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IoannisGk
Building Reliable HA Kubernetes Clusters | [email protected]

Ioannis Gkourtzounis

Ioannis Gkourtzounis has a High First Degree in Computing (BSc) and holds two ISTQB® certifications, he is a Certified Jenkins Engineer (CJE), a Certified Kubernetes Application Developer (CKAD), a Kubernetes Administrator (CKA), and a Kubernetes Security Specialist (CKS).

After the DevOps World in Lisbon 2019, Ioannis focused exclusively in Continuous Integration, Continuous Delivery, Cloud Native technologies and especially Kubernetes. During the last years, he was a key member in various CI/CD and Kubernetes related DevOps projects, where Security was always a first class citizen.

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What I Do

Build HA Kubernetes clusters

Build and manage reliable Highly Available Kubernetes clusters: a management cluster handles application deployments and provides monitoring and alerting of other Kubernetes clusters, that act as isolated environments. Setup HA Control Plane nodes with HAProxy and keepalived. Explore HA topologies and utilize Kube-vip in a stacked ETCD cluster. Create a step by step plan for disaster recovery.

Implement CI/CD pipelines

Install and configure Argo CD to apply GitOps principles. Describe and configure environments in one or multiple Kubernetes clusters. Use automation pipelines to reset these environments and revert them to their initial state. Create automated pipelines that build applications and deploy them to different environments, by updating the Git repository that defines the desired state of the clusters.

Deploy essentials to Kubernetes

Create automation scripts that configure GitOps with Argo CD. Use NFS shares for Pod storage with dynamic NFS Provisioner, and Vault for secure secrets management in the cluster. Deploy Harbor Registry and sign container images with Cosign. Setup Jenkins with dynamic Agents for cluster optimized CI/CD pipelines. Get cluster metrics with Prometheus and display them in Grafana dashboards.

Security in all stages of the SDLC

Make sure that all new images pass the security assessments in the Build pipelines. Deploy only signed images and perform automated vulnerability scans with Trivy on all container images. Install and configure Falco for security monitoring of containers at runtime. Use Wazuh to get CIS benchmark results on hosts with Ubuntu and RHEL OS, and perform mitigation actions.

My Certifications

Certified Kubernetes Security Specialist
Certified Kubernetes Administrator
Certified Kubernetes Application Developer
Certified Jenkins Engineer
AWS Certified Cloud Practitioner
Professional Scrum Master PSM-I
ISTQB Foundation Level Agile Tester Extension
ISTQB Foundation Level Certificate in Software Testing

Resume

6+ Years of Experience

Experience

2023 - Today
ARHS Developments Hellas

Senior DevOps Engineer

Setup, manage Highly Available Kubernetes clusters, and prepare for disaster recovery. Incorporate container image signing and vulnerability scanning in the SDLC. Develop CI/CD pipelines that build containers, use GitOps to automatically deploy the new versions of applications. Implement observability with monitoring, alerting for metrics and application logs. Execute CIS benchmarks on Linux hosts and perform risk mitigation.

2020 - 2022
Onelity

DevOps Engineer

Install Kubernetes on bare metal with Nginx Ingress Controller and a network Load Balancer implementation for on-premises clusters. Apply multi-container POD design patterns and follow best practices. Create an NFS Server for implementing persistence. Apply the GitOps principles for automated Continuous Delivery with Argo CD. Create pipelines that perform autoscaling on services based on specific metrics.

2018 - 2019
Onelity

QA Automation Engineer

Analysis, planning, creation and execution of manual and automated tests. Creation, development and maintenance of a test automation framework. Defect management and error analysis to support the development. Configure Jenkins jobs for dynamically creating customized environments in containers, and executing the test scenarios.

Education

2016 - 2018
University of Northampton

Undergraduate BSc (Hons) Degree in Computing

Graduated with High First-Class Honours A+ > See Award > See Grades
Published paper at EUMAS 2018 Conference on Multi-Agent Systems > Publication

DevOps Skills

Cloud Security

75%

HA Kubernetes Clusters

80%

Kubernetes Administration

85%

Cloud Native Applications

75%

CI/CD Pipelines

85%

Docker & Containers

75%

Scripting & Automation

75%

Linux Administration

75%

Soft Skills

Leadership

80%

Communication

85%

Collaboration

80%

Adaptability

75%

Portfolio

My Works
Homelab with VMware & Kubernetes

Homelab with VMware & Kubernetes

Presentations & Demos
Multi-Cloud Active-Active

Multi-Cloud Active-Active

Topologies & Diagrams
Multi-Cloud Active-Passive

Multi-Cloud Active-Passive

Topologies & Diagrams
HA Stateful Applications

HA Stateful Applications

Topologies & Diagrams
Kerberos Overview

Kerberos Overview

Topologies & Diagrams
HA with External ETCD

HA with External ETCD

Topologies & Diagrams
HA with Stacked ETCD

HA with Stacked ETCD

Topologies & Diagrams
Kubernetes with Jenkins X

Kubernetes with Jenkins X

Presentations & Demos
EV Sharing: Web Platform + Android App

EV Sharing: Web Platform + Android App

Presentations & Demos
Car Sharing Platform for EVs

Car Sharing Platform for EVs

Publications & Reports
Web Authentication Approaches

Web Authentication Approaches

Publications & Reports
NLP Travel Assistant Chatbot

NLP Travel Assistant Chatbot

Publications & Reports
Microdata Web Parser

Microdata Web Parser

Publications & Reports

Posts

My Blog Posts

Contact

Get in Touch

+306945806510

Thessaloniki, Greece

Freelance Available

How Can I Help You?