Working around Docker’s download limit on RedHat OpenShift

Taken from “How to work around Docker’s new download rate limit on Red Hat OpenShift” from RedHat Developer.

Docker recently changed its policy for downloading images as an anonymous user. The company now has a limit of 100 downloads every six hours from a single IP address.

If you are using the OpenShift Developer Sandbox to experiment with a free OpenShift cluster, you might encounter the error message shown in Figure 1.

All you have to do to avoid Docker’s new rate-limit error is authenticate to your Docker Hub account. After you’ve authenticated to the account, you won’t be pulling the image as an anonymous user but as an authenticated user. The image download will count against your personal limit of 200 downloads per six hours instead of the 100 downloads shared across all anonymous cluster users.

For the complete article, do take a look at “How to work around Docker’s new download rate limit on Red Hat OpenShift” from RedHat Developer.

Implementing Docker Group using Centrify

Why Privilege Access For Docker Container?

Taken from Centrify HOWTO: Secure container/docker environments by managing privileges for admins and users

“To perform any docker operation, you need to either be root or part of a local group, ‘docker’, on your Linux machine. Why is that? Because access into a docker container is via a UNIX socket and any socket related operations require the user to have privileged access. ‘Docker’ group membership is sufficient for all container operations, exception is starting the docker daemon itself, which must always run as the root user.”

Step 1:

We need to create a group called Docker and put in the necessary members

Step 2: Verify the permission of the Linux Server

# ls -lZ /var/run/docker.sock
srw-rw----. root root system_u:object_r:container_var_run_t:s0 /var/run/docker.sock
# getenforce

Step 3: Change Owner of the Docker

# chown root:docker /var/run/docker.sock

Step 4: Test the change permission issues

[user1@node1 ~]$ docker search openfoam
INDEX NAME DESCRIPTION STARS OFFICIAL AUTOMATED Offical image of OpenFOAM+ (v3.0+) provide... 8 Offical image of OpenFOAM+ (v1606+) provid... 6 Image of OpenFOAM v5 and ParaView 5.4.0 on... 5 Image of OpenFOAM v6 and ParaView 5.6.0 on... 5 Offical image of OpenFOAM+ (v1612+) provid... 5 Image of OpenFOAM v7 and ParaView 5.6.0 on... 4 Offical image of OpenFOAM(v1706) provided ... 4 Offical docker image of OpenFOAM(v1712) pr... 4 Image of OpenFOAM v6 and ParaView 5.4.0 on... 3 Offical docker image of OpenFOAM(v1806) pr... 3 Offical docker image of OpenFOAM(v1806) pr... 2 Official docker image of OpenFOAM(v1906 ve... 2 OpenFOAM image for use in DICE (Dynamic In... 1 OpenFOAM-dev on Ubuntu 16.04 using the ope... 1 OpenFOAM-dev and ParaView 5.4.0 on Ubuntu ... 1 Image of OpenFOAM-dev and ParaView 5.6.0 o... 1 Image of OpenFOAM v4 and ParaView 5.0.1 on... 1 Image of OpenFOAM v5 on Ubuntu 16.04 from ... 1 Image of OpenFOAM v6 on Ubuntu 18.04 from ... 1 Docker Image for OpenFOAM and Calculix 1 [OK] This image makes it easy to run OpenFOAM o... 0 [OK] OpenFOAM-dev and ParaView 5.0.1 on Ubuntu ... 0 OpenFOAM 0 OpenFOAM240 with Python Paraview 0 OpenFOAM Base Container 0


  1. HOWTO: Secure container/docker environments by managing privileges for admins and users
  2. How to fix docker: Got permission denied while trying to connect to the Docker daemon socket

Installing Docker on CentOS 7


Point 1: Install the Dependencies

# yum install yum-utils device-mapper-persistent-data lvm2
  • yum-utils ->Include yum-config-manager
  • device-mapper-persistent-data and lvm2 -> Device Mapper Storage Drivers

Point 2: Add Docker Repository to CentOS

# yum-config-manager --add-repo

Point 3: Install Docker on CentOS

# yum install docker

Point 4: Manage Docker Service (Start, Enable and Check Status)

# systemctl start docker
# systemctl enable docker
# systemctl status docker 0

Point 5: Installing specific version of docker

# yum list docker-ce --showduplicates
docker-ce.x86_64 17.03.0.ce-1.el7.centos docker-ce-stable
docker-ce.x86_64 17.03.1.ce-1.el7.centos docker-ce-stable
docker-ce.x86_64 17.03.2.ce-1.el7.centos docker-ce-stable
docker-ce.x86_64 18.06.0.ce-3.el7 docker-ce-stable
docker-ce.x86_64 18.06.1.ce-3.el7 docker-ce-stable
docker-ce.x86_64 18.06.2.ce-3.el7 docker-ce-stable
docker-ce.x86_64 18.06.3.ce-3.el7 docker-ce-stable

Point 5b:

# yum install docker-ce-18.06.3.ce


  1. How to Install Docker on CentOS 7