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CentOS8

CentOS 8

CentOS 8 was released in 2019

1.uses dnf instead of yum(dnf has been in fedora for a long time) 2.base os 3.podman compatible with docker

chronyc sources

sudo systemctl status chronyd

ls -lhaF | grep ^l # find out symlink using grep in current directory

sudo ln -nfs /usr/share/zoneinfo/Australia/Sydney localtime # this creates a symlink to current time zone

sudo systemcl restart chronyd # if required

date # check if time zone has changed

Podman red hat’s container product supposed to be compatible with docker

sudo dnf install podman

podman info

podman --version

podman images

podman container list
 
podman pull nginx

podman run -it nginx bash

podman ps -a

Linux CentOS Basics

Ssh-keygen
Ssh-copy-id  root@ipaddress

Once the keys are geneated go to 
~/.ssh folder and go for the pub key this needs to go to remote system

for localsystem just copy id_rsa.pub to authorized_keys in same folder

for remote system
ssh-copy-id ~/.ssh/id_rsa.pub root@ipaddress -p 22



https://puppet.com/blog/how-i-stopped-worrying-learned-love-public-key-authentication-ssh

Centos no ip address

sudo vim /etc/sysconfig/network-scripts/ifcfg-emp0s3

And set the ONBOOT to yes

ONBOOT=yes

Sudo Sestatus Sudo setenforce 0 sudo nano /etc/selinux/config Change SELINUX=enforcing to disabled Sudo reboot

## disable firewall

systemctl stop firewalld systemctl disable firewalld

### VirtualBox NAT port forwarding

You can use the address of the host, e.g. 127.0.0.1 if you are on that machine. You will need to set up port forwarding in VirtualBox, which can be found in the networking settings:

![Image Title](/images/VBoxNetwork.png)

Set up the rule using whatever host port you want (as long as it doesn't conflict with another service on the host), and whatever your guest IP and port values are

![Image Title](/images/PortForwardingVBox.png)


#### RedHat 8 and CentOS 8 have Podman for containers compatible with docker to a certain extent

dnf install podman podman –info podman –version podman –help podman images podman container podman pull nginx

The order for pulling images by default is as below 
Trying to pull registry.access.redhat.com/nginx...
  unsupported: This repo requires terms acceptance and is only available on registry.redhat.io

Trying to pull registry.fedoraproject.org/nginx...
  manifest unknown: manifest unknown

Trying to pull registry.centos.org/nginx...
  manifest unknown: manifest unknown

Trying to pull docker.io/library/nginx...

Getting image source signatures

the pulled nginx image is based on debian

podman run -it nginx bash # interactive bash shell, nginx is image service nginx status service nginx start apt update ```