It would be better to refactor these three changes into a function, instead of three if-else blocks.

We have promised to support the latest three versions of OpenResty, so we still need to cover 1.19.3.2.
What about updating the test case and only running it when the version is matched, like https://github.com/apache/apisix/blob/release/2.14/t/plugin/ext-plugin/sanity-openresty-1-19.t?

It would be better to refuse to start when the OpenResty is too old and k8s discovery is used in the stream.

We have promised to support the latest three versions of OpenResty, so we still need to cover 1.19.3.2.
What about updating the test case and only running it when the version is matched, like https://github.com/apache/apisix/blob/release/2.14/t/plugin/ext-plugin/sanity-openresty-1-19.t?

ok, i will try it later.

It would be better to refuse to start when the OpenResty is too old and k8s discovery is used in the stream.

Is it a good choice if we add a boolean field like enable_stream(default is false) into apisix/discovery/kubernetes/schema.lua as a property and check OpenResty version when enable_stream is true?

Can you give me some hints? thanks.

something like

@spacewander

• first, it will cause err like below when start apisix with openresty 1.19.3.2, because local discovery = require("apisix.discovery.init").discovery in apisix/upstream.lua:19 will import discovery/kubernetes/init.lua.

$ ./bin/apisix start
/usr/local/openresty-debug//luajit/bin/luajit ./apisix/cli/apisix.lua start
nginx: [error] init_by_lua error: /usr/local/openresty-debug/lualib/ngx/process.lua:5: unsupported subsystem: stream
stack traceback:
        [C]: in function 'error'
        /usr/local/openresty-debug/lualib/resty/core/base.lua:223: in function 'allows_subsystem'
        /usr/local/openresty-debug/lualib/ngx/process.lua:5: in main chunk
        [C]: in function 'require'
        ...ng/Documents/apisix/apisix/discovery/kubernetes/init.lua:29: in main chunk
        [C]: in function 'require'
        /home/ronething/Documents/apisix/apisix/discovery/init.lua:28: in main chunk
        [C]: in function 'require'
        /home/ronething/Documents/apisix/apisix/upstream.lua:19: in main chunk
        [C]: in function 'require'
        /home/ronething/Documents/apisix/apisix/http/service.lua:18: in main chunk
        [C]: in function 'require'
        /home/ronething/Documents/apisix/apisix/init.lua:35: in main chunk
        [C]: in function 'require'
        init_by_lua:3: in main chunk

• then, something like if conf.pass_host == "node" and conf.nodes and in check_upstream_conf function may only print error log when check upstream if in_dp is true, or cause err when create/modify upstream or other resource which need to check upstream_conf both in http and stream subsystem. But we need to refuse to start apisix when the OpenResty is too old and k8s discovery is used in the stream?

so maybe we should consider other solutions? if something i was wrong, please tell me, thanks.

But we need to refuse to start apisix when the OpenResty is too old and k8s discovery is used in the stream?

Yes. Unlike the upstream conf which is a runtime conf, the wrong discovery conf in the yaml can't be corrected without restarting APISIX.

And we need to provide a clear error message so people don't need to debug it.

We can pass the id as the argument, and put the constant kubernetes in this function? There is no need to repeat it.

We can use ',' here

@spacewander do you mean something like below? .. ngx.config.subsystem .. ", "

if not support_process then
    core.log.error("kubernetes discovery not support in subsystem: "
                   .. ngx.config.subsystem .. ", "
                   .. "please check if your openresty version >= 1.19.9.1 or not")
    return
end

Err. What I mean is that we can use ',' instead of '..'.

ok, i see. I will change it later.