introduction
SERVER_REQUEST_ORIGINis an environment variable used in Angular applications to manage the source of server requests. In this article, I will explain in detail the meaning, function of this environment variable and how to use it in Angular applications. First, let us understand the background and importance of this environment variable.
1. Angular application and environment variables
Angular is a popular front-end framework for building modern single-page applications (SPAs). SPA is a web application that dynamically loads content from the server via AJAX requests after loading, rather than reloading the entire page every time the user navigates to a new page. To achieve this dynamic loading, Angular applications need to communicate with the server to obtain data, resources, and perform other operations. In this process, there is a key issue that needs to be solved, namely, determine the source of the server request.
The source of a server request refers to which domain names or URLs are considered trusted and can communicate with Angular applications. Typically, browsers implement a Same-Origin Policy, which means that a page can only communicate with resources from the same source (protocol, domain name, and port). This is due to security limitations to prevent attacks such as Cross-Site Request Forgery (CSRF).
However, in practical applications, it may be necessary to communicate with servers of different domain names, for example, interact with API servers or third-party services. At this time, a mechanism is needed to tell the browser which domain names are trustworthy. This isSERVER_REQUEST_ORIGINWhere does environmental variables work.
2. The role of SERVER_REQUEST_ORIGIN
SERVER_REQUEST_ORIGINEnvironment variables are used to define the source of server requests trusted by Angular applications. Its main functions are as follows:
a. Security
By specifying a trusted source of server requests, the security of the application can be improved and potential security risks can be reduced. Only requests from specified sources are allowed, reducing the risk of cross-site attacks.
b. Cross-domain communication
Cross-domain communication is a common requirement in modern web applications. For example, your application may need to obtain data or resources from servers with different domain names. By configurationSERVER_REQUEST_ORIGIN, you can tell the browser which domain names are trustworthy, allowing cross-domain requests.
c. Environment configuration
SERVER_REQUEST_ORIGINis an environment variable, which means it can be configured according to the needs of different environments. You can set different request sources in development, testing, and production environments to ensure the security and flexibility of applications in different environments.
3. Configure SERVER_REQUEST_ORIGIN
To configureSERVER_REQUEST_ORIGINEnvironment variables, you need to understand how to manage your environment in your Angular application. Angular provides a name calledenvironmentfolder containing configuration files for different environments. Usually, these files include(Development environment),(production environment), etc.
The following is the configurationSERVER_REQUEST_ORIGINGeneral steps:
Step 1: Open the environment configuration file
First, you need to open the environment configuration file corresponding to your current development environment. For example, in a development environment, opendocument.
Step 2: Define SERVER_REQUEST_ORIGIN
In the environment configuration file, you can addSERVER_REQUEST_ORIGINvariable and give it the value of the trusted server request source. This value is usually the server's domain name or URL. For example:
export const environment = {
production: false,
SERVER_REQUEST_ORIGIN: '',
// Other environment configuration items...};Step 3: Use SERVER_REQUEST_ORIGIN in your application
Once configuredSERVER_REQUEST_ORIGIN, you can use it in your application's services or components to build requests. Usually, you will set it in the HTTP request headerOriginfield, set its value toSERVER_REQUEST_ORIGINto tell the server the source of the request. Here is a simple example:
import { Injectable } from '@angular/core';
import { HttpClient, HttpHeaders } from '@angular/common/http';
import { environment } from '../environments/environment';
@Injectable({
providedIn: 'root',
})
export class ApiService {
private readonly serverRequestOrigin: string = environment.SERVER_REQUEST_ORIGIN;
constructor(private http: HttpClient) {}
getData() {
const headers = new HttpHeaders({
'Origin': ,
// Other request headers... });
return (`${}/api/data`, { headers });
}
}4. Example of the source of the server request
To better understandSERVER_REQUEST_ORIGINThe concept of , let’s look at several example scenarios, including different server request sources.
Example 1: Single Source
Suppose your Angular application is with a namedThe backend server communicates. In this case, you canSERVER_REQUEST_ORIGINSet as the domain name of this server:
export const environment = {
production: false,
SERVER_REQUEST_ORIGIN: '',
// Other environment configuration items...};This means that the browser will only allow the browser toThe resources under this domain name communicate.
Example 2: Multiple Sources
In some cases, your application may need to communicate with multiple servers with different domain names. For example, your application might get data from a backend server and also need to interact with the authentication server. Here
In this case, you can configureSERVER_REQUEST_ORIGINTo be a string containing multiple domain names, or set different values in different environments.
export const environment = {
production: false,
SERVER_REQUEST_ORIGIN: ',',
// Other environment configuration items...};After this configuration, the browser will allow theandThe resources under these two domain names communicate.
Example 3: Dynamic configuration
Sometimes, you may want to dynamically configure it according to the application's environment.SERVER_REQUEST_ORIGIN. For example, you can use a different server source in a development environment and another source in a production environment. This can be achieved by setting different values in different environment configuration files.
// inexport const environment = {
production: false,
SERVER_REQUEST_ORIGIN: '',
// Other environment configuration items...};
// inexport const environment = {
production: true,
SERVER_REQUEST_ORIGIN: '',
// Other environment configuration items...};This way, you can ensure that you use different server request sources in different environments to meet security and configuration needs.
5. Browser's homologous policy
In useSERVER_REQUEST_ORIGINWhen it comes to environment variables, you need to understand the browser's homologous strategy. Same-origin policy is a security mechanism for browsers that restrict how documents or scripts loaded from one source interact with resources from another source.
Specifically, if the protocol, domain name, and port number of the two resources do not match exactly, the browser will block cross-origin requests. that's whySERVER_REQUEST_ORIGINVery important because it tells the browser which domain names are trusted.
6. Security and best practices
In configurationSERVER_REQUEST_ORIGINWhen , be aware of the following security and best practices:
a. Trust only the necessary domain names
Don't putSERVER_REQUEST_ORIGINSet to wildcards or allow all domain names. Trust only the domain names you need to apply to reduce security risks.
b. Use HTTPS
Always define using the HTTPS protocolSERVER_REQUEST_ORIGINto ensure the security of data during transmission.
c. Avoid storing sensitive information on the client
Do not store sensitive information in client environment variables, even in environment configuration files. Sensitive information should be stored securely on the server side.
Summarize
In Angular app,SERVER_REQUEST_ORIGINEnvironment variables are a key configuration item that manages the source of server requests. By correctly configuring this environment variable, you can improve the security of your application, allow cross-domain communication, and dynamically configure the request source according to different environmental requirements. Understand and use correctlySERVER_REQUEST_ORIGINIt is an important step in building secure, flexible and scalable Angular applications.
The above is the detailed content of the meaning analysis of the environment variable SERVER_REQUEST_ORIGIN in Angular application. For more information about Angular environment variables, please pay attention to my other related articles!