feat: support to use `plugin_config_id` for `consumer` object

[membphis]

Issue description

Now, the router object supports the plugin_config_id, here is the doc link: https://github.com/apache/apisix/blob/master/docs/en/latest/admin-api.md#route

And I think we need to support plugin_config_id for consumer object.

What do you think?

Environment

• all version

[kaori-seasons]

@membphis

Issue description
https://www.processon.com/view/link/626a5b656376891e1c158aad
At present, the configuration items of the nginx file of apisix and the processing flow of APISIX are shown in the following figure

In the calling phase of the ``http_access_phase```` method, the relevant upstream id will be obtained to split the sent data.
And in the init.lua method, the following code will appear

init.lua

function _M.http_access_phase()

    local ngx_ctx = ngx.ctx

    if not verify_tls_client(ngx_ctx.api_ctx) then
        return core.response.exit(400)
    end

    -- always fetch table from the table pool, we don't need a reused api_ctx
    local api_ctx = core.tablepool.fetch("api_ctx", 0, 32)
    ngx_ctx.api_ctx = api_ctx
     local up_id = route.value.upstream_id

    -- used for the traffic-split plugin
    if api_ctx.upstream_id then
        up_id = api_ctx.upstream_id
    end

    if up_id then
 >     local upstream = get_upstream_by_id(up_id)
        api_ctx.matched_upstream = upstream

end

local function get_upstream_by_id(up_id)
    local upstreams = core.config.fetch_created_obj("/upstreams")
    if upstreams then
        local upstream = upstreams:get(tostring(up_id))
        if not upstream then
            core.log.error("failed to find upstream by id: " .. up_id)
            if is_http then
                return core.response.exit(502)
            end

            return ngx_exit(1)
        end

        if upstream.has_domain then
            local err
            upstream, err = parse_domain_in_up(upstream)
            if err then
                core.log.error("failed to get resolved upstream: ", err)
                if is_http then
                    return core.response.exit(500)
                end

                return ngx_exit(1)
            end
        end

        core.log.info("parsed upstream: ", core.json.delay_encode(upstream, true))
        return upstream.dns_value or upstream.value
    end
end

To understand how router.lua is called based on upstream_id, I traced the following code.
In the request process of Route's admin api:

local function filter(route)
    route.orig_modifiedIndex = route.modifiedIndex
    route.update_count = 0

    route.has_domain = false
    if not route.value then
        return
    end

    if route.value.host then
        route.value.host = str_lower(route.value.host)
    elseif route.value.hosts then
        for i, v in ipairs(route.value.hosts) do
            route.value.hosts[i] = str_lower(v)
        end
    end

    apisix_upstream.filter_upstream(route.value.upstream, route)

    core.log.info("filter route: ", core.json.delay_encode(route, true))

To sum up, I think that consumer.lua should do some attribute extraction before calling the apisix_upstream.filter_upstream method and then execute the filter. So based on this idea, I decided to follow up the related call link of route call /upstream

I would like to know suppose now that I want to configure a set of admin api as shown below, how should I do the relevant verification on the consumer side to complete the connectivity test of calling /upstream from the route /consumer?

location /apisix/admin {
            set $upstream_scheme             'http';
            set $upstream_host               $http_host;
            set $upstream_uri                '';

                allow 127.0.0.0/24;
                deny all;

            content_by_lua_block {
                apisix.http_admin()
            }
        }

[tzssangglass]

Hi @complone , from your trace path, I think you have missed the key point, APISIX merge the consumer's plugins and route's plugins is here:

apisix/apisix/plugin.lua

Lines 491 to 513 in 4afc8a7

	local function merge_consumer_route(route_conf, consumer_conf)
	if not consumer_conf.plugins or
	core.table.nkeys(consumer_conf.plugins) == 0
	then
	core.log.info("consumer no plugins")
	return route_conf
	end
	local new_route_conf = core.table.deepcopy(route_conf)
	for name, conf in pairs(consumer_conf.plugins) do
	if not new_route_conf.value.plugins then
	new_route_conf.value.plugins = {}
	end
	if new_route_conf.value.plugins[name] == nil then
	conf._from_consumer = true
	end
	new_route_conf.value.plugins[name] = conf
	end
	core.log.info("merged conf : ", core.json.delay_encode(new_route_conf))
	return new_route_conf
	end

[kaori-seasons]

@tzssangglass

I understand that I should define the relevant plugin_config_id in shcema_def.lua, and then set the relevant plugin_config_id in consumer.lua#plugin_consumer

shcema_def.lua

_M.consumer = {
    type = "object",
    properties = {
        username = {
            type = "string", minLength = 1, maxLength = rule_name_def.maxLength,
            pattern = [[^[a-zA-Z0-9_]+$]]
        },
  >    id = id_schema,
        plugins = plugins_schema,
        labels = labels_def,
        create_time = timestamp_def,
        update_time = timestamp_def,
        desc = desc_def,
    },
    required = {"username"},
}

consumer.lua

local function plugin_consumer()
    local plugins = {}

    if consumers.values == nil then
        return plugins
    end

    for _, consumer in ipairs(consumers.values) do
        if type(consumer) ~= "table" then
            goto CONTINUE
        end

        for name, config in pairs(consumer.value.plugins or {}) do
            local plugin_obj = plugin.get(name)
            if plugin_obj and plugin_obj.type == "auth" then
                if not plugins[name] then
                    plugins[name] = {
                        nodes = {},
                        conf_version = consumers.conf_version
                    }
                end

                local new_consumer = core.table.clone(consumer.value)
                -- Note: the id here is the key of consumer data, which
                -- is 'username' field in admin
          >     new_consumer.id = consumer.value.id

                new_consumer.consumer_name = new_consumer.id
                new_consumer.auth_conf = config
                core.log.info("consumer:", core.json.delay_encode(new_consumer))
                core.table.insert(plugins[name].nodes, new_consumer)
            end
        end

        ::CONTINUE::
    end

    return plugins
end

I will start testing the relevant request processing link in the near future