Using custom Kong Configuration

[venkatb-zelar]

Is is possible to customise the Kong configuration through a kong.conf file or through and environment variable?

for ex:

env:
  MY_CUSTOM_ENV: mycustomval

[Tieske]

in the tests you can specify enviornment variables, that will override whatever is in kong.conf

[venkatb-zelar]

But i need this during development. Let's say i want to connect to AWS secret manager, i'll have to add few environment variables.

[Tieske]

see here: https://github.com/Kong/kong-plugin/blob/master/spec/myplugin/02-integration_spec.lua#L29-L36

each entry in that table is exported. For example it has plugins = "...". that value will be exported as export "KONG_PLUGINS=..." before starting Kong.

This allows you to override all of the kong.conf file settings

[venkatb-zelar]

If i'm not wrong that will take affect only during test runs. But what if i want to do something like:

pongo up
pongo shell
kms

and then:

pongo expose

Make code code changes in the plugin and i need a custom config like said above?

[Tieske]

after you start the shell (before kms in your example) you can add them?

If you want to automate it you can use the initialization scripts. See https://github.com/Kong/kong-pongo?tab=readme-ov-file#test-initialization

[venkatb-zelar]

after you start the shell (before kms in your example) you can add them?

I tried but i think it has no affect.

If you want to automate it you can use the initialization scripts. See https://github.com/Kong/kong-pongo?tab=readme-ov-file#test-initialization

Again we are talking about tests here. And my requirement is not with tests but with development.

One hacky workaround is to simply add these env vars in the assets/docker-compose.yaml in the pongo source itself.

[Tieske]

the test initialization scripts run whenever a container is started, either on run or on shell. So that should work for your use case.

Please provide more details and exact commands you tried with expected and received output.

[pieterjvrensburg]

Hello @Tieske, I am coming to this open issue with a similar and different requirement. I need to customise what happens in my tests as I am using a redis cluster dependancy in the custom plugin, and it requires one to set up a lua_shared_dict. I have tried to change nginx template and forced rebuild of the test image, however when the tests run it seems that the dictionary is still not there.

kong-versions/3.9.0/kong/spec/fixtures/custom_nginx.template

Do you have any suggestions on how to achieve this?

[Tieske]

@pieterjvrensburg see here for definition of the environment variables: Kong/kong#14346 this defines a shared dict. That issue is actually about defining multiple at the same time.

Now when you start kong in your tests, you can define the environment variable, see the start_kong call here: https://github.com/Kong/kong-plugin/blob/master/spec/myplugin/10-integration_spec.lua#L28-L37

In that code the entry plugins = "bundled," .. PLUGIN_NAME results in an environment variable KONG_PLUGINS=bundled,myplugin being defined when Kong is started for the tests (key is converted to all-caps and prefixed with "KONG_").

So adding in that table nginx_main_lua_shared_dict = "my_cache 10m", should result in a dictionary being created in your test instance.

[Arjen10]

@pieterjvrensburg see here for definition of the environment variables: Kong/kong#14346 this defines a shared dict. That issue is actually about defining multiple at the same time.

Now when you start kong in your tests, you can define the environment variable, see the start_kong call here: https://github.com/Kong/kong-plugin/blob/master/spec/myplugin/10-integration_spec.lua#L28-L37

In that code the entry plugins = "bundled," .. PLUGIN_NAME results in an environment variable KONG_PLUGINS=bundled,myplugin being defined when Kong is started for the tests (key is converted to all-caps and prefixed with "KONG_").

So adding in that table nginx_main_lua_shared_dict = "my_cache 10m", should result in a dictionary being created in your test instance.

after trying your solution, the generated configuration file and the error message are as follows.

assert(helpers.start_kong({
        -- use the custom test template to create a local mock server
        nginx_conf = "spec/fixtures/custom_nginx.template",
        -- make sure our plugin gets loaded
        plugins = "bundled," .. PLUGIN_NAME,
        nginx_main_lua_shared_dict = "my_cache 10m"
      }))

nginx.conf

  1 # This is a custom nginx configuration template for Kong specs
  2 
  3 pid pids/nginx.pid; # mandatory even for custom config templates
  4 
  5 
  6 error_log logs/error.log debug;
  7 
  8 # injected nginx_main_* directives
  9 daemon on;
 10 lua_shared_dict my_cache 10m;
 11 user kong kong;
 12 worker_processes 1;
 13 worker_rlimit_nofile 4096;

erro message

Error: nginx configuration is invalid (exit code 1):
nginx: [emerg] "lua_shared_dict" directive is not allowed here in /kong-plugin/servroot/nginx.conf:10
nginx: configuration file /kong-plugin/servroot/nginx.conf test failed

however, it works perfectly when I use the HTTP include method

local inject_file_path = "/tmp/token-cache.conf"
      local f = assert(io.open(inject_file_path, "w"))
      f:write([[
          lua_shared_dict kong_token_cache 10m;
      ]])
      f:close()
      assert(helpers.start_kong({
        -- use the custom test template to create a local mock server
        nginx_conf = "spec/fixtures/custom_nginx.template",
        -- make sure our plugin gets loaded
        plugins = "bundled," .. PLUGIN_NAME,
        nginx_http_include = inject_file_path
      }))