Docker configuration using the systemd configuration style

Expanded on my comment for readability

Problem

Couldn't connect to a remote insecure repository. Unable to add "insecure_repository" to docker options on startup.

Using docker installed via package manager on Ubuntu 16.04 LTS

Solution

1. Verify docker under is control of systemd

$systemctl status docker should return details for running docker service. You can view the default setup it's using under Loaded:

2. Add insecure repository systemd conf file

This file will load the DOCKER_OPTS env variable.

Create file at /etc/systemd/system/docker.service.d/insecure_repository.conf

Add file contents:

[Service]Environment='DOCKER_OPTS=--insecure-registry="myregistryserver.mydomain.com:5000"'

3. Add docker systemd workaround conf file

This file will modify the ExecStart to use the DOCKER_OPTS environment variable.

Create file at /etc/systemd/system/docker.service.d/docker-systemd-workaround.conf

Add file contents:

[Service]ExecStart=ExecStart=/usr/bin/dockerd -H fd:// $DOCKER_OPTS

4. Reload

$sudo systemctl daemon-reload

$sudo service docker restart

5. Verify

$docker info should contain myregistryserver.mydomain.com:5000 under Insecure Registries:

$systemctl status docker should have your systemd configs (aka drop-ins) under the Drop-In: header. You should also see your modified ExecStart under the CGroup: header.

I had a similar problem and struggled for ages until I found this blog.

Basically follow these steps :

sudo vi /etc/systemd/system/docker.service.d/docker.conf andadd the following :

[Service] #You need the below or you 'ExecStart=' or you will get and error 'Service has more than one ExecStart= setting, which is only allowed'ExecStart= ExecStart=/usr/bin/docker daemon -H fd://ExecStart=/usr/bin/docker daemon -H fd:// --insecure-registry youregistry.mydomain.com:5000

Then finally :

• sudo systemctl daemon-reload
• sudo systemctl restart docker