这是坚持技术写作计划（含翻译）的第13篇，定个小目标999，每周最少2篇。
书接上篇 012-P2P加速Docker镜像分发(阿里Dragonfly) ,讲解了如何快速搭建Dragonfly,但是访问的是公开镜像，本文主要讲解如何下载私有镜像。
实验环境
主机
| 类型 | 主机名 | 系统 | ip | docker version |
|---|---|---|---|---|
| supernode | d7y-1 | Ubuntu Server 16.04.6 LTS X64 | 192.168.0.75 | 17.06.2ubuntu |
| clinet1 | d7y-2 | Ubuntu Server 16.04.6 LTS X64 | 192.168.0.76 | 17.06.2ubuntu |
| clinet2 | d7y-3 | Ubuntu Server 16.04.6 LTS X64 | 192.168.0.77 | 17.06.2ubuntu |
私有registry
本次以阿里云私有镜像库为例，可以自行开通。
文档之坑
官方文档比较简单,甚至带有误导性，下意识的以为应该在dfdaemon节点上配置auth信息，并且配的是真实的私有registry，如果真这么搞了，肯定被坑。（但是也能解释通，比较绕，dfdaemon本身就是一个伪装成registry，用来加速私有registry，那么登陆信息就应该换成dfdaemon ip，只是示例不太恰当而已，对初学者相当不友好倒是真的）
supernode步骤
安装supernode
root@d7y-1:~# docker run --name dragonfly-supernode --restart=always \
-d -p 8001:8001 -p 8002:8002 -v /data/dragonfly/supernode:/home/admin/supernode \
registry.cn-hangzhou.aliyuncs.com/dragonflyoss/supernode:0.3.0 \
-Dsupernode.advertiseIp=192.168.0.75
root@d7y-1:~# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
be7fb931db0b registry.cn-hangzhou.aliyuncs.com/dragonflyoss/supernode:0.3.0 "/bin/sh -c '/root..." About a minute ago Up About a minute 0.0.0.0:8001-8002->8001-8002/tcp dragonfly-supernode
root@d7y-1:/data/dragonfly/supernode/logs# cat app.log
2019-03-30 01:04:40.065 INFO [ main] c.d.d.s.SuperNodeStarter - Starting SuperNodeStarter on be7fb931db0b with PID 9 (/supernode.jar started by root in /)
2019-03-30 01:04:40.069 INFO [ main] c.d.d.s.SuperNodeStarter - No active profile set, falling back to default profiles: default
2019-03-30 01:04:42.151 INFO [ main] c.d.d.s.c.SupernodeProperties - init local ip of supernode, use ip:192.168.0.75
2019-03-30 01:04:42.253 INFO [ main] c.d.d.s.c.SupernodeProperties - cluster members: [{"downloadPort":8001,"ip":"localhost","registerPort":8002}]
2019-03-30 01:04:42.263 INFO [ main] c.d.d.s.c.util.MonitorService - available processors count is 4
2019-03-30 01:04:42.272 ERROR [ Thread-2] c.d.d.s.c.util.MonitorService - process fields:null error
java.io.IOException: Cannot run program "tsar": error=2, No such file or directory
at java.lang.ProcessBuilder.start(ProcessBuilder.java:1048)
at java.lang.Runtime.exec(Runtime.java:620)
at java.lang.Runtime.exec(Runtime.java:450)
at java.lang.Runtime.exec(Runtime.java:347)
at com.dragonflyoss.dragonfly.supernode.common.util.MonitorService$1.run(MonitorService.java:56)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.io.IOException: error=2, No such file or directory
at java.lang.UNIXProcess.forkAndExec(Native Method)
at java.lang.UNIXProcess.<init>(UNIXProcess.java:247)
at java.lang.ProcessImpl.start(ProcessImpl.java:134)
at java.lang.ProcessBuilder.start(ProcessBuilder.java:1029)
... 5 common frames omitted
2019-03-30 01:04:43.507 INFO [ main] c.d.d.s.SuperNodeStarter - Started SuperNodeStarter in 3.906 seconds (JVM running for 4.59)
2019-03-30 01:04:49.472 INFO [ spring-1] c.d.d.s.s.p.PreheatServiceImpl - deleteExpiresPreheatTask, count:0
复制代码从 2019-03-30 01:04:42.151 INFO [ main] c.d.d.s.c.SupernodeProperties - init local ip of supernode, use ip:192.168.0.75 看，启动ip设置成功.
