nginx proxy_pass POST 404 错误

我有 nginx 代理到应用程序服务器，具有以下配置：

location /app/ {
        # send to app server without the /app qualifier
        rewrite /app/(.*)$ /$1 break;
        proxy_set_header Host $http_host;
        proxy_pass http://localhost:9001;
        proxy_redirect http://localhost:9001 http://localhost:9000;
    }

对 /app 的任何请求都会转到 :9001，而默认站点托管在 :9000。

GET 请求工作正常。但是每当我向 /app/any/post/url 提交 POST 请求时，它都会导致 404 错误。通过 GET /app/any/post/url 直接在浏览器中点击 url 会按预期点击应用服务器。

我在网上找到其他有类似问题的人并添加了

proxy_set_header Host $http_host;

但这并没有解决我的问题。

没有记录错误，访问日志如下：

# For http://localhost:9000 (no proxying)

127.0.0.1 - - [08/Dec/2012:12:29:28 -0800] "GET / HTTP/1.1" 304 0 "-" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.4 (KHTML, like Gecko) Chrome/22.0.1229.94 Safari/537.4"

# For http://localhost:9000/app/get/priorities (GET proxy)

127.0.0.1 - - [08/Dec/2012:12:32:17 -0800] "GET /app/get/priorities HTTP/1.1" 200 77 "-" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.4 (KHTML, like Gecko) Chrome/22.0.1229.94 Safari/537.4"

# When posting to http://localhost:9000/app/create/priority:

127.0.0.1 - - [08/Dec/2012:12:33:50 -0800] "POST /app/create/priority/ HTTP/1.1" 404 188 "http://localhost:9000/form-test.html" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.4 (KHTML, like Gecko) Chrome/22.0.1229.94 Safari/537.4"

任何见解表示赞赏。

谢谢。

完整配置如下：

server {
    listen   9000; ## listen for ipv4; this line is default and implied
    #listen   [::]:80 default_server ipv6only=on; ## listen for ipv6

    root /home/scott/src/ph-dox/html;
    # root ../html; TODO: how to do relative paths?
    index index.html index.htm;

    # Make site accessible from http://localhost/
    server_name localhost;

    location / {
        # First attempt to serve request as file, then
        # as directory, then fall back to displaying a 404.
        try_files $uri $uri/ /index.html;
        # Uncomment to enable naxsi on this location
        # include /etc/nginx/naxsi.rules
    }

    location /app/ {
        # rewrite here sends to app server without the /app qualifier
        rewrite /app/(.*)$ /$1 break;
        proxy_set_header Host $http_host;
        proxy_pass http://localhost:9001;
        proxy_redirect http://localhost:9001 http://localhost:9000;
    }

    location /doc/ {
        alias /usr/share/doc/;
        autoindex on;
        allow 127.0.0.1;
        allow ::1;
        deny all;
    }

}