Image Registry Basic Operations

Starting from February 1, 2021, the Cloud Container Engine (CCE) image registry will only support read-only mode (existing image can still be pulled, but new image cannot be pushed). Please migrate to the Cloud Container Registry (CCR) as soon as possible (refer to Image Migration Documentation). CCR will provide you with more secure, reliable, and fast services. For other requests or questions, please Submit a Ticket.

Introduction

The image registry delivers secure, dependable, and user-friendly container image management services, minimizing the setup and maintenance overhead of the registry while improving the delivery capacity and user experience of cloud-native applications.

You can use the image registry function provided by the Cloud Container Engine (CCE) Cloud Container Engine - Image Registry

You can also use the more function-rich and user-friendly Cloud Container Registry (CCR) Container Image Registry Console

Note: This document is specific to the image registry in the Cloud Container Engine (CCE), with the image registry domain name of hub.baidubce.com. To refer to this document to use the Cloud Container Registry (CCR), replace the image registry domain name with registry.baidubce.com.

Enable image registry

When accessing the image registry for the first time, a setup page will appear. Enter the username and set a password as prompted.

Note:

Username: Naming rules of image registry username: lowercase letters and numbers only, with a length of 4-30, unmodifiable after submission.

Password: This is the credential for users to sign in to the docker image registry. Password creation rules: 8-32 characters; it must contain English letters, numbers, and symbols (limited to !@#^*()) simultaneously

Create namespace

1. Within the image registry section, choose a namespace, then click Create Namespace in the namespace list.
2. Provide the new namespace name, select the namespace type, and click OK to finish creating the namespace.

Note:

Namespace naming rules are as follows: Names must be between 1 and 65 characters long, using lowercase letters, numbers, and the special characters -\_. Special characters cannot begin or end the name, nor appear consecutively.

Create an image

1. On the Image List page, click the Create button.
2. Select the namespace, enter the image name and version number, then click OK.

Note:

1. The image name must consist of lowercase letters, numbers, and the special characters -_ /., with a length of 1-65 characters. Special characters cannot start or end the name, nor appear consecutively.
2. The version name must consist of lowercase letters, numbers, and the special characters -_ ., with a length of 1-65 characters. Special characters cannot start or end the name, nor appear consecutively.
3. If the user opts not to create a new image, the above basic details will also be generated automatically upon completing the image push to the corresponding namespace.

Delete image

Select the image name to delete, click the Delete button, and confirm the action in the pop-up deletion window.

Note: Deleted image cannot be recovered or used.

Push the image to the image registry

Starting from February 1, 2021, the Cloud Container Engine (CCE) image registry will only support read-only mode (existing image can still be pulled, but new image cannot be pushed). Please migrate to the Cloud Container Registry (CCR) as soon as possible (refer to Image Migration Documentation). CCR will provide you with more secure, reliable, and fast services. For other requests or questions, please Submit a Ticket.

Note: This document is specific to the image registry in the Cloud Container Engine (CCE), with the image registry domain name of hub.baidubce.com. To refer to this document to use the Cloud Container Registry (CCR), replace the image registry domain name with registry.baidubce.com.

Sign in to Baidu AI Cloud Image Registry

1    >$ sudo docker login --username=[username] hub.baidubce.com

Username: The image registry name corresponds to the username input during registry activation. Complete the login process by entering the password.

Upload images

1    $ sudo docker tag [ImageId] hub.baidubce.com/[namespace]/[ImageName]: [Image Version No.]
2 $ sudo docker push hub.baidubce.com/[namespace]/[ImageName]:[Image Version No.]

• Fill in the ImageId and image version No. based on the image information
• Namespace refers to the namespace entered when activating the image registry
• ImageName refers to the image name created in the console

Download Image

To sign in to the Image Registry, you need to enter the password

1    $ sudo docker pull hub.baidubce.com/[namespace]/[ImageName]:[Image Version No.]

