feat: kong plugin (#1073)

| 🚥 Resolves ISSUE_ID |
| :------------------- |

## 🧰 Changes

Add kong plugin

## 🧬 QA & Testing

Follow the "Deploying locally" instructions in the PR

---------

Co-authored-by: Jon Ursenbach <[email protected]>
Co-authored-by: Jon Ursenbach <[email protected]>

.github/MAINTAINERS.md

@@ -97,6 +97,15 @@ This will output a new key, associated with your email address to /tmp/new-ssh-k
 5. Update `./bin/split.sh` and `./.github/workflows/split-monorepo.yml` to include the new mirror and SSH key.
 6. Update the main README.md to include information about the new package.
 
+### Kong Plugin
+
+This does not require a release. Users will simply copy the `kong` directory within `packages/kong-plugin` into their Kong image [see this guide](https://docs.konghq.com/gateway/latest/plugin-development/get-started/deploy/).
+
+In the future:
+
+- We will build a Docker image for the plugin and release it to the Kong Community plugins site.
+- We will offer a zip file with the plugin code.
+
 ## 🧑‍🔬 Integration Testing
 
 We have an integration testing layer for both Metrics and webhooks to ensure that the different SDKs, and how they may be used within a variety of HTTP frameworks, are compliant to the Metrics API and all behave the same given certain parameters.

packages/kong-plugin/.busted

@@ -0,0 +1,7 @@
+return {
+  default = {
+    verbose = true,
+    coverage = false,
+    output = "gtest",
+  },
+}

packages/kong-plugin/.editorconfig

@@ -0,0 +1,22 @@
+root                     = true
+
+[*]
+end_of_line              = lf
+insert_final_newline     = true
+trim_trailing_whitespace = true
+charset                  = utf-8
+
+[*.lua]
+indent_style             = space
+indent_size              = 2
+
+[kong/templates/nginx*]
+indent_style             = space
+indent_size              = 4
+
+[*.template]
+indent_style             = space
+indent_size              = 4
+
+[Makefile]
+indent_style             = tab

packages/kong-plugin/.gitignore

@@ -0,0 +1,12 @@
+# servroot typically is the Kong working directory for tests
+servroot
+# exclude generated packed rocks
+*.rock
+# exclude Pongo shell history
+.pongo/.bash_history
+# exclude LuaCov statistics file
+luacov.stats.out
+# exclude LuaCov report
+luacov.report.out
+# exclude Pongo containerid file
+.containerid

packages/kong-plugin/.luacheckrc

@@ -0,0 +1,35 @@
+std             = "ngx_lua"
+unused_args     = false
+redefined       = false
+max_line_length = false
+
+
+include_files = {
+  "**/*.lua",
+  "*.rockspec",
+  ".busted",
+  ".luacheckrc",
+}
+
+
+globals = {
+    "_KONG",
+    "kong",
+    "ngx.IS_CLI",
+}
+
+
+not_globals = {
+    "string.len",
+    "table.getn",
+}
+
+
+ignore = {
+    "6.", -- ignore whitespace warnings
+}
+
+
+files["spec/**/*.lua"] = {
+    std = "ngx_lua+busted",
+}

packages/kong-plugin/.luacov

@@ -0,0 +1,7 @@
+include = {
+   "%/kong%-plugin%/kong%/.+$",
+}
+
+statsfile = "/kong-plugin/luacov.stats.out"
+reportfile = "/kong-plugin/luacov.report.out"
+runreport = true

packages/kong-plugin/.pongo/pongorc

@@ -0,0 +1 @@
+--postgres

packages/kong-plugin/Dockerfile

@@ -0,0 +1,17 @@
+FROM kong/kong-gateway:3.7
+# Ensure any patching steps are executed as root user
+USER root
+
+# Add custom plugin to the image
+COPY ./kong/plugins/readme-plugin /usr/local/share/lua/5.1/kong/plugins/readme-plugin
+ENV KONG_PLUGINS=bundled,readme-plugin
+
+# Ensure kong user is selected for image execution
+USER kong
+
+# Run kong
+ENTRYPOINT ["/entrypoint.sh"]
+EXPOSE 8000 8443 8001 8444
+STOPSIGNAL SIGQUIT
+HEALTHCHECK --interval=10s --timeout=10s --retries=10 CMD kong health
+CMD ["kong", "docker-start"]

