 json 文件。注：有时候空间不够可以看看这个json文件是不是太大可否清理

7）docker container run， --restart=always 服务化，容器停了会再给起来

注： --restart，容器退出时的重启策略，默认no

这里试试新起一个带--restart=always的容器nginx02，然后重启docker，比较一nginx01和nginx02，发现容器nginx02自动起了，而容器nginx01处于停止状态

8）容器资源限制（CPU、内存），可以使用 docker container stats 查看容器运行参数

--cpus decimal Number of CPUs 例如宿主机有多核CPU，限制容器只使用1核

--memory bytes Memory limit 例如限制容器使用内容上限512M，swap默认是内存的两倍

[root@localhost ~]# docker container run -itd --cpus 1 --name nginx03 nginx
a120b86d31618502a889532e46edf0515c00b6ca7873b9982515af5d91947620
[root@localhost ~]#
[root@localhost ~]# docker container run -itd --memory 512m --name nginx04 nginx
cc74fb0809723882b6765b10d1e4560f0326fc1390f15e1f4f6fda92e9acba85
[root@localhost ~]#
[root@localhost ~]# docker container stats nginx04
CONTAINER ID        NAME                CPU %               MEM USAGE / LIMIT   MEM %               NET I/O             BLOCK I/O           PIDS
cc74fb080972        nginx04             0.00%               1.383MiB / 512MiB   0.27%               656B / 0B           0B / 0B             2
……

（End）

学习的大大教学视频传送门 -> https://ke.qq.com/course/366769?taid=2769871654197425

[Docker学习笔记] 创建容器常见选项

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