Introduction

This project aims to create a full ceph environment in a KVM-based Virtual Machines (VMs). It creates VMs that are used to build the ceph environment.

What will I have when executing this?

This role installs the virt packages and It creates (by default) 3 VMs (ceph-mon, ceph-osd0 and ceph-osd1). Those VMs will be available to be managed using the Virsh tool and you will be able to access it using the followin command:

virt-manager

Requirements

Ansible;
lxcbr0 bridge interface in machines that will run the VMs;
ceph0 bridge interface in machines that will run the VMs;

How to create the bridge interfaces

First of all, install the bridge-utils package using the Package Manager available on your system. Second, Create the bridges using the brctl command. The list of commands below show how to create and bring up the bridge interfaces. Run the commands and answer then, if asked:

brctl addbr ceph0
brctl addbr lxcbr0
ip link set up dev ceph0
ip link set up dev lxcbr0

Executing this playbook

Using Packer

TO DO

Using cloud-init

Cloud-init images are available for some linux server distributions. Usually, they are small sized images that have the cloud-init lib installed and configured to start at boot time and wait for the cloud-config file. The loud-config file allows you to configure several options like users, passwords, ssh keys, routers and more.

The cloud-config file in this repository is set to use user/password as authentication method for the VMs. You may change the cloud-config file in the roles/ansible_vms/templates/cloud-config.j2 Jinja2 file if you want to use ssh keys instead.

Some images that are prepared to use cloud-init:

ubuntu-16.04: https://cloud-images.ubuntu.com/xenial/current/xenial-server-cloudimg-amd64-disk1.img
centos-7.0: https://cloud.centos.org/centos/7/images/CentOS-7-x86_64-GenericCloud-1802.qcow2

if you want to change the default behavior, you need to override the default value of the variables. The variables are in the roles/ansible_vms/vars/main.yml Yaml file and are described below:

VM cloud init image link

vm_cloud_image: "https://cloud-images.ubuntu.com/xenial/current/xenial-server-cloudimg-amd64-disk1.img"

Name of vm cloud init image that will be defined

vm_image_name: "ubuntu-16.04"

Password used for default user

vm_user_password: "str0ng_p@ssw0rd"

Cloud config templates used to configure VMs

vm_templates: "/home/eduardo/Projects/ceph-environment-automator/raw_imgs"

Running

Define locals where VMs will be configured in inventory file. If the inventory is not changed the VMs will be configure in the localhost.

Copy the Master's ssh key on the servers that will hold the VMs using:

The Master's ssh key is the public part of the private key of the machine from which the main ansible script is being ran from.

ssh-copy-id <user>@<ip>

After that, you can run the playbook using:

ansible-playbook -i inventory prepare-hosts.yml -b --ask-sudo-pass

Enter the user's password (the user needs to have sudo permissions) and wait the playbook to finish .

Install ceph

TO DO

Improvements

When I wrote this role/playbook, I needed some modules that are not implemented on Ansible yet. To use the functions I needed, I used the shell module to execute some commands.

Those modules are:

qemu-img: A module to allow the creation of VM images.
packer: A module to work with Packer.
cloud-localds: A module to prepare cloud-config.cdrom images.
cloud-config: A module to create cloud-config files.
iproute2: A module to manage volatile virtual network interfaces (This module is being created by me, the project is a WIP) .

lets00/ceph-environment-automator