Still no luck, just documenting my trials and unsuccessful attempts:
After reading Permission denied - #2 by myshevchuk (Answer to Eneas thread) I thought I might have a conflicting docker / kernel issue as well:
I checked my installed docker (on Ubuntu), it was docker-engine:
apt list --installed | grep docker
docker --version
Docker version 17.05.0-ce, build 89658be)
Then I instaled docker.io instead (see [1] for differences)
apt purge docker-engine; apt install docker.io
docker --version
Docker version 1.12.6, build 78d1802
However, the error remains exactly the same:
[details=docker -l debug logs -f DOCKER_ID]> Generating RSA private key, 2048 bit long modulus
…+++
…+++
e is 65537 (0x10001)
Signature ok
subject=/C=DE/ST=BW/L=Stuttgart/O=Dummy Authority/CN=localhost
Getting CA Private Key
loolforkit version details: 2.1.0 - b2e736a3
wsd-00024-00024 06:54:08.272296 [ loolwsd ] FTL Failed to fork child processes.| wsd/LOOLWSD.cpp:2405
Failed to fork child processes.
wsd-00024-00024 06:54:08.274339 [ loolwsd ] FTL Failed to fork child processes.| wsd/LOOLWSD.cpp:2551
Failed to fork child processes.
wsd-00024-00024 06:54:08.278844 [ loolwsd ] WRN Waking up dead poll thread [admin], started: false, finished: false| ./net/Socket.hpp:445
wsd-00024-00024 06:54:08.279161 [ loolwsd ] WRN Waking up dead poll thread [admin], started: false, finished: false| ./net/Socket.hpp:445
-00024 06:54:08.283357 [ loolwsd ] WRN Waking up dead poll thread [accept_poll], started: false, finished: false| ./net/Socket.hpp:445
-00024 06:54:08.283444 [ loolwsd ] WRN Waking up dead poll thread [accept_poll], started: false, finished: false| ./net/Socket.hpp:445
-00024 06:54:08.283526 [ loolwsd ] WRN Waking up dead poll thread [websrv_poll], started: false, finished: false| ./net/Socket.hpp:445
-00024 06:54:08.283566 [ loolwsd ] WRN Waking up dead poll thread [websrv_poll], started: false, finished: false| ./net/Socket.hpp:445
-00024 06:54:08.283630 [ loolwsd ] WRN Waking up dead poll thread [accept_poll], started: false, finished: false| ./net/Socket.hpp:445
-00024 06:54:08.283705 [ loolwsd ] WRN Waking up dead poll thread [accept_poll], started: false, finished: false| ./net/Socket.hpp:445
-00024 06:54:08.284083 [ loolwsd ] WRN Waking up dead poll thread [websrv_poll], started: false, finished: false| ./net/Socket.hpp:445
-00024 06:54:08.284149 [ loolwsd ] WRN Waking up dead poll thread [websrv_poll], started: false, finished: false| ./net/Socket.hpp:445
frk-00026-00026 06:54:08.289767 [ forkit ] FTL Pipe closed.| common/IoUtil.cpp:309[/details]
So I’m still not able to run collabora/code docker, unfortunately.
[1] https://www.quora.com/What-is-the-difference-between-docker-engine-and-docker-io-packages