1 --> First acquaintance with OpenStack

Currently the most popular open source operating system kernel, the main private cloud management system.

• OpenStack's architectural positioning and technical scope
  OpenStack is just the control plane of the system.
  OpenStack does not include the data plane components of the system, such as hypervisor, storage, and network equipment.
• The difference between cloud and virtualization
  Cloud computing: service-based IT capabilities; use on demand, billing by volume; multi-tenant isolation;
  virtualization: environment isolation, resource reuse; reduce isolation loss and improve operating efficiency; provide advanced virtualization features .

Its main features are as follows:

1. Resource abstraction
   OpenStack abstracts various hardware resources into resource pools through virtualization and software definition.
2. Resource allocation and load scheduling
   OpenStack allocates resources in the resource pool to different users and carries different applications according to the needs of administrators/users.
3. Application life cycle management
   OpenStack can already provide preliminary application deployment/removal, and automatic scale adjustment capabilities.
4. System operation and maintenance
   OpenStack can already provide certain system monitoring capabilities.
5. Human-computer interaction
   OpenStack provides a human-computer interface, and the outside world can participate in OpenStack interaction through API, command line or graphical interface.

Basic design ideas:

1. Open
   and open source, and reuse existing open source projects as much as possible.
   Don't "reinvent the wheel", but "stand on the shoulders of giants."
2. Flexible
   Do not use any proprietary/commercial components that cannot be too low.
   Extensive use of plug-in methods for architecture design and implementation.
3. Extensible It
   consists of multiple independent projects.
   Each project contains multiple independent components.
   No central architecture.
   Stateless architecture.

OpenStack is just the key components to build a cloud, the kernel, backbone, framework, and bus. To build a cloud, many things are needed;

Introduction to OpenStack services:

service	project name	description
Dashboard	Horizon	Provides a web-based autonomous service portal to interact with OpenStack underlying services, such as starting an instance, assigning IP addresses, and configuring access control.
Computer	Nova	Lifecycle management of computing instances in the OpenStack environment. On-demand response includes operations such as generating, scheduling, and recycling virtual machines.
Network	Neutron	Make sure to provide network connection as a service for other OpenStack services, such as OpenStack computing. Provide users with API to define the network and use. It supports many network providers and technologies based on plug-in architecture.
Objecet Storage	Swift	Store and arbitrarily retrieve unstructured data objects through a RESTful, HTTP-based application program interface. It has a high fault tolerance mechanism, based on data replication and a scalable architecture. Its implementation is not like a file server needs to mount a directory. In this way, it writes objects and files to multiple hard drives to ensure that the data is replicated across multiple servers in the cluster.
Block Storage	Cinder	Persistent block storage provided for running instances. Its pluggable drive architecture function helps to create and manage block storage devices.
Identity Service	Keystone	Provide authentication and authorization services for other OpenStack services, and provide an endpoint directory for all OpenStack services.
Image Service	Glance	Storage and retrieval of virtual machine disk images, OpenStack computing will use this service during instance deployment.
Telemetry Service	Ceilmeter	Provide monitoring and metering for OpenStack cloud billing, benchmarking, scalability, and statistics purposes.
Orchestration Service	Heat	You can use either the local template format or the AWS CloudFormation template format to orchestrate multiple comprehensive cloud applications, through the OpenStack native REST API or CloudFormation-compatible queue API.

Layering of

OpenStack : OpenStack new cloud host process: