Kubernetes

Kubernetes : Minikube on CentOS 7

Deploy  Kubernetes on a developer's workstation.

This example is on CentOS 7with KVM. It is a VM. To follow along, you'll need metal or nested KVM.

It can be used to develop applications locally and then publish them to OpenShift, GKE or even Azure AKS. 

Install the required packages and start libvirt

yum -y install qemu-kvm libvirt libvirt-daemon-kvm
systemctl enable --now libvirtd

Setup the repo for Kubernetes.

cat <<'EOF' > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://packages.cloud.google.com/yum/repos/kubernetes-el7-$basearch
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
EOF

Install Kubectl

yum -y install kubectl

Download the minikube binary and docker machine driver

wget https://storage.googleapis.com/minikube/releases/latest/minikube-linux-amd64 -O minikube
wget https://storage.googleapis.com/minikube/releases/latest/docker-machine-driver-kvm2
chmod 755 minikube docker-machine-driver-kvm2
mv minikube docker-machine-driver-kvm2 /usr/local/bin/

Run a quick minikube check to make sure it's working.

minikube version

minikube version: v1.0.1

Run a kubectl check

kubectl -o json
{
  "clientVersion": {
    "major": "1",
    "minor": "14",
    "gitVersion": "v1.14.1",
    "gitCommit": "b7394102d6ef778017f2ca4046abbaa23b88c290",
    "gitTreeState": "clean",
    "buildDate": "2019-04-08T17:11:31Z",
    "goVersion": "go1.12.1",
    "compiler": "gc",
    "platform": "linux/amd64"
  }
}

Start minikube

minikube start --vm-driver kvm2

After the the start command runs, check the status

minikube status

You should see out put like this.

host: Running
kubelet: Running
apiserver: Running
kubectl: Correctly Configured: pointing to minikube-vm at 192.168.39.33

Setup the environment

minikube docker-env

Output will look like this:

Kubernetes master is running at https://192.168.39.33:8443
KubeDNS is running at https://192.168.39.33:8443/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy

Log into the minikube

minikube ssh

Check the docker status

docker ps

At this point you are in a normal VM shell. All tools work as expected.

To stop minikube.

minikube stop

To remove minikube, do like follows

minikube delete

 

Istio: Install

Setup and Configure

Download Istio by running the following command:

curl -L https://istio.io/downloadIstio | sh -

Move to the Istio package directory. For example, if the package is istio-1.11.2:

cd istio-1.14.1

Add the istioctl client tool to the PATH for your workstation.

export PATH=$PWD/bin:$PATH

Validate if the cluster meets Istio install requirements by running the precheck:

istioctl x precheck

Output should look simalar to:

✔ No issues found when checking the cluster. 
Istio is safe to install or upgrade!

Install and Adding Integration

istioctl install

kubectl apply -f samples/addons/prometheus.yaml
kubectl apply -f samples/addons/grafana.yaml

kubectl apply -f samples/addons/jaeger.yaml

kubectl apply -f samples/addons/kiali.yaml

Dashboards

istioctl dashboard <service>

Where <service> is one of:

Additional Setup

Gateway

Install the Gateway

kubectl create namespace istio-ingress
helm install istio-ingress istio/gateway -n istio-ingress

Operator Framework

Operator SDK

Download the release binary

Set platform information:

export ARCH=$(case $(uname -m) in x86_64) echo -n amd64 ;; aarch64) echo -n arm64 ;; *) echo -n $(uname -m) ;; esac)
export OS=$(uname | awk '{print tolower($0)}')

Download the binary for your platform:

export OPERATOR_SDK_DL_URL=https://github.com/operator-framework/operator-sdk/releases/download/v1.22.2
curl -LO ${OPERATOR_SDK_DL_URL}/operator-sdk_${OS}_${ARCH}

Verify the downloaded binary

Import the operator-sdk release GPG key from keyserver.ubuntu.com:

gpg --keyserver keyserver.ubuntu.com --recv-keys 052996E2A20B5C7E

Verify the signature:

curl -LO ${OPERATOR_SDK_DL_URL}/checksums.txt
curl -LO ${OPERATOR_SDK_DL_URL}/checksums.txt.asc
gpg -u "Operator SDK (release) <cncf-operator-sdk@cncf.io>" --verify checksums.txt.asc

You should see something similar:

gpg: assuming signed data in 'checksums.txt'
gpg: Signature made Fri 30 Oct 2020 12:15:15 PM PDT
gpg:                using RSA key ADE83605E945FA5A1BD8639C59E5B4762496218
gpg: Good signature from "Operator SDK (release) <cncf-operator-sdk@cncf.io>" [ultimate]

Make sure the checksums match:

grep operator-sdk_${OS}_${ARCH} checksums.txt | sha256sum -c -

You should see something similar to the following:

operator-sdk_linux_amd64: OK

Install the release binary in your PATH

chmod +x operator-sdk_${OS}_${ARCH} && sudo mv operator-sdk_${OS}_${ARCH} /usr/local/bin/operator-sdk

Bash completion

operator-sdk completion bash > /etc/bash_completion.d/operator-sdk

Install OLM

operator-sdk olm install

Operators

Prometheus

Clone the operator from Github

git clone https://github.com/prometheus-operator/kube-prometheus.git
cd kube-prometheus

Create the namespace and CRDs, and then wait for them to be availble before creating the remaining resources

kubectl create -f manifests/setup

Wait until the "servicemonitors" CRD is created. The message "No resources found" means success in this context.

until kubectl get servicemonitors --all-namespaces ; do date; sleep 1; echo ""; done

Deploy the rest of the operator manifests

kubectl create -f manifests/