# Frequently Asked Questions

## How do I shut everything down and restart from scratch?

You can use `kubectl delete -f` to remove the resources specified in a YAML file. So for the resources in this assignment:

```
kubectl delete -f proxy/k8
kubectl delete -f GiftcardSite/k8
kubectl delete -f db/k8
```

Note that removing pods will *not* remove their persistent storage, and even deleting the persistent volume and persistent volume claim won't do it. To actually delete the data, you'll need to use `minikube ssh` to get access to the host container, and then remove the files there.

For example, to get rid of the persistent volume associated with the database (`mysql-pv`), you would do:

```
youruser@$ minikube ssh
docker@minikube:~$ sudo rm -rf /data/mysql-pv
docker@minikube:~$ logout
```

You can find out where the data for a persistent volume is located by looking at its `hostPath` in the PersistentVolume YAML file:

```
  hostPath:
    path: /data/mysql-pv
```

## How do I see what's going wrong?

Start by looking at what pods are running, and their states:

```
kubectl get pods
```

If a pod is in a state other than "Running", you can get more details about it:

```
kubectl describe pod <pod_name>
```

You can also ask for logs from a pod:


```
kubectl logs <pod_name>
```

Finally, it might be helpful to run a shell inside the pod's container so that you can run commands and see what's going on. You can do that by running:

```
kubectl exec --stdin --tty <pod_name> -- bash
```

Some pods (e.g., the GiftcardSite pod) don't have bash installed, so you'll need to use `sh` instead.

## Why can't kubectl find my Docker image?

The most common reason is that you forgot to run `eval $(minikube docker-env)` before running `docker build`. This points the Docker client at the minikube Docker daemon.

Another common mistake is specifying the image version in the YAML file as `latest` (e.g., `my_image:latest`). This will make kubectl try to fetch the image from a remote repository, which will fail if it's an image you've created locally. You can override this behavior either by removing the `:latest` tag, or by adding `imagePullPolicy: Never` to the YAML file.

## How can I open the web interface for a service?

You can find out what services are available by doing `minikube service list`:

```
caterina:k8s moyix$ minikube service list 
|----------------------|-------------------------------|--------------|-----|
|      NAMESPACE       |             NAME              | TARGET PORT  | URL |
|----------------------|-------------------------------|--------------|-----|
| default              | assignment3-django-service    |         8000 |     |
| default              | kubernetes                    | No node port |
| default              | mysql-service                 | No node port |
| default              | prometheus-alertmanager       | No node port |
| default              | prometheus-kube-state-metrics | No node port |
| default              | prometheus-node-exporter      | No node port |
| default              | prometheus-pushgateway        | No node port |
| default              | prometheus-server             | No node port |
| default              | proxy-service                 |         8080 |     |
| kube-system          | kube-dns                      | No node port |
| kubernetes-dashboard | dashboard-metrics-scraper     | No node port |
| kubernetes-dashboard | kubernetes-dashboard          | No node port |
|----------------------|-------------------------------|--------------|-----|
```

Then pick a service and use `minikube service <name>` to open a browser to that service's URL:

```
caterina:k8s moyix$ minikube service prometheus-server
|-----------|-------------------|-------------|--------------|
| NAMESPACE |       NAME        | TARGET PORT |     URL      |
|-----------|-------------------|-------------|--------------|
| default   | prometheus-server |             | No node port |
|-----------|-------------------|-------------|--------------|
😿  service default/prometheus-server has no node port
🏃  Starting tunnel for service prometheus-server.
|-----------|-------------------|-------------|------------------------|
| NAMESPACE |       NAME        | TARGET PORT |          URL           |
|-----------|-------------------|-------------|------------------------|
| default   | prometheus-server |             | http://127.0.0.1:61867 |
|-----------|-------------------|-------------|------------------------|
🎉  Opening service default/prometheus-server in default browser...
❗  Because you are using a Docker driver on darwin, the terminal needs to be open to run it.
```