Docker on Jalen's blog

【Docker】Configure the Alibaba Cloud Registry Mirror on CentOS

Fri, 25 Sep 2020 00:00:00 +0000

As we all know, after installing Docker on CentOS, pulling official Docker images locally can be very slow. In this case, you can configure a registry mirror. Docker and many cloud service providers in China offer registry mirror services, for example:

NetEase: https://hub-mirror.c.163.com/
Alibaba Cloud: https://.mirror.aliyuncs.com
Qiniu Cloud: https://reg-mirror.qiniu.com

Most cloud platforms in China provide image acceleration services. It is recommended that you select the corresponding service provider based on the cloud platform where Docker is hosted.

For example, since my service is deployed on Alibaba Cloud, I will configure the Alibaba Cloud registry mirror here.

Obtain the Alibaba Cloud Registry Mirror URL

The Alibaba Cloud registry mirror service is available at https://cr.console.aliyun.com/cn-hangzhou/instances/mirrors.

After opening the page and logging in, copy the mirror URL from the location shown in the image below:

Configure the Registry Mirror

This applies primarily to users running Docker client version 1.10.0 or later.

You can use the registry mirror by modifying the daemon configuration file at /etc/docker/daemon.json.

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$sudo mkdir -p /etc/docker

$sudo tee /etc/docker/daemon.json <<-'EOF'
{
 "registry-mirrors": ["https://你的ID.mirror.aliyuncs.com"]
}
EOF
//Reload daemon
$sudo systemctl daemon-reload
$sudo systemctl restart docker

【Docker】Error Installing Docker on CentOS 8.0: Problem package docker-ce-3...

Fri, 25 Sep 2020 00:00:00 +0000

What Happened

While installing Docker with yum on CentOS 8.0, an error occurred after running the command, indicating that containerd.io version >= 1.2.2-3 was required.

The command executed was:

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sudo yum install docker-ce docker-ce-cli containerd.io

Detailed error message:

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Last metadata expiration check: 0:01:32 ago on Sat 26 Sep 2020 12:10:38 AM CST.
Error: 
 Problem: package docker-ce-3:19.03.13-3.el7.x86_64 requires containerd.io >= 1.2.2-3, but none of the providers can be installed
 - cannot install the best candidate for the job
 - package containerd.io-1.2.10-3.2.el7.x86_64 is filtered out by modular filtering
 - package containerd.io-1.2.13-3.1.el7.x86_64 is filtered out by modular filtering
 - package containerd.io-1.2.13-3.2.el7.x86_64 is filtered out by modular filtering
 - package containerd.io-1.2.2-3.3.el7.x86_64 is filtered out by modular filtering
 - package containerd.io-1.2.2-3.el7.x86_64 is filtered out by modular filtering
 - package containerd.io-1.2.4-3.1.el7.x86_64 is filtered out by modular filtering
 - package containerd.io-1.2.5-3.1.el7.x86_64 is filtered out by modular filtering
 - package containerd.io-1.2.6-3.3.el7.x86_64 is filtered out by modular filtering
 - package containerd.io-1.3.7-3.1.el7.x86_64 is filtered out by modular filtering
(try to add '--skip-broken' to skip uninstallable packages or '--nobest' to use not only best candidate packages)

Solutions

Install an older version of Docker
Manually install a newer version of containerd.io

For the first method, this article provides a detailed explanation. Here, we will focus on the second method.

Download the RPM package for containerd.io and install the new version of containerd.io

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## If your system isn't installed, install it first.
$sudo yum install -y wget

## Centos 7 executes the following orders.
$wget https://download.docker.com/linux/centos/7/x86_64/edge/Packages/containerd.io-1.3.7-3.1.el7.x86_64.rpm

## Cantos 8 carries out the following orders.
$wget https://download.docker.com/linux/centos/8/x86_64/edge/Packages/containerd.io-1.3.7-3.1.el8.x86_64.rpm

## After implementation, there will be a containerd.io-1.3.7-XXX.rpm file under the current directory
## Install with this rpm
$sudo yum install -y containerd.io-1.3.7-3.1.el8.x86_64.rpm

## Docker will be installed after installation
$sudo yum install docker-ce docker-ce-cli containerd.io

Verify That Docker Was Installed Successfully

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#Start Docker

$systemctl start docker

#Check the docker version
$docker -v

【Docker】Fixing the Repository Not Found Error When Installing Docker with yum on CentOS 8.0

Fri, 25 Sep 2020 00:00:00 +0000

When installing Docker on an Alibaba Cloud server running CentOS 8, a repository not found error occurred, as shown below:

Solution

Approach: Install Docker using the Docker repository.

Set Up the Repository

Install the required packages. Here, yum-utils is installed; yum-utils provides yum-config-manager, while the device mapper storage driver requires device-mapper-persistent-data and lvm2.

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sudo yum install -y yum-utils \
 device-mapper-persistent-data \
 lvm2

Configure the Alibaba Cloud Mirror in China

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sudo yum-config-manager \
 --add-repo \
 http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

Install docker-ce

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sudo yum install docker-ce docker-ce-cli containerd.io

P.S. If the installation fails, click here.