Simple Log Service:Parse CSV-formatted logs

Standard CSV-formatted logs

• Raw log

  _program_:error
  _severity_:6
  _priority_:14
  _facility_:1
  topic:syslog-forwarder
  content:198.51.100.1|10/Jun/2019:11:32:16 +0800|aliyundoc.com|GET /zf/11874.html HTTP/1.1|200|0.077|6404|198.51.100.10:8001|200|0.060|https://example.com/s?q=%25%24%23%40%21&from=wy878378&uc_param_str=dnntnwvepffrgibijbprsvdsei|-|Mozilla/5.0 (Linux; Android 9; HWI-AL00 Build/HUAWEIHWI-A00) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Mobile Safari/537.36|-|-

• Requirements

  1. If the _program_ field is set to access, parse the content field as a pipe-separated value (PSV). Then, delete the content field.

  2. Split the request field into the request_method, request, and http_version fields.

  3. http_referer is URL-decoded.

  4. Format the time field.

• Solution

  1. If the _program_ field is set to access, you can use the e_psv function to parse the content field and then delete the original content field.

     e_if(e_search("_program_==access"), e_compose(e_psv("content", "remote_addr, time_local,host,request,status,request_time,body_bytes_sent,upstream_addr,upstream_status, upstream_response_time,http_referer,http_x_forwarded_for,http_user_agent,session_id,guid", restrict=True), e_drop_fields("content")))

     The log is updated as follows:

     __source__:  192.168.0.1
     __tag__:__client_ip__:  192.168.0.10
     __tag__:__receive_time__:  1562845168
     __topic__:  
     _facility_:  1
     _priority_:  14
     _program_:  access
     _severity_:  6
     body_bytes_sent:  6404
     guid:  -
     host:  aliyundoc.com
     http_referer:  https://example.com/s?q=%25%24%23%40%21&from=wy878378&uc_param_str=dnntnwvepffrgibijbprsvdsei
     http_user_agent:  Mozilla/5.0 (Linux; Android 9; HWI-AL00 Build/HUAWEIHWI-A00) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Mobile Safari/537.36
     http_x_forwarded_for:  -
     remote_addr:  192.168.0.100
     request:  GET /zf/11874.html HTTP/1.1
     request_time:  0.077
     session_id:  -
     status:  200
     time_local:  10/Jun/2019:11:32:16 +0800
     topic:  syslog-forwarder
     upstream_addr:  192.168.0.100:8001
     upstream_response_time:  0.060
     upstream_status:  200

  2. You can use the e_regex function to parse the request field into the request_method, request, and http_version fields.

     e_regex("request",r"^(?P<request_method>\w+) (?P<request>.+) (?P<http_version>\w+/[\d\.]+)$")

     The log is updated as follows:

     request:  /zf/11874.html
     request_method:  GET
     http_version:  HTTP/1.1

  3. You can URL-decode the http_referer field.

     e_set("http",url_decoding("http_referer"))

     The log is updated as follows:

     http: https://example.com/s?q=%$#@!&from=wy878378&uc_param_str=dnntnwvepffrgibijbprsvdsei

  4. You can format the time value.

     e_set("time_local",dt_strptime(v("time"),"%d/%b/%Y:%H:%M:%S +0800"))

     The log is updated as follows:

     time_local:  2019-06-13 13:45:11

  5. The complete solution is as follows:

     e_if(e_search("_program_==access"), e_compose(e_psv("content", "remote_addr, time_local,host,request,status,request_time,body_bytes_sent,upstream_addr,upstream_status, upstream_response_time,http_referer,http_x_forwarded_for,http_user_agent,session_id,guid", restrict=True), e_drop_fields("content")))
     e_regex("request",r"^(?P<request_method>\w+) (?P<request>.+) (?P<http_version>\w+/[\d\.]+)$")
     e_set("http",url_decoding("http_referer"))
     e_set("time_local",dt_strptime(v("time"),"%d/%b/%Y:%H:%M:%S +0800"))

• Resulting log

  __source__:  192.168.0.1
  __tag__:__client_ip__:  192.168.0.10
  __tag__:__receive_time__:  1562840879
  __topic__:  
  _facility_:  1
  _priority_:  14
  _program_:  access
  _severity_:  6
  body_bytes_sent:  6404
  guid:  -
  host:  aliyundoc.com
  http_referer:  https://example.com/s?q=example+search+query&from=wy878378&uc_param_str=dnntnwvepffrgibijbprsvdsei
  http_user_agent:  Mozilla/5.0 (Linux; Android 9; HWI-AL00 Build/HUAWEIHWI-A00) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Mobile Safari/537.36
  http_x_forwarded_for:  -
  remote_addr:  192.168.0.100
  request:  GET /zf/11874.html HTTP/1.1
  request_time:  0.077
  session_id:  -
  status:  200
  time_local:  10/Jun/2019:11:32:16 +0800
  topic:  syslog-forwarder
  upstream_addr:  192.168.0.100:8001
  upstream_response_time:  0.060
  upstream_status:  200
  http: https://example.com/s?q=example search query&from=wy878378&uc_param_str=dnntnwvepffrgibijbprsvdsei

Abnormal CSV-formatted logs