How to use "]" in a regsub converter inside a log format

[lukastribus]

FYI I posted a workaround via LUA, which also works for log formats here:

Mask sensitive data in logs

No easy way as far as I can see, a feature request for a simpler solution has been posted here: Here’s a LUA workaround: /etc/haproxy/anonymizeToken.lua: local function anonymizeToken(url) if url == nil then return end url = url:gsub("token=[^&]+", "token=******") return url end core.register_converters("anonymizeToken", anonymizeToken) Config: global lua-load /etc/haproxy/anonymizeToken.lua frontend blabla log-format "%[capture.req.uri,lua.anonymizeToken]"