Docker: Container Support & Proxy

Pigsty has a DOCKER module, which provides a set of playbooks to install and manage Docker on the target nodes.

This document will guide you through how to enable Docker support in Pigsty, and how to configure a proxy server for DockerHub.

Install Docker

To install docker on specified nodes, you can use the docker.yml playbook:

./docker.yml -l <ip|group|cls>

That’s it.

Proxy 101

Assuming you have a working HTTP(s) proxy server, if you wish to connect to docker hub or other registry sites via the proxy server:

You proxy service should provide you with something like

• http://<ip|domain>:<port> | https://[user]:[pass]@<ip|domain>:<port>

For example, if you have a proxy server configuring like this:

export ALL_PROXY=http://192.168.0.104:8118
export HTTP_PROXY=http://192.168.0.104:8118
export HTTPS_PROXY=http://192.168.0.104:8118
export NO_PROXY="localhost,127.0.0.1,10.0.0.0/8,192.168.0.0/16,*.pigsty,*.aliyun.com,mirrors.*,*.myqcloud.com,*.tsinghua.edu.cn"

You can check the proxy server by using the curl command, for example:

curl -x http://192.168.0.104:8118 -I http://www.google.com

How to configure proxy for Docker Daemon?

If you wish to use a proxy server when Docker pulls images, you should specify the proxy_env parameter in the global variables of the pigsty.yml configuration file:

all:
  vars:
    proxy_env:                        # global proxy env when downloading packages
      no_proxy: "localhost,127.0.0.1,10.0.0.0/8,192.168.0.0/16,*.pigsty,*.aliyun.com,mirrors.*,*.myqcloud.com,*.tsinghua.edu.cn"
      http_proxy: http://192.168.0.104:8118
      all_proxy: http://192.168.0.104:8118
      https_proxy: http://192.168.0.104:8118

And when the Docker playbook is executed, these configurations will be rendered as proxy configurations in /etc/docker/daemon.json:

{
  "proxies": {
    "http-proxy": "{{ proxy_env['http_proxy'] }}",
    "https-proxy": "{{ proxy_env['http_proxy'] }}",
    "no-proxy": "{{ proxy_env['no_proxy'] }}"
  }
}

Please note that Docker Daemon does not use the all_proxy parameter

If you wish to manually specify a proxy server, you can directly modify the proxies configuration in /etc/docker/daemon.json;

Or you can modify the service definition in /lib/systemd/system/docker.service (Debian/Ubuntu) and /usr/lib/systemd/system/docker.service to add environment variable declarations in the [Service] section

[Service]
Environment="HTTP_PROXY=http://192.168.0.104:8118"
Environment="HTTPS_PROXY=http://192.168.0.104:8118"
Environment="NO_PROXY=localhost,127.0.0.1,10.0.0.0/8,192.168.0.0/16,*.pigsty,*.aliyun.com,mirrors.*,*.myqcloud.com,*.tsinghua.edu.cn"

And restart dockerd service to take effect:

systemctl restart docker

How to use other registry?

You can specify other registry sites in the docker_registry_mirrors parameter.

It may look like this:

[ "https://mirror.ccs.tencentyun.com" ]         # tencent cloud mirror, intranet only
["https://registry.cn-hangzhou.aliyuncs.com"]   # aliyun cloud mirror, login required

You can also log in to other mirror sites, such as quay.io, by executing:

docker login quay.io
username #> # input your username
password #> # input your password