Issue with upgrading Kong custom plugin

[narendrapatel]

Kong version 2.5.0
OS : Centos 7.9
POstgreSQL : 9.6

Trying to upgrade a custom plugin developed for Kong version 0.13.0. In this plugin we are extending the API endpoint to add custom functionality. Facing an error around it in the before section of the endpoint config.

custom endpoint : /eg-rate-limiting/rules/:rule_name

Errors in Kong logs: 2021/07/27 12:32:46 [error] 5004#0: *66 [kong] endpoints.lua:117 [postgres] invalid primary key: '{id="not a primary key",rule_name="missing primary key"}', client: 192.168.33.1, server: kong_admin, request: "GET /eg-rate-limiting/rules/only_request_uri HTTP/1.1", host: "192.168.33.11:8001"

The said key rule_name is already a primary key in eg_ratelimiting_rules table in PostgreSQL.

schema in daos.lua:

local RULES_SCHEMA = {
	primary_key = {"rule_name"},
	name = "eg_ratelimiting_rules",
    fields = {
		{ rule_id = typedefs.uuid },
		{ rule_name = { type = "string" },},
		{ rule = { type = "string" }, }
    },
}
return {
  eg_ratelimiting_rules = RULES_SCHEMA
}

Endpoint config in api.lua:

local eg_ratelimiting_rules_schema = kong.db.eg_ratelimiting_rules.schema
["/eg-rate-limiting/rules/:eg_ratelimiting_rules"] = {
    schema = eg_ratelimiting_rules_schema,
    methods = {
      before = function(self, db, helpers) 
        local rules, err_t = endpoints.select_entity(self, db, eg_ratelimiting_rules_schema)
        if err_t then
          return endpoints.handle_error(err_t)
        end
        if not rules then
          return kong.response.exit(HTTP_NOT_FOUND, { message = "Not found" })
        end                                          
      self.rule = rules[1]
      end,
      GET  = endpoints.get_entity_endpoint(eg_ratelimiting_rules_schema),
  }

schema is postgresql db:

kong=> \d eg_ratelimiting_rules
Table "public.eg_ratelimiting_rules"
  Column   | Type | Modifiers 
-----------+------+-----------
 rule_id   | uuid | 
 rule_name | text | not null
 rule      | text | 
Indexes:
    "eg_ratelimiting_rules_pkey" PRIMARY KEY, btree (rule_name)

kong=> 

Any help would be appreciated.

[locao]

Hello @narendrapatel!

It seems that Kong infers that your endpoint key is an id, which happens by your daos.lua is missing an endpoint_key field. Please take a look at how it is used in the transformations test plugin. It might fix your issue.

[narendrapatel]

@locao
I confirm the endpoint_key config worked for me.
Thank you so much.