CentOS 7搭建Docker私有库及删除库内镜像

环境准备

系统：

cat /etc/RedHat-release

CentOS Linux release 7.4.1708 (Core)

主机两台，分别是docker私有库服务器（IP 192.168.121.121）和用户开发机（IP 192.168.121.122），开发机从私有库服务器拉取镜像。

--------------------------------------------------------------------------------

1、配置软件源并安装安装docker

两台主机安装docker

yum install docker-ce

2、搭建私有镜像仓库

登陆私有库服务器

创建docker管理账户并设置密码

useradd dkuser

passwd dkuser

把账户加入docker组，这一步是为了可以使用普通账户管理docker，而不用使用sudo命令

usermod -G docker dkuser

为账户配置sudo权限

visudo

添加下面一行

dkuser ALL=(ALL) NOPASSWD:ALL

切换账户

su dkuser

启动docker服务

sudo systemctl start docker

可以通过官方提供的registry镜像来搭建本地的私有仓库，所以拉取官方镜像

docker pull registry

创建存放镜像和docker配置文件的目录

sudo mkdir /data/docker

创建配置文件，storage配置中的delete=true配置项，是为了允许删除镜像。默认的镜像是没有这个参数

sudo vi /data/docker/config.yml

version: 0.1

log: fields: service: registry storage: delete: enabled: true cache: blobdescriptor: inmemory filesystem: rootdirectory: /var/lib/registry http: addr: :5000 headers: X-Content-Type-Options: [nosniff] health: storagedriver: enabled: true interval: 10s threshold: 3

运行registry容器

docker run -d -p 5000:5000 -v /data/docker/registry:/var/lib/registry -v /data/docker/config.yml:/etc/docker/registry/config.yml --restart always --name registry registry

说明： -d -p 5000:5000 端口映射 -v /data/docker/registry:/var/lib/registry 默认情况下，会将仓库存放于容器内的/var/lib/registry目录下，指定本地目录挂载到容器 --restart always 在容器退出时总是重启容器,主要应用在生产环境 --name registry 指定容器的名称

查看容器

docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 071105c54db3 registry "/entrypoint.sh /etc…" 3 minutes ago Up About a minute 0.0.0.0:5000->5000/tcp registry

3、把本地镜像上传到私有仓库 在私有库服务器上

这里以busybox镜像为例，因为比较小

首先把镜像下载到本地

docker pull busybox

为镜像打标签

docker tag busybox 192.168.121.121:5000/busybox

查看镜像

docker images REPOSITORY TAG IMAGE ID CREATED SIZE 192.168.121.121:5000/busybox latest db8ee88ad75f 7 hours ago 1.22MB busybox latest db8ee88ad75f 7 hours ago 1.22MB

编辑配置文件，添加配置是为了能够在本地上传镜像。

sudo vi /usr/lib/systemd/system/docker.service

在 ExecStart=/usr/bin/dockerd 后边添加

--insecure-registry 192.168.121.121:5000

重启docker服务

sudo systemctl daemon-reload sudo systemctl restart docker

推送镜像到私有库

docker push 192.168.121.121:5000/busybox The push refers to repository [192.168.121.121:5000/busybox] 0d315111b484: Pushed latest: digest: sha256:895ab622e92e18d6b461d671081757af7dbaa3b00e3e28e12505af7817f73649 size: 527

报错解决：

docker push 192.168.121.121:5000/busybox The push refers to repository [192.168.121.121:5000/busybox] Get https://192.168.121.121:5000/v2/: http: server gave HTTP response to HTTPS client

因为Docker从1.3.X之后，与docker registry交互默认使用的是https，然而此处搭建的私有仓库只提供http服务，所以当与私有仓库交互时就会报上面的错误。为了解决这个问题需要在启动docker server时增加启动参数为默认使用http访问

sudo vi /usr/lib/systemd/system/docker.service

ExecStart=/usr/bin/dockerd 后边添加

--insecure-registry 192.168.121.121:5000

4、开发机从私有库载入镜像

同样的也需要添加配置

vi /usr/lib/systemd/system/docker.service

ExecStart=/usr/bin/dockerd 后边添加

--insecure-registry 192.168.121.121:5000

启动docker服务

systemctl start docker

从私有库载入镜像

docker pull 192.168.121.121:5000/busybox Using default tag: latest latest: Pulling from busybox ee153a04d683: Pull complete Digest: sha256:895ab622e92e18d6b461d671081757af7dbaa3b00e3e28e12505af7817f73649 Status: Downloaded newer image for 192.168.121.121:5000/busybox:latest

