Nginx设置跨域详解

一、Nginx设置跨域代理

跨域代理是指把请求发送到另外一个域名下的服务器进行处理，再将处理结果返回给客户端。在前端开发中，我们常常需要在本地开发环境中调用远端服务器的接口，此时就需要使用到跨域代理。

示例代码：

location / {
    proxy_pass https://example.com;
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
}

二、Nginx如何设置允许跨域

Nginx可以设置允许跨域请求的HTTP头字段来解决跨域问题。一般来说，需要设置Access-Control-Allow-Origin头字段为允许跨域请求的域名。

示例代码：

add_header 'Access-Control-Allow-Origin' 'http://example.com' always;
add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS' always;
add_header 'Access-Control-Allow-Credentials' 'true' always;
add_header 'Access-Control-Allow-Headers' 'Authorization,Content-Type' always;

三、Nginx设置跨域请求

在使用ajax进行跨域请求时，需要设置请求头字段X-Requested-With为XMLHttpRequest，以便确保后端可以正确处理跨域请求。

示例代码：

location /api/ {
    add_header 'Access-Control-Allow-Origin' 'http://example.com' always;
    add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS' always;
    add_header 'Access-Control-Allow-Credentials' 'true' always;
    add_header 'Access-Control-Allow-Headers' 'Authorization,Content-Type,X-Requested-With' always;
}

四、Nginx设置跨域不生效

在Nginx配置文件中，如果location匹配成功后，还有其他规则也和匹配上了，那么不会使用顶层location的跨域规则。此时需要使用break或者return来终止其他规则的匹配。

示例代码：

location /api/ {
    add_header 'Access-Control-Allow-Origin' 'http://example.com' always;
    add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS' always;
    add_header 'Access-Control-Allow-Credentials' 'true' always;
    add_header 'Access-Control-Allow-Headers' 'Authorization,Content-Type,X-Requested-With' always;
    break;
}

五、Nginx设置跨域白名单

在Nginx配置文件中，可以使用if语句判断请求的来源是否在白名单中，以决定是否允许跨域请求。

示例代码：

set $allow_cors 0;
if ($http_origin ~* (https?://example\.com(:[0-9]+)?$)) {
    set $allow_cors 1;
}
if ($request_method = 'OPTIONS') {
    set $allow_cors "${allow_cors}opt";
}
if ($allow_cors = "1opt") {
    add_header 'Access-Control-Allow-Origin' "$http_origin" always;
    add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS' always;
    add_header 'Access-Control-Allow-Credentials' 'true' always;
    add_header 'Access-Control-Allow-Headers' 'Authorization,Content-Type,X-Requested-With' always;
    add_header 'Access-Control-Max-Age' 1728000 always;
    add_header 'Content-Length' 0 always;
    return 204;
}

六、Nginx配置跨域代理

Nginx可以配置反向代理来实现跨域请求。将请求发送到本地Nginx，然后Nginx再将请求转发到目标服务器。

示例代码：

location /api/ {
    proxy_pass https://example.com;
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    add_header 'Access-Control-Allow-Origin' "$http_origin" always;
    add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS' always;
    add_header 'Access-Control-Allow-Credentials' 'true' always;
    add_header 'Access-Control-Allow-Headers' 'Authorization,Content-Type,X-Requested-With' always;
}

七、Nginx设置跨域请求携带cookie

在Nginx配置中，需要设置add_header ‘Access-Control-Allow-Credentials’ ‘true’才能允许跨域请求携带cookie。

示例代码：

location /api/ {
    proxy_pass https://example.com;
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    add_header 'Access-Control-Allow-Origin' "$http_origin" always;
    add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS' always;
    add_header 'Access-Control-Allow-Credentials' 'true' always;
    add_header 'Access-Control-Allow-Headers' 'Authorization,Content-Type,X-Requested-With' always;
}

八、Nginx跨域怎么配置

Nginx配置跨域有多种方案，需要综合考虑业务需求和安全性要求，选择合适的方案。

示例代码：

location /api/ {
    if ($http_origin ~* (https?://example\.com(:[0-9]+)?$)) {
        add_header 'Access-Control-Allow-Origin' "$http_origin" always;
        add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS' always;
        add_header 'Access-Control-Allow-Credentials' 'true' always;
        add_header 'Access-Control-Allow-Headers' 'Authorization,Content-Type,X-Requested-With' always;
        add_header 'Access-Control-Max-Age' 1728000 always;
        add_header 'Content-Length' 0 always;
        if ($request_method = 'OPTIONS') {
            return 204;
        }
        proxy_pass https://example.com;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    }
    if ($http_origin ~* (https?://example2\.com(:[0-9]+)?$)) {
        add_header 'Access-Control-Allow-Origin' "$http_origin" always;
        add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS' always;
        add_header 'Access-Control-Allow-Credentials' 'true' always;
        add_header 'Access-Control-Allow-Headers' 'Authorization,Content-Type,X-Requested-With' always;
        add_header 'Access-Control-Max-Age' 1728000 always;
        add_header 'Content-Length' 0 always;
        if ($request_method = 'OPTIONS') {
            return 204;
        }
        proxy_pass https://example2.com;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    }
}

九、Nginx解决跨域

Nginx解决跨域可以从多个方面入手，如设置允许跨域的HTTP头字段、设置跨域代理、设置跨域白名单等。

示例代码：

location /api/ {
    if ($http_origin ~* (https?://example\.com(:[0-9]+)?$)) {
        add_header 'Access-Control-Allow-Origin' "$http_origin" always;
        add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS' always;
        add_header 'Access-Control-Allow-Credentials' 'true' always;
        add_header 'Access-Control-Allow-Headers' 'Authorization,Content-Type,X-Requested-With' always;
        add_header 'Access-Control-Max-Age' 1728000 always;
        add_header 'Content-Length' 0 always;
        if ($request_method = 'OPTIONS') {
            return 204;
        }
        proxy_pass https://example.com;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    }
}

十、总结

本文详细介绍了Nginx设置跨域的多种方案，包括设置跨域代理、设置允许跨域的HTTP头字段、设置跨域白名单等。在实际开发中，需要根据业务需求和安全性要求选择最合适的方案。