2024-03-14
Openshift
Redhat OpenShift is a platform that allows us to manage,deploy and orchestrate containerized applications in the cloud.Red hat openshift solves the biggest problem of developing and deploying microservice based applications.
oc command lets you work with the entire OpenShift cluster and deploy new applications.The CLI exposes the underlying Kubernetes orchestration system with the enhancements made by OpenShift. Users familiar with Kubernetes will be able to adapt to OpenShift quickly.
oc login -u admin -p admin https://api.crc.testing:6443 --insecure-skip-tls-verify=true
the command to login into openshift for the user (-u option) admin with password (-poption above) admin
oc whoami : displays the logged in openshift user.
Containers
Getting started with containers
Like a normal linux program,containers have two states - rest and running. When the container is at rest, a container is a like a file that is stored on the disk like other files.This is referred to as Container Image or Container Repository. When the container is started, the Container Engine unpacks the required files and meta-data, then hands them to the linux kernel.The next process is to start the container just like another linux process making an API call to the linux kernel. This API call makes an isolation and mounts a copy of the files stored in the container image.
- Registry Server
A container registry server is a tool which hosts and distributes container images. The container registry server can either be public or private.These container registries connect directly to container orchestration platforms like Docker and Kubernetes.
- Container Image
A container image, which is a file, pulled from the registry server and used locally as a mount point when the containers are started