Call Telemetry for Cisco

# Call Telemetry Cluster and High Availability Deployment Guide

This guide provides detailed instructions for setting up and deploying the Call Telemetry application using Kuberenetes with load balancing an a HA PostgreSQL Cluster.

Kubernetes Clustering is free to use on your own, with paid support is available please context Support for more information.

# Architecture

k3s

# Prerequisites

Before beginning the installation, ensure you have the following requirements. A 3 node cluster will need 7 IP Addresses on the same subnet to complete the install.

  • Node IPs: Multiple nodes as typically installed for a highly available cluster. 3 nodes are recommended for a production environment. These are standard IP addresses for the OS.
  • Primary Virtual IP: The Virtual IP address of the Primary CURRI API service.
  • Secondary Virtual IP: The Virtual IP address of the Secondary CURRI API service.
  • Admin Virtual IP: The Virtual IP address used by the Call Telemetry Management API.
  • Management Virtual IP: The Virtual IP addresses used for the Call Telemetry Management Web Page.
  • K3S Token: A pre-shared key among K3s nodes for authentication. You can set it now, or get it post-install from the primary node with sudo cat /var/lib/rancher/k3s/server/node-token.

# Installation Steps

# OS Preparation

This step configures the firewall, and installs some tools needed for managing Kubernetes.

# Supported OS Versions

  • AlmaLinux 9.x
  • RHEL 9.x
  • CentOS Stream 9.x
# Disable Firewall and selinux
sudo systemctl stop firewalld
sudo systemctl disable firewalld
sudo setenforce permissive
sudo systemctl disable rpcbind

# Install Kubectl and Helm via SNAPS
sudo yum install -y wget epel-release
sudo yum install -y snapd
sudo systemctl enable --now snapd.socket
sudo ln -s /var/lib/snapd/snap /snap
sudo snap wait system seed.loaded
sudo systemctl restart snapd.seeded.service
sudo snap install kubectl --classic
sudo snap install helm --classic

# Install K9s Kubernetes Management tool
echo "Installing k9s toolkit - https://github.com/derailed/k9s/"
wget https://github.com/derailed/k9s/releases/download/v0.32.5/k9s_Linux_x86_64.tar.gz
tar -xzf k9s_Linux_x86_64.tar.gz
sudo mv k9s /usr/local/bin
mkdir ~/.k9s
rm -rf k9s*

# Install GIT
sudo dnf install -y git

# K3s Installation

K3s is a lightweight Kubernetes distribution designed for easy installation and operation of Kuberenetes.

# Setting Up the Primary Node

  1. Install K3s Install K3s on the primary node. Note the token value, which is hashed into the shared cluster secret value.

    # From Primary Node.
export K3S_TOKEN="calltelemetry"
curl -sfL https://get.k3s.io | K3S_KUBECONFIG_MODE=0644 sh -s server --cluster-init --disable traefik --disable servicelb

    This command initializes the K3s server, disables Traefik (a default ingress controller), and the default service load balancer.

  2. Configure Kubectl Set up kubectl, the command-line tool for interacting with the Kubernetes cluster:

    # From Primary node.
mkdir -p ~/.kube
sudo cat /etc/rancher/k3s/k3s.yaml > ~/.kube/config

# Optionally Setting Up Secondary Nodes

3 Nodes is typical for a Kubenretes cluster, but you can skip this step and just run a single node.

  1. Install K3s on Secondary Nodes Join secondary nodes to the K3s cluster. Note the token value, and the primary node IP address.

    # From the secondary node to be installed.
export primary_ip="192.168.123.156"
export K3S_TOKEN="calltelemetry"
sudo curl -sfL https://get.k3s.io | K3S_URL="https://$primary_ip:6443" K3S_KUBECONFIG_MODE=0644 sh -s server --disable traefik --disable servicelb
mkdir -p ~/.kube
sudo cat /etc/rancher/k3s/k3s.yaml > ~/.kube/config

    Checking Nodes

    # From any node.
[calltelemetry@ct-node-1 ~]$ kubectl get node
NAME        STATUS   ROLES                       AGE   VERSION
ct-node-1   Ready    control-plane,etcd,master   34h   v1.29.6+k3s2
ct-node-2   Ready    control-plane,etcd,master   33h   v1.29.6+k3s2
ct-node-3   Ready    control-plane,etcd,master   34h   v1.29.6+k3s2
[calltelemetry@ct-node-1 ~]$

  2. Scale DNS Pods Adjust DNS pod replicas to match the number of total nodes. This helps with failover.

    # From any node.
kubectl scale deployment.v1.apps/coredns --replicas=3 -n kube-system

    Check DNS Pod Scale

    # From any node.
[calltelemetry@ct-node-1 ~]$ kubectl get pods -A | grep dns
kube-system         coredns-6799fbcd5-2v68f                  1/1     Running     0                   13m
kube-system         coredns-6799fbcd5-55mdh                  1/1     Running     0                   13m
kube-system         coredns-6799fbcd5-6skkc                  1/1     Running     2 (<invalid> ago)   34h
[calltelemetry@ct-node-1 ~]$

# MetalLB Installation for Load Balancing

MetalLB is a load balancer implementation for bare metal Kubernetes clusters, enabling external access to services.

  1. Install MetalLB Using Helm Helm is a package manager for Kubernetes, and it simplifies the deployment of applications:

    # From Primary node.
kubectl create namespace metallb-system
helm repo add metallb https://metallb.github.io/metallb
helm install -n metallb-system metallb metallb/metallb

# CrunchyData PostgreSQL Operator Installation

The CrunchyData PostgreSQL Operator automates PostgreSQL database cluster deployment, management, and monitoring in Kubernetes.

  1. Install PostgreSQL Operator and CRDs

    # From Primary node.
kubectl create namespace postgres-operator
git clone https://github.com/CrunchyData/postgres-operator-examples.git
kubectl apply --server-side -k postgres-operator-examples/kustomize/install/default

  2. Create CT PostgreSQL Database Cluster

    # From Primary node.
kubectl create namespace ct
kubectl apply -n ct -f calltelemetry/kuberentes/postgres/ct-postgres.yaml

# Call Telemetry Application Deployment

  1. Add Call Telemetry Helm Repository

    # From Primary node.
helm repo add ct_charts https://storage.googleapis.com/ct_charts/
helm repo update

  2. Create Custom Configuration File Customize deployment parameters such as hostname and IPs:

    # From Primary node.
cat <<EOF > ./ct_prod.yaml
hostname: calltelemetry.local
environment: prod
primary_ip: 192.168.123.203
secondary_ip: 192.168.123.204
cluster_ip_start: 192.168.123.205
cluster_ip_end: 192.168.123.205
admin_ip: 192.168.123.206
management_ip: 192.168.123.207
EOF

  3. Deploy Using Helm Helm is used to deploy the application with the specified configuration. The release name is ct, the namespace is ct.

    # From primary node.
helm install -n ct ct ct_charts/stable-ha -f ./ct_prod.yaml

# Upgrading the Application

To upgrade the Call Telemetry application, use:

# From Primary node.
helm upgrade -n ct ct ct_charts/stable-ha -f ./ct_prod.yaml

# Troubleshooting

# Uninstall K3s

To uninstall K3s, use:

# Node to be uninstalled.
/usr/local/bin/k3s-uninstall.sh

# References

# SQL - Crunchy Data PostgreSQL Operator

Cruncy Data PostgreSQL Operator Github (opens new window)

Crunch Data PostgreSQL Operator Docs (opens new window)

Last Updated: 8/3/2024, 7:10:36 PM

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