OpenStack all-in-one setup on CentOS

OpenStack is an open-source cloud operating system for setting up IAAS (infrastructure as a service). OpenStack provides a flexible solution for both public and private clouds, covering the two important requirements i.e. cloud must be simple to implement and massively scalable. For production a minimal OpenStack setup requires at-least 2 separate machine, one controller and one compute node. To get started with OpenStack, a common practice is to setup an all-in-one deployment i.e. using a single machine.
This guide is about setting-up an all-in-one setup for OpenStack Queens, the latest release.

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All you need to know about SSH


SSH stands for Secure SHell, a tool developed by SSH Communication Security Ltd, for secure remote log-in and command execution. It’s a secure alternative of it’s predecessors rlogin, rsh, etc. SSH has become industry de-facto for securely communicating with remote machines i.e. the entire session is encrypted.
The SSH is based on public-key cryptography (also known as asymmetric cryptography), a cryptography system employing key pair i.e. a public key which is meant to be shared, and private key which has to be kept safe and secret, only known to the owner. This pair serves two purpose 1. authentication, the public key verifies the owner of the paired private key, and 2. encryption, the public key encrypts the message, and only the paired private key can decrypt it. In simple words, you can share your public key (content of ~/.ssh/ with anyone via email, for example: to access a remote machine securely and without password, all you need to do is copy your public key to authorized_keys (default – ~/.ssh/authorized_keys) file.

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Install Ansible on CentOS 7

For an overview of what is Ansible – Getting started with Ansible

For this tutorial we are using 3 VMs, with IPs and hostnames – one Ansible controller/manager (ansible-controller) which will be doing the provisioning on the two remote servers i.e. ansible-node1 and ansible-node2: ansible-controller ansible-node1 ansible-node2
ansible-controller‘ is the manger node, the one performing the provisioning on the rest of the hosts i.e. on ansible-controller we’ll be installing and configuring Ansible.

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