注意：如下解决方案，只能解决pull的问题，不能解决push的问题，方案请参考：解决docker push问题

Docker 1.7版本和Docker CE的配置文件的位置是不同的

• Docker 1.7版本 /etc/sysconfig/docker
• Docker CE版本使用 /etc/docker/daemon.json

使用docker 1.7版本如果要pull docker registry v2或者harbor里的镜像，如果没有配置CA证书的话，需要配置insecure-registry，并且需要将这个参数加到docker daemon的启动参数里。配置步骤：

Docker 1.7解决办法

setp 1 配置DOCKER_OPTS参数

[root@123 ] # vi /etc/sysconfig/docker
other_args=
DOCKER_CERT_PATH=/etc/docker

## add 
DOCKER_OPTS="--insecure-registry ip:port"

save之后

setp 2 修改启动项

[root@123 ] # vi /etc/init.d/docker
## 找到 start 函数,在exec处增加 刚配置的DOCKER_OPTS，参见下边空行处
start() {
    if [ ! -x $exec ]; then
      if [ ! -e $exec ]; then
        echo "Docker executable $exec not found"
      else
        echo "You do not have permission to execute the Docker executable $exec"
      fi
      exit 5
    fi

    check_for_cleanup

    if ! [ -f $pidfile ]; then
        prestart
        printf "Starting $prog:\t"
        echo "\n$(date)\n" >> $logfile

        ## add DOCKER_OPTS
        $exec -d $DOCKER_OPTS &>> $logfile &

        pid=$!
        touch $lockfile
        # wait up to 10 seconds for the pidfile to exist.  see
        # https://github.com/docker/docker/issues/5359
        tries=0
        while [ ! -f $pidfile -a $tries -lt 10 ]; do
            sleep 1
            tries=$((tries + 1))
        done
        success
        echo
    else
        failure
        echo
        printf "$pidfile still exists...\n"
        exit 7
    fi
}

setp 3 重启docker

[root@123 ] # service docker restart

setp 4 验证是否可以pull

---

Another way

不这么费事，直接修改启动项，原理和结果都是相同的

[root@123 ] # vi /etc/init.d/docker
## 找到exec，直接添加--insecure-registry ip:port
prog="docker"
exec="/usr/bin/$prog --insecure-registry ip:port"
pidfile="/var/run/$prog.pid"
lockfile="/var/lock/subsys/$prog"
logfile="/var/log/$prog"

然后重启docker daemon

---

Docker CE版本

检查/etc/docker目录下是否有daemon.json文件，如果没有则创建，或者直接vi /etc/docker/daemon.json修改完在:wq也行

[root@123 ] # vi /etc/docker/daemon.json

## add 
{
  "registry-mirrors": ["https://registry.docker-cn.com"],
  "insecure-registries" : ["ip:port","ip:port"]
}

添加完成后重启docker服务service docker restart

Docker 1.13.1 pull 问题

表象就是pull 自己搭建的镜像是提示V1 V2的错误。然后配置了/etc/docker/daemon.json了，也配置了insecure-registries。然后重启systemctl restart docker出现错误了：

[root@localhost docker]# systemctl restart docker
Job for docker.service failed because the control process exited with error code. See "systemctl status docker.service" and "journalctl -xe" for details.

查看journalctl --no-pager

Apr 20 04:59:27 localhost.localdomain systemd[1]: Started Docker Application Container Engine.
Apr 20 05:00:00 localhost.localdomain systemd[1]: Starting Docker Cleanup...
Apr 20 05:00:00 localhost.localdomain systemd[1]: Started Docker Cleanup.
Apr 20 05:00:01 localhost.localdomain systemd[1]: Created slice User Slice of root.
Apr 20 05:00:01 localhost.localdomain systemd[1]: Starting User Slice of root.
Apr 20 05:00:01 localhost.localdomain systemd[1]: Started Session 7 of user root.
Apr 20 05:00:01 localhost.localdomain CROND[30810]: (root) CMD (/usr/lib64/sa/sa1 1 1)
Apr 20 05:00:01 localhost.localdomain systemd[1]: Starting Session 7 of user root.
Apr 20 05:00:01 localhost.localdomain systemd[1]: Removed slice User Slice of root.
Apr 20 05:00:01 localhost.localdomain systemd[1]: Stopping User Slice of root.
Apr 20 05:00:16 localhost.localdomain polkitd[669]: Registered Authentication Agent for unix-process:30986:300800 (system bus name :1.79 [/usr/bin/pkttyagent --notify-fd 5 --fallback], object path /org/freedesktop/PolicyKit1/AuthenticationAgent, locale en_US.UTF-8)
Apr 20 05:00:16 localhost.localdomain systemd[1]: Stopping Docker Application Container Engine...
Apr 20 05:00:16 localhost.localdomain dockerd-current[30297]: time="2018-04-20T05:00:16.148690884+08:00" level=info msg="Processing signal 'terminated'"
Apr 20 05:00:16 localhost.localdomain dockerd-current[30297]: time="2018-04-20T05:00:16.180397672+08:00" level=info msg="stopping containerd after receiving terminated"
Apr 20 05:00:17 localhost.localdomain systemd[1]: Starting Docker Storage Setup...
Apr 20 05:00:17 localhost.localdomain systemd[1]: Started Docker Storage Setup.
Apr 20 05:00:17 localhost.localdomain systemd[1]: Starting Docker Application Container Engine...
Apr 20 05:00:17 localhost.localdomain dockerd-current[31044]: unable to configure the Docker daemon with file /etc/docker/daemon.json: the following directives are specified both as a flag and in the configuration file: insecure-registries: (from flag: [gcr.io], from file: [192.168.1.130:5000])
Apr 20 05:00:17 localhost.localdomain systemd[1]: docker.service: main process exited, code=exited, status=1/FAILURE
Apr 20 05:00:17 localhost.localdomain polkitd[669]: Unregistered Authentication Agent for unix-process:30986:300800 (system bus name :1.79, object path /org/freedesktop/PolicyKit1/AuthenticationAgent, locale en_US.UTF-8) (disconnected from bus)
Apr 20 05:00:17 localhost.localdomain systemd[1]: Failed to start Docker Application Container Engine.
Apr 20 05:00:17 localhost.localdomain systemd[1]: Unit docker.service entered failed state.
Apr 20 05:00:17 localhost.localdomain systemd[1]: docker.service failed.

关键是这一句unable to configure the Docker daemon with file /etc/docker/daemon.json: the following directives are specified both as a flag and in the configuration file: insecure-registries: (from flag: [gcr.io], from file: [192.168.1.130:5000])看来还是配置有问题。于是删除了daemon.json里的insecure-registries配置。重启docker，好使。
然后又查看了docker的版本 docker info，原来是1.13.1版本的。看来还得参考最上边的解决方法

问题又来了，在/etc/init.d/下边，找不到docker，全系统里也没找到docker启动的配置函数，有知道的大侠望不吝赐教。
最终通过修改/etc/sysconfig/docker，有这么一段

# /etc/sysconfig/docker

# Modify these options if you want to change the way the docker daemon runs
OPTIONS='--selinux-enabled=false --log-driver=journald --signature-verification=false --insecure-registry gcr.io'
if [ -z "${DOCKER_CERT_PATH}" ]; then
    DOCKER_CERT_PATH=/etc/docker
fi

既然是 Modify these options if you want to change the way the docker daemon runs，那就在OPTIONS后边加上OPTIONS='--selinux-enabled=false --log-driver=journald --signature-verification=false --insecure-registry gcr.io --insecure-registry ip:port'

在重启docker服务，就好使了