Question

What's the proper way (if there is one) to update an already existing Kong custom plugin? And what about uninstalling it?

Details

I've been struggling a bit while trying to test and debug my Kong custom plugins.

The documentation provides a section "Deploying custom plugins" that explains how to install the custom plugin, while installing Kong, so that it can be used later on.

Given that I already installed Kong, I tried using helm upgrade, instead of helm install, to update the values. This way I was able to use the plugin the first time:

1. I sent a request to a route using the plugin:

curl -i localhost/foobar/test/custom/myheader[...]

2. The gateway logs showed the following entry:

2023/11/28 09:11:24 [notice] 1262#0: *392 [kong] handler.lua:8 [myheader] "LOG: test", client: X.X.0.1, server: kong, request: "GET /foobar/test/custom/myheader HTTP/1.1", host: "localhost"X.X.0.1 - - [28/Nov/2023:09:11:24 +0000] "GET /foobar/test/custom/myheader HTTP/1.1" 200 17 "-" "curl/8.2.1"

However, it seems like I cannot change them a second time:

1. I deleted the ConfigMap kong-plugin-myheader;
2. I deleted the KongPlugin my-custom-plugin;
3. I upgraded helm with an empty values.yaml;
4. I created a new ConfigMap kong-plugin-myheader with the new code (see below "after");
5. I created a new KongPlugin my-custom-plugin;
6. I sent another request, but still see the same log message (therefore I'm guessing the custom plugin was not updated).

To effectively see the changes, I have to uninstall and reinstall Kong entirely. Isn't there a better/quicker approach?

Resources

Custom Plugin "myheader"

File Structure

myheader/myheader/handler.luamyheader/schema.lua

File handler.lua before

local MyHeader = {}MyHeader.PRIORITY = 1000MyHeader.VERSION = "1.0.0"function MyHeader:header_filter(conf)    -- test    kong.log('"LOG: test"')endreturn MyHeader

File handler.lua after

local MyHeader = {}MyHeader.PRIORITY = 1000MyHeader.VERSION = "1.0.0"function MyHeader:header_filter(conf)    -- test    kong.log('"LOG: test NEW"')endreturn MyHeader

File schema.lua

return {    name = "myheader",    fields = {        {            config = {                    type = "record",                    fields = {                    { header_value = { type = "string", default = "roar", }, },                },            },         },    }}

File values.yaml

gateway:  plugins:    configMaps:    - name: kong-plugin-myheader      pluginName: myheader

KongPlugin my-custom-plugin

apiVersion: configuration.konghq.com/v1kind: KongPluginmetadata:  name: my-custom-pluginconfig:  header_value: "my first plugin"plugin: myheader

Service foobar

# DeploymentapiVersion: apps/v1kind: Deploymentmetadata:  labels:    app: foobar  name: foobar[...]---# ServiceapiVersion: v1kind: Servicemetadata:  labels:    app: foobar-service  name: foobar-servicespec:  [...]  selector:    app: foobar # referencing metadata.labels.app (set of key-value)---# Route /foobar/test/custom/myheaderapiVersion: gateway.networking.k8s.io/v1kind: HTTPRoutemetadata:  name: foobar-route-test-custom-myheader  annotations:    konghq.com/strip-path: 'true'    konghq.com/plugins: 'my-custom-plugin'spec:  parentRefs:  - name: kong  rules:  - matches:    - path:        type: PathPrefix        value: /foobar/test/custom/myheader    backendRefs:    - name: foobar-service      kind: Service      port: 3000