Error "plugin is in use but not enabled" in kong environment - lua

Question

We are trying to use the hello-world plugin described in this page - https://streamdata.io/blog/developing-an-helloworld-kong-plugin/
also we have tried this as well - https://github.com/brndmg/kong-plugin-hello-world
We are facing this error in logs:
2017/09/19 09:47:15 [error] 1#0: init_by_lua error: /usr/local/share/lua/5.1/kong.lua:154: hello-world plugin is in use but not enabled
stack traceback:
[C]: in function 'assert'
/usr/local/share/lua/5.1/kong.lua:154: in function 'init'
init_by_lua:3: in main chunk
The Kong version we are using is 0.11.0.
Can someone suggest what could we be missing?

Answer 1

Kong raises this error because you are asking it to run a plugin called hello-world, without providing the code for this plugin.
This error is trying to say that this plugin is configured to be running on an API/Consumer in the datastore (PostgreSQL or Cassandra), but not added to the Kong configuration custom_plugins settings.
To load a custom plugin, you need two things:
The plugin must be installed in the LUA_PATH (refer to the docs here)
The plugin name must be added to the custom_plugins setting for Kong to load it (from the LUA_PATH)
You can edit your configuration file to make Kong load the plugin:
custom_plugins = hello-world
or specify it via an environment variable:
export KONG_CUSTOM_PLUGINS=hello-world
If you are still seeing this error, it could mean that you are not starting Kong with the configuration file you are editing. Start Kong in verbose mode to see what configuration file it is reading and what is the values of custom_plugins:
$ kong start --vv
You can read more on how to install and custom plugins for 0.11 in the Plugins Development Guide section of the website.

Answer 2

I fixed this issue by adding things in custom_plugins and lua_package_path .
Here are the steps to enable and use custom plugin in kong Env.
1 - Add custom plugin name in --- custom_plugins = hello-world
2 - Install hello-world plugin by using following steps ---
If you have source code of your plugin then move into it and execute the command --- "luarocks make"
it will install your plugin.
now you have to execute a command "make install-dev" make sure your plugin have makefile like as --
Once you execute this command "make install-dev". it will create lua file at a location something like that -
/your-plugin-path/lua_modules/share/lua/5.1/kong/plugins/your-plugin-name/?.lua
just copy this path and add it into the kong configuration file in lua_package_path
Something like that --
lua_package_path=/your-plugin-path/lua_modules/share/lua/5.1/kong/plugins/your-plugin-name/?.lua
Now you done your job.
Just start kong -- kong start --vv
You will see that the plugin loaded into kong plugin env.
#Enjoy