Month: March 2019

How to enable EPEL Repository on RHEL7/CentOS7

In this post, we are going to see How to enable EPEL Repository on RHEL7/CentOS7

How to enable EPEL Repository on RHEL7/CentOS7

Need to install EPEL rpm by using below command:

[root@localhost ~]# rpm -Uvh https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm

Out will be like below

Retrieving https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
warning: /var/tmp/rpm-tmp.CmU1nG: Header V3 RSA/SHA256 Signature, key ID 352c64e5: NOKEY
Preparing... ################################# [100%]
Updating / installing...
 1:epel-release-7-11 ################################# [100%]
[root@localhost ~]#

Now we installed the Repo and need to check by listing the installed repo using below command:

[root@localhost ~]# yum repolist

List the available packages from EPEL Repository using below command:

[root@localhost ~]# yum --disablerepo=* --enablerepo=epel list

Now we Enabled EPEL Repository successfully on our server and we can use yum to install the packages.

 

Thanks for the reading this post.

Reference: ITZgeek

Architecture of Ansible

we are going to see the Architecture of Ansible in this post.

Communication:

Architecture of Ansible

Communication established between control node(Server) and Managed hosts(Client machines) using SSH Protocol.

A normal user will be sufficient for communication between Control and Managed hosts.

A normal user can able to perform a few tasks but for other tasks, we need administrators user or other users who have sudo access to perfom that tasks.

complete Architecture detail of Ansible:

Architecture of Ansible

 

This will explain how the ansible working and what are all the things contains as architecture.

As we can see the above diagram ansible automation engine will interact directly with the person who writes playbooks to do tasks.

It also interacts with the cloud(public/private) directly. Basically its CMDB(Configuration Management Data Base).

Also, it contains the below components:

  1. Inventory
  2. Modules
  3. API
  4. Plugins

 

Inventory:

Inventory will contain the List of Host or IP Address of Host/ Wildcards where we are going to do automation tasks using ansible.

default ansible inventory path: /etc/ansible/hosts

We can specify the different inventory path using -i option.

Modules:

Ansible has more 1000 readymade playbooks in it and we should use those modules in paybooks to do automation tasks. Modules will be copied from Control node to managed hosts while executing the tasks and it will run the program based on playbook and Module then will give back us the output.

Also, the user can create custom playbooks based on their needs.

We should mention the modules in playbooks and modules will be directly executed in remote hosts through playbooks and will get the output.

API:

Ansible uses API as transport  for Cloud services.

Plugins:

Plugins will enhance the features ansible.

Plugins will allow executing the task on build stat. Its a piece of code.

Using ansible we can automate the tasks on different types of network.