docker快速入门-原创手记-慕课网

1、docker简介

docker通过内核虚拟化技术（namespace及cgroups等）来提供容器的资源隔离与安全保障等，由于docker通过操作系统层的虚拟化实现隔离，所以docker容器在运行时，不需要类似虚拟机额外的操作系统开销，提供资源利用率

2、docker vs kvm

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3、docker组件

镜像、容器、仓库

4、docker安装

[root@docker ~]#tee /etc/yum.repos.d/docker.repo <<-'EOF'

[dockerrepo]

name=Docker Repository

baseurl=https://yum.dockerproject.org/repo/main/centos/7/

enabled=1

gpgcheck=1

gpgkey=https://yum.dockerproject.org/gpg

EOF

[root@docker ~]# yum install docker-engine -y

5、docker基础操作

[root@docker ~]# systemctl enable docker.service

Created symlink from /etc/systemd/system/multi-user.target.wants/docker.service to /usr/lib/systemd/system/docker.service.

[root@docker ~]# systemctl start docker.service

[root@docker ~]#

[root@docker ~]# docker pull centos #拉取镜像

[root@docker ~]# docker pull daocloud.io/library/nginx

有时候拉取速度很慢，采用国内源加速

root@docker ~]# vim /usr/lib/systemd/system/docker.service 增加下面这行

EnvironmentFile=/etc/sysconfig/docker

新建配置文件[root@docker ~]# vim /etc/sysconfig/docker

在https://dashboard.daocloud.io/ 注册，然后点击加速器生成加速链接

OPTIONS=--registry-mirror=curl -sSL https://get.daocloud.io/daotools/set_mirror.sh | sh -s

[root@docker ~]# docker search nginx #搜索镜像

[root@docker ~]# docker p_w_picpaths

REPOSITORY TAG IMAGE ID CREATED SIZE

centos latest 0584b3d2cf6d 2 weeks ago 196.5 MB

导出镜像

[root@docker ~]# docker save -o nginx.tar daocloud.io/library/nginx

[root@docker ~]# docker save -o cnetos.tar centos

导入镜像

[root@docker ~]# docker load --input cnetos.tar 或者 [root@docker ~]# docker load < cnetos.tar

删除镜像

[root@docker ~]# docker rmi 0584b3d2cf6d （镜像ID）

[root@docker ~]# docker run centos /bin/echo "Hello world"

Hello world

[root@docker ~]# docker ps -a

CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES

5e381e68a385 centos "/bin/echo 'Hello wor" 6 seconds ago Exited (0) 5 seconds ago clever_lamarr

[root@docker ~]# docker run --name mydocker -t -i centos /bin/bash

[root@1a67f4c92b6e /]#

[root@1a67f4c92b6e /]# ps -ef

UID PID PPID C STIME TTY TIME CMD

root 1 0 0 18:56 ? 00:00:00 /bin/bash

root 14 1 0 18:56 ? 00:00:00 ps -ef

[root@1a67f4c92b6e /]# exit

exit

[root@docker ~]# docker ps -a

CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES

1a67f4c92b6e centos "/bin/bash" 12 minutes ago Exited (0) 6 seconds ago mydocker

5e381e68a385 centos "/bin/echo 'Hello wor" 16 minutes ago Exited (0) 16 minutes ago clever_lamarr

[root@docker ~]# docker run --name docker-demo -d centos /bin/bash -d代表放入后台执行

6c5a777467b9552714f9cd3322e677750e2b8b5b0bd2d81e79094ad560828a5e

[root@docker ~]# docker ps -a

CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES

6c5a777467b9 centos "/bin/bash" 11 seconds ago Exited (0) 11 seconds ago docker-demo

1a67f4c92b6e centos "/bin/bash" 17 minutes ago Exited (0) 4 minutes ago mydocker

5e381e68a385 centos "/bin/echo 'Hello wor" 21 minutes ago Exited (0) 21 minutes ago clever_lamarr

