Re: [DISCUSS] chash key support more flexible ways

[Ming Wen]

yuansheng, what do you think?

Thanks,
Ming Wen, Apache APISIX
Twitter: _WenMing


Ming Wen <wenm...@apache.org> 于2019年12月23日周一 下午9:03写道：

> hi, codjust,
> I prefer your design than the existing one[1].
>
> These categories "vars", "header", "cookie", "consumer" are friendly for
> developer.
>
> [1]
> https://github.com/apache/incubator-apisix/blob/master/lua/apisix/schema_def.lua#L261
>
> Thanks,
> Ming Wen, Apache APISIX
> Twitter: _WenMing
>
>
> codjust <hcw1...@foxmail.com> 于2019年12月23日周一 下午8:58写道：
>
>> Now chash key only support fetch from nginx variable. We need to be more
>> flexible approach，
>> eg: cookie, custom header and so on.
>> Here is an example to achieve:
>> upstream json schema：
>> hash_on = {
>> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; type = "string",
>> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; default = "vars",
>> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; enum = {
>> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; "vars",
>> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; "header",
>> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; "cookie",
>> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; "consumer"
>> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; },
>> &nbsp; &nbsp; &nbsp; &nbsp; },
>> &nbsp; &nbsp; &nbsp; &nbsp; key = {
>> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; description = "the key of chash
>> for dynamic load balancing",
>> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; type = "string"
>> &nbsp; &nbsp; &nbsp; &nbsp; },
>>
>>
>> eg:
>> local function create_chash_hash_key(ctx, upstream)
>> &nbsp; &nbsp; local key = upstream.key&nbsp;
>> &nbsp; &nbsp; local hash_on = upstream.hash_on
>> &nbsp; &nbsp; local chash_key
>> &nbsp; &nbsp; -- from nginx variable
>> &nbsp; &nbsp; if hash_on == "vars" then&nbsp;
>> &nbsp; &nbsp; &nbsp; &nbsp; chash_key = ctx.var[key]
>> &nbsp; &nbsp; elseif hash_on == "header" then&nbsp;
>> &nbsp; &nbsp; &nbsp; &nbsp; chash_key = ngx.req.get_headers()[key]
>> &nbsp; &nbsp; elseif hash_on == "cookie" then&nbsp;
>> &nbsp; &nbsp; &nbsp; &nbsp; chash_key = ctx.var["cookie_" .. key]
>> &nbsp; &nbsp; &nbsp; &nbsp; -- TODO chash_key doesn't exist, set-cookie
>> &nbsp; &nbsp; end
>> &nbsp; &nbsp; if not chash_key then&nbsp;
>> &nbsp; &nbsp; &nbsp; &nbsp; chash_key = ctx.var["remote_addr"]
>> &nbsp; &nbsp; end
>> &nbsp; &nbsp; return chash_key
>> end
>>
>>
>> hash_on type desc:
>> 1 vars: fetchs nginx variable
>> 2 header: custom headers or standard http headers
>> 3 cookie: fetch chash key from cookie. It can be used to sticky session
>> 4 consumer: hash by consumer_id
>> If the specified chash key is not present, use default key:
>> remote_addr(it can also provide default settings).
>>
>>
>> everybody have a better idea?
>>
>> github issue:
>> https://github.com/apache/incubator-apisix/issues/992
>
>