Enable TCP port 2375 for external connection to Docker

docker-api-port.md

Enable TCP port 2375 for external connection to Docker

See this issue.
Docker best practise to Control and configure Docker with systemd.

1. Create daemon.json file in /etc/docker:

    {"hosts": ["tcp://0.0.0.0:2375", "unix:///var/run/docker.sock"]}
   

2. Add /etc/systemd/system/docker.service.d/override.conf

    [Service]
    ExecStart=
    ExecStart=/usr/bin/dockerd
   

3. Reload the systemd daemon:

    systemctl daemon-reload
   

4. Restart docker:

    systemctl restart docker.service
   

For everyone finding this page and looking for instructions for Synology's new Container Manager,

1. sudo vi /var/packages/ContainerManager/etc/dockerd.json

change to: {"data-root":"/var/packages/ContainerManager/var/docker","log-driver":"db","registry-mirrors":[],"storage-driver":"aufs","hosts": ["tcp://0.0.0.0:2375", "unix:///var/run/docker.sock"]}
(basically add the stuff from the original step 1 to the end, without the curly-brackets {} )

2. systemctl daemon-reload
3. sudo systemctl restart pkg-ContainerManager-dockerd

You may need to repeat these steps when the Container Manager package gets updated. So far it's working for me

Hi,bro. I'm trying to add the proxy option for the dockerd.json,there is some problem for me. I had read the docs of how to set the value of daemon-proxy,but the error still exsit.

  "proxies": {
    "http-proxy": "http://proxy.example.com:80",
    "https-proxy": "https://proxy.example.com:443",
    "no-proxy": "*.test.example.com,.example.org",
  }

unable to configure the Docker daemon with file /var/packages/ContainerManager/etc/dockerd.json: the following directives don't match any configuration option: http-proxy, https-proxy, no-proxy

{"data-root":"/var/packages/ContainerManager/var/docker","log-driver":"db","proxies":{"http-proxy":"http://127.0.0.1:7890","https-proxy":"http://127.0.0.1:7890","no-proxy":"localhost,127.0.0.1"},"registry-mirrors":[],"storage-driver":"aufs"} can you give me some help? appreciate it.

requre docked 23.0 or later,the synology is 20.10.3

Here's another way that worked for me:

/etc/systemd/system/docker.service.d/override.conf

[Service]
 ExecStart=
 ExecStart=/usr/bin/dockerd --config-file /etc/docker/daemon.json

/etc/docker/daemon.json

{
  "hosts": ["tcp://0.0.0.0:2375", "unix:///var/run/docker.sock"]
}

is worked thank you so much

Exposing the docker daemon on 0.0.0.0 especially on something which faces the internet is a TERRIBLE idea!

It's literally like giving everyone sudo access...

Bind to 127.0.0.1 and portforward.

You don't even have to, the docker client can speak ssh) via: DOCKER_HOST=“ssh://user@remotehost

i had to do the following:

$ cat /etc/systemd/system/docker.service.d/override.conf
[Service]
 ExecStart=
 ExecStart=/usr/sbin/dockerd --config-file /etc/docker/daemon.overrided.json

$ cat /etc/docker/daemon.overrided.json
{
  "hosts": ["tcp://0.0.0.0:2375", "unix:///var/run/docker.sock"]
}

The binary is in /usr/sbin/dockerd, and changing the daemon.json conflicted with the default parameter -H fd://