What is OpenStack? The operation process of OpenStack core components

1. Introduction to OpenStack

1. Overview of OpenStack

• Co-sponsored by NASA (National Aeronautics and Space Administration) and Rackspace
• Free software and open source projects licensed under the Apache license
• An open source project that provides software for the construction and management of public and private clouds
• Covers all aspects of networking, virtualization, operating systems, servers, etc.

2. OpenStack Service

2.1 8 core services

All provide services for virtual machines

• Commpute
• NetWork
• Identity
• Identity
• Identity
• Image Server
• Block Storage
• Object Storage
• Telemetry

2.2 8 core components

• Nova
• Neutron
• Keystone
• Horizon
• GIance
• Cinder
• Swift
• Ceilometer

2.3 Detailed explanation of components

2.3.1 Nova (core component) (responsible for life cycle management)

• OpenStack obtains the underlying virtualization technology, that is, the converted virtual resources are received through a unified entrance. This entrance is Nova, which means that Nova manages all virtualized resources and can bring the virtualized resources over to the virtual The virtual machine is used to make the virtual machine run normally.
  That is to say, the object it calls is the resource foundation that supports the operation of the instance, and it can manage the life cycle of the instance.
• Hypervisor (virtual machine manager), which converts physical resources into virtualized resources for use by virtual machines. After the instance is created, resources are not provided to virtual machines through hypervisor or other virtualization technologies, but are called by Nova as a unified The Hypervisor will be shielded after being delivered by Nova to the virtual machine. Nova can also support a variety of different virtualization technologies through a variety of different drivers to achieve horizontal expansion and achieve a universality

2.3.2 Neutron (responsible for the management of the virtual network)

• It is equivalent to connecting the internal and external networks, allowing the instance to be the same as the outside world
• A lease order for part of the resources, so that you can define your own allocation of resources, and do not affect each other with other tenants, making it easier to manage

2.3.3 Keystone (Global Components)

• Mainly used for the authentication mechanism of mutual interaction and docking between all components in OpenStack, which can authenticate and authorize users, etc.

2.3.4 Horizon (Ui surface)

• Provide users with a friendly management interface, select the specifications of their own needs in the console, and then create them. The console will pass our needs to the bottom layer of OpenStack to create our needs

2.3.5 Glance (mirror template)

• Provide registration and management of virtual machine image templates, such as building a load balancing architecture and encapsulating it as an image. This image is equivalent to a load balancing architecture template. You only need to download this image to provide multiple users for use, and then use this Mirror to create a virtual machine, what is created is an operating system with a load balancing architecture

2.3.6 Cinder (Block Storage)

• Responsible for providing durable block storage devices for running instances, which can be easily expanded and paid on demand, because it not only provides services for one user but also provides services for multiple users, so it supports multiple back-end storage types

2.3.7 Swift (Object Storage)

• Provides cloud-based elastic storage for OpenStack and supports clusters with no single point of failure. It is actually the storage of key-value pairs. The stored resources are static resources. It cannot directly modify the source files inside the object storage, but needs to download You can modify it after you come down, and then update it on the push

2.3.8 Ceilometer (measurement, monitoring)

• Used to manage the user's lease management of resources, and provide users with a way to keep accounts

2.4 Keystone workflow

Two, OpenStack advantages

Controllability

• Fully open source platform, providing API interface, easy to integrate with third-party technology

compatibility

• OpenStack is compatible with other public clouds, facilitating data migration

Scalability

• Modular design, you can increase nodes and resources through horizontal expansion

flexibility

• Establish corresponding infrastructure and increase cluster size according to your own needs

Industry Standard

• Many leading IT companies have joined the OpenStack project

Three, OpenStack architecture specifications

Before learning openstack deployment and operation and maintenance, you need to be familiar with its architecture and operating principles. As an open source, scalable, and elastic cloud operating system, the basic design principles of OpenStack are as follows:

• Divide different projects according to different functions and versatility, split subsystems
• According to the logical plan, standardize the communication between subsystems
• Design the entire system architecture by layering
• Provide a unified API interface between different functional subsystems

Four, OpenStack architecture concept

4.1 OpenStack architecture diagram

The core is for the virtual machine, and all components provide services around the virtual machine

4.2 The global components in the red box:

Keystone: Provides authentication and authorization for all service modules.
Ceilometer: measures and monitors all data resources.
Horizon: manages the UI platform and provides a web management page for the underlying interaction

4.3 External (auxiliary) components (mainly providing some necessary management and resource services) in the green box:

Ironic (isoft you): Provides a bare metal environment (computer hardware without an operating system, referred to as bare metal)
Trove: Provides management database services (controls relational and non-relational databases)
heat (Hey special), sahara ( Die so good): Provide data management and orchestration

4.4 The blue box is the internal core components (mainly some components that maintain the normal operation of the virtual machine):

Glance (Gelangci): Provide mirroring service
Neutron: Provide network service
Swift: Provide object storage resources
Cinder (cing): Provide block storage resources (provide persistent storage, but also One copy will be backed up to solve the problem of single point of failure)
Nova: Manage the life cycle of the instance, and is responsible for managing the four resources above to be used by the virtual machine

4.5 Specific process

After the cloud platform user is authenticated and authorized by the Keystone service, he
creates a virtual machine service through the Horizon or Rest API mode. The
creation process includes using the Nova service to create a virtual machine instance. The
virtual machine instance uses Glance to provide mirroring services,
and then uses Neutron to create a new virtual machine. The machine allocates an IP address and incorporates it into the virtual network.
After that, the volume created by Cinder is used to mount the storage block for the virtual machine. The
entire process is monitored by the resources of the Ceilometer module.
The volume (Volume) generated by Cinder and the volume provided by Glance Image can be saved through Swift's object storage mechanism