[docker] Add Insecure Registry to Docker

I have a docker 1.12 running on CentOS. I am trying to add insecure registry to it and things mentioned in documentation just don't work. The system uses systemd so I created a /etc/systemd/system/docker.service.d/50-insecure-registry.conf file.

$ cat /etc/systemd/system/docker.service.d/50-insecure-registry.conf
[Service]
Environment='DOCKER_OPTS=--insecure-registry="hostname.cloudapp.net:5000"'

After loading daemon and restarting docker service, systemd shows that the environment variable is there

$ sudo systemctl show docker | grep Env
Environment=DOCKER_OPTS=--insecure-registry="hostname.cloudapp.net:5000"

But when I run docker info I don't see that insecure registry added

$ docker info
........
Registry: https://index.docker.io/v1/
WARNING: bridge-nf-call-iptables is disabled
WARNING: bridge-nf-call-ip6tables is disabled
Insecure Registries:
    127.0.0.0/8

Pushing images to hostaneme.cloudapp.net fails with

Pushing application     (hostname.cloudapp.net:5000/application:latest)...
The push refers to a repository     [hostname.cloudapp.net:5000/mozart_application]
ERROR: Get https://hostname.cloudapp.net:5000/v1/_ping: http: server gave HTTP response to HTTPS client

Is there something that could be done ? Am I missing something ?

UPDATE

Resolved the issue by adding a file /etc/docker/daemon.json with following content

{
    "insecure-registries" : [ "hostname.cloudapp.net:5000" ]
}

And then restart docker

sudo systemctl daemon-reload
sudo systemctl restart docker

After that insecure registry hostname.cloudapp.net:500 works.

If you already have a config.json file then the final file should look something like this... Here registry.myprivate.com is the one which was giving me problems.

{ "auths": { "https://index.docker.io/v1/": { "auth": "xxxxxxxxxxxxxxxxxxxx==" }, "registry.myprivate.com": { "auth": "xxxxxxxxxxxxxxxxxxxx=" } }, "HttpHeaders": { "User-Agent": "Docker-Client/19.03.8 (linux)" }, "insecure-registries" : ["registry.myprivate.com"] }

The solution with the /etc/docker/daemon.json file didn't work for me on Ubuntu.

I was able to configure Docker insecure registries on Ubuntu by providing command line options to the Docker daemon in /etc/default/docker file, e.g.:

# /etc/default/docker    
DOCKER_OPTS="--insecure-registry=a.example.com --insecure-registry=b.example.com"

The same way can be used to configure custom directory for docker images and volumes storage, default DNS servers, etc..

Now, after the Docker daemon has restarted (after executing sudo service docker restart), running docker info will show:

Insecure Registries:
  a.example.com
  b.example.com
  127.0.0.0/8

Create /etc/docker/daemon.json file where you want to pull docker images and add the following content to that file

{
    "insecure-registries" : [ "hostname.cloudapp.net:5000" ]
}

Refer to my blog article for an in-depth explanation of creating a private docker registry: https://geekdosage.com/how-to-create-a-private-docker-registry-in-ubuntu-20-04/

I happened to encounter a similar kind of issue after setting up local internal JFrog Docker Private Registry on Amazon Linux.

THE followings I did to solve the issue:

Added "--insecure-registry xx.xx.xx.xx:8081" by modifying the OPTIONS variable in the /etc/sysconfig/docker file:

OPTIONS="--default-ulimit nofile=1024:40961 --insecure-registry hostname:8081"

Then restarted the docker.

I was then able to login to the local docker registry using:

docker login -u admin -p password hostname:8081

For me the solution was to add the registry to here:

/etc/sysconfig/docker-registries

DOCKER_REGISTRIES=''
DOCKER_EXTRA_REGISTRIES='--insecure-registry  b.example.com'

Anyone looking to add insecure registry on amazon linux 2: You will have to change the setting under /etc/sysconfig/docker and then restart docker daemon: here's how my /etc/sysconfig/docker looks like

# The max number of open files for the daemon itself, and all
# running containers.  The default value of 1048576 mirrors the value
# used by the systemd service unit.
DAEMON_MAXFILES=1048576

# Additional startup options for the Docker daemon, for example:
# OPTIONS="--ip-forward=true --iptables=true"
# By default we limit the number of open files per container
OPTIONS="--default-ulimit nofile=1024:4096 --insecure-registry yourinsecureregistryhostname:port"

# How many seconds the sysvinit script waits for the pidfile to appear
# when starting the daemon.
DAEMON_PIDFILE_TIMEOUT=10

Creating /etc/docker/daemon.json file and adding the below content and then doing a docker restart on CentOS 7 resolved the issue.

{
    "insecure-registries" : [ "hostname.cloudapp.net:5000" ]
}

(Copying answer from question)

To add an insecure docker registry, add the file /etc/docker/daemon.json with the following content:

{
    "insecure-registries" : [ "hostname.cloudapp.net:5000" ]
}

and then restart docker.