In earlier versions of haproxy, the txn.f object had a `date()` method when
called from a fetch context which returned the current unix timestamp. In
HAproxy 2.2, this method is removed.
The `date()` fetch is still documented and works fine from bare haproxy
config, so I'm not sure why Lua can't hit it.
For a minimal reproducer, stick the following in "helpers.lua":
core.register_fetches("date_wrapper", function(txn)
core.Debug("fetching r_u_i\n")
local date = txn.f:date()
core.Debug(string.format("current date is %d", date))
return string.format("%08x", date)
end)
Then run the following haproxy config:
global
maxconn 65536
lua-load "helpers.lua"
hard-stop-after 30m
defaults
timeout server 10s
timeout client 10s
timeout connect 1s
frontend test_fe
mode http
bind 127.0.0.1:9993
http-response add-header Lua-Fetch %[lua.date_wrapper]
http-response add-header Regular-Fetch %[date]
default_backend test_be
backend test_be
mode http
server localhost 127.0.0.1:9992
This will work fine in haproxy 2.0.x (didn't test 2.1.x yet) and will fail
with "Lua sample-fetch 'date_wrapper': runtime error: helpers.lua:3:
attempt to call a nil value (method 'date') from helpers.lua:3 C function
line 1" on haproxy 2.2.x.
My best guess is that this is related to ae6f125c
<https://github.com/haproxy/haproxy/commit/ae6f125c7b33454770aaa363101384e8daafc2a2>
but
I don't really understand how sample fetchers are mapped into the Lua API,
so this is just a guess. Is it possible that two-optional-argument sample
fetchers just don't work?
I can work around this by doing `os.time()` but I'd just as soon be reusing
haproxy's unix timestamp rather than doing another system call, and afaik
os.time() isn't portably guaranteed to be a unix timestamp or to be in UTC.
Unrelatedly: the "Lua reference manual" linked in the documentation
<http://www.haproxy.org/#docs>z` (
http://www.arpalert.org/src/haproxy-lua-api/2.0dev/index.html) is now a
403. I believe the correct URL is
https://www.arpalert.org/src/haproxy-lua-api/2.2dev/index.html.
--
James Brown
Engineer
