Unable to connect to docker client

Question

Recently installed Docker on Ubuntu 19.04 disco running on VMWare for testing. On top of it, I am running malice (https://github.com/maliceio/malice). When I scan a sample using command

malice scan [binary] it shows the following error: Unable to connect to docker client

Would appreciate a response

Answer 1

Verify that dockerd is running

Assuming docker in installed (sudo apt install docker.io or like this), you should see a running daemon in the process list:

$ ps axuf | grep docker
root       7694  0.2  0.2 1932540 75504 ?       Ssl  Apr28   4:19 /usr/bin/dockerd -H fd://
root       7721  0.2  0.1 1917924 38596 ?       Ssl  Apr28   3:12  \_ docker-containerd --config /var/run/docker/containerd/containerd.toml --log-level info

If not, try to start/restart the daemon with:

$ sudo systemctl restart docker

$ systemctl show docker | grep State
StateDirectoryMode=0755
LoadState=loaded
ActiveState=active
SubState=running
...

If the daemon fails to start, check the output of journalctl -u docker for error messages.

Add user to group

The user you are working with, must be in the docker group. Check you current group membership with:

$ groups
username adm cdrom sudo dip plugdev lpadmin sambashare docker

If you are not part of the docker group add you current user with:

$ sudo adduser $(whoami) docker

Logout and login again for the changes to take effect.