OpenStack is a set of software tools for managing and building cloud computing platforms for private and
public clouds. It’s a free and open source software cloud computing platform.

The three components that make modular architecture for OpenStack are

OpenStack Compute: For managing large networks of the virtual machine

OpenStack Object Storage: A storage system that provides support for both block storage and object
storage

Image Service: The delivery service provides discovery and registration for virtual disk images

OpenStack offers services like

• Keystone: Provides authorization and authentication for users
• Glance: Manages images in different formats
• Cinder: Provides persistent block storage
• Neutron: Enables users to create and attach interfaces to networks
• Nova: Provides instances on user's demand
• Swift: Storage platform integrated directly into applications
• Ceilometer: Openstack for billing
• Heat: Allows automated infrastructure deployment

In OpenStack, a tenant is referred for the group of users while role indicates the authorization level of the
user.

Hypervisor is a piece of computer software or hardware that creates and run virtual machines. A system on
which one or more virtual machines is defined is referred as host machine.

The types of hypervisor that supports OpenStack are

• KVM
• VMware
• Containers
• Xen and HyperV

OpenStack provides two classes of block storage,

Ephemeral Storage: It is associated with a single unique instance. Based on the instance, the size is
defined. When the instance associated with it is terminated, data on ephemeral storage ceases to exist

Volume Storage: This storage is not dependent on any particular instance and is persistent. Volumes are
user created and within Quota

The basic functions of Identity Service is

User Management: It tracks the users and their permissions

Service Catalog: It provides a catalog of available services with their API endpoints

For handling persistent storage for virtual machines, OpenStack provides the service referred as Cinder.
There are multiple backend for cinder. The one that is utilized by default is LVM, called Cinder-Volumes.

• OpenStack Object Storage
• File system
• S3
• HTTP
• RBD or Rados Block Device
• GridFS

Cells functionality enables you to scale an OpenStack Compute cloud in a more simplistic way. When this
functionality is enabled, the hosts in an OpenStack Compute cloud are partitioned into group called cells.
Cells are configured as trees.

In OpenStack, networking is done in following ways

• Networks
• Routers
• Subnets
• Ports
• Vendor Plugins

You can transfer a volume from one owner to another by using the command cinder transfer*.

nova floating-ip-*

It gives access to control bare metal driver, through which you can control physical hardware resources on
the same network.

Bare metal node is comprised of two separate components

• Bare metal node Orchestrator: It’s a management software, which acts as a dispatcher to all nodes in the cluster.

• Bare metal node Operating System: It is a base software, which runs on each node in the cluster.

To remove network interface from bare-metal node command used is bare-metal – interface remove.

Cinder Scheduler or routing volume create requests to the appropriate volume service.

Token is an alpha-numeric string which allows access to a certain set of services depending upon the
access level of the user

For writing python scripts and managing in Openstack cloud, SDK (Software Development Kit) is used.
The SDK implements Python binding to the OpenStack API, which enables you to achieve automation
tasks in Python by making calls on Python objects instead of making REST calls directly.

• To pause an instance, command used is $ nova pause INSTANCE_NAME

• To unpause an instance, command used is $ nova unpause INSTANCE_NAME

$ nova floating-ip-pool-list

A flavor is an available hardware configuration for a server, which defines the size of a virtual server that
can be launched.

Python SDK (Software Development Kit) is used to help users to write applications for performing
automation tasks in Python by calling Python objects.

It provides a platform to work with multiple OpenStack services at one place.

OpenStack offers services like

Keystone: Provides authorization and authentication for users

Glance: Manages images in different formats

Cinder: Provides persistent block storage

Neutron: Enables users to create and attach interfaces to networks

Nova: Provides instances on user’s demand

Swift: Storage platform integrated directly into applications

Ceilometer: Openstack for billing

Heat: Allows automated infrastructure deployment

In OpenStack, a tenant is referred for the group of users while role indicates the authorization level of the
user.

Hypervisor is a piece of computer software or hardware that creates and run virtual machines. A system on
which one or more virtual machines is defined is referred as host machine.

The types of hypervisor that supports OpenStack are

– KVM

– VMware

– Containers

– Xen and HyperV

OpenStack provides two classes of block storage,

Ephemeral Storage: It is associated with a single unique instance. Based on the instance, the size is
defined. When the instance associated with it is terminated, data on ephemeral storage ceases to exist

Volume Storage: This storage is not dependent on any particular instance and is persistent. Volumes are
user created and within Quota

The basic functions of Identity Service is

User Management: It tracks the users and their permissions

Service Catalog: It provides a catalog of available services with their API endpoints

• Users: It is a digital representation of a person, service or system who uses OpenStack cloud services
• Tenants: A container used to group or isolate resource or identity objects. Depending on service operator a tenant may map to a customer, account, organization or project
• Roles: A role includes a set of rights and privileges. A role determines what operations a user is permitted to perform in a given tenant

The networking options used in OpenStack are

Flat Network Manager: IP addresses for VM instances are fetched from the subnet, and then injected into
the image on launch

Flat DHCP Network Manager: IP addresses for VM instances are fetched from the subnet specified by the
network administrator

VLAN Network Manager: Compute creates a VLAN and bridge; DHCP server is started for each VLAN
to pass out IP addresses to VM instances.

For handling persistent storage for virtual machines, OpenStack provides the service referred as Cinder.
There are multiple backends for cinder. The one that is utilized by default is LVM, called Cinder-Volumes.

• OpenStack Object Storage
• Filesystem
• S3
• HTTP
• RBD or Rados Block Device
• GridFS

Cells functionality enables you to scale an OpenStack Compute cloud in a more simplistic way. When this
functionality is enabled, the hosts in an OpenStack Compute cloud are partitioned into group called cells.
Cells are configured as trees.

sudo nova-manage user create user-name

By using the command sudo nova-manage user create user-name

Yes, by using keystone role-list

It provides an interface for the external world to interact with the cloud infrastructure.

ssh-keygen

cd .ssh

nova keypair-add –pub_key id_rsa.pub mykey

Bare-metal node grants access to control bare-metal driver that handles the provisioning of OpenStack
Compute physical hardware utilizing the standard cloud APIs and tools like Heat. It is generally used for
single tenant clouds like high-performance cluster computing. For using the bare-metal driver, a network
interface must be created with the bare-metal node inserted into it. Afterwards, users can launch an
instance from the node. Users can also list and delete bare-metal nodes by removing the associated
network instances.

Hypervisor is a term to define virtual machine monitor (VMM) including hardware, software and firmware
components running on a virtual machine. Host machine is the one having hypervisor with one or more
virtual machines.

OpenStack Compute allows multiple hypervisors. There are functionalities to choose one among them for
a specific purpose.

Token is a type of authentication similar to password-based validation. A token gets generated once the
user inserts the credentials and authenticates as a Keystone user. The token can then be used to access
OpenStack services without any revalidation. It is interesting to note that a token is active for a limited
period and must be renewed after regular intervals.

To create a token, users first need to authenticate their Keystone credentials.

Python SDK (Software Development Kit) helps users to write applications for performing automation
tasks in Python by calling Python objects. It provides a platform to work with multiple OpenStack services
at one place. It consists of language bindings to access OpenStack clouds, complete API reference, easy
interaction with REST API and sample code for initial applications.