Docker私有仓库搭建及镜像删除

在我们平时使用docker创建我们自己的镜像时，有些人/公司的镜像不想上传到公共的hub上去，这时搭建一个私有仓库就很有必要了，内部人员使用私有仓库也很方便

VV把踩到的私有仓库删除镜像的坑总结了一下，于是，今天给大家带来这篇文章：Docker私有仓库搭建及镜像删除，希望能够帮助大家

创建私有仓库

[root@uat-app01 ~]# docker pull registry

查看image

[root@uat-app01 docker]# docker images
REPOSITORY                                               TAG                 IMAGE ID            CREATED             SIZE
docker.io/registry                                       latest              177391bcf802        3 weeks ago         33.26 MB

下载完后,执行如下命令，启动registry容器

docker run -d -p 5000:5000 --privileged=true -v /opt/registry:/var/lib/registry -v /opt/registry/config.yml:/etc/docker/registry/config.yml --name registry registry

注意：/opt/registry目录不存在需要提前创建

参数说明：

-d 守住状态后台运行

-p 端口映射，端口号可自定义

-v 挂载本地目录 /opt/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

–privileged=true 

CentOS7中的安全模块selinux把权限禁掉了，参数给容器加特权，不加上传镜像会报权限错误

[root@uat-app01 registry]# cat  /opt/registry/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

–name指定容器名

下面要在客户端向私有仓库上传镜像，VV这里使用的是hello-world的镜像

修改配置文件后，重启docker

[root@uat-app01 opt]# service docker restart
Redirecting to /bin/systemctl restart docker.service

修改docker tag，将原有的hello-world修改

[root@uat-app01 registry]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
docker.io/hello-world latest f2a91732366c 5 weeks ago 1.848 kB

[root@uat-app01 registry]# docker tag docker.io/hello-world 192.168.1.40:5000/hello
[root@uat-app01 registry]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
docker.io/registry latest 177391bcf802 3 weeks ago 33.26 MB
192.168.1.40:5000/hello latest f2a91732366c 5 weeks ago 1.848 kB
docker.io/hello-world latest f2a91732366c 5 weeks ago 1.848 kB

上传镜像：

[root@uat-app01 registry]# docker push 192.168.1.40:5000/hello
The push refers to a repository [192.168.1.40:5000/hello]
Put http://192.168.1.40:5000/v1/repositories/hello/: dial tcp 192.168.1.40:5000: getsockopt: connection refused

push的时候发生异常，连接被拒绝

原因：docker重启后registry容器没有运行

[root@uat-app01 opt]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES

[root@uat-app01 opt]# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
bdd399396473 registry "/entrypoint.sh /etc/" 36 minutes ago Exited (2) 1 minutes ago 0.0.0.0:5000->5000/tcp registry

[root@uat-app01 opt]# docker start registry

[root@uat-app01 registry]# docker push 192.168.1.40:5000/hello
The push refers to a repository [192.168.1.40:5000/hello]
f999ae22f308: Pushed
latest: digest: sha256:8072a54ebb3bc136150e2f2860f00a7bf45f13eeb917cca2430fcd0054c8e51b size: 524

镜像上传成功

查看上传的镜像

[root@uat-app01 registry]# curl --header "Accept: application/vnd.docker.distribution.manifest.v2+json"  -I -X  
\ HEAD http://192.168.1.40:5000/v2/hello/manifests/latest
HTTP/1.1 200 OK
Content-Length: 524
Content-Type: application/vnd.docker.distribution.manifest.v2+json
Docker-Content-Digest: sha256:8072a54ebb3bc136150e2f2860f00a7bf45f13eeb917cca2430fcd0054c8e51b
Docker-Distribution-Api-Version: registry/2.0
Etag: "sha256:8072a54ebb3bc136150e2f2860f00a7bf45f13eeb917cca2430fcd0054c8e51b"
X-Content-Type-Options: nosniff
Date: Tue, 26 Dec 2017 07:57:45 GMT

使用其它客户端进行pull镜像

注意：

使用其它客户端下载镜像时，也需要修改etc/sysconfig/docker配置文件

添加如下内容

OPTIONS=’–insecure-registry 192.168.1.40:5000′（IP地址及端口，可根据实际情况填写）

修改后，重启docker服务

pull刚刚上传的hello镜像，pull成功，说明私有仓库配置完成。

[root@uat-ucs02 ~]# docker pull 192.168.1.40:5000/hello
Using default tag: latest
Trying to pull repository 192.168.1.40:5000/hello ... 
latest: Pulling from 192.168.1.40:5000/hello
Digest: sha256:8072a54ebb3bc136150e2f2860f00a7bf45f13eeb917cca2430fcd0054c8e51b

起初，安装私有仓库的时候，并没有思考到删除镜像的问题，当想要删除上传的镜像时，镜像删不掉，很麻烦，就得重新弄私有仓库

Docker仓库在2.1版本中支持了删除镜像的API，但这个删除操作只会删除镜像元数据，不会删除层数据。在2.4版本中对这一问题进行了解决，增加了一个垃圾回收命令，删除未被引用的层数据

