https://github.com/tankibaj/httpenv

A very simple docker image serving environment variables over HTTP.
https://github.com/tankibaj/httpenv

Last synced: 5 months ago
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A very simple docker image serving environment variables over HTTP.

README

A very simple image serving environment variables over HTTP. I use this image to test kubernetes ClusterIP service.

## Quick Start

### Docker

- Run docker container and expose port

```bash
docker run --rm -p8888:8888 thenaim/httpenv
```

- Test endpoint

```bash
curl http://localhost:8888

curl http://localhost:8888/blue

curl http://localhost:8888/green

curl http://localhost:8888/red
```

### Kubernetes

#### Create deployment and service

- In another window, watch the pods (to see when they are created):

```bash
kubectl get pods -w
```

- Create a deployment for this very lightweight HTTP server:

```bash
kubectl create deployment httpenv --image=thenaim/httpenv
```

- Scale it to 10 replicas:

```bash
kubectl scale deployment httpenv --replicas=10
```

- Expose the HTTP port of our server. We'll create a default ClusterIP service

```bash
kubectl expose deployment httpenv --port 8888
```

- Look up which IP address was allocated:

```bash
kubectl get service
```

#### Test endpoint

- Let's obtain the IP address that was allocated for our service:

```bash
IP=$(kubectl get svc httpenv -o go-template --template '{{ .spec.clusterIP }}')
```

- Generate URL

```bash
echo http://$IP:8888/
```

- Run Busybox to access ClusterIP

```bash
kubectl run busybox --image=radial/busyboxplus:curl -i --tty
```

- Send a few requests:

```bash
curl http://$IP:8888/
```

- Too much output? Filter it with jq:

```bash
curl -s http://$IP:8888/ | jq .HOSTNAME
```

- Others

```bash
curl http://$IP:8888/blue

curl http://$IP:8888/green

curl http://$IP:8888/red
```