1. 程式人生 > >Docker介紹,安裝docker,映象管理,通過容器建立映象,使用模板建立映象

Docker介紹,安裝docker,映象管理,通過容器建立映象,使用模板建立映象

Docker介紹

官網 www.docker.com github https://github.com/docker/docker.github.io 開源的容器引擎,可以讓開發者打包應用以及依賴的庫,然後釋出到任何流行的linux發行版上,移植很方便 由go語言編寫,基於apache2.0協議釋出 基於linux kernel,要想在win下執行需要藉助一個vm(虛擬機器)來實現 自2013年開始,近些年發展迅猛 docker從1.13x開始,版本分為社群版ce和企業版ee,並且基於年月的時間線形式,當前最新穩定版為17.09 參考 http://blog.csdn.net/chenhaifeng2016/article/details/68062414

docker和傳統的虛擬化比較

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docker核心概念:

映象,是一個只讀的模板,類似於安裝系統用到的那個iso檔案,我們通過映象來完成各種應用的部署。

容器,映象類似於作業系統,而容器類似於虛擬機器本身。它可以被啟動、開始、停止、刪除等操作,每個容器都是相互隔離的。

倉庫,存放映象的一個場所,倉庫分為公開倉庫和私有倉庫。 最大的公開倉庫是Docker hub(hub.docker.com),國內公開倉庫(dockerpool.com)

安裝docker

先下載一個repo的yum源:

[[email protected] ~]# curl https://download.docker.com/linux/centos/docker-ce.repo -o  /etc/yum.repos.d/docker.repo

不下載yum源也可以用本地的yum安裝,只不過會版本比較老。

安裝docker:

[[email protected] ~]# yum install -y docker-ce

啟動docker:

[[email protected] ~]# systemctl start docker
[[email protected] ~]# ps aux |grep docker
root       3168  4.6  5.0 592564 50040 ?        Ssl  12:53   0:00 /usr/bin/dockerd
root       3174  1.6  2.7 317248 27720 ?        Ssl  12:53   0:00 docke-containerd --config /var/run/docker/containerd/containerd.toml
root       3316  0.0  0.0 112680   976 pts/0    R+   12:53   0:00 grep --color=auto docker

docker會在啟動時候自動新增一些iptables規則,最好將iptables規則儲存起來。而且,作為docker伺服器,一般不要動這臺機器上的iptables規則。一旦弄疵了規則,docker服務就要重啟,重啟完服務還得重啟容器。

映象管理

docker下載一個centos映象:

[[email protected] ~]# docker pull centos

這個是在docker官方下載的映象。在國外,可能下載速度回比較慢。可以通過配置docker加速器加快下載速度。

配置docker加速器:

[[email protected] ~]# vim /etc/docker/daemon.json

{
 "registry-mirrors": ["https://dhq9bx4f.mirror.aliyuncs.com"]
}

這個URL是加速器地址,可以到阿里雲申請。

配置完成之後。從起docker服務,下載映象就會快些。

檢視映象:

[[email protected] ~]# docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
ubuntu              latest              cd6d8154f1e1        4 weeks ago         84.1MB
centos              latest              5182e96772bf        2 months ago        200MB

名字 , 標籤 , 唯一標識 ,建立時間 ,大小 搜尋一下映象:

[[email protected] ~]# docker search jumpserver

這個就可以根據你得需要,去選擇下載映象。

給映象打標籤:

[[email protected] ~]# docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
ubuntu              latest              cd6d8154f1e1        4 weeks ago         84.1MB
centos              latest              5182e96772bf        2 months ago        200MB
[[email protected] ~]# docker tag centos shuailinux_centos
[[email protected] ~]# docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
ubuntu              latest              cd6d8154f1e1        4 weeks ago         84.1MB
centos              latest              5182e96772bf        2 months ago        200MB
shuailinux_centos   latest              5182e96772bf        2 months ago        200MB
[[email protected] ~]# docker tag centos tset:111
[[email protected] ~]# docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
ubuntu              latest              cd6d8154f1e1        4 weeks ago         84.1MB
shuailinux_centos   latest              5182e96772bf        2 months ago        200MB
tset                111                 5182e96772bf        2 months ago        200MB
centos              latest              5182e96772bf        2 months ago        200MB

