andyrepton / tweakers-workshop

Repository for the Schuberg Philis and Tweakers workshop

Guestbook

Dependencies

Docker

Mysql

Repository

Clone this repository and go to the directory:

git clone $REPO
cd guestbook

Workshop 2-2

Create our Dockerfile in the guestbook directory

cd guestbook
vim Dockerfile

Copy of the final Dockerfile if needed:

https://gist.githubusercontent.com/Seth-Karlo/01a3b35cf7f7a373d0764dbff819735b/raw/346e05797294566922ecfe4b56f8ea74c58c0297/Dockerfile

Workshop 2-3

Building our image

cd guestbook
docker build .

Tagging our image

docker tag $image_id_from_before sbpdemo/guestbook

Running our image

docker run -p 80:80 sbpdemo/guestbook

Running as a daemon

docker run -p 80:80 -d sbpdemo/guestbook

Workshop 2-4

Adding a volume

docker run -p 80:80 --mount source=test,target=/usr/src/app/db -d sbpdemo/guestbook

Test restart

docker kill $your_container_id
docker run -p 80:80 --mount source=test,target=/usr/src/app/db -d sbpdemo/guestbook

Workshop 2-5

Adding an environment variable

docker run -p 80:80 --env NAME="$your_name" --mount source=test,target=/usr/src/app/db/ -d sbpdemo/guestbook

Workshop 3-1

Connect to your cluster using the script

cd tweakers-workshop
./workshop.sh connect ${your_user_id}

mv ~/.kube/config my_kube_config_backup
mv user22.kubeconfig ~/.kube/config

Alternatively, you can add kubeconfig --kubeconfig ${user_id}.kubeconfig to all of your commands

Workshop 3-2

Tagging our image

docker tag sbpdemo/guestbook sbpdemo/guestbook:${user_ID}

Log into the sbpdemo docker hub account

docker login

If you are already logged into another account, please log out of it first (or feel free to use your own docker hub account if you prefer)

Push our image

docker push sbpdemo/guestbook:${user_ID}

Workshop 3-3

Creating our deployment

kubectl run my-guestbook --image sbpdemo/guestbook:${user_id}

Check on the pods and get the pod name:

kubectl get pods

And port-forward to it, replacing the pod name with your pod name:

kubectl port-forward my-guestbook-54cc64dbcf-fwds2 8080:80

Expose your guestbook to the internet

kubectl expose deployment my-guestbook --type=LoadBalancer --port=80

Get the service cname:

$ kubectl get services
NAME           TYPE           CLUSTER-IP     EXTERNAL-IP                                                              PORT(S)        AGE
kubernetes     ClusterIP      100.64.0.1     <none>                                                                   443/TCP        2d
my-guestbook   LoadBalancer   100.67.30.86   a8ef38fb4cfcb11e89b610afb2428ec8-705870703.eu-west-1.elb.amazonaws.com   80:32567/TCP   39s

And you can now open it in your browser

Workshop 3-4

Redeploy with an environment variable

kubectl delete deployment my-guestbook

kubectl run my-guestbook --image sbpdemo/guestbook:user1 --env NAME=${your_name_here}

Workshop 3-5

Create the database

kubectl apply -f mariadb/

Option 1: Creating the schema yourself (more advanced)

Get the pod name:

$ kubectl get pods
NAME                            READY   STATUS    RESTARTS   AGE
my-guestbook-5cd7c6b86d-jbq29   1/1     Running   0          2m
mysql-5766c846b5-jx5qf          1/1     Running   0          2m

Port-forward:

$ kubectl port-forward mysql-5766c846b5-jx5qf 3306
Forwarding from 127.0.0.1:3306 -> 3306
Forwarding from [::1]:3306 -> 3306

Now open a new shell/powershell window

Running mysql ourselves to import the schema

Test the connection:

docker run -it mysql:5.6 mysql -h host.docker.internal -u root -p

The password is 'password'

And import the schema:

$ docker run -i mysql:5.6 mysql -h host.docker.internal -u root -ppassword < guestbook/database.sql
Warning: Using a password on the command line interface can be insecure.
Handling connection for 3306

Confirm the table is created:

docker run -it mysql:5.6 mysql -h host.docker.internal -u root -p messages -e "SHOW TABLES;"
Enter password:
Handling connection for 3306
+--------------------+
| Tables_in_messages |
+--------------------+
| messages           |
+--------------------+

Option 2: use a pre-made image

kubectl patch deployment mysql -p '{"spec":{"template":{"spec":{"containers":[{"name":"mysql","image":"sbpdemo/mysql:5.6"}]}}}}'

Configure the guestbook to now use the database

kubectl delete deployment my-guestbook

kubectl run my-guestbook --image sbpdemo/guestbook:user1 --env NAME=Andy --env DATABASE_TYPE="mysql"

Workshop 4-2

Create the quota

kubectl create -f quotas-limits/quota.yml

Scale up the guestbook

kubectl scale deployment my-guestbook --replicas=10

You can see the quota prevented the scale up:

$ kubectl get pods
NAME                            READY   STATUS    RESTARTS   AGE
my-guestbook-7965b5f789-ck9jv   1/1     Running   0          8m
mysql-5d76fb8d49-dxnnb          1/1     Running   0          9m

Debugging what went wrong

$ kubectl get replicasets
NAME                      DESIRED   CURRENT   READY   AGE
my-guestbook-7965b5f789   10        1         1       22m
mysql-5d76fb8d49          1         1         1       19m

kubectl describe replicaset my-guestbook-7965b5f789
Name:           my-guestbook-7965b5f789
Events:
  Type     Reason            Age                   From                   Message
  ----     ------            ----                  ----                   -------
  Normal   SuccessfulCreate  24m                   replicaset-controller  Created pod: my-guestbook-7965b5f789-dbctw
~~~Truncated~~~
  Warning  FailedCreate      3m23s                 replicaset-controller  Error creating: pods "my-guestbook-7965b5f789-j2wkr" is forbidden: failed quota: k8s-quota: must specify limits.cpu,limits.memory,requests.memory
  Warning  FailedCreate      2m3s (x6 over 3m22s)  replicaset-controller  (combined from similar events): Error creating: pods "my-guestbook-7965b5f789-wdhgm" is forbidden: failed quota: k8s-quota: must specify limits.cpu,limits.memory,requests.memory

Workshop 4-3

Redeploying with requests and limits set

kubectl delete deployment my-guestbook
kubectl run my-guestbook --image sbpdemo/guestbook:user1 --env NAME=Andy --env=DATABASE_TYPE=mysql --requests='cpu=100m,memory=256Mi' --limits='cpu=150m,memory=512Mi' --replicas=10

The quota prevented more than four pods from starting:

$ kubectl get pods
NAME                           READY   STATUS    RESTARTS   AGE
my-guestbook-97f659799-6jmq9   1/1     Running   0          1m
my-guestbook-97f659799-9c4p6   1/1     Running   0          1m
my-guestbook-97f659799-btxcs   1/1     Running   0          1m
my-guestbook-97f659799-x9w59   1/1     Running   0          1m
mysql-5d76fb8d49-dxnnb         1/1     Running   0          15m

Another describe of the replica set shows this:

$ kubectl describe replicaset my-guestbook-97f659799
  Warning  FailedCreate      3m30s                   replicaset-controller  Error creating: pods "my-guestbook-97f659799-kdm8g" is forbidden: exceeded quota: k8s-quota, requested: limits.memory=512Mi, used: limits.memory=2Gi, limited: limits.memory=2Gi