## Simple logging Api in nginx

A HTTP POST API `/log` for hobby apps.

1. log rotate by `/etc/logrotate.d/nginx` without extra configuring
2. api limit by `limit_req_zone` 
3. app client might add a sample rate to prevent abuse requests such as sentry javascript sdk [sample rate 0 to 1](https://github.com/getsentry/sentry-javascript/blob/master/packages/core/src/baseclient.ts#L550)


`/etc/nginx/sites-enable/default.conf` 


```

.....

limit_req_zone $binary_remote_addr zone=mytracking:10m rate=10r/s;

log_format my-tracking-format escape=json '$remote_addr - $remote_user [$time_local] '
                       '"$request" $status $bytes_sent '
                       '"$http_referer" "$http_user_agent" "$request_body"';

server {
  listen 80 default_server;
  
.....

location = /log {
  limit_req zone=mytracking burst=20 nodelay;
  access_log /mnt/logs/nginx/my-tracking.access.log my-tracking-format;
  proxy_pass http://localhost:80/empty;
}

location = /empty {
  access_log off;
  return 200 'logged';
}

.....
}

server {
  listen 443 ssl;
  
  .....
  
  location = /log {
    limit_req zone=mytracking burst=20 nodelay;
    access_log /mnt/logs/nginx/my-tracking.access.log my-tracking-format;
    proxy_pass http://localhost:80/empty;
  }
  .....
}
```

version: `nginx version: nginx/1.14.0 (Ubuntu)`

### Test

request 

`curl -d '{"key1":"value1", "key2":"value2"}' -H "Content-Type: application/json" -X POST https://yourserver.com/log`

checking log

`tail  -f /var/log/nginx/my-tracking.access.log`


references:

https://stackoverflow.com/questions/17609472/really-logging-the-post-request-body-instead-of-with-nginx

https://stackoverflow.com/a/14034744/6414615