把映象啟動成容器:

[[email protected] ~]# docker run -itd centos
cf4d1603dde4724819fda9a54eaacc96ae2702dcb0aec61e8a05f0e804d18095 
-i  : 讓容器的標準輸入開啟  -t : 分配一個偽終端  -d : 標識後臺啟動
檢視執行的容器,-a : 檢視所有容器
[[email protected] ~]# docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
cf4d1603dde4        centos              "/bin/bash"         12 seconds ago      Up 4 seconds                            gracious_lalande

刪除指定映象:

[[email protected] ~]# docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
ubuntu              latest              cd6d8154f1e1        4 weeks ago         84.1MB
centos              latest              5182e96772bf        2 months ago        200MB
shuailinux_centos   latest              5182e96772bf        2 months ago        200MB
tset                111                 5182e96772bf        2 months ago        200MB
[[email protected] ~]# docker rmi tset
Error: No such image: tset
[[email protected] ~]# docker rmi tset:111
Untagged: tset:111
[[email protected] ~]# docker rmi shuailinux_centos
Untagged: shuailinux_centos:latest

通過容器建立映象

進入到一個啟動的容器裡:

[[email protected] ~]# docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
cf4d1603dde4        centos              "/bin/bash"         6 hours ago         Up 6 hours                              gracious_lalande
[[email protected] ~]# docker exec -it cf4d16 bash
[[email protected] /]# ls
anaconda-post.log  dev  home  lib64  mnt  proc  run   	srv  tmp  var
bin                etc  lib   media  opt  root  sbin  sys  usr

在容器裡面,也是可以執行一些命令,還可以使用yum.

[[email protected] /]# ifconfig
bash: ifconfig: command not found
[[email protected] /]# ip add
bash: ip: command not found
[[email protected] /]# yum install -y net-tools

這個IP是docker自己搞得IP

[[email protected] /]# ifconfig
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 172.17.0.2  netmask 255.255.0.0  broadcast 172.17.255.255
        ether 02:42:ac:11:00:02  txqueuelen 0  (Ethernet)
        RX packets 5529  bytes 13443112 (12.8 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 3683  bytes 202645 (197.8 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        loop  txqueuelen 1  (Local Loopback)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

你在本機系統裡檢視網絡卡會有docker專用的網絡卡。

[[email protected] ~]# ifconfig
docker0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 172.17.0.1  netmask 255.255.0.0  broadcast 172.17.255.255
        inet6 fe80::42:1ff:fe28:f453  prefixlen 64  scopeid 0x20<link>
        ether 02:42:01:28:f4:53  txqueuelen 0  (Ethernet)
        RX packets 3683  bytes 151083 (147.5 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 5521  bytes 13442464 (12.8 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
veth0b66efc: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet6 fe80::4097:2fff:fe59:66d7  prefixlen 64  scopeid 0x20<link>
        ether 42:97:2f:59:66:d7  txqueuelen 0  (Ethernet)
        RX packets 3683  bytes 202645 (197.8 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 5529  bytes 13443112 (12.8 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

把容器建立成映象: docker commit -m “change somth” -a “somebody info” container_id new_image_name //container_id通過docker ps -a獲取,後面的new_image_name為新映象名字 例如: docker commit -m “install net-tools” -a “Aming” 2c74d574293f centos_with_nettool 這個命令有點像svn的提交,-m 加一些改動資訊,-a 指定作者相關資訊 2c74d這一串為容器id,再後面為新映象的名字

[[email protected] ~]# docker commit -m "install net-tools" -a "shuai" cf4d1603dde4 centos-with-net
sha256:cea798f6bbf6f28ed79d4eef50ee18cdde1a6e9aad7ed03931b8c644d8b37393
[[email protected] ~]# docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
centos-with-net     latest              cea798f6bbf6        11 seconds ago      299MB
ubuntu              latest              cd6d8154f1e1        4 weeks ago         84.1MB
centos              latest              5182e96772bf        2 months ago        200MB

