Senior Linux Administrator

Location: Harrisburg, PA | Position Type: Hybrid (1 day in office per week minimum, flexible for 5 days on-site if required) | Contract Length: 6 months, contract-to-hire

About the role

This is a highly technical position responsible for the architecture and design of complex Linux/Unix and Kubernetes computing environments, in both on-prem and Cloud/AWS arenas. Focus is on AIX/RHEL administration, Kubernetes, virtualization, and storage technologies, and Disaster Recovery processes. Collaborate closely with developers and other technology personnel to develop, migrate and manage services in the Amazon Web Services (AWS) cloud environment, and in physical data centers.

Responsibilities

• Administer, configure, and maintain Linux (RHEL/AIX) servers across on-premises and AWS cloud environments.
• Deploy, manage, and troubleshoot Kubernetes clusters, including Rancher-managed environments.
• Create, update, and maintain Kubernetes manifests, Helm charts, and containerized application deployments.
• Monitor system performance, availability, and security while implementing system hardening, vulnerability remediation, and access controls.
• Manage Linux networking, storage, virtualization, and container technologies, including DNS, firewalls, SAN/NAS, Docker, and Podman.
• Develop and maintain automation scripts using Bash, Korn shell, and Python to streamline administration tasks.
• Support CI/CD pipelines and source control processes using Git and GitLab.
• Collaborate with development teams to deploy, migrate, and support applications in AWS and on-premises environments.
• Perform backup, disaster recovery, and system recovery activities to ensure business continuity.
• Troubleshoot operating system, Kubernetes, application, Java/Tomcat, and PostgreSQL issues while providing ongoing operational support.

Requirements

• Proven ability to create, configure, and manage Enterprise Linux-based systems.
• Strong understanding of TCP/IP networking services, configuration, and troubleshooting, including:
  • Routing
  • Firewall filtering
  • Load balancing
  • DNS
  • VLAN isolation
  • Service APIs
  • Gateways and proxies
  • Packet capture and network analysis
• Demonstrated experience developing and maintaining shell scripts using:
  • Bash
  • Korn shell (ksh)
  • Python
• Experience implementing and maintaining secure, hardened Linux systems, including:
  • Certificate and key management
  • Access Control Lists (ACLs)
  • Pluggable Authentication Modules (PAM)
  • Identity and Access Management (IAM)
  • Vulnerability scanning and remediation
• Solid understanding of Linux storage technologies, including:
  • SAN and NAS storage
  • Object storage (Amazon S3)
  • Logical Volume Manager (LVM)
  • RAID
  • Backup and recovery
• Good understanding of virtualization and container technologies, including:
  • KVM
  • VirtIO
  • Xen
  • QEMU
  • Podman
  • Docker
  • LXC

Desired Skills

• Strong experience implementing, administering, and managing Kubernetes environments, including the Rancher container management platform.
• Ability to create, manage, and troubleshoot Kubernetes manifest files.
• Experience developing, reading, updating, and maintaining Helm charts for Kubernetes deployments.
• Familiarity with CI/CD concepts, tools, and best practices, including:
  • Git
  • GitLab
• Ability to review, troubleshoot, and optimize Java Virtual Machine (JVM) and Apache Tomcat configurations and errors.
• Understanding of PostgreSQL deployment, configuration, administration, and troubleshooting.
• Knowledge of application build and dependency management using:
  • Gradle
  • Maven
• Experience deploying and managing containerized applications in public cloud environments, including:
  • AWS Elastic Kubernetes Service (EKS)
  • AWS Elastic Container Service (ECS)
  • Azure Container Instances (ACI)
  • Azure Kubernetes Service (AKS)