Can I add a path parameter from plugin_api?

[elvus]

I want to add a path parameter, like:

local function public_api(conf, ctx) --  not working
    -- Extract the path parameter (e.g., `:route_id` from the URI)
    local route_id = ctx.var.route_id 
    
    return 200, {
        msg = "public_api",
        route_id = route_id
    }
end

-- module interface for export public api
function _M.api()
    return {
        {
            methods = {"GET"},
            uri = "/apisix/plugin/demo/public_api/:route_id", -- not working
            handler = public_api,
        }
    }
end

[dosubot[bot]]

Yes, you can add a URL (path) parameter to a plugin API endpoint using the :param syntax in the URI. However, to extract the parameter in your handler, you should use ctx.curr_req_matched.route_id instead of ctx.var.route_id. The value will be available in ctx.curr_req_matched if the route is matched and the router supports parameter extraction.

So, update your handler like this:

local function public_api(conf, ctx)
    local route_id = ctx.curr_req_matched and ctx.curr_req_matched.route_id
    return 200, {
        msg = "public_api",
        route_id = route_id
    }
end

This approach matches how APISIX exposes path variables in the context for parameterized routes, including plugin APIs, as described in the APISIX documentation. If ctx.curr_req_matched is nil, double-check that your plugin API is registered correctly and that the router logic for plugin APIs is being used.

To reply, just mention @dosu.

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[SkyeYoung]

Hi, pls check the doc https://apisix.apache.org/docs/apisix/router-radixtree/.

and

apisix/apisix/utils/router.lua

Line 24 in e90570a

no_param_match = true

[SkyeYoung]

Also, is it absolutely necessary to do it this way? If it's not necessary, something like

apisix/apisix/plugins/jwe-decrypt.lua

Lines 226 to 227 in e90570a

	local args = core.request.get_uri_args()
	if not args or not args.key then

might be simpler.

[SkyeYoung]

As a simpler alternative, you can also try the prefix matching mentioned in the above documentation.

[elvus]

Thanks @SkyeYoung I solved it:

{
    methods = {"GET"},
    uri = string.format("%s/example/*", prefix),
    handler = function(ctx)
        local path = ctx.var.uri:match("/example/(.*)$") -- extract the path parameter
        return 200, {message = "OK", path = path}
    end,
}