容器技术之Docker Machine

　　前文我们聊了下docker容器的资源限制，回顾请参考https://www.cnblogs.com/qiuhom-1874/p/13138725.html；今天我们来聊一聊docker machine；docker machine是docker 官方提供的工具，这个工具可以在不同主机/不同系统上快速安装、管理docker环境；docker machine 的实现原理就是通过不同的驱动来连接不同类型节点，来实现docker machine管理不同平台上的docker环境；

　　docker machine 安装

　　1、下载二进制程序文件到本地

[root@node1 ~]# base=https://github.com/docker/machine/releases/download/v0.16.0 &&
>   curl -L $base/docker-machine-$(uname -s)-$(uname -m) >/tmp/docker-machine &&
>   sudo mv /tmp/docker-machine /usr/local/bin/docker-machine &&
>   chmod +x /usr/local/bin/docker-machine
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   638  100   638    0     0    590      0  0:00:01  0:00:01 --:--:--   590
100 26.8M  100 26.8M    0     0  11911      0  0:39:24  0:39:24 --:--:-- 16907
[root@node1 ~]# ll /usr/local/bin/docker-machine
-rwxr-xr-x 1 root root 28164576 Jun 18 11:28 /usr/local/bin/docker-machine
[root@node1 ~]# docker-machine version
docker-machine version 0.16.0, build 702c267f
[root@node1 ~]#

　　提示：以上命令主要就做了三件事，下载对应系统的对应系统架构的docker-machine到本地/tmp/下，并保存为docker-machine;然后把/tmp/docker-machine移动至/usr/local/bin/下，然后给/usr/local/bin/docker-machine添加执行权限；如果下载完我们可以在终端运行docker-machine version 能够看到对应的版本信息，就表示docker-machine安装好了；docker-machine程序是安装好了，现在我们还不能直接使用；我们上面说过docker-machine本质就是通过不同的驱动去连接节点，连接节点实际上就是通过ssh链到节点服务器上，然后执行安装docker;所以为了能够很好的使用docker-machine 我们需要对管理的节点做免密登录；

　　2、管理节点对work节点做免密登录

[root@node1 ~]# ssh-keygen
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa):
/root/.ssh/id_rsa already exists.
Overwrite (y/n)? y
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /root/.ssh/id_rsa.
Your public key has been saved in /root/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:4HrdVnoO+W/+J/ewP4A1m8HnneKWAKMKo3Ad2uExJ1k root@node1
The key's randomart image is:
+---[RSA 2048]----+
|                 |
|      E          |
|     o.     .    |
|    B... o   = . |
|   = B. S o + B o|
|. oo+. o . * = o.|
|... + o . * + =  |
| .   o   . = +o+o|
|            +++=B|
+----[SHA256]-----+
[root@node1 ~]# ssh-copy-id root@192.168.0.42
/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub"
The authenticity of host '192.168.0.42 (192.168.0.42)' can't be established.
ECDSA key fingerprint is SHA256:EG9nua4JJuUeofheXlgQeL9hX5H53JynOqf2vf53mII.
ECDSA key fingerprint is MD5:57:83:e6:46:2c:4b:bb:33:13:56:17:f7:fd:76:71:cc.
Are you sure you want to continue connecting (yes/no)? yes
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
root@192.168.0.42's password: 

Number of key(s) added: 1

Now try logging into the machine, with:   "ssh 'root@192.168.0.42'"
and check to make sure that only the key(s) you wanted were added.

[root@node1 ~]# ssh-copy-id root@192.168.0.43
/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub"
The authenticity of host '192.168.0.43 (192.168.0.43)' can't be established.
ECDSA key fingerprint is SHA256:EG9nua4JJuUeofheXlgQeL9hX5H53JynOqf2vf53mII.
ECDSA key fingerprint is MD5:57:83:e6:46:2c:4b:bb:33:13:56:17:f7:fd:76:71:cc.
Are you sure you want to continue connecting (yes/no)? yes
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
root@192.168.0.43's password: 

Number of key(s) added: 1

Now try logging into the machine, with:   "ssh 'root@192.168.0.43'"
and check to make sure that only the key(s) you wanted were added.

