有時候使用 Docker Hub 這樣的公共倉庫可能不方便，使用者可以建立一個本地倉庫供私人使用。本節介紹如何使用本地倉庫。 docker-registry 是官方提供的工具，可以用於建立私有的映像檔倉庫。
安裝執行 docker-registry
容器執行
在安裝了 Docker 後，可以透過取得官方 registry 映像檔來執行。
$ sudo docker run -d -p 5000:5000 registry
這將使用官方的 registry 映像檔來啟動本地的私有倉庫。使用者可以透過指定參數來設定私有倉庫位置，例如設定映像檔儲存到 Amazon S3 服務。
$ sudo docker run \
-e SETTINGS_FLAVOR=s3 \
-e AWS_BUCKET=acme-docker \
-e STORAGE_PATH=/registry \
-e AWS_KEY=AKIAHSHB43HS3J92MXZ \
-e AWS_SECRET=xdDowwlK7TJajV1Y7EoOZrmuPEJlHYcNP2k4j49T \
-e SEARCH_BACKEND=sqlalchemy \
-p 5000:5000 \
registry
此外，還可以指定本地路徑（如 /home/user/registry-conf ）下的設定檔案。
$ sudo docker run -d -p 5000:5000 -v /home/user/registry-conf:/registry-conf -e DOCKER_REGISTRY_CONFIG=/registry-conf/config.yml registry
預設情況下，倉庫會被建立在容器的 /tmp/registry 下。可以透過 -v 參數來將映像檔檔案存放在本地的指定路徑。 例以下面的例子將上傳的映像檔放到 /opt/data/registry 目錄。
$ sudo docker run -d -p 5000:5000 -v /opt/data/registry:/tmp/registry registry
本地安裝
對於 Ubuntu 或 CentOS 等發行版，可以直接透過套件庫安裝。
Ubuntu
$ sudo apt-get install -y build-essential python-dev libevent-dev python-pip liblzma-dev swig
$ sudo pip install docker-registry
CentOS
$ sudo yum install -y python-devel libevent-devel python-pip gcc xz-devel
$ sudo python-pip install docker-registry
$ sudo apt-get install build-essential python-dev libevent-dev python-pip libssl-dev liblzma-dev libffi-dev
$ git clone https://github.com/docker/docker-registry.git
$ cd docker-registry
$ sudo python setup.py install
然後修改設定檔案，主要修改 dev 模板段的 storage_path 到本地的儲存倉庫的路徑。
$ cp config/config_sample.yml config/config.yml
之後啟動 Web 服務。
$ sudo gunicorn -c contrib/gunicorn.py docker_registry.wsgi:application
或者
$ sudo gunicorn --access-logfile - --error-logfile - -k gevent -b 0.0.0.0:5000 -w 4 --max-requests 100 docker_registry.wsgi:application
此時使用連結本地的 5000 連接埠，看到輸出 docker-registry 的版本訊息說明執行成功。
*註：config/config_sample.yml 檔案是範例設定檔案。
在私有倉庫上傳、下載、搜尋映像檔
建立好私有倉庫之後，就可以使用 docker tag 來標記一個映像檔，然後推送它到倉庫，別的機器上就可以下載下來了。例如私有倉庫位址為 192.168.7.26:5000。
先在本機查看已有的映像檔。
$ sudo docker images
REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE
ubuntu latest ba5877dc9bec 6 weeks ago 192.7 MB
ubuntu 14.04 ba5877dc9bec 6 weeks ago 192.7 MB
使用docker tag 將 ba58 這個映像檔標記為 192.168.7.26:5000/test（格式為 docker tag IMAGE[:TAG] [REGISTRYHOST/][USERNAME/]NAME[:TAG]）。
$ sudo docker tag ba58 192.168.7.26:5000/test
root ~ # docker images
REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE
ubuntu 14.04 ba5877dc9bec 6 weeks ago 192.7 MB
ubuntu latest ba5877dc9bec 6 weeks ago 192.7 MB
192.168.7.26:5000/test latest ba5877dc9bec 6 weeks ago 192.7 MB
使用 docker push 上傳標記的映像檔。
$ sudo docker push 192.168.7.26:5000/test
The push refers to a repository [192.168.7.26:5000/test] (len: 1)
Sending image list
Pushing repository 192.168.7.26:5000/test (1 tags)
Image 511136ea3c5a already pushed, skipping
Image 9bad880da3d2 already pushed, skipping
Image 25f11f5fb0cb already pushed, skipping
Image ebc34468f71d already pushed, skipping
Image 2318d26665ef already pushed, skipping
Image ba5877dc9bec already pushed, skipping
Pushing tag for rev [ba5877dc9bec] on {http://192.168.7.26:5000/v1/repositories/test/tags/latest}
用 curl 查看倉庫中的映像檔。
$ curl http://192.168.7.26:5000/v1/search
{"num_results": 7, "query": "", "results": [{"description": "", "name": "library/miaxis_j2ee"}, {"description": "", "name": "library/tomcat"}, {"description": "", "name": "library/ubuntu"}, {"description": "", "name": "library/ubuntu_office"}, {"description": "", "name": "library/desktop_ubu"}, {"description": "", "name": "dockerfile/ubuntu"}, {"description": "", "name": "library/test"}]}
這裡可以看到 {"description": "", "name": "library/test"}，表明映像檔已經被成功上傳了。
現在可以到另外一臺機器去下載這個映像檔。
$ sudo docker pull 192.168.7.26:5000/test
Pulling repository 192.168.7.26:5000/test
ba5877dc9bec: Download complete
511136ea3c5a: Download complete
9bad880da3d2: Download complete
25f11f5fb0cb: Download complete
ebc34468f71d: Download complete
2318d26665ef: Download complete
$ sudo docker images
REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE
192.168.7.26:5000/test latest ba5877dc9bec 6 weeks ago 192.7 MB
$ wget https://github.com/yeasy/docker_practice/raw/master/_local/push_images.sh; sudo chmod a+x push_images.sh
$ ./push_images.sh ubuntu:latest centos:centos7
The registry server is 127.0.0.1
Uploading ubuntu:latest...
The push refers to a repository [127.0.0.1:5000/ubuntu] (len: 1)
Sending image list
Pushing repository 127.0.0.1:5000/ubuntu (1 tags)
Image 511136ea3c5a already pushed, skipping
Image bfb8b5a2ad34 already pushed, skipping
Image c1f3bdbd8355 already pushed, skipping
Image 897578f527ae already pushed, skipping
Image 9387bcc9826e already pushed, skipping
Image 809ed259f845 already pushed, skipping
Image 96864a7d2df3 already pushed, skipping
Pushing tag for rev [96864a7d2df3] on {http://127.0.0.1:5000/v1/repositories/ubuntu/tags/latest}
Untagged: 127.0.0.1:5000/ubuntu:latest
Done
Uploading centos:centos7...
The push refers to a repository [127.0.0.1:5000/centos] (len: 1)
Sending image list
Pushing repository 127.0.0.1:5000/centos (1 tags)
Image 511136ea3c5a already pushed, skipping
34e94e67e63a: Image successfully pushed
70214e5d0a90: Image successfully pushed
Pushing tag for rev [70214e5d0a90] on {http://127.0.0.1:5000/v1/repositories/centos/tags/centos7}
Untagged: 127.0.0.1:5000/centos:centos7
Done