Solve the Docker x509 insecure registry problem

After installing Docker, I encountered the x509 problem when I tried to pull from the private server Harbor built by the company. The reason for this problem is that Docker will verify the certificate of the website. The private server does not have the corresponding certificate, so Docker refuses to access. However, we can also allow Docker to connect to "unsafe" websites. Here is a solution:

Environment: Ubuntu 16.04, Docker CE 18.09

Modify or create a new configuration file:

sudo vim /etc/default/docker

Enter i to switch to edit mode, enter DOCKER_OPTS="--insecure-registry 127.0.0.1" (replace 127.0.0.1 with the URL you need to allow. If there is a port number, add the port number, such as 127.0.0.1:8080), :wq to save and exit:

DOCKER_OPTS="--insecure-registry 127.0.0.1"

Edit the docker service configuration file:

sudo vim /lib/systemd/system/docker.service

In command mode:/ExecStart, find ExecStart. My default ExecStart looks like this: ExecStart=/usr/bin/dockerd -H unix://

Add EnvironmentFile (note that there is a "-" before the file path name, I recommend copying my configuration directly) and modify ExecStart, save and exit:

EnvironmentFile=-/etc/default/docker
ExecStart=/usr/bin/dockerd -H unix:// $DOCKER_OPTS

Refresh the service configuration and restart Docker:

systemctl daemon-reload
service docker restart

After that, docker pull can be used normally.

Supplement: Docker 1.13.1 version adds --insecure-registry

Divide into three steps (add the content in the red box: the IP needs to be changed)

1. vi /etc/sysconfig/docker

2. vi /usr/lib/systemd/system/docker.service

3. vi /etc/docker/daemon.json

The above is my personal experience. I hope it can give you a reference. I also hope that you will support 123WORDPRESS.COM. If there are any mistakes or incomplete considerations, please feel free to correct me.