mars / tinyrobot-science-mesh-web-ui

🚧🔬 experiment using Kong service mesh in a Heroku app

🚧🔬 tinyrobot.science "Kong 1.0 Mesh" experiment

Based on this microservices example app.

Let's discover how Kong's new sidecar deployment style integrates with Heroku.

Results

Kong's actual mesh networking (service-to-service, mutual TLS) features are facilitated by changing iptables configuration on the hosts, which is not possible on Heroku.

Even without the true mesh networking, deploying Kong sidecar-style does still provide some benefits:

• less latency than a separate Kong proxy app (the proxy-backend connection is on localhost)
• Kong cluster inherently scales with the app's dyno scaling

Open questions

Can a single Kong controller operate many apps worth of Kong sidecars?

• Do backend PORT values conflict?
• Does the KONG_ORIGINS config solve this? (Setting hostnames into config vars is gross 😣)

Deployment

First, deploy a Kong app as the mesh controller.

Then, deploy this app:

heroku create tinyrobot-science-mesh-web-ui
heroku buildpacks:add heroku/nodejs
heroku buildpacks:add heroku-community/kong
heroku buildpacks:add https://github.com/danp/heroku-buildpack-runit

# Attach the ID of the mesh controller's Postgres add-on.
heroku addons:attach postgresql-cylindrical-98791

git push heroku master

Then, create the mesh service & route:

(Note: port 5000 is the local listener set in bin/start-app)

## Create mesh service
curl -X "PUT" "https://tinyrobot-science-mesh-control.herokuapp.com/kong-admin/services/web-ui" \
     -H 'apikey: xxxxx' \
     -H 'Content-Type: application/json; charset=utf-8' \
     -d $'{
  "url": "http://127.0.0.1:5000"
}'

## Create mesh route
curl -X "POST" "https://tinyrobot-science-mesh-control.herokuapp.com/kong-admin/services/web-ui/routes" \
     -H 'apikey: xxxxx' \
     -H 'Content-Type: application/json; charset=utf-8' \
     -d $'{
  "name": "web-ui",
  "hosts": [
    "tinyrobot-science-mesh-web-ui.herokuapp.com"
  ],
  "protocols": [
    "https"
  ]
}'

## Add the current app name as the origin for the web-ui services
heroku config:set KONG_ORIGINS=https://tinyrobot-science-mesh-web-ui.herokuapp.com:443=http://localhost:5000

✨ Visit the app's URL https://tinyrobot-science-mesh-web-ui.herokuapp.com/ in a web browser.