ProxySQL on Kubernetes

Tools used for sample deployment:

• KVM / Libvirt
• Kubectl
• Minikube
• Helm

Cloud Deployment Notes

# Connect via SSH and forward Kubernetes dashboard URL
ssh -L 8001:10.18.120.41:8001 root@51.15.64.202

# Change to to a non-root user e.g. `centos` (do not run this under `root`)
su - centos

# Start a proxy for the Kubernetes dashboard using the internal IP (this will launch a foreground process, must keep running to access dashboard)
kubectl proxy --address=10.18.120.41 --accept-hosts='^.*'

# In a browser on your local machine open:
http://127.0.0.1:8001/api/v1/namespaces/kubernetes-dashboard/services/http:kubernetes-dashboard:/proxy/#/overview?namespace=default

Installing tools (note packaged installation is also an option).

These steps assume "/usr/local/bin" is defined in your PATH and you are using Linux :)

Installing Kubectl

Detailed install

• https://kubernetes.io/docs/tasks/tools/install-kubectl/#install-kubectl-on-linux

TL;DR

curl -LO https://storage.googleapis.com/kubernetes-release/release/`curl -s https://storage.googleapis.com/kubernetes-release/release/stable.txt`/bin/linux/amd64/kubectl
chmod +x ./kubectl
sudo mv ./kubectl /usr/local/bin/

Installing Minikube (KVM,VirtualBox,VMWare or similar should be pre-installed)

Detailed install

• https://kubernetes.io/docs/tasks/tools/install-minikube/

TL;DR

curl -Lo minikube https://storage.googleapis.com/minikube/releases/latest/minikube-linux-amd64 \
&& chmod +x minikube
sudo mv ./minikube /usr/local/bin/

Installing Helm

Detailed install

• https://helm.sh/docs/intro/install/

TL;DR

curl -fsSL -o get_helm.sh https://raw.githubusercontent.com/helm/helm/master/scripts/get-helm-3
chmod 700 get_helm.sh
./get_helm.sh

Configuring environment

Minikube

minikube config set memory 6144
minikube config set cpus 3
minikube config set disk-size 50000MB
minikube config set vm-driver kvm2
minikube start 
minikube status

Add dashboard

kubectl apply -f https://raw.githubusercontent.com/kubernetes/dashboard/v2.0.0/aio/deploy/recommended.yaml
minikube addons enable dashboard

# Get dashboard URL (ctrl+c to exit if stuck)
minikube dashboard --url

🤔  Verifying dashboard health ...
🚀  Launching proxy ...
🤔  Verifying proxy health ...
http://127.0.0.1:45536/api/v1/namespaces/kube-system/services/http:kubernetes-dashboard:/proxy/

# Start dashboard on local IP (forwarded from within Minikube VM) - default port is 8001
# and the address in this example 10.18.120.41 is the host physical machine IP (not the VM)
kubectl proxy --address=10.18.120.41 --accept-hosts='^.*'

Combining the URL and the kubectl proxy --address on default port 8001 the resulting url is: http://10.18.120.41:8001/api/v1/namespaces/kube-system/services/http:kubernetes-dashboard:/proxy/ (or alternatively use the SSH tunnel if on Scaleway and connect to your 127.0.0.1:8001)

Deploying with Helm

Install MySQL with bitnami charts

Note: You can configure custom settings (root password / number of slaves / etc. in mysql/values.yaml

helm repo add bitnami https://charts.bitnami.com/bitnami
helm install mysql-8 -f ./mysql/values.yaml bitnami/mysql

# Get password for MySQL
echo Password : $(kubectl get secret --namespace default mysql-8 -o jsonpath="{.data.mysql-root-password}" | base64 --decode)
Password : XHCO2ydDXj

ProxySQL deployment options overview

• Deploy a ProxySQL "layer" (standalone config)
• Deploy a ProxySQL "layer" with a controller (aka core / satellite)
• Deploy ProxySQL as a sidecar
• Deploy ProxySQL Cascaded i.e. ProxySQL "layer" and ProxySQL as a sidecar

Deploy ProxySQL Layer

Install ProxySQL (proxy layer with service)

helm install proxysql-cluster ./proxysql-cluster

Change settings and re-deploy

vi proxysql-cluster/files/proxysql.cnf 
helm upgrade proxysql-cluster ./proxysql-cluster

Optionally do a rolling restart (note, templates are configured to re-deploy on configmap changes, i.e. this step is not required unless configmap checksum is removed)

kubectl rollout restart deployment/proxysql-cluster

Delete proxysql-cluster deployment

helm delete proxysql-cluster

Deploy sidecar

helm install proxysql-sidecar ./proxysql-sidecar

...

helm delete proxysql-sidecar

Deploy core / satelite

helm install proxysql-cluster-controller ./proxysql-cluster-controller
helm install proxysql-cluster-passive ./proxysql-cluster-passive

...

helm delete proxysql-cluster-controller proxysql-cluster-passive

Deploy sidecar that connects to proxysql-cluster-passive (i.e. Cascaded ProxySQL)

helm install proxysql-sidecar-cascade ./proxysql-sidecar-cascade
helm delete proxysql-sidecar-cascade

Install Ingress controller and add a TCP service to the ingress

NOTE: This is only required if you want to connect to you local physical IP and run commands within the Kubernetes ProxySQL Service

minikube addons enable ingress
kubectl patch configmap tcp-services -n kube-system --patch '{"data":{"6033":"default/proxysql-cluster:6033"}}'

To verify

kubectl get configmap tcp-services -n kube-system -o yaml

Patch nginx ingress

vi nginx-ingress-controller-patch.yaml
---
spec:
  template:
    spec:
      containers:
      - name: nginx-ingress-controller
        ports:
         - containerPort: 6033
           hostPort: 26033
---
        hostname="proxysql-cluster-controller"
        port=6032
        weight=0
        comment="proxysql-cluster-controller"
kubectl patch deployment nginx-ingress-controller --patch "$(cat nginx-ingress-controller-patch.yaml)" -n kube-system

Connect to ProxySQL

mysql -h$(minikube ip) -P26033 -uroot -pXHCO2ydDXj

Useful commands

Helm

helm install <releasename> <path>
helm upgrade <releasename> <path>
helm delete <releasename>

Kubectl

kubectl get services
kubectl get pods
kubectl get deployment
kubectl get pods --all-namespaces
kubectl describe service <servicename>
kubectl rollout restart deployment/proxysql-cluster

Minicube

minikube start
minikube delete