Best Practices for Container Security
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As part of the “Best Practices” series by Uplatz
Welcome to another installment of the Uplatz Best Practices series — equipping you to build secure, scalable, cloud-native systems.
Today’s topic: Container Security — a must-have discipline in every DevSecOps pipeline.
🧱 What is Container Security?
Container Security focuses on protecting containerized applications throughout their lifecycle — from development and image creation to runtime and orchestration.
Containers are isolated, lightweight, and portable — but they also introduce risks:
- Vulnerable images
- Misconfigured containers
- Weak secrets management
- Escalation into the host or other containers
Security must be baked in at every layer.
✅ Best Practices for Container Security
Here’s how to secure containers across build, deploy, and runtime stages — without slowing down development.
1. Use Minimal, Trusted Base Images
📦 Start from Scratch or Alpine Where Possible – Smaller footprint, fewer vulnerabilities
🔐 Use Verified Images from Trusted Registries – Avoid “latest” or unscanned sources
📅 Pin Image Versions for Predictability – No surprises in prod
2. Scan Images for Vulnerabilities
🔍 Integrate Image Scanning into CI/CD (e.g., Trivy, Clair, Grype)
⚠️ Fail Builds with Critical CVEs
🧪 Scan Regularly, Not Just at Build Time
3. Avoid Running Containers as Root
🚫 Drop Root Privileges Using USER in Dockerfiles
🔐 Use Kubernetes PodSecurity Standards or PSPs
🔒 Restrict Host Access and Capabilities
4. Use Read-Only File Systems
📁 Mount Filesystems as Read-Only When Possible
📦 Avoid Writing to /tmp or /var/lib Without Need
🧱 Separate Data Volumes from Core Containers
5. Manage Secrets Securely
🔐 Use Secrets Managers (Vault, KMS, Sealed Secrets)
🧾 Avoid Embedding Secrets in Images or Env Files
🔍 Audit Secret Access and Rotate Frequently
6. Set Resource Limits and Quotas
⚖️ Define CPU and Memory Limits for All Containers
🚫 Prevent DoS via Resource Abuse
🛑 Avoid Running Without Limits in Shared Clusters
7. Enforce Network Isolation
🌐 Use Kubernetes Network Policies – Limit pod-to-pod communication
🛡 Segment Services into Trust Boundaries
🔌 Disable Unnecessary Ports and Protocols
8. Enable Runtime Protection
👀 Use Runtime Threat Detection (e.g., Falco, Sysdig)
📦 Block Unauthorized Processes or Connections
📊 Monitor File System, Syscalls, Network Behavior
9. Keep Your Container Stack Updated
📅 Patch Images Regularly – Base images, app layers, dependencies
📦 Keep Docker, Kubernetes, and Container Runtimes Updated
🔍 Subscribe to CVE Feeds for Your Stack
10. Audit and Log Everything
📋 Log Container Lifecycle Events (Start, Stop, Fail, etc.)
🔐 Capture Auth Attempts and Network Access Logs
📊 Centralize Logs for Security Analytics and Compliance
💡 Bonus Tip by Uplatz
Containers move fast — so must your security.
Treat container security as code, just like your infrastructure and pipelines.
Automate, monitor, and never trust defaults.
🔁 Follow Uplatz to get more best practices in upcoming posts:
- DevSecOps and Secure Pipelines
- Kubernetes Security Policies
- Zero Trust for Containerized Workloads
- Runtime Threat Detection Tools
- Securing Multi-Tenant Clusters
…and 50+ more on cloud, DevOps, AI, and platform architecture.