centos7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。

 

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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

 1 version: 0.1
 2 
 3 log:
 4 fields:
 5 service: registry
 6 storage:
 7 delete:
 8 enabled: true
 9 cache:
10 blobdescriptor: inmemory
11 filesystem:
12 rootdirectory: /var/lib/registry
13 http:
14 addr: :5000
15 headers:
16 x-content-type-options: [nosniff]
17 health:
18 storagedriver:
19 enabled: true
20 interval: 10s
21 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

 

参考：

https://www.cnblogs.com/tempted/p/7768694.html
https://blog.csdn.net/jiangeeq/article/details/81056055
https://www.cnblogs.com/hwystudy/p/10483163.html
https://blog.51cto.com/302876016/1966816