What is a Docker Hub Docker Hub is the central place used for keeping the Docker images either in a public or private repository. Docker Hub provides features, such as a repository for Docker images, user authentications, automated image builds, integration with GitHub or Bitbucket, and managing organizations and groups. The Docker Registry component of […]
DevOps
How To Get Information About a Container In Docker
Here is a short note on how to pull information of the container running on the host. This is similar to the “xm list –long [domain_ID]” command in xen. Getting information from outside of the Docker Container 1. Below are the list of images that are residing on the host node. # docker images REPOSITORY […]
How to install docker on CentOS / RHEL / Fedora
What is docker Docker is a container-management system that helps us easily manage Linux Containers (LXC) in an easier and universal fashion. Docker is supported on many Linux platforms, such as RHEL, Ubuntu, Fedora, CentOS, Debian, Arch Linux, and so on. It is also supported on many cloud platforms, such as Amazon EC2, Rackspace Cloud, […]
How to use variables in shell scripts
A variable is simply a placeholder for some value. The value can change; however, the variable name will always be the same. Shell variables are capitalized by convention. The shell maintains two lists of variables: 1. Those local to the current shell 2. Those global to all shells (environment variables). Use the set and env […]
How to debug shell scripts
When a script does not work properly, we need to determine the location of the problem. The UNIX/Linux shells provide a debugging mode. Run the entire script in debug mode or just a portion of the script. To run an entire script in debug mode, add -x after the #!/bin/[shell] on the first line: For […]
How to configure docker to use proxy
A proxy is required when the server running Docker does not have direct access to the Internet. Configure the Docker daemon to use a proxy server to access images stored on the official Docker Hub Registry or 3rd-party registries. There are 2 ways to configure the proxy for docker : Configuring proxy variables in the […]