[root@node1 ~]

　　提示：有关免密登录的详细说明可以参考本人博客https://www.cnblogs.com/qiuhom-1874/p/11783371.html；接下来我们就可以使用docker-machine来对节点主机进行操作了；

　　对节点主机安装docker环境

　　提示：提示：以上命令表示创建一个docker-machine主机，使用generic驱动，generic表示对linux主机，如果是windows需要用到--virtualbox;--generic-ip-address表示指定节点主机的ip地址；然后在给上一名称；从上面的信息可以看到，docker-node01这台machine已经启动，它告诉我们要查看怎么连接docker-node01这台虚拟主机，请运行docker-machine env docker-node01 查看；

　　查看怎么连接docker-node01这台虚拟主机

　　提示：它告诉我们运行下面的命令可以配置我们的shell

　　提示：从上面的信息可以看到我们运行 eval $(docker-machine env docker-node01)这条命令就表示把环境切换到docker-node01上；接下来的操作都会发送到docker node01上；

　　提示：从上面的信息可以看到，当我们使用eval $(docker-machine env docker-node01)把当前环境切换到docker-node01后，在当前终端运行的容器和下载的镜像，在退出当前终端重新登录后，本地的是没有nginx镜像的；这意味着我们切换环境后，运行容器的操作上发送给docker-node01上执行了；

　　测试：我们登录到docker-node01看看是否有nginx镜像和n1容器？

　　提示：用docker-machine创建虚拟主机来对节点主机管理时，我们给定虚拟主机的名称docker-machine会把该名称当作主机名，把节点主机的主机名更改为我们指定的名称；从上面的信息可以看到docker-node01这台主机上有nginx镜像和n1容器；这说明我们刚才的操作都是发送给docker-node01上了；从上面的演示可以看到，我们在docker-machine上切换环境，当前shell并不能反映我们是否切换到对应的环境了；这样一来在主机特别多的情况，很容易出错；接下来我们配置当前shell的PS1的环境变量；

　　下载docker-machine-wrapper.bash、docker-machine-prompt.bash和docker-machine.bash

[root@node01 ~]# cat /etc/bash_completion.d/down.bash
base=https://raw.githubusercontent.com/docker/machine/v0.16.0
for i in docker-machine-prompt.bash docker-machine-wrapper.bash docker-machine.bash
do
  sudo wget "$base/contrib/completion/bash/${i}" -P /etc/bash_completion.d
done
[root@node01 ~]#

　　提示：以上脚本主要是循环下载上面说的三个脚本；执行该脚本直接有source命令即可；

　　提示：我们用source命令来执行上面的脚本，提示我们连接拒绝；这是因为没有解析到raw.githubusercontent.com的地址造成的；解决办法在/etc/hosts文件中介入raw.githubusercontent.com的解析地址即可；https://site.ip138.com/raw.githubusercontent.com/；这个网站可以查询到raw.githubusercontent.com的地址；

　　提示：更改/etc/hosts文件后，接下在用source命令执行上面的脚本就不会提示我们链接拒绝了；

　　提示：可以看到/etc/bash_completion.d/目录下有我们要的脚本了；接下来我们就需要配置当前用户的PS1环境的值；

　　提示：以上信息表示导入上面的三个脚本到当前登录用户的终端；配置好以上.bashrc后，我们在来切换环境，当前shell就不一样了；

　　提示：导入了docker-machine-wrapper.bash、docker-machine-prompt.bash和docker-machine.bash这三个脚本配合现在新定义的PS1变量，我们切换环境就很容易的辨识，我们操作的node节点主机是那一台；退出当前环境，直接使用exit即可；

