function _M.encode(facility, severity, hostname, appname, pid, project,
                   logstore, access_key_id, access_key_secret, msg)
    local pri = (Facility[facility] * 8 + Severity[severity])
    local t = log_util.get_rfc3339_zulu_timestamp()
    if not hostname then
        hostname = "-"
    end

    if not appname then
        appname = "-"
    end

    return "<" .. pri .. ">1 " .. t .. " " .. hostname .. " " .. appname .. " " .. pid
           .. " - [logservice project=\"" .. project .. "\" logstore=\"" .. logstore
           .. "\" access-key-id=\"" .. access_key_id .. "\" access-key-secret=\""
           .. access_key_secret .. "\"] " .. msg .. "\n"
end

return _M