# 1. Core Concepts (13%)
### Creating a Pod and Inspecting it
1. Create the namespace `ckad-prep`.
2. In the namespace `ckad-prep` create a new Pod named `mypod` with the image `nginx:2.3.5`. Expose the port `80`.
3. Identify the issue with creating the container. Write down the root cause of issue in a file named `pod-error.txt`.
4. Change the image of the Pod to `nginx:1.15.12`.
5. List the Pod and ensure that the container is running.
6. Log into the container and run the `ls` command. Write down the output. Log out of the container.
7. Retrieve the IP address of the Pod `mypod`.
8. Run a temporary Pod using the image `busybox`, shell into it and run a `wget` command against the nginx Pod using port 80.
9. Render the logs of Pod `mypod`.
10. Delete the Pod and the namespace.
First, create the namespace.
```
$ kubectl create namespace ckad-prep
```
Next, create the Pod in the new namespace.
```
$ kubectl run mypod --image=nginx:2.3.5 --restart=Never --port=80 --namespace=ckad-prep
pod/mypod created
```
You will see that the image cannot be pulled as it doesn’t exist with this tag.
```
$ kubectl get pod -n ckad-prep
NAME READY STATUS RESTARTS AGE
mypod 0/1 ImagePullBackOff 0 1m
```
The list of events can give you a deeper insight.
```
$ kubectl describe pod -n ckad-prep
...
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Scheduled 3m3s default-scheduler Successfully assigned mypod to docker-for-desktop
Normal SuccessfulMountVolume 3m2s kubelet, docker-for-desktop MountVolume.SetUp succeeded for volume "default-token-jbcl6"
Normal Pulling 84s (x4 over 3m2s) kubelet, docker-for-desktop pulling image "nginx:2.3.5"
Warning Failed 83s (x4 over 3m1s) kubelet, docker-for-desktop Failed to pull image "nginx:2.3.5": rpc error: code = Unknown desc = Error response from daemon: manifest for nginx:2.3.5 not found
Warning Failed 83s (x4 over 3m1s) kubelet, docker-for-desktop Error: ErrImagePull
Normal BackOff 69s (x6 over 3m) kubelet, docker-for-desktop Back-off pulling image "nginx:2.3.5"
Warning Failed 69s (x6 over 3m) kubelet, docker-for-desktop Error: ImagePullBackOff
```
Go ahead and edit the existing Pod. Alternatively, you could also just use the kubectl set image pod mypod mypod=nginx --namespace=ckad-prep command.
```
$ kubectl edit pod mypod --namespace=ckad-prep
```
After setting an image that does exist, the Pod should render the status Running.
```
$ kubectl get pod -n ckad-prep
NAME READY STATUS RESTARTS AGE
mypod 1/1 Running 0 14m
```
You can shell into the container and run the ls command.
```
$ kubectl exec mypod -it --namespace=ckad-prep -- /bin/sh
/ # ls
bin boot dev etc home lib lib64 media mnt opt proc root run sbin srv sys tmp usr var
/ # exit
```
Retrieve the IP address of the Pod with the -o wide command line option.
```
$ kubectl get pods -o wide -n ckad-prep
NAME READY STATUS RESTARTS AGE IP NODE
mypod 1/1 Running 0 12m 192.168.60.149 docker-for-desktop
```
Remember to use the --rm to create a temporary Pod.
```
$ kubectl run busybox --image=busybox --rm -it --restart=Never -n ckad-prep -- /bin/sh
```
If you don’t see a command prompt, try pressing enter.
```
/ # wget -O- 192.168.60.149:80
Connecting to 192.168.60.149:80 (192.168.60.149:80)
Welcome to nginx!
Welcome to nginx!
If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.
For online documentation and support please refer to
nginx.org.
Commercial support is available at
nginx.com.
Thank you for using nginx.
- 100% |**********************************************************************| 612 0:00:00 ETA
/ # exit
```
The logs of the Pod should show a single line indicating our request.
```
$ kubectl logs mypod -n ckad-prep
192.168.60.162 - - [17/May/2019:13:35:59 +0000] "GET / HTTP/1.1" 200 612 "-" "Wget" "-"
```
Delete the Pod and namespace after you are done.
```
$ kubectl delete pod mypod --namespace=ckad-prep
pod "mypod" deleted
$ kubectl delete namespace ckad-prep
namespace "ckad-prep" deleted
```