Category: kubernetes

Install Minikube with docker driver on Ubuntu
Minikube is a Kubernetes implementation for development and testing. By default, it uses Virtualbox. The newer version support docker driver, this allows you to use docker to run your minikube Kubernetes cluster. You can find documentation for minikube at

https://minikube.sigs.k8s.io/docs/start/

First of all, we need to install Docker, for this, run the command.

You must be user root, if you are not root, run command “sudo su” to become user root.
```
wget -qO- https://get.docker.com/ | sh
```
Minikube only allows us to run as a normal user, so we need to add the user we will be using in group docker.
```
usermod -aG docker YOUR_USER_NAME_HERE
```
Next, install minikube with
```
wget https://storage.googleapis.com/minikube/releases/latest/minikube-linux-amd64
mv minikube-linux-amd64 /usr/local/bin/minikube
chmod 755 /usr/local/bin/minikube
```
We have minikube and docker installed. To continue, we need to switch to a normal user, that is in docker group.
```
su - YOUR_USER_NAME_HERE
```
To delete older minikube installation, run
```
minikube delete --all --purge
```
Now create a new minikube cluster with the command
```
minikube start --driver=docker 
```
To see status
```
minikube status
```
Now you will be able to run all normal kubectl commands. For minikube installation, instead of kubectl, you need to use command “minikube kubectl –“. It is better create an alias, so you don’t need to type “minikube kubectl” every time you need to run kubectl command.

https://minikube.sigs.k8s.io/docs/handbook/kubectl/
```
vi ~/.bashrc
```
At end of the file, add
```
alias kubectl='minikube kubectl --'
```
Activate it with command
```
source ~/.bashrc
```
To get nodes, pods, and service, you can use commands
```
kubectl get nodes
kubectl get pods
kubectl get service
```
See MiniKube
June 7, 2021
Google Kubernetes Engine Node Pools
In Google Kubernetes Engine, Nodes are Google Complete Engine (Virtual Machiens). Pods run inside Nodes. A Kubernetes cluster can contain multiple node pools. A node pool contain multiple nodes of same instance type.

To create a Node Pool in Google Kubernetes Engine, run
```
gcloud container node-pools create POOL_NAME \
  --cluster=CLUSER_NAME \
  --machine-type=e2-standard-2 \
  --num-nodes=1 \
  --zone=ZONE_NAME
```
To delete a node pool, run
```
gcloud container node-pools delete POOL_NAME --cluster CLUSER_NAME --zone ZONE_NAME
```
To resize a node pool, run
```
gcloud container clusters resize CLUSER_NAME --node-pool POOL_NAME \
    --num-nodes 3 --zone ZONE_NAME
```
See Google Kubernetes Engine
May 16, 2021
Install Minikube in Ubuntu
Minikube is an easy-to-use Kubernetes that run on one machine. It is used for testing purposes.

https://github.com/kubernetes/minikube
Install Minikube with docker driver on Ubuntu

To install minikube, run
```
wget https://storage.googleapis.com/minikube/releases/latest/minikube-linux-amd64
sudo mv minikube-linux-amd64 /usr/local/bin/minikube
sudo chmod 755 /usr/local/bin/minikube
```
Before you can start minikube, you need to install VirtualBox, this can be done with the command
```
sudo apt install virtualbox
```
To start minikube, run
```
minikube start
```
To stop
```
minikube stop
```
To connect to minikube node
```
minikube ssh
```
See minikube logs
```
minikube logs
```
Delete minikube
```
minikube delete
```
Mount a file system
```
minikube mount $(pwd):/var/www/html/
```
See Kubernetes
March 10, 2019

Deploy MySQL Server in Kubernetes using Helm

To install MySQL server in Kubernetes, run

helm install stable/mysql

Once install is completed, you will get something like

NOTES:
MySQL can be accessed via port 3306 on the following DNS name from within your cluster:
incendiary-monkey-mysql.default.svc.cluster.local

To get your root password run:

    MYSQL_ROOT_PASSWORD=$(kubectl get secret --namespace default incendiary-monkey-mysql -o jsonpath="{.data.mysql-root-password}" | base64 --decode; echo)

To connect to your database:

1. Run an Ubuntu pod that you can use as a client:

    kubectl run -i --tty ubuntu --image=ubuntu:16.04 --restart=Never -- bash -il

2. Install the mysql client:

    $ apt-get update && apt-get install mysql-client -y

3. Connect using the mysql cli, then provide your password:
    $ mysql -h incendiary-monkey-mysql -p

To connect to your database directly from outside the K8s cluster:
    MYSQL_HOST=127.0.0.1
    MYSQL_PORT=3306

    # Execute the following command to route the connection:
    kubectl port-forward svc/incendiary-monkey-mysql 3306

    mysql -h ${MYSQL_HOST} -P${MYSQL_PORT} -u root -p${MYSQL_ROOT_PASSWORD}

To connect to this MySQL, you need to create a temporary Ubuntu server in Kubernetes as MySQL is only available inside the cluster.

