一.Docker常见端口
常见docker端口包括：
2375：未加密的docker socket,远程root无密码访问主机
2376：tls加密套接字,很可能这是您的CI服务器4243端口作为https 443端口的修改
2377：群集模式套接字,适用于群集管理器,不适用于docker客户端
5000：docker注册服务
4789和7946：覆盖网络
二.IDEA远程访问Docker
因为IDEA集成Docker环境，实质上是通过远程访问的形式，进行连接，因此需要开启Docker的2375端口的远程访问权限。
1.编辑docker.service文件：
# 编辑docker.service文件
vim /usr/lib/systemd/system/docker.service
# 将ExecStart新增参数
# 编辑前
ExecStart=/usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock
# 编辑后
# tcp://0.0.0.0:2375 -> 表示允许任何远程客户端通过 2375 端口连接 Docker Daemon。
# unix://var/run/docker.sock -> 表示允许任何远程客户端通过 2375 端口连接 Docker Daemon。
ExecStart=/usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock -H tcp://0.0.0.0:2375 -H unix://var/run/docker.sock
2.修改配置以后
# 重新读取配置文件
systemctl daemon-reload
# 重启docker服务
systemctl restart docker
3.查看docker进程：
ps -ef|grep docker
# 执行结果：Docker守护进程打开一个HTTP Socket,这样才能实现远程通信
root 44221 1 1 18:16 ? 00:00:06 /usr/bin/dockerd -H tcp://0.0.0.0:2375 -H unix://var/run/docker.sock
三.完整的Docker.service文件
[Unit]
Description=Docker Application Container Engine
Documentation=https://docs.docker.com
After=network-online.target docker.socket firewalld.service containerd.service time-set.target
Wants=network-online.target containerd.service
Requires=docker.socket
[Service]
Type=notify
# the default is not to use systemd for cgroups because the delegate issues still
# exists and systemd currently does not support the cgroup feature set required
# for containers run by docker
ExecStart=/usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock
ExecReload=/bin/kill -s HUP $MAINPID
TimeoutStartSec=0
RestartSec=2
Restart=always
# Note that StartLimit* options were moved from "Service" to "Unit" in systemd 229.
# Both the old, and new location are accepted by systemd 229 and up, so using the old location
# to make them work for either version of systemd.
StartLimitBurst=3
# Note that StartLimitInterval was renamed to StartLimitIntervalSec in systemd 230.
# Both the old, and new name are accepted by systemd 230 and up, so using the old name to make
# this option work for either version of systemd.
StartLimitInterval=60s
# Having non-zero Limit*s causes performance problems due to accounting overhead
# in the kernel. We recommend using cgroups to do container-local accounting.
LimitNPROC=infinity
LimitCORE=infinity
# Older systemd versions default to a LimitNOFILE of 1024:1024, which is insufficient for many
# applications including dockerd itself and will be inherited. Raise the hard limit, while
# preserving the soft limit for select(2).
LimitNOFILE=1024:524288
# Comment TasksMax if your systemd version does not support it.
# Only systemd 226 and above support this option.
TasksMax=infinity
# set delegate yes so that systemd does not reset the cgroups of docker containers
Delegate=yes
# kill only the docker process, not all processes in the cgroup
KillMode=process
OOMScoreAdjust=-500
[Install]
WantedBy=multi-user.target
