Jenkins反向代理，nginx将POST请求重定向后变成了GET请求

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项目场景：

nginx 1.12.2，jenkins 2.357，jenkins访问链接：jenkins.com:8080

需求是配置二级路径访问jenkins，如http://100.76.74.11/jenkins

原nginx配置

        #Jenkins
        location ^~ /jenkins/ {
            proxy_pass         http://jenkins.com:8080/;
            # Required for Jenkins websocket agents
            proxy_set_header   Connection        $connection_upgrade;
            proxy_set_header   Upgrade           $http_upgrade;
            proxy_set_header   X-Real-IP         $remote_addr;
            proxy_set_header   X-Forwarded-For   $proxy_add_x_forwarded_for;
            proxy_set_header   X-Forwarded-Proto $scheme;
        }

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问题一：

访问jenkins.com:8080过程中，某些页面会跳至jenkins.com，导致不能访问

因为没有配置80端口，导致不能访问。

解决方案：配置反向代理

暂时查不到为什么会跳到jenkins.com，就配置jenkins.com反向代理到http://jenkins.com:8080，这样80和8080都可以访问。

    server {
        listen        80;
        server_name   jenkins.com;
        location / {
            proxy_pass         http://jenkins.com:8080;
        }
    }

再把二级目录代理到jenkins.com，修改配置

    server {
        listen       80 default_server;

        #首页,有其他配置，不能动。
        location / {
            proxy_pass      http://xxx;
        }      
        #Jenkins
        location ^~ /jenkins/ {
            proxy_pass         http://jenkins.com/;
            # Required for Jenkins websocket agents
            proxy_set_header   Connection        $connection_upgrade;
            proxy_set_header   Upgrade           $http_upgrade;
            proxy_set_header   X-Real-IP         $remote_addr;
            proxy_set_header   X-Forwarded-For   $proxy_add_x_forwarded_for;
            proxy_set_header   X-Forwarded-Proto $scheme;
        }
    server {
        listen        80;
        server_name   jenkins.com;
        location / {
            proxy_pass         http://jenkins.com:8080;
        }
    }

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问题二：

二级路径访问404

http://100.76.74.11/jenkins访问会404，跳到http://100.76.74.11/login?from=%2F

测试http://100.76.74.11/jenkins/login?from=%2F是可以访问的。

解决方案：配置rewrite重写

观察到请求都是Referer: http://100.76.74.11/jenkins/

#referer来自100.76.74.11/jenkins的请求，且没有/jenkins路径的，转跳到/jenkins

        #referer来自100.76.74.11/jenkins的请求，且没有/jenkins路径的，转跳到/jenkins
        set $test1 "";
        if ($http_referer ~* "100.76.74.11/jenkins") {
            set $test1 "Y";
        }
        if ($uri !~* ^/jenkins){
            set $test1 "${test1}Y";
        }
        if ($test1 = "YY"){
            rewrite ^/(.*)$ http://100.76.74.11/jenkins/$1 last;
        }

转跳是成功的，可以访问了。

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问题三：

nginx将POST请求重定向后变成了GET请求

http反馈状态是405

解决方案：取消POST的重写，直接反向代理到后端

只有部分post请求改成get请求后405，单独把这部分url取消重写，再代理到后端。

#url取消重写

        #Proxy|check|render是POST请求不转跳，用proxy_pass代理到后端。
        if ($uri ~* (.*)(Proxy|check|render|queue|doDelete)(.*)$){
            set $test1 "POST";
        }

#把这部分url代理到后端

        location ~* (.*)(Proxy|check|render|queue|doDelete)(.*)$ {
            if ($http_referer ~* "100.76.74.11/jenkins") {
                proxy_pass      http://jenkins.com;
            }
            proxy_set_header   Connection        $connection_upgrade;
            proxy_set_header   Upgrade           $http_upgrade;
            proxy_set_header   X-Real-IP         $remote_addr;
            proxy_set_header   X-Forwarded-For   $proxy_add_x_forwarded_for;
            proxy_set_header   X-Forwarded-Proto $scheme;
        }

POST请求就成功了。

最终nginx配置

    # Required for Jenkins websocket agents
    map $http_upgrade $connection_upgrade {
      default upgrade;
      '' close;
    }

    server {
        listen       80 default_server;

        #首页,有其他配置，不能动。
        location / {
            proxy_pass      http://xxx;
        }      
        #Jenkins
        location ^~ /jenkins/ {
            proxy_pass         http://jenkins.com/;
            # Required for Jenkins websocket agents
            proxy_set_header   Connection        $connection_upgrade;
            proxy_set_header   Upgrade           $http_upgrade;
            proxy_set_header   X-Real-IP         $remote_addr;
            proxy_set_header   X-Forwarded-For   $proxy_add_x_forwarded_for;
            proxy_set_header   X-Forwarded-Proto $scheme;
        }
        location ~* (.*)(Proxy|check|render|queue|doDelete)(.*)$ {
            if ($http_referer ~* "100.76.74.11/jenkins") {
                proxy_pass      http://jenkins.com;
            }
            proxy_set_header   Connection        $connection_upgrade;
            proxy_set_header   Upgrade           $http_upgrade;
            proxy_set_header   X-Real-IP         $remote_addr;
            proxy_set_header   X-Forwarded-For   $proxy_add_x_forwarded_for;
            proxy_set_header   X-Forwarded-Proto $scheme;
        }
        #referer来自100.76.74.11/jenkins的请求，且没有/jenkins路径的，转跳到/jenkins
        set $test1 "";
        if ($http_referer ~* "100.76.74.11/jenkins") {
            set $test1 "Y";
        }
        if ($uri !~* ^/jenkins){
            set $test1 "${test1}Y";
        }
        #Proxy|check|render是POST请求不转跳，用proxy_pass代理到后端。
        if ($uri ~* (.*)(Proxy|check|render|queue|doDelete)(.*)$){
            set $test1 "POST";
        }
        if ($test1 = "YY"){
            rewrite ^/(.*)$ http://100.76.74.11/jenkins/$1 last;
        }
        
    server {
        listen        80;
        server_name   jenkins.com;
        location / {
            proxy_pass         http://jenkins.com:8080;
        }
    }

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最后：

看了下网上大佬的方法

1、我没成功，大家可以研究试试

    error_page 405 =200 @405;  
    location @405 {  
        proxy_method POST;  
        proxy_pass http://static_backend;  

2、我也没成功，大家可以研究试试

    return 307 http://xxx.xxx.com$request_uri;  

3、通过修改 jenkins.xml 配置文件并将 --prefix=/jenkins 添加到 条目来设置上下文路径。

可以考虑，但我的需求是不改动jenkins，所以不合适我的环境。

附一些nginx匹配和重写的知识，可以参考
https://blog.csdn.net/weixin_48404074/article/details/121317859

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