CentOS 7 docker registry的搭建
系统配置： CentOS 7 内核 3.10.0-229.20.1.el7.x86_64 ， Docker version 1.8.2
运行 docker registry执行下列命令：
docker run / -d / --name private_registry --restart=always / -e SETTINGS_FLAVOUR=dev / -e STORAGE_PATH=/registry-storage / -v /data/docker/private-registry/storage:/registry-storage / -u root / -p 5000:5000 / registry:2如果本地已有registry镜像，它会直接运行，否则它会到docker hub共有仓库下载之后再运行， -v /data/docker/private-registry/storage:/registry-storage 该命令将之后私有仓库的镜像存放到本地。
之后执行：
docker tag docker.io/docker:1.8 192.168.100.9:5000/docker:1.8 docker push 192.168.100.9:5000/docker:1.8这时会报很多错误：
FATA[0000] Error response from daemon: v1 ping attempt failed with error: Get https://192.168.100.9:5000/v1/_ping: tls: oversized record received with length 20527/. If this private registry supports only HTTP or HTTPS with an unknown CA certificate,please add `--insecure-registry 192.168.100.9:5000` to the daemon's arguments. In the case of HTTPS, if you have access to the registry's CA certificate, no need for the flag; simply place the CA certificate at /etc/docker/certs.d/192.168.100.9:5000/ca.crt最简单的解决方法是修改 /etc/sysconfig/docker 文件添加 INSECURE_REGISTRY='--insecure-registry 192.168.100.9:5000' , Ubuntu 14.04 的配置文件在 /etc/default/docker 在该文件里添加 DOCKER_OPTS="--insecure-registry 192.168.100.9:5000" ，添加过之后重启 docker ,重新运行 docker registry 即可生效。这样做的缺点是你的私有仓库不安全，其次，其他要下载或者上传镜像的机器都要修改相应的配置文件。
安全的做法是去认证机构购买签名证书，在此我们使用自认证的方式。
自签名认证首先执行：
# mkdir -p certs && openssl req / -newkey rsa:4096 -nodes -sha256 -keyout certs/domain.key / -x509 -days 365 -out certs/domain.crt Country Name (2 letter code) [AU]:CN State or Province Name (full name) [Some-State]:Beijing Locality Name (eg, city) []:Beijing Organization Name (eg, company) [Internet Widgits Pty Ltd]:SERCXTYF Organizational Unit Name (eg, section) []:IT Common Name (e.g. server FQDN or YOUR name) []:192.168.100.9:5000 Email Address []:xxx.yyy@ymail.com生成认证证书和密钥。接下来将刚生成的 certs/domain.crt 复制到 /etc/docker/certs.d/192.168.100.9:5000/ca.crt ，之后重启 docker 并运行：
docker run / -d / --name private_registry --restart=always / -e SETTINGS_FLAVOUR=dev / -e STORAGE_PATH=/registry-storage / -v /data/docker/private-registry/storage:/registry-storage / -u root / -p 5000:5000 / -v /root/certs:/certs / -e REGISTRY_HTTP_TLS_CERTIFICATE=/certs/domain.crt / -e REGISTRY_HTTP_TLS_KEY=/certs/domain.key / registry:2这样之后应该可以成功了吧，于是执行：
# docker push 192.168.100.9:5000/docker:1.8结果它还是报错了：
The push refers to a repository 192.168.100.9:5000/docker:1.8 unable to ping registry endpoint https://192.168.100.9:5000/v0/ v2 ping attempt failed with error: Get https://192.168.100.9:5000/v2/: x509: cannot validate certificate for 192.168.100.9 because it doesn't contain any IP SANs v1 ping attempt failed with error: Get https://192.168.100.9:5000/v1/_ping: x509: cannot validate certificate for 192.168.100.9 because it doesn't contain any IP SANs解决方法：修改 /etc/pki/tls/openssl.cnf 配置，在该文件中找到 [ v3_ca ] ，在它下面添加如下内容：
[ v3_ca ] # Extensions for a typical CA subjectAltName = IP:123.56.157.144之后再次重启docker,并重新 run registry ，启动成功之后，执行：
# docker push 192.168.100.9:5000/docker:1.8 The push refers to a repository [192.168.100.9:5000/docker] (len: 1) 793ab2f3d322: Pushed e1232be51d09: Pushed 71ef33d4e0e5: Pushed e9d235d200dc: Pushed 3fb9a265fbfc: Pushed 9f50b4b1f00b: Pushed 413668359dd0: Pushed da0daae25b21: Pushed f4fddc471ec2: Pushed 1.8: digest: sha256:28a02a8a50b750a300904b53e802bdf76516d591b2d233ae21cf771b8c776d44 size: 17621至此，上传终于成功。换台机器下载刚上传的镜像：
# docker pull 192.168.100.9:5000/docker:1.8 Trying to pull repository 192.168.100.9:5000/docker ... failed unable to ping registry endpoint https://192.168.100.9:5000/v0/ v2 ping attempt failed with error: Get https://192.168.100.9:5000/v2/: x509: certificate signed by unknown authority v1 ping attempt failed with error: Get https://192.168.100.9:5000/v1/_ping: x509: certificate signed by unknown authority仔细分析错误信息，发现是没有证书，将在 192.168.100.9 上生成的证书拷贝到相应的目录下 /etc/docker/certs.d/192.168.100.9:5000/ca.crt ，拷贝之后重启 docker ，再次执行:
# docker pull 192.168.100.9:5000/docker:1.8 1.8: Pulling from docker 9d58b928bc15: Pull complete dbe7e8a7807c: Pull complete ce14982b73d4: Pull complete b9f70905d763: Pull complete b9c93a2fb3cf: Pull complete 1321a4d5d3ea: Pull complete 5941048a7e27: Pull complete f57edf7c2e71: Pull complete 5de2ade00f1b: Pull complete Digest: sha256:28a02a8a50b750a300904b53e802bdf76516d591b2d233ae21cf771b8c776d44 Status: Downloaded newer image for 192.168.100.9:5000/docker:1.8