Run a local process in Kubernetes with Telepresence

This repository contains two Node.js applications.

• echo-server a server which returns status messages.
• task-runner a client which calls the echo-server every 3 seconds.

The corresponding article to this repository was published on the Coder Society blog.

Getting Started

1. Clone the repository

$ git clone https://github.com/coder-society/kubernetes-with-telepresence

2. Run the echo-server

$ node ./echo-server/server.js
Echo Server listening on http://localhost:3000

3. Make a request to the status route

$ curl http://localhost:3000
{"status":"ok","time":1504645235278,"hostname":"kewa.local"}

4. Deploy to Kubernetes

Deploy the two apps to Kubernetes by applying the manifest files.

$ kubectl apply -f ./echo-server/echo-server.yaml
deployment "echo-server" created
service "echo-server" created

$ kubectl apply -f ./task-runner/task-runner.yaml
deployment "task-runner" created

5. Run the task-runner locally without Telepresence

$ node ./task-runner/index.js
getaddrinfo ENOTFOUND echo-server echo-server:80
getaddrinfo ENOTFOUND echo-server echo-server:80
getaddrinfo ENOTFOUND echo-server echo-server:80

You can't connect to the echo-server, because it's not publicly available.

6. Run the task-runner locally with Telepresence

$ telepresence --run node task-runner/index.js
...
{"status":"ok","time":1504647042810,"hostname":"echo-server-1203620631-fpfvw"}
{"status":"ok","time":1504647043491,"hostname":"echo-server-1203620631-swsk5"}
{"status":"ok","time":1504647046640,"hostname":"echo-server-1203620631-fpfvw"}

This shows that you can connect to the echo-server although it's not publicly exposed.