Why is the program hanging when using LUA filter?

[chenmonster]

• The contents of the fluent-bit.conf file are as follows:

[INPUT]
    name     udp
    tag      test-udp
    listen   0.0.0.0
    port     5170
    format   none

[FILTER]
    name     lua
    alias    extract-lua
    match    test-udp
    script   extract.lua
    call     handle
    protected_mode false

[OUTPUT]
    name  stdout
    match *

• The contents of the extract.lua file are as follows:

print(_VERSION)
package.path = "./?.lua;D:/cjson/lua/?.lua"
package.cpath = "./?.dll;D:/cjson/?.dll"
print(package.path)
print(package.cpath)
local cjson = require("cjson")
print("path: ", package.path)
print("cpath: ", package.cpath)

function handle(tag, timestamp, record)
  local log_str = record["log"]
  print("log is: ", log_str)

  local pri, month_str, day, hour, min, sec, pro, json_str = string.match(log_str, "<(%d+)>(%a+) +(%d+) (%d+):(%d+):(%d+) bastion bh_audit_sender%[(%d+)%]: (.+)")
  if pri == nil or month_str == nil or day == nil or hour == nil or min == nil or sec == nil or pro == nil or json_str == nil then
    print("invalid log: ", log_str)
    return -1, timestamp, record
  end
  
  record["pri"] = tonumber(pri)
  record["pro"] = tonumber(pro)
  local json_table = cjson.decode(json_str)
  for k, v in pairs(json_table) do
    record[k] = v
  end

  local month_map = {
    Jan = 1, Feb = 2, Mar = 3, Apr = 4, May = 5, Jun = 6,
    Jul = 7, Aug = 8, Sep = 9, Oct = 10, Nov = 11, Dec = 12
  }

  local time_table = {
    year = os.date("*t").year,
    month = month_map[month_str],
    day = tonumber(day),
    hour = tonumber(hour),
    min = tonumber(min),
    sec = tonumber(sec),
  }

  local date = os.time(time_table)
  local date_str = os.date("%Y-%m-%d %H:%M:%S", date)
  record["time"] = date_str
  return 2, timestamp, record
end

• When running the command,

fluent-bit -c D:/Developer/fluent-bit-3.1.9-win64/conf/fluent-bit.conf

• the program hangs and the print prints are not output.
  

cjson.zip

[patrick-stephens]

Is it actually receiving any data to feed the filter?
I would switch to a dummy input to start with and test with that.

[patrick-stephens]

Ah, you're requiring the cjson LUA module - is that installed and in the right place for it to be found?
It prints out stuff before that require statement then nothing after.

[chenmonster]

Ah, you're requiring the cjson LUA module - is that installed and in the right place for it to be found? It prints out stuff before that require statement then nothing after.

The cjson LUA module is in the correct location, which is the contents of cjson.zip, under the D drive.

[patrick-stephens]

So other LUA scripts work when you use it? That's my suspicion if you're receiving data to feed the filter. Normally I just put it in the same directory.

[chenmonster]

So other LUA scripts work when you use it? That's my suspicion if you're receiving data to feed the filter. Normally I just put it in the same directory.

When I comment out the local cjson = require("cjson") related code, it outputs the logs properly

print(_VERSION)
package.path = "./?.lua;D:/cjson/lua/?.lua"
package.cpath = "./?.dll;D:/cjson/?.dll"
print(package.path)
print(package.cpath)
-- local cjson = require("cjson")
print("path: ", package.path)
print("cpath: ", package.cpath)

function handle(tag, timestamp, record)
  local log_str = record["log"]
  print("log is: ", log_str)

  local pri, month_str, day, hour, min, sec, pro, json_str = string.match(log_str, "<(%d+)>(%a+) +(%d+) (%d+):(%d+):(%d+) bastion bh_audit_sender%[(%d+)%]: (.+)")
  if pri == nil or month_str == nil or day == nil or hour == nil or min == nil or sec == nil or pro == nil or json_str == nil then
    print("invalid log: ", log_str)
    return -1, timestamp, record
  end
  
  record["pri"] = tonumber(pri)
  record["pro"] = tonumber(pro)
  --[[
  local json_table = cjson.decode(json_str)
  for k, v in pairs(json_table) do
    record[k] = v
  end
  --]]

  local month_map = {
    Jan = 1, Feb = 2, Mar = 3, Apr = 4, May = 5, Jun = 6,
    Jul = 7, Aug = 8, Sep = 9, Oct = 10, Nov = 11, Dec = 12
  }

  local time_table = {
    year = os.date("*t").year,
    month = month_map[month_str],
    day = tonumber(day),
    hour = tonumber(hour),
    min = tonumber(min),
    sec = tonumber(sec),
  }

  local date = os.time(time_table)
  local date_str = os.date("%Y-%m-%d %H:%M:%S", date)
  record["time"] = date_str
  return 2, timestamp, record
end

[patrick-stephens]

Sounds like it's something with loading that module then