Before You Start

Welcome to Cloud Application Engine (CAE). CAE provides serverless hosting for applications. This one-stop application hosting solution features fast deployment, low cost, and lean O&M. CAE releases applications from source code, software packages, and image packages quickly and easily, with auto scaling in seconds, all billed pay-per-use, and simple O&M infrastructure. The whole application lifecycle is manageable with observable metrics.

This document describes how to use application programming interfaces (APIs) to perform operations on CAE, such as creating, deleting, and modifying resources. For details about all supported operations, see API Overview.

Before calling APIs, ensure that you are familiar with CAE concepts. For details, see Service Overview.

Endpoint

An endpoint is the request address for calling an API. Endpoints vary depending on services and regions. For the endpoints of CAE, see Regions and Endpoints.

The following table lists CAE endpoints. Select a desired one based on the service requirements.

**Table 1** CAE endpoints
Region Name	Region	Endpoint
AP-Singapore	ap-southeast-3	cae.ap-southeast-3.myhuaweicloud.com

Concepts

Account
An account is created upon successful registration with the cloud platform. The account has full access permissions for all of its cloud services and resources. It can be used to reset user passwords and grant user permissions. The account is a payment entity, which should not be used directly to perform routine management. For security purposes, create Identity and Access Management (IAM) users and grant them permissions for routine management.
User
A user is created in Identity and Access Management (IAM) to use cloud services. Each user has its own identity credentials (password and access keys).

An IAM user can view the account ID and user ID on the My Credentials page of the console. The account name, username, and password will be required for API authentication.
Region
Regions are divided based on geographical location and network latency. Public services, such as Elastic Cloud Server (ECS), Elastic Volume Service (EVS), Object Storage Service (OBS), Virtual Private Cloud (VPC), Elastic IP (EIP), and Image Management Service (IMS), are shared within the same region. Regions are classified into universal and dedicated regions. A universal region provides universal cloud services for common tenants. A dedicated region provides specific services for specific tenants.

For details, see Region and AZ.
AZ
An availability zone (AZ) comprises one or more physical data centers equipped with independent ventilation, fire, water, and electricity facilities. Compute, network, storage, and other resources in an AZ are logically divided into multiple clusters. AZs within a region are interconnected using high-speed optical fibers to support cross-AZ high-availability systems.
Project
A project corresponds to a region. Default projects are defined to group and physically isolate resources (including compute, storage, and network resources) across regions. Users can be granted permissions in a default project to access all resources under their accounts in the region associated with the project. If you need more refined access control, create subprojects under a default project and create resources in subprojects. Then you can assign users the permissions required to access only the resources in the specific subprojects.

For details about how to check the project ID, see Obtaining a Project ID.

Figure 1 Project isolating model

To view a project ID, go to the My Credentials page.
Enterprise Project
Enterprise projects group and manage resources across regions. Resources in enterprise projects are logically isolated. An enterprise project can contain resources in multiple regions, and resources can be transferred between enterprise projects.

For details about how to obtain the enterprise project ID and features, see Enterprise Management User Guide.