[root@docker ~]# docker stop mydocker 停止容器

[root@docker ~]# docker start 1a67f4c92b6e 启动容器

[root@docker ~]# docker run -d --name mynginx daocloud.io/library/nginx

225a9b0459630c62dcf2199d6244b16a74ad9412471abf0be03755768df3ae63

[root@docker ~]#

[root@docker ~]# docker ps

CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES

225a9b045963 daocloud.io/library/nginx "nginx -g 'daemon off" 6 seconds ago

Up 5 seconds 80/tcp, 443/tcp mynginx

进入容器脚步

[root@docker ~]# cat docker_in.sh

#!/bin/bash

docker_in(){

NAME_ID=$1

PID=$(docker inspect --format "{{ .State.Pid }}" $NAME_ID)

nsenter -t $PID -m -u -i -n -p

}

docker_in $1

6、docker网络

root@docker ~]# docker run -d -P --name nginx-test1 daocloud.io/library/nginx

9b1d36d40127fe2c84bbe7750802e435a817a15b4159b24fc49bfb1107a2cb74

[root@docker ~]# docker ps -l

CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES

9b1d36d40127 daocloud.io/library/nginx "nginx -g 'daemon off" 2 minutes ago Up 2 minutes 0.0.0.0:32769->80/tcp, 0.0.0.0:32768->443/tcp nginx-test1

[root@docker ~]# netstat -lntup|grep 32768

tcp6 0 0 :::32768 :::* LISTEN 11213/docker-proxy

[root@docker ~]# curl -I http://172.16.80.132:32769

HTTP/1.1 200 OK

Server: nginx/1.11.5

Date: Thu, 24 Nov 2016 05:58:47 GMT

Content-Type: text/html

Content-Length: 612

Last-Modified: Tue, 11 Oct 2016 15:03:01 GMT

Connection: keep-alive

ETag: "57fcff25-264"

Accept-Ranges: bytes

转换前

[root@docker ~]# iptables -L -n

Chain INPUT (policy ACCEPT)

target prot opt source destination

ACCEPT all -- 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED

ACCEPT icmp -- 0.0.0.0/0 0.0.0.0/0

ACCEPT all -- 0.0.0.0/0 0.0.0.0/0

ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 state NEW tcp dpt:22

REJECT all -- 0.0.0.0/0 0.0.0.0/0 reject-with icmp-host-prohibited

Chain FORWARD (policy ACCEPT)

target prot opt source destination

DOCKER-ISOLATION all -- 0.0.0.0/0 0.0.0.0/0

DOCKER all -- 0.0.0.0/0 0.0.0.0/0

ACCEPT all -- 0.0.0.0/0 0.0.0.0/0 ctstate RELATED,ESTABLISHED

ACCEPT all -- 0.0.0.0/0 0.0.0.0/0

REJECT all -- 0.0.0.0/0 0.0.0.0/0 reject-with icmp-host-prohibited

Chain OUTPUT (policy ACCEPT)

target prot opt source destination

Chain DOCKER (1 references)

target prot opt source destination

Chain DOCKER-ISOLATION (1 references)

target prot opt source destination

RETURN all -- 0.0.0.0/0 0.0.0.0/0

转换后

[root@docker ~]# docker run -d -P --name nginx-test1 daocloud.io/library/nginx

42783cf5053639383004f82b9e72fe0223c7c028d2754b2d0f74429824715f05

[root@docker ~]# docker ps -l

CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES

42783cf50536 daocloud.io/library/nginx "nginx -g 'daemon off" 9 seconds ago Up 7 seconds 0.0.0.0:32769->80/tcp, 0.0.0.0:32768->443/tcp nginx-test1

[root@docker ~]# iptables -L -n

Chain INPUT (policy ACCEPT)

target prot opt source destination

ACCEPT all -- 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED

ACCEPT icmp -- 0.0.0.0/0 0.0.0.0/0

ACCEPT all -- 0.0.0.0/0 0.0.0.0/0

ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 state NEW tcp dpt:22

REJECT all -- 0.0.0.0/0 0.0.0.0/0 reject-with icmp-host-prohibited

Chain FORWARD (policy ACCEPT)

target prot opt source destination

DOCKER-ISOLATION all -- 0.0.0.0/0 0.0.0.0/0

DOCKER all -- 0.0.0.0/0 0.0.0.0/0

ACCEPT all -- 0.0.0.0/0 0.0.0.0/0 ctstate RELATED,ESTABLISHED

ACCEPT all -- 0.0.0.0/0 0.0.0.0/0

REJECT all -- 0.0.0.0/0 0.0.0.0/0 reject-with icmp-host-prohibited

Chain OUTPUT (policy ACCEPT)