將新建的映象執行起來:可以直接執行ifconfig命令

[[email protected] ~]# docker run -itd centos-with-net bash
8749952da5172bf1bb3e72e577b501b45bd377311a874c95c12f3718b8909f1a
[[email protected] ~]# docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
8749952da517        centos-with-net     "/bin/bash"         14 seconds ago      Up 7 seconds                            cranky_swartz
cf4d1603dde4        centos              "/bin/bash"         7 hours ago         Up 7 hours                              gracious_lalande
[[email protected] ~]# docker exec -it 8749952da517 bash
[[email protected] /]# ifconfig
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 172.17.0.3  netmask 255.255.0.0  broadcast 172.17.255.255
        ether 02:42:ac:11:00:03  txqueuelen 0  (Ethernet)
        RX packets 8  bytes 648 (648.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        loop  txqueuelen 1  (Local Loopback)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

docker使用模板建立映象

先下載一個模板:

[[email protected] ~]# wget https://download.openvz.org/template/precreated/centos-6-x86-minimal.tar.gz

把模板導成映象檔案:

[[email protected] ~]# cat centos-6-x86-minimal.tar.gz |docker import - centos6
sha256:64326114b1eff608e49f436acd1a4058478b6ebbd5c222368e26bc6352228b87
[[email protected] ~]# docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
centos6             latest              64326114b1ef        18 seconds ago      512MB
centos-with-net     latest              cea798f6bbf6        About an hour ago   299MB
ubuntu              latest              cd6d8154f1e1        4 weeks ago         84.1MB
centos              latest              5182e96772bf        2 months ago        200MB

啟動製作的映象:

[[email protected] ~]# docker run -itd centos6 bash
0850110acb986d32e365206446e133c4a94d1f00ee2e3926d5ef9a9578b8e646
[[email protected] ~]# docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
0850110acb98        centos6             "bash"              17 seconds ago      Up 10 seconds                           compassionate_cori
8749952da517        centos-with-net     "/bin/bash"         About an hour ago   Up About an hour                        cranky_swartz
cf4d1603dde4        centos              "/bin/bash"         8 hours ago         Up 8 hours                              gracious_lalande
[[email protected] ~]# docker exec -it 0850110acb98 bash

把映象匯出來為一個檔案:

[[email protected] ~]# docker save -o centos7_with_nettools.tar centos-with-net
[[email protected] ~]# du -sh centos7_with_nettools.tar 
294M	centos7_with_nettools.tar

用檔案恢復映象:

刪掉映象前要先停掉容器

[[email protected] ~]# docker rm -f 8749952da517
8749952da517
[[email protected] ~]# docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
centos6             latest              64326114b1ef        14 minutes ago      512MB
centos-with-net     latest              cea798f6bbf6        About an hour ago   299MB
ubuntu              latest              cd6d8154f1e1        4 weeks ago         84.1MB
centos              latest              5182e96772bf        2 months ago        200MB
[[email protected] ~]# docker rmi cea798f6bbf6
Untagged: centos-with-net:latest
Deleted: sha256:cea798f6bbf6f28ed79d4eef50ee18cdde1a6e9aad7ed03931b8c644d8b37393
Deleted: sha256:fabc68085404013af1f36dc08e6449d536557206ff47fc4e1565c4702d3659d9

從儲存檔案中匯入映象:

[[email protected] ~]# docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
centos6             latest              64326114b1ef        14 minutes ago      512MB
ubuntu              latest              cd6d8154f1e1        4 weeks ago         84.1MB
centos              latest              5182e96772bf        2 months ago        200MB
[[email protected] ~]# docker load < centos7_with_nettools.tar 
c9e25e335de2: Loading layer  99.07MB/99.07MB
Loaded image: centos-with-net:latest
[[email protected] ~]# docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
centos6             latest              64326114b1ef        16 minutes ago      512MB
centos-with-net     latest              cea798f6bbf6        About an hour ago   299MB
ubuntu              latest              cd6d8154f1e1        4 weeks ago         84.1MB
centos              latest              5182e96772bf        2 months ago        200MB

docker push image_name //可以把自己的映象傳到dockerhub官方網站上去,但前提是需要先註冊一個使用者