　　到此docker-machine的环境就搭建好了；接下我们再来说说docker-machine的常用命令使用和说明

　　docker-machine active:查看当前激活状态的docker主机

[root@node01 ~]# docker-machine active
docker-node01
[root@node01 ~]#

　　提示：所谓激活状态的docker主机就是指的当前的DOCKER_HOST环境变量所指向的主机；

　　docker-machine ls：列出所有管理的主机

[root@node01 ~]# docker-machine ls
NAME            ACTIVE   DRIVER    STATE     URL                       SWARM   DOCKER      ERRORS
docker-node01   *        generic   Running   tcp://192.168.0.42:2376           v19.03.11
docker-node02   -        generic   Running   tcp://192.168.0.43:2376           v19.03.11
[root@node01 ~]#

　　docker-machine config:查看激活的docker主机的连接信息；

[root@node01 ~]# docker-machine config docker-node01
--tlsverify
--tlscacert="/root/.docker/machine/machines/docker-node01/ca.pem"
--tlscert="/root/.docker/machine/machines/docker-node01/cert.pem"
--tlskey="/root/.docker/machine/machines/docker-node01/key.pem"
-H=tcp://192.168.0.42:2376
[root@node01 ~]#

　　docker-machine inspect :以json格式输出指定docker主机的详细信息

[root@node01 ~]# docker-machine inspect docker-node01
{
    "ConfigVersion": 3,
    "Driver": {
        "IPAddress": "192.168.0.42",
        "MachineName": "docker-node01",
        "SSHUser": "root",
        "SSHPort": 22,
        "SSHKeyPath": "",
        "StorePath": "/root/.docker/machine",
        "SwarmMaster": false,
        "SwarmHost": "",
        "SwarmDiscovery": "",
        "EnginePort": 2376,
        "SSHKey": ""
    },
    "DriverName": "generic",
    "HostOptions": {
        "Driver": "",
        "Memory": 0,
        "Disk": 0,
        "EngineOptions": {
            "ArbitraryFlags": [],
            "Dns": null,
            "GraphDir": "",
            "Env": [],
            "Ipv6": false,
            "InsecureRegistry": [],
            "Labels": [],
            "LogLevel": "",
            "StorageDriver": "",
            "SelinuxEnabled": false,
            "TlsVerify": true,
            "RegistryMirror": [],
            "InstallURL": "https://get.docker.com"
        },
        "SwarmOptions": {
            "IsSwarm": false,
            "Address": "",
            "Discovery": "",
            "Agent": false,
            "Master": false,
            "Host": "tcp://0.0.0.0:3376",
            "Image": "swarm:latest",
            "Strategy": "spread",
            "Heartbeat": 0,
            "Overcommit": 0,
            "ArbitraryFlags": [],
            "ArbitraryJoinFlags": [],
            "Env": null,
            "IsExperimental": false
        },
        "AuthOptions": {
            "CertDir": "/root/.docker/machine/certs",
            "CaCertPath": "/root/.docker/machine/certs/ca.pem",
            "CaPrivateKeyPath": "/root/.docker/machine/certs/ca-key.pem",
            "CaCertRemotePath": "",
            "ServerCertPath": "/root/.docker/machine/machines/docker-node01/server.pem",
            "ServerKeyPath": "/root/.docker/machine/machines/docker-node01/server-key.pem",
            "ClientKeyPath": "/root/.docker/machine/certs/key.pem",
            "ServerCertRemotePath": "",
            "ServerKeyRemotePath": "",
            "ClientCertPath": "/root/.docker/machine/certs/cert.pem",
            "ServerCertSANs": [],
            "StorePath": "/root/.docker/machine/machines/docker-node01"
        }
    },
    "Name": "docker-node01"
}
[root@node01 ~]#