先来查看刚才成功上传的hello镜像信息，可以查得到

[root@uat-app01 registry]# curl --header "Accept: application/vnd.docker.distribution.manifest.v2+json"  -I -X  
\ HEAD http://192.168.1.40:5000/v2/hello/manifests/latest
HTTP/1.1 200 OK
Content-Length: 524
Content-Type: application/vnd.docker.distribution.manifest.v2+json
Docker-Content-Digest: sha256:8072a54ebb3bc136150e2f2860f00a7bf45f13eeb917cca2430fcd0054c8e51b
Docker-Distribution-Api-Version: registry/2.0
Etag: "sha256:8072a54ebb3bc136150e2f2860f00a7bf45f13eeb917cca2430fcd0054c8e51b"
X-Content-Type-Options: nosniff
Date: Tue, 26 Dec 2017 07:57:45 GMT

[root@uat-ucs02 ~]# docker pull 192.168.1.40:5000/hello
Using default tag: latest
Trying to pull repository 192.168.1.40:5000/hello ... 
latest: Pulling from 192.168.1.40:5000/hello
Digest: sha256:8072a54ebb3bc136150e2f2860f00a7bf45f13eeb917cca2430fcd0054c8e51b

下面我们要删除该镜像：

删除镜像的API如下：

DELETE /v2/<name>/manifests/<reference>

name:镜像名称

reference: 镜像对应sha256值

示例：运行后，发现Accepted接收请求，说明删除成功

[root@uat-app01 registry]# curl -v -X DELETE http://192.168.1.40:5000/v2/hello/manifests/sha256:8072a54ebb3bc136150e2f2860f00a7bf45f13eeb917cca2430fcd0054c8e51b
* About to connect() to 192.168.1.40 port 5000 (#0)
*   Trying 192.168.1.40...
* Connected to 192.168.1.40 (192.168.1.40) port 5000 (#0)
> DELETE /v2/hello/manifests/sha256:8072a54ebb3bc136150e2f2860f00a7bf45f13eeb917cca2430fcd0054c8e51b HTTP/1.1
> User-Agent: curl/7.29.0
> Host: 192.168.1.40:5000
> Accept: */*
> 
< HTTP/1.1 202 Accepted
< Docker-Distribution-Api-Version: registry/2.0
< X-Content-Type-Options: nosniff
< Date: Tue, 26 Dec 2017 07:58:56 GMT
< Content-Length: 0
< Content-Type: text/plain; charset=utf-8
< 
* Connection #0 to host 192.168.1.40 left intact

再去查该镜像时，提示not found

[root@uat-app01 registry]# docker pull 192.168.1.40:5000/hello
Using default tag: latest
Trying to pull repository 192.168.1.40:5000/hello ... 
Pulling repository 192.168.1.40:5000/hello
Error: image hello:latest not found

但这只是删除了元数据，镜像数据并没有删除

如果镜像过大，占用磁盘空间过多，遗留的镜像数据，会继续占用系统资源，于是要将垃圾数据删除

进入到registry容器中

[root@uat-app01 registry]# docker ps 
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                    NAMES
bdd399396473	  registry            "/entrypoint.sh /etc/"   8 minutes ago       Up 8 minutes        0.0.0.0:5000->5000/tcp   registr

进入容器后，查看/var/lib/registry目录大小

默认情况下，会将仓库存放于容器内的/var/lib/registry目录下

[root@uat-app01 registry]# docker exec -it registry  sh
/var/lib # du -sh registry/
24.0K	registry/

执行容器垃圾回收命令，这里使用的配置文件为开启容器时挂载到容器中/etc/docker/registry目录下的config.yml文件

/var/lib # registry garbage-collect /etc/docker/registry/config.yml 
hello
0 blobs marked, 3 blobs eligible for deletion
blob eligible for deletion: sha256:8072a54ebb3bc136150e2f2860f00a7bf45f13eeb917cca2430fcd0054c8e51b
INFO[0000] Deleting blob: /docker/registry/v2/blobs/sha256/80/8072a54ebb3bc136150e2f2860f00a7bf45f13eeb917cca2430fcd0054c8e51b  go.version=go1.7.6 instance.id=50ad6bf8-36ea-4eba-adf6-b78fc369c560
blob eligible for deletion: sha256:ca4f61b1923c10e9eb81228bd46bee1dfba02b9c7dac1844527a734752688ede
INFO[0000] Deleting blob: /docker/registry/v2/blobs/sha256/ca/ca4f61b1923c10e9eb81228bd46bee1dfba02b9c7dac1844527a734752688ede  go.version=go1.7.6 instance.id=50ad6bf8-36ea-4eba-adf6-b78fc369c560
blob eligible for deletion: sha256:f2a91732366c0332ccd7afd2a5c4ff2b9af81f549370f7a19acd460f87686bc7
INFO[0000] Deleting blob: /docker/registry/v2/blobs/sha256/f2/f2a91732366c0332ccd7afd2a5c4ff2b9af81f549370f7a19acd460f87686bc7  go.version=go1.7.6 instance.id=50ad6bf8-36ea-4eba-adf6-b78fc369c560

再次查看该目录，发现文件夹变小，说明镜像数据已删除

/var/lib # du -sh registry/
12.0K	registry/

镜像数据删除成功

好了，我们下篇文章见

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