Docker plugin discovery does not work


on my Ubuntu 18.04 I installed Moby using apt.
I know how to create an own docker plugin using the go-helper and I can ‘docker plugin install’ a self-made log plugin with its own rootfs.
Intention of all this is to forward the stdout of all containers to an already existing log-system, that is non-standard.
Due to several reasons, I need to make the plugin an external plugin. Such, that it is started externally and discovered by Docker by one of the three methods described here:

(I am aware, that they do not state log-plugins there explicitly)

I created a plugin using the ServeUnix function call, which after starting creates a .sock in /run/docker/plugins
I also created a plugin using the ServeTCP function call, which creates a .spec file containing the target IP address in /var/lib/docker/

When starting a container using this command
docker run --log-driver=logdrivertcp hello-world
it says
docker: Error response from daemon: logger: no log driver named ‘logdrivertcp’ is registered.

Should this be working with Moby?

dev@dev-VirtualBox:/src/co/moby$ docker version
Version: 3.0.10+azure
API version: 1.40
Go version: go1.12.14
Git commit: 99c5edceb48d64c1aa5d09b8c9c499d431d98bb9
Built: Tue Nov 5 00:55:15 2019
OS/Arch: linux/amd64
Experimental: false

Version: 3.0.10+azure
API version: 1.40 (minimum version 1.12)
Go version: go1.12.14
Git commit: ea84732a77
Built: Fri Jan 24 20:08:11 2020
OS/Arch: linux/amd64
Experimental: false
Version: v1.2.11
GitCommit: f772c10a585ced6be8f86e8c58c2b998412dd963
Version: 1.0.0-rc10
GitCommit: dc9208a3303feef5b3839f4323d9beb36df0a9dd
Version: 0.18.0
GitCommit: fec3683

dev@dev-VirtualBox:/src/co/moby$ uname -a
Linux dev-VirtualBox 5.3.0-40-generic #32~18.04.1-Ubuntu SMP Mon Feb 3 14:05:59 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

Log drivers plugins are a joy supporter for managed plugins, not external ones.

Hey. Okay sad, but thanks.
Are there any means to export a managed plugin and import it somewhere else?
Preferably but just copying a folder?

Wow autocorrect really messed me up on the last message…

Managed plugins are special container images. You can create one from a tarball, and push/pull to/from a registry.

I got it anyhow :slight_smile:

Yes I know but unfortunately our repo does not support plugins, it seems.
I should create it such as I would tag a container, like
and push it, right?
This does not work in our private repo.

How can I tar one and restore it?
With docker save it did not work for me, as there is no “normal” image.

Apart from that, can I just copy a folder to the other device?

@cpuguy83 do you have any idea?