target prot opt source destination

Chain DOCKER (1 references)

target prot opt source destination

ACCEPT tcp -- 0.0.0.0/0 172.17.0.2 tcp dpt:443

ACCEPT tcp -- 0.0.0.0/0 172.17.0.2 tcp dpt:80

Chain DOCKER-ISOLATION (1 references)

target prot opt source destination

RETURN all -- 0.0.0.0/0 0.0.0.0/0

[root@docker ~]# sh docker_in.sh nginx-test1

root@42783cf50536:/#

root@42783cf50536:/# ip addr

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default

link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00

inet 127.0.0.1/8 scope host lo

valid_lft forever preferred_lft forever

inet6 ::1/128 scope host

valid_lft forever preferred_lft forever

4: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default

link/ether 02:42:ac:11:00:02 brd ff:ff:ff:ff:ff:ff

inet 172.17.0.2/16 scope global eth0

valid_lft forever preferred_lft forever

inet6 fe80::42:acff:fe11:2/64 scope link

valid_lft forever preferred_lft forever

7、docker数据存储

[root@docker ~]# docker run -d --name nginx-volume-test1 -v /data daocloud.io/library/nginx

88b24d79a4f3b021325592ceac20e86291166d675b213d60db017548c4d9d960

[root@docker ~]# sh docker_in.sh nginx-volume-test1

root@88b24d79a4f3:/# cd /data/

root@88b24d79a4f3:/data# ls

root@88b24d79a4f3:/data# touch hehe

root@88b24d79a4f3:/data# ls -l

total 0

-rw-r--r-- 1 root root 0 Nov 24 06:30 hehe

[root@docker ~]# cd /var/lib/docker/

[root@docker docker]# ll

total 32

drwx------ 6 root root 4096 Nov 24 14:28 containers

drwx------ 5 root root 4096 Nov 24 02:05 devicemapper

drwx------ 3 root root 4096 Nov 24 01:20 p_w_picpath

drwxr-x--- 3 root root 4096 Nov 24 01:20 network

drwx------ 2 root root 4096 Nov 24 01:20 swarm

drwx------ 2 root root 4096 Nov 24 10:09 tmp

drwx------ 2 root root 4096 Nov 24 01:20 trust

drwx------ 3 root root 4096 Nov 24 14:28 volumes

[root@docker docker]# cd volumes/

[root@docker volumes]# ls

4c60775f938a840e5484aee9088bc612977c25a01f5bd164690d94c962e66e60 metadata.db

[root@docker volumes]# cd 4c60775f938a840e5484aee9088bc612977c25a01f5bd164690d94c962e66e60/

[root@docker 4c60775f938a840e5484aee9088bc612977c25a01f5bd164690d94c962e66e60]# ls

_data

[root@docker 4c60775f938a840e5484aee9088bc612977c25a01f5bd164690d94c962e66e60]# cd _data/ 容器内的文件实际在物理机上面的的保存目录

[root@docker _data]# ls

hehe

[root@docker ~]# docker run -d --name nginx-volume-test2 -v /data/mysql:/mysql daocloud.io/library/nginx

f7278ce9bd88c26a0c5aaefcb2b39f1f9df0066bc94edb7a530213815e166f5e

#-v /data/mysql:/mysql 表示把物理机的/data/mysql目录挂载到容器内的/mysql目录下面

[root@docker ~]# docker run -d --name nginx-volumes -v /data/mysql:/mysql daocloud.io/library/nginx

28c616e44352fc4eafeb2f87dbbb7b6eb9df447235afe027034efa96df1c5071

[root@docker ~]#

[root@docker ~]# docker run -d --name web-node1 --volumes-from nginx-volumes daocloud.io/library/nginx

0f022ce56e8b800cb1a4ac76bb8a326d42e198093146e8661ad3ac8925ad317d

[root@docker ~]#

[root@docker ~]# docker run -d --name web-node2 --volumes-from nginx-volumes daocloud.io/library/nginx

03d5e88c15f6604eeee2b8af500b8f356ba69adc34710f3c19b813530f19dc3d

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