1. Why post?

1.1. Sometimes I need to check the HTTP logs such as post body and some headers from the cloud services. So, I just choose the nginx for this.

1.2. In order to install nginx modules, you have to install manually, not using package managements such as apt-get and yum.

2. Installation

2.1. Install the echo-nginx-module module and its dependencies (Ubuntu)

 $ sudo apt-get install build-essential zlib1g-dev libpcre3 libpcre3-dev unzip

2.2. Go to Nginx Download Site then download stable version.

2.3. Download echo-nginx-module from the github

 $ wget http://nginx.org/download/nginx-1.12.2.tar.gz
 $ tar -xvzf nginx-1.12.2.tar.gz
 
 $ wget https://github.com/openresty/echo-nginx-module/archive/v0.61.zip
 $ unzip v0.61.zip
 
 $ cd nginx-1.12.2
 # you would install you nginx under /usr/local/nginx/.
 $ ./configure --prefix=/usr/local/nginx --add-module=../echo-nginx-module-0.61 --with-http_perl_module
 $ make -j2
 $ make install

3. Setting nginx.conf to see the http post log

$ cd /usr/local/nginx
$ sudo vim conf/nginx.conf

• See the request_body in “log_format” and if statement in “location /”.

http {
    # ...

    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for" ' 
                      '"$request_body"';

    # ...

    server {
        listen       80;
        server_name  localhost;

        #charset koi8-r;

        access_log  logs/host.access.log  main;

        location / {
            default_type text/html;
            root   html;
            index  index.html index.htm;

            if ($request_method = POST) {
                error_page  405     =200 $uri;
                echo_read_request_body;
                echo $request_body;
            }
        }
    }
}

4. Run Nginx

 $ cd /usr/local/nginx
 
 # Test Configuration
 $ sudo sbin/nginx -t
 
 # Start nginx
 $ sudo sbin/nginx
 
 # $ sudo sbin/nginx -s reload
 # $ sudo sbin/nginx -s stop

 # Check the Process 
 $ ps aux | grep nginx

4.1. Then, test like this.

 $ curl -X POST http://localhost --data 'hello world'

And

http://localhost in your browser.

4.2. Finally Check the logs.

 $ cat /usr/local/nginx/logs/access.log
 $ cat /usr/local/nginx/logs/host.access.log

5. Further works

• Nginx preference directives
• Use more functions for ‘echo-nginx-module’
• Other usuful nginx modules installation
• Vim shortcut

6. Reference

6.1. https://github.com/openresty/echo-nginx-module#installation
6.2. https://github.com/openresty/echo-nginx-module#echo_read_request_body