Use DockerHub accelerator

How to use the DockerHub image accelerator

Docker software repository address: https://mirror.baidubce.com

CCE Cluster Baidu Cloud Compute

No manual configuration is required. The docker service will be automatically installed when creating a node, and the mirror image will be configured as follows:

1    [root@VM_1_2_centos ~]# cat /etc/systemd/system/docker.service
2    IPTABLES="--iptables=false"
3    STORAGE_DRIVER="--storage-driver=overlay2"
4    IP_MASQ="--ip-masq=false"
5    LOG_LEVEL="--log-level=warn"
6    REGISTRY_MIRROR="--registry-mirror=https://mirror.baidubce.com"

BCC and server configuration

Linux:

1. Applicable to Ubuntu14.04, Debian, CentOS6, Fedora and OpenSUSE. Other versions may have slight differences

Modify the docker configuration file /etc/default/docker as follows:

1     DOCKER_OPTS="--registry-mirror=https://mirror.baidubce.com"

2. For CentOS7: Modify docker configuration file vi /etc/sysconfig/docker by adding the following

   Plain Text Copy

   1OPTIONS='--registry-mirror=https://mirror.baidubce.com'

Note

The DockerHub mirror mechanism is supported only in Docker version 1.3.2 or higher. If Docker is not installed or if the version is outdated, please install Docker or upgrade to a newer version.

Windows

If Boot2Docker is used, the configuration command is: Enter the Boot2Docker Start Shell and execute

1    sudo su echo "EXTRA_ARGS=\"–registry-
2 mirror=http://https://mirror.baidubce.com"">> /var/lib/boot2docker/profile  exit #  RebootBoot2Docker

Start docker

Execute the following commands to start docker

1    sudo service docker start

Build docker image

DockerHub has provided developers with a vast collection of high-quality available images. For details, visit the DockerHub Official Website.

Given the variety of practical scenarios, not all applications can find suitable images for use on DockerHub. You can follow the tutorial below to learn how to build custom Docker images.

Docker currently supports two methods for generating images:

• Automatically build an image using Dockerfile;
• Create and generate an image by running the commit command on an existing container.

Automatically compiled and generated by Dockerfile

Take Dockerhub's official WordPress as an example. Refer to GitHub for details

The relevant Dockerfile source code is as follows:

1        FROM php:5.6-apache
2        
3        # install the PHP extensions we need
4        RUN apt-get update && apt-get install -y libpng12-dev libjpeg-dev && rm -rf /var/lib/apt/lists/* \
5            && docker-php-ext-configure gd --with-png-dir=/usr --with-jpeg-dir=/usr \
6            && docker-php-ext-install gd mysqli opcache
7        
8        # set recommended PHP.ini settings
9        # see https://secure.php.net/manual/en/opcache.installation.php
10        RUN { \
11                echo 'opcache.memory_consumption=128'; \
12                echo 'opcache.interned_strings_buffer=8'; \
13                echo 'opcache.max_accelerated_files=4000'; \
14                echo 'opcache.revalidate_freq=2'; \
15                echo 'opcache.fast_shutdown=1'; \
16                echo 'opcache.enable_cli=1'; \
17            } > /usr/local/etc/php/conf.d/opcache-recommended.ini
18        
19        RUN a2enmod rewrite expires
20        
21        VOLUME /var/www/html
22        
23        ENV WORDPRESS_VERSION 4.6.1
24        ENV WORDPRESS_SHA1 027e065d30a64720624a7404a1820e6c6fff1202
25        
26        RUN set -x \
27            && curl -o wordpress.tar.gz -fSL "https://wordpress.org/wordpress-${WORDPRESS_VERSION}.tar.gz" \
28            && echo "$WORDPRESS_SHA1 *wordpress.tar.gz" | sha1sum -c - \
29        # upstream tarballs include ./wordpress/ so this gives us /usr/src/wordpress
30            && tar -xzf wordpress.tar.gz -C /usr/src/ \
31            && rm wordpress.tar.gz \
32            && chown -R www-data:www-data /usr/src/wordpress
33        
34        COPY docker-entrypoint.sh /usr/local/bin/
35        RUN ln -s usr/local/bin/docker-entrypoint.sh /entrypoint.sh # backwards compat
36        
37        # ENTRYPOINT resets CMD
38        ENTRYPOINT ["docker-entrypoint.sh"]
39        CMD ["apache2-foreground"]

The Dockerfile above explains how to set up the basic environment needed for a WordPress application.