查看镜像

docker images REPOSITORY TAG IMAGE ID CREATED SIZE 192.168.121.121:5000/busybox latest db8ee88ad75f 7 hours ago 1.22MB

5、删除镜像 在私有库服务器上

相应的参考命令: #查询镜像 curl <仓库地址>/v2/_catalog

#查询镜像tag(版本) curl <仓库地址>/v2/<镜像名>/tags/list

#查询镜像digest_hash curl --header "Accept:application/vnd.docker.distribution.manifest.v2+json" -I -XGET <仓库地址>/v2/<镜像名>/manifests/<tag>

#删除镜像API curl -I -X DELETE "<仓库地址>/v2/<镜像名>/manifests/<镜像digest_hash>"

在服务器执行下面命令 查询镜像

curl -XGET http://192.168.121.121:5000/v2/_catalog {"repositories":["busybox"]}

查询镜像tag

curl http://192.168.121.121:5000/v2/busybox/tags/list {"name":"busybox","tags":["latest"]}

查询镜像digest_hash，删除命令里边要填写的 镜像digest_hash 就是 查询结果里边 Docker-Content-Digest: 后边的内容

curl --header "Accept:application/vnd.docker.distribution.manifest.v2+json" -I -XGET http://192.168.121.121:5000/v2/busybox/manifests/latest HTTP/1.1 200 OK Content-Length: 527 Content-Type: application/vnd.docker.distribution.manifest.v2+json Docker-Content-Digest: sha256:895ab622e92e18d6b461d671081757af7dbaa3b00e3e28e12505af7817f73649 Docker-Distribution-Api-Version: registry/2.0 Etag: "sha256:895ab622e92e18d6b461d671081757af7dbaa3b00e3e28e12505af7817f73649" X-Content-Type-Options: nosniff Date: Fri, 19 Jul 2019 06:09:44 GMT

删除私有库镜像

curl -I -XDELETE http://192.168.121.121:5000/v2/busybox/manifests/sha256:895ab622e92e18d6b461d671081757af7dbaa3b00e3e28e12505af7817f73649 HTTP/1.1 202 Accepted Docker-Distribution-Api-Version: registry/2.0 X-Content-Type-Options: nosniff Date: Fri, 19 Jul 2019 06:10:56 GMT Content-Length: 0

查看镜像信息可以看到镜像的标签显示为空 null

curl http://192.168.121.121:5000/v2/busybox/tags/list {"name":"busybox","tags":null}

 这里虽然删除了，但是实际上硬盘地址还没有释放，是因为docker删除p_w_picpath只是删除的p_w_picpath的元数据信息。层数据并没有删除。现在进入registry中进行垃圾回收。

进入registry容器

docker exec -it 071105c54db3 /bin/sh / # cd /var/lib/registry/

查看镜像大小

/var/lib/registry # du -sch 756.0K . 756.0K total

执行回收命令

/var/lib/registry # registry garbage-collect /etc/docker/registry/config.yml busybox

0 blobs marked, 3 blobs and 0 manifests eligible for deletion blob eligible for deletion: sha256:895ab622e92e18d6b461d671081757af7dbaa3b00e3e28e12505af7817f73649 INFO[0000] Deleting blob: /docker/registry/v2/blobs/sha256/89/895ab622e92e18d6b461d671081757af7dbaa3b00e3e28e12505af7817f73649 go.version=go1.11.2 instance.id=7c37e39d-6ad1-4139-b9d1-592a900b0902 service=registry blob eligible for deletion: sha256:db8ee88ad75f6bdc74663f4992a185e2722fa29573abcc1a19186cc5ec09dceb INFO[0000] Deleting blob: /docker/registry/v2/blobs/sha256/db/db8ee88ad75f6bdc74663f4992a185e2722fa29573abcc1a19186cc5ec09dceb go.version=go1.11.2 instance.id=7c37e39d-6ad1-4139-b9d1-592a900b0902 service=registry blob eligible for deletion: sha256:ee153a04d6837058642958836062f20badf39f558be3e6c7c7773ef7d8301d90 INFO[0000] Deleting blob: /docker/registry/v2/blobs/sha256/ee/ee153a04d6837058642958836062f20badf39f558be3e6c7c7773ef7d8301d90 go.version=go1.11.2 instance.id=7c37e39d-6ad1-4139-b9d1-592a900b0902 service=registry

再次查询，发现回收资源执行成功

/var/lib/registry # du -sch 0 . 0 total