CentOS7.9. Install Docker offline

Install Docker offline on CentOS 7

Download the Docker installation package for CentOS 7:

 https://download.docker.com/linux/static/stable/x86_64/

Upload the downloaded docker-24.0.4.tgzfile to the CentOS 7 system. For example, it can be uploaded to /rootthe directory.
Unzip docker-24.0.4.tgzthe file:
```
tar -xf docker-24.0.4.tgz
```
Copy all the extracted Docker files to /usr/bin/the directory:
```
cp docker/* /usr/bin/
```
Register Docker as a service, enter /etc/systemd/system/the directory, and create docker.servicea file:
```
vi /etc/systemd/system/docker.service
```

Copy the following content into docker.servicethe file. Replace 192.168.3.10with the IP address of your own server:

[Unit]
Description=Docker Application Container Engine
Documentation=https://docs.docker.com
After=network-online.target firewalld.service
Wants=network-online.target

[Service]
Type=notify
ExecStart=/usr/bin/dockerd --selinux-enabled=false --insecure-registry=192.168.3.10
ExecReload=/bin/kill -s HUP $MAINPID
LimitNOFILE=infinity
LimitNPROC=infinity
LimitCORE=infinity
Delegate=yes
KillMode=process
Restart=on-failure
StartLimitBurst=3
StartLimitInterval=60s

[Install]
WantedBy=multi-user.target

Give docker.servicethe file execution permission:

chmod 644 /etc/systemd/system/docker.service

Reload the systemd daemon to apply the changes:
```
systemctl daemon-reload
```
Start Docker and set it to start automatically at boot:
```
systemctl start docker
systemctl enable docker
```
Test Docker to make sure it's working.

Uninstall Docker on CentOS 7

Cancel Docker's boot self-start:
```
systemctl disable docker
```

Delete the Docker service file:

rm -rf /etc/systemd/system/docker.service

Remove Docker related binaries:

rm -rf /usr/bin/containerd
rm -rf /usr/bin/containerd-shim
rm -rf /usr/bin/ctr
rm -rf /usr/bin/runc
rm -rf /usr/bin/docker*

Delete the Docker configuration file:
```
rm -rf /etc/docker/
```
If images or containers exist, delete them:
```
rm -rf /var/lib/docker
```

Extension: import image and run

If you want to run the image on a machine without an external network connection, take PaddleOCR as an example:

On a machine connected to the Internet, download the PaddleOCR Docker image and its dependencies (version 1.6.server):

docker pull registry.cn-hongkong.aliyuncs.com/llapi/ppocr:1.6.server

Save the Docker image and its dependencies as a tar file:

docker save -o ppocr_1.6.server.tar registry.cn-hongkong.aliyuncs.com/llapi/ppocr:1.6.server

Copy the Docker image file "ppocr_1.6.server.tar" to the target machine without external network connection.
Install Docker on the target machine.
Load the Docker image with the following command:

docker load -i ppocr_1.6.server.tar

Run the PaddleOCR container:

docker run -itd --name ppocr -p 9000:9000 registry.cn-hongkong.aliyuncs.com/llapi/ppocr:1.6.server /bin/bash -c "sh /PaddleOCR/start.sh"

The PaddleOCR container version 1.6.server should now be running on the target machine with no external internet connection, and you can access it on port 9000. This concludes the tutorial