Open a terminal, create a folder to store the Dockerfile, and use the docker build command to create the image.

1    [root@instance-hlf45x1g-1 worldpress]# docker build ./
2    Sending build context to Docker daemon 3.072 kB
3    Step 1 : FROM php:5.6-apache
4    Trying to pull repository docker.io/library/php ...
5    5.6-apache: Pulling from docker.io/library/php
6    386a066cd84a: Pull complete
7    269e95c6053a: Pull complete
8    ......

Use the docker images command to check the created image.

1    [root@instance-hlf45x1g-1 worldpress]# docker images
2    REPOSITORY                                     TAG                 IMAGE ID            CREATED             SIZE
3    worldpress                                     latest              9f0b470b5ddb        13 minutes ago      420 MB
4    docker.io/php                                  5.6-apache          eb8333e24502        7 days ago          389.7 MB

The following recommendations apply when using Dockerfile to build images:

• It is recommended to use official Docker base images as the starting point.
• The initial instructions in the Dockerfile should focus on general and versatile commands for installing and managing dependencies to improve cache efficiency.
• Install only the necessary packages to minimize the image size.
• Use multiple RUN commands linked with '\' to improve readability and simplify maintenance.
• Use the -t tag when building images to make managing the created images easier.
• Clear annotations help improve readability.
• After building, run a local startup to verify functionality.

Execute commit to package and generate the image

The Dockerfile allows for fast image creation, while the commit command helps convert an existing container into an image.

The steps to build an image via commit are as follows:

1. Run and access the container based on the base image.

   Plain Text Copy

   1[root@instance-hlf45x1g-1 ~]# docker run -i -t centos

2. Install the required software and apply configurations.

   Plain Text Copy

   1    [root@c4f1basa4w76 /]# yum update && yum install  openssh-server
   2    Loaded plugins: fastestmirror, ovl
   3    base                                                                                                                                                                    | 3.6 kB  00:00:00     
   4    extras                                                                                                                                                                  | 3.4 kB  00:00:00     
   5    updates                                                                                                                                                                 | 3.4 kB  00:00:00     
   6    (1/4): base/7/x86_64/group_gz                                                                                                                                           | 155 kB  00:00:00     
   7    (2/4): extras/7/x86_64/primary_db                                                                                                                                       | 166 kB  00:00:00     
   8    (3/4): base/7/x86_64/primary_db                                                                                                                                         | 5.3 MB  00:00:00     
   9    (4/4): updates/7/x86_64/primary_db
   10    ......
   11    ......
   12    ......
   13    Dependency Installed:
   14    fipscheck.x86_64 0:1.4.1-5.el7     fipscheck-lib.x86_64 0:1.4.1-5.el7              openssh.x86_64 0:6.6.1p1-25.el7_2  tcp_wrappers-libs.x86_64 0:7.6-77.el7

3. Once configuration is complete, open a new terminal to save the image.

   Plain Text Copy

   1[root@instance-hlf45x1g-1 ~]# docker ps
   2    CONTAINER ID    IMAGE       COMMAND       CREATED          STATUS        PORTS       NAMES
   3    c4f1basa4w76   centos     "/bin/bash"   13 minutes ago   Up 13 minutes            fashion_surl
   4[root@instance-hlf45x1g-1 ~]# docker commit c4f1basa4w76 my_centos:1.0      
   5    sha256:65325ffd2af9d574afca917a8ce81cf8a710e6d1067ee611a87087e1aa88e4a4
   6[root@instance-hlf45x1g-1 ~]# docker images
   7    REPOSITORY      TAG       IMAGE ID            CREATED             SIZE
   8    my_centos       1.0     65325ffd2af9        16 seconds ago      307.8 MB