注意，官方的镜像没改时区，默认是UTC时间，比北京东八区早8小时。
登陆私有registry并推送镜像
root@d7y-1:~# docker login https://registry.cn-qingdao.aliyuncs.com
Username: //你阿里云账号
Password: //你阿里云密码
Login Succeeded
root@d7y-1:~# docker pull nginx:alpine
root@d7y-1:~# docker tag nginx:alpine registry.cn-qingdao.aliyuncs.com/d7y-test/nginx:alpine
root@d7y-1:~# docker push registry.cn-qingdao.aliyuncs.com/d7y-test/nginx:alpine
alpine: digest: sha256:857e6f195df0e9b497be0c7fad0f013126407aaeb71edcef66a24e8b990d94b3 size: 1153
复制代码dfdaemon 步骤
安装dfdaemon
在两台client节点分别执行如下命令
root@d7y-2:~# cat <<EOD >/etc/dragonfly.conf
[node]
address=192.168.0.75
EOD
root@d7y-2:~# docker run --name dragonfly-dfclient --restart=always \
-d -p 65001:65001 -v /root/.small-dragonfly:/root/.small-dragonfly \
-v /etc/dragonfly.conf:/etc/dragonfly.conf dragonflyoss/dfclient:v0.3.0 \
--registry=https://registry.cn-qingdao.aliyuncs.com --ratelimit 100M
Unable to find image 'dragonflyoss/dfclient:v0.3.0' locally
v0.3.0: Pulling from dragonflyoss/dfclient
169185f82c45: Pull complete
f58f64214283: Pull complete
bd8f062dc2d2: Pull complete
Digest: sha256:5bcabd5b34f4da0c2d489c8f99a23a401fb9ec57e54d4fa90457a93c5a85371f
Status: Downloaded newer image for dragonflyoss/dfclient:v0.3.0
b491e90489a584119b82ca934cf2ae087abc136f7f9de3542e14fb12bc1c7512
root@d7y-2:~# cat <<EOD >/etc/docker/daemon.json
{
"registry-mirrors": ["http://127.0.0.1:65001"]
}
EOD
root@d7y-2:~# systemctl restart docker
root@d7y-2:~# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
b491e90489a5 dragonflyoss/dfclient:v0.3.0 "/dfclient/dfdaemo..." 28 seconds ago Up 4 seconds 0.0.0.0:65001->65001/tcp dragonfly-dfclient
root@d7y-2:~/.small-dragonfly/logs# cat dfdaemon.log
2019-03-30 01:18:21.331 INFO sign:1 : init...
2019-03-30 01:18:21.331 INFO sign:1 : rotate log routine start...
2019-03-30 01:18:21.338 INFO sign:1 : dfget version:
2019-03-30 01:18:21.338 ERRO sign:1 : init properties failed:open /etc/dragonfly/dfdaemon.yml: no such file or directory
2019-03-30 01:18:21.338 INFO sign:1 : init properties:{"Registries":[{"Schema":"https","Host":"registry.cn-qingdao.aliyuncs.com","Certs":null,"Regx":"(^localhost$)|(^127.0.0.1$)|(^127.0.0.1$)"}]}
2019-03-30 01:18:21.338 INFO sign:1 : init finish
2019-03-30 01:18:21.338 INFO sign:1 : start dfdaemon param: &{DfPath:/dfclient/dfget DFRepo:/root/.small-dragonfly/dfdaemon/data/ RateLimit:100M CallSystem:com_ops_dragonfly URLFilter:Signature&Expires&OSSAccessKeyId Notbs:true MaxProcs:4 Version:false Verbose:false HostIP:127.0.0.1 Port:65001 Registry:https://registry.cn-qingdao.aliyuncs.com DownRule: CertFile: KeyFile: TrustHosts:[] ConfigPath:/etc/dragonfly/dfdaemon.yml}
2019-03-30 01:18:21.338 INFO sign:1 : launch dfdaemon http server on 127.0.0.1:65001
复制代码登陆dfdaemon
root@d7y-2:~# docker login http://127.0.0.1:65001
Username: //你阿里云账号
Password: //你阿里云密码
Login Succeeded
root@d7y-2:~# cat ~/.docker/config.json
{
"auths": {
"127.0.0.1:65001": {
"auth": "zzxxxxxx="
}
}
}
复制代码pull 私有镜像
root@d7y-2:~# docker pull 127.0.0.1:65001/d7y-test/nginx:alpine
alpine: Pulling from d7y-test/nginx
8e402f1a9c57: Pull complete
56b0d9b69cc9: Pull complete
b66c8bb200cc: Pull complete
4ec77fc9c55f: Pull complete
Digest: sha256:857e6f195df0e9b497be0c7fad0f013126407aaeb71edcef66a24e8b990d94b3
Status: Downloaded newer image for 127.0.0.1:65001/d7y-test/nginx:alpine
复制代码可以通过iftop 等命令，观察流量。
其他
排错
如果有遇到其他问题，可以通过查看日志来获取更多信息。
dfdaemon log : /root/.small-dragonfly/logs/{dfclient.log,dfdaemon.log,dfserver.log}
supernode log: /home/admin/supernode/{app.log,data-gc.log,downloader.log,piece-hit.log,space-gc.log}
公开和私有registry混用
如果大量都是私有registry的话，可以在/etc/docker/daemon.json 中配置dfdaemon和加速器，如果是一半一半的话，那就干脆起两个dfdaemon就行了，一个--registry写私有的，一个--registry写公有的，然后也是配置 /etc/docker/daemon.json
cat /etc/docker/daemon.json
{
"registry-mirrors": ["http://127.0.0.1:65001","https://xxx.mirror.aliyuncs.com"],
"dns": ["223.5.5.5"]
}
复制代码吐槽
再次吐槽一下d7y的产品很好，解决了很大问题。但是这文档，真心不是给新手看的。从未见过如此坑多且深的文档。没见过哪家quick start 写的这么复杂。
鸣谢
非常感谢钉钉群内的 d7y 的 contributor 太云-lowzj 耐心解答，从开始研究d7y开始，遇到的很多坑都是在 太云-lowzj 帮助下蹚过去的。但是还是觉得，如果文档足够友好，肯定会减少群内被打扰的次数，进而节省自己时间的。
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