nginx-log-peeker

nginx-log-peeker

Tool to peek at the NGINX access logs only when needed, without saving them to disk.

NGINX can send its access logs to a named pipe (FIFO) on the filesystem, and it does a reasonably good job at fault isolation if the pipe can't be written to during normal operation. Unfortunately, it will still block on reloads and other occasions unless there is an active listener on the pipe. The purpose of this program is to constantly read from the logs FIFO, and provide a copy of it to clients connecting to the daemon through a local UNIX socket.

This allows real-time debugging and analysis, without necessarily having to store logs to disk at any time (which may be undesirable for compliance purposes).

Usage

1. Create the FIFO used to communicate with NGINX, and make sure that the user that NGINX is running as can write to it:

    $ mkfifo --mode=0700 /var/run/nginx/log-fifo
    $ chown www-data /var/run/nginx/log-fifo
   

2. Edit your nginx.conf to tell NGINX to write the HTTP access logs to the named pipe:

    http {
        access_log /var/run/nginx/log-fifo
        ...
    }
   

3. Start the nginx-log-peeker daemon:

    $ nginx-log-peeker &
   

4. Connect to the log peeker UNIX socket to retrieve logs in real-time whenever you need to debug something:

    $ socat UNIX-CONNECT:/var/run/nginx/log-peek -