　　提示：以上命令也支持-f选项来指定格式，用法同docker image/container inspect 类似；

[root@node01 ~]# docker-machine inspect -f {{.HostOptions.AuthOptions.StorePath}} docker-node01
/root/.docker/machine/machines/docker-node01
[root@node01 ~]# docker-machine inspect -f {{.DriverName}} docker-node01
generic
[root@node01 ~]#

　　docker-machine ip :获取指定docker主机的ip地址

[root@node01 ~]# docker-machine ip docker-node01
192.168.0.42
[root@node01 ~]# docker-machine ip docker-node02
192.168.0.43
[root@node01 ~]#

　　docker-machine ssh :连接指定docker执行命令

[root@node01 ~]# docker-machine ssh docker-node01 "ip a"
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1
    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
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:91:99:30 brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.42/24 brd 192.168.0.255 scope global ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fe91:9930/64 scope link
       valid_lft forever preferred_lft forever
4: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default
    link/ether 02:42:0f:e1:e0:f7 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:fff:fee1:e0f7/64 scope link
       valid_lft forever preferred_lft forever
[root@node01 ~]#

　　docker-machine scp：在docker主机间以及docker主机和本地之间通过scp命令来远程复制文件

[root@node01 ~]# echo "this is test file" > /tmp/test.txt
[root@node01 ~]# cat /tmp/test.txt
this is test file
[root@node01 ~]# docker-machine scp /tmp/test.txt docker-node01:/root/
test.txt                                                                                                                                 100%   18     5.4KB/s   00:00
[root@node01 ~]# docker-machine ssh docker-node01 "ls -l /root/"
total 4
-rw-r--r-- 1 root root 18 Jun 19 11:26 test.txt
[root@node01 ~]# docker-machine ssh docker-node01 "cat /root/test.txt"
this is test file
[root@node01 ~]#

　　提示：同scp命令用法类似；

　　docker-machine rm：删除指定名称的docker主机对应的虚拟主机；

[root@node01 ~]# docker-machine ls
NAME            ACTIVE   DRIVER    STATE     URL                       SWARM   DOCKER      ERRORS
docker-node01   *        generic   Running   tcp://192.168.0.42:2376           v19.03.11
docker-node02   -        generic   Running   tcp://192.168.0.43:2376           v19.03.11
[root@node01 ~]# docker-machine rm docker-node02
About to remove docker-node02
WARNING: This action will delete both local reference and remote instance.
Are you sure? (y/n): y
Successfully removed docker-node02
[root@node01 ~]# docker-machine ls
NAME            ACTIVE   DRIVER    STATE     URL                       SWARM   DOCKER      ERRORS
docker-node01   *        generic   Running   tcp://192.168.0.42:2376           v19.03.11
[root@node01 ~]#

　　提示：docker-machine rm 只是删除docker-machine上的虚拟主机，对于真正的物理节点上的docker环境并没有删除；实际上就切断对指定docker主机的管控；

　　docker-machine upgrade:将指定主机的docker版本更新为最新

[root@node01 ~]# docker-machine upgrade docker-node01
Waiting for SSH to be available...
Detecting the provisioner...
Upgrading docker...
Restarting docker...
[root@node01 ~]# docker-machine ls
NAME            ACTIVE   DRIVER    STATE     URL                       SWARM   DOCKER      ERRORS
docker-node01   *        generic   Running   tcp://192.168.0.42:2376           v19.03.11
[root@node01 ~]#

　　提示：如果指定docker主机的版本已经是最新的版本，那么它将不会再更新；

　　docker-machine url：获取指定主机监听URL

[root@node01 ~]# docker-machine url docker-node01
tcp://192.168.0.42:2376
[root@node01 ~]#

　　提示：通过docker-machine安装的docker环境，实际上就是把yum安装的docker环境，客户端和服务端分离了，各个节点就是各个服务端，而docker-machine就是同一的客户端，因为客户端和服务端不再同一主机，所以它会把docker监听在一个TCP端口上，方便客户端的来连接管理；