To create a server, run

kubectl run -i --tty ubuntu --image=ubuntu:18.04 --restart=Never -- bash -il

Install MySQL client inside this server with

apt update
apt install mariadb-client -y

To connect to MySQL, use the command provided after install, in my case

mysql -h incendiary-monkey-mysql -u root -p

You can get password by running

kubectl get secret --namespace default incendiary-monkey-mysql -o jsonpath="{.data.mysql-root-password}" | base64 --decode; echo

You can list packages installed using helm with

boby@sok-01:~$ helm list
NAME             	REVISION	UPDATED                 	STATUS  	CHART       	APP VERSION	NAMESPACE
incendiary-monkey	1       	Tue Feb 26 22:24:13 2019	DEPLOYED	mysql-0.15.0	5.7.14     	default  
boby@sok-01:~$

To delete, run

boby@sok-01:~$ helm delete incendiary-monkey
release "incendiary-monkey" deleted
boby@sok-01:~$

February 26, 2019

Install WordPress in Kubernetes

To install WordPress in Kubernetes, you need to install helm package manager.

Now run

helm install stable/wordpress

After the helm chart is run, you will get commands to get login for WordPress admin area.

Here is services it create

boby@sok-01:~$ kubectl get service
NAME                             TYPE           CLUSTER-IP      EXTERNAL-IP    PORT(S)                      AGE
kubernetes                       ClusterIP      10.39.240.1              443/TCP                      34m
whopping-labradoodle-mariadb     ClusterIP      10.39.248.140            3306/TCP                     2m
whopping-labradoodle-wordpress   LoadBalancer   10.39.253.160   35.193.33.14   80:32054/TCP,443:30939/TCP   2m
boby@sok-01:~$

List of all pods

boby@sok-01:~$ kubectl get pod
NAME                                             READY   STATUS      RESTARTS   AGE
ubuntu                                           0/1     Completed   0          21m
whopping-labradoodle-mariadb-0                   1/1     Running     0          3m
whopping-labradoodle-wordpress-8bddb5fdf-2l24d   1/1     Running     0          3m
boby@sok-01:~$

Deployments

boby@sok-01:~$ kubectl get deployment
NAME                             DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
whopping-labradoodle-wordpress   1         1         1            1           4m
boby@sok-01:~$

To scale the deployment, run

boby@sok-01:~$ kubectl scale deployment/whopping-labradoodle-wordpress --replicas=2
deployment.extensions/whopping-labradoodle-wordpress scaled
boby@sok-01:~$

See Helm Kubernetes Package Manager, Kubernetes

February 26, 2019

Helm Kubernetes Package Manager
Helm is Package Manager for Kubernetes. Helm packages are called “Charts”. Charts allow you to deploy various software on Kubernetes cluster.

https://helm.sh/

To install helm, run
```
curl https://raw.githubusercontent.com/kubernetes/helm/master/scripts/get > get_helm.sh
bash get_helm.sh
```
If you are on Ubuntu, you can install from snap
```
snap install helm --classic
```
To update helm repos, run
```
helm repo update
```
To deploy MySQL chart to Kubernetes, run
```
helm install stable/mysql
```
Install WordPress in Kubernetes
Deploy MySQL Server in Kubernetes using Helm

See Kubernetes
February 26, 2019
Google Kubernetes Engine
To list all Kubernetes clusters, run
```
gcloud container clusters list
```
To create a Kubernetes cluster, run
```
gcloud container clusters create CLUSTER_NAME
```
Get credential for kubectl
```
gcloud container clusters get-credentials CLUSTER_NAME
```
List all nodes (GCP instances)
```
kubectl get nodes
```
February 24, 2019

Category: kubernetes

Install Minikube with docker driver on Ubuntu

Google Kubernetes Engine Node Pools

Install Minikube in Ubuntu

Deploy MySQL Server in Kubernetes using Helm

Install WordPress in Kubernetes

Helm Kubernetes Package Manager

Google Kubernetes Engine