packages/kong-plugin/README.md

@@ -0,0 +1,90 @@
+# ReadMe Metrics + Kong
+
+<p align="center">
+  <img src="https://user-images.githubusercontent.com/33762/182927634-2aebeb46-c215-4ac3-9e98-61f931e33583.png" />
+</p>
+
+<p align="center">
+  Track usage of your API and troubleshoot issues faster.
+</p>
+
+With [ReadMe's Metrics API](https://readme.com/metrics) your team can get deep insights into your API's usage. If you're a developer, it takes a few small steps to send your API logs to [ReadMe](http://readme.com). Here's an overview of how the integration works:
+
+- Install this plugin into your Kong Gateway by copying the `kong` directory into your Kong environment or use the provided Dockerfile. see [this](https://docs.konghq.com/gateway/latest/plugin-development/get-started/deploy/) for details.
+- The plugin runs during the log phase of the Kong pipeline and sends ReadMe the details of your API's incoming requests and outgoing responses, with the option for you to redact any private headers using the configuration options.
+- ReadMe uses these request and response details to create an API Metrics Dashboard which can be used to analyze specific API calls or monitor aggregate usage data.
+
+### 📦 Deploying locally
+
+```bash
+# Build kong image with the plugin
+docker build -t kong-readme-plugin:latest .
+# Run kong with the plugin
+curl -Ls https://get.konghq.com/quickstart |  bash -s -- -r "" -i kong-readme-plugin -t latest
+# Enable the plugin
+curl -isX POST http://localhost:8001/plugins -d name=readme-plugin -d 'config.api_key=<Your API Key>'
+```
+
+### 🧑‍🔬 Testing
+
+Requires [pongo](https://github.com/Kong/kong-pongo) to test and develop.
+
+```bash
+pongo up
+pongo shell
+kms
+
+# Check if the plugin is available
+curl -s localhost:8001 | jq '.plugins.available_on_server."readme-plugin"'
+```
+
+#### Enable for all services
+
+```bash
+curl -sX POST http://localhost:8001/plugins -d name=readme-plugin -d 'config.api_key=<Your API Key>' | jq
+```
+
+#### Enable for a specific service
+
+```bash
+# Add a new service
+curl -isX POST http://localhost:8001/services -d name=example_service -d url='http://httpbin.org'
+
+# Associate the custom plugin with the `example_service` service
+curl -isX POST http://localhost:8001/services/example_service/plugins -d 'name=readme-plugin' -d "config.queue.max_retry_time=1"
+
+# Add a new route for sending requests through the `example_service` service
+curl -iX POST http://localhost:8001/services/example_service/routes -d 'paths[]=/mock' -d name=example_route
+
+# Test
+curl -i http://localhost:8000/mock/anything
+```
+
+### 🧙 Development tricks
+
+```bash
+# Get plugin config
+curl -s http://localhost:8001/plugins  | jq '.data | map(select(.name == "readme-plugin")) | first'
+
+# Retrieve the plugin ID
+export PLUGIN_ID=$(curl -s http://localhost:8001/plugins  | jq '.data | map(select(.name == "readme-plugin")) | first | .id' | tr -d '"')
+
+# Configure the plugin with your API key
+curl -sX PATCH http://localhost:8001/plugins/$PLUGIN_ID -d "config.api_key=<Your API Key>" | jq '.config.api_key'
+
+# Configure `hide_headers`
+curl -sX PATCH -H'Content-Type: application/json' http://localhost:8001/plugins/$PLUGIN_ID -d '{"config": {"hide_headers": {"foo": "", "bar": "default"}}}' | jq '.config.hide_headers'
+
+# Configure `id_header`
+curl -sX PATCH -H'Content-Type: application/json' http://localhost:8001/plugins/$PLUGIN_ID -d '{"config": {"id_header": "email"}}' | jq '.config.id_header'
+
+# Configure `group_by`
+curl -sX PATCH -H'Content-Type: application/json' http://localhost:8001/plugins/$PLUGIN_ID -d '{"config": {"group_by": {"x-user-email": "email", "x-org-name": "label"}}}' | jq '.config.group_by'
+
+# Delete the plugin
+curl -sX DELETE http://localhost:8001/plugins/$PLUGIN_ID
+```
+
+> 🚧 Any Issues?
+>
+> Integrations can be tricky! [Contact support](https://docs.readme.com/guides/docs/contact-support) if you have any questions/issues.