Source application pