Can I replicate nginx's "time_iso8601" variable in unit?

[bunny-therapist]

I am experimenting with porting an nginx+uwsgi setup to unit, and when trying to replicate the access log format, I ran into the problem that the nginx format used the time_iso8601 variable (described here), but I could not find such a variable in unit, just time_local. Is there another way to get ISO 8601 format for the time?

[lcrilly]

You can get an ISO date string with a JavaScript template literal. Here is a sample configuration for a very simple log format.

{
  "access_log": {
    "path": "/dev/stdout",
    "format": "`@timestamp=${new Date().toISOString()} ip=${remoteAddr} uri=${uri}`"
  }
}

However, when using JavaScript, you don't currently have access to the rest of Unit's variables (issue #977) until (PR #1024) arrives in the next release.

[bunny-therapist]

I am not sure what this "key=value" structure represents. Is that the raw shape of the log text? I want the log output to be in json format, so I wrote the whole log string as a json string. I tried using the "new Date()..." code there, but it did not work. Was that just because I used ot

This is my current log format that I want to have an ISO timestamp in:

"{\"@timestamp\":\"$time_local\",\"remote_addr\":\"$remote_addr\",\"request\":\"$request_line\",\"status\": \"$status\",\"body_bytes_sent\":\"$body_bytes_sent\",\"request_time\":\"$request_time\",\"http_referrer\":\"$header_referer\",\"http_user_agent\":\"$header_user_agent\", \"request_id\":\"$response_header_x_request_id\"}"

This is the old nginx log config that I am trying to replicate:

log_format json_combined
  '{"@timestamp":"$time_iso8601","remote_addr":"$remote_addr","remote_user":"$remote_user","request":"$request","status": "$status","body_bytes_sent":"$body_bytes_sent","request_time":"$request_time","http_referrer":"$http_referer","http_user_agent":"$http_user_agent", "request_id":"$sent_http_x_request_id"}';
  access_log /dev/stdout json_combined

Will I be able to replicate this somehow?

[lcrilly]

This is as close as I can get with Unit 1.31.1

"format": "`{\"@timestamp\":\"${new Date().toISOString()}\",\"remote_addr\":\"${remoteAddr}\",\"request\":\"${uri}\",\"http_referer\":\"${headers['Referer'] === undefined ? '-' : headers['Referer']}\",\"http_user_agent\":\"${headers['User-Agent']}\"}`"

Note that request is just the URI and that status, bytes, request_time are missing.

$ curl -i localhost:9000
HTTP/1.1 204 No Content
Server: Unit/1.31.1
Date: Thu, 08 Feb 2024 15:11:33 GMT
Content-Length: 0

{"@timestamp":"2024-02-08T15:11:33.616Z","remote_addr":"127.0.0.1","request":"/","http_referer":"-","http_user_agent":"curl/8.4.0"}

As I mentioned, JavaScript doesn't currently allow you to access all of Unit's variables. That's coming in 1.32.

However, it does allow you to do things you cannot with nginx, such as log all of the request headers

"format": "`{\"timestamp\":\"${new Date().toISOString()}\",\"connection\":{\"client_ip\":\"${remoteAddr}\"},\"request\":{\"uri\":\"${uri}\",\"headers\":${(() => { var h = {}; Object.keys(headers).map(k => h[k] = headers[k]); return JSON.stringify(h); } )()}}}\n`"

[bunny-therapist]

Thank you!