CentOS 7 Docker 连接 Docker Hub 失败解决方案

[root@localhost ~]# docker search nginx
Error response from daemon: Get "https://index.docker.io/v1/search?q=nginx&n=25": 
dial tcp 157.240.9.36:443: connect: connection refused

# 测试外网连通性 - 正常
[root@localhost ~]# curl -I https://www.baidu.com
HTTP/1.1 200 OK

# 测试 Docker Hub 连接 - 失败
[root@localhost ~]# curl -4 -I https://index.docker.io/v1/
curl: (7) Failed connect to index.docker.io:443; 拒绝连接
# DNS 解析正常
[root@localhost ~]# nslookup index.docker.io
Name:   index.docker.io
Address: 199.59.150.49

# firewalld 状态
[root@localhost ~]# systemctl status firewalld
● firewalld.service - firewalld - dynamic firewall daemon
   Active: active (running) ...
# 查看防火墙规则
[root@localhost ~]# firewall-cmd --list-all
public (active)
  services: dhcpv6-client ssh
  ports: 

cat > /etc/docker/daemon.json << 'EOF'
{
  "registry-mirrors": [
    "https://hub-mirror.c.163.com",
    "https://docker.mirrors.ustc.edu.cn"
  ]
}
EOF
systemctl restart docker

[root@localhost ~]# docker info | grep -A 5 "Registry Mirrors"
 Registry Mirrors:
  https://hub-mirror.c.163.com/
  https://docker.mirrors.ustc.edu.cn/

cat > /etc/docker/daemon.json << 'EOF'
{
  "registry-mirrors": ["https://docker.m.daocloud.io"]
}
EOF
systemctl restart docker

[root@localhost ~]# docker search nginx
NAME                                     DESCRIPTION                                      STARS     OFFICIAL
nginx                                    Official build of Nginx.                         21186     [OK]
nginx/nginx-ingress                      NGINX and  NGINX Plus Ingress Controllers fo…   114       
nginx/nginx-prometheus-exporter          NGINX Prometheus Exporter for NGINX and NGIN…   50        
nginx/unit                               This repository is retired, use the Docker o…   66        
nginx/nginx-ingress-operator             NGINX Ingress Operator for NGINX and NGINX P…   3         
nginx/nginx-quic-qns                     NGINX QUIC interop                               1         
nginx/nginxaas-loadbalancer-kubernetes                                                    1         
nginx/unit-preview                       Unit preview features                            0         
bitnami/nginx                            Bitnami Secure Image for nginx                   202       
bitnamicharts/nginx                      Bitnami Helm chart for NGINX Open Source         3         
ubuntu/nginx                             Nginx, a high-performance reverse proxy & we…   138       
kasmweb/nginx                            An Nginx image based off nginx:alpine and in…   8         
rancher/nginx                                                                             3         
linuxserver/nginx                        An Nginx container, brought to you by LinuxS…   236       
dtagdevsec/nginx                         T-Pot Nginx                                      0  

{
  "registry-mirrors": ["https://docker.m.daocloud.io"]
}

# 拉取镜像
docker pull nginx
# 运行容器
docker run -d -p 80:80 --name my-nginx nginx
# 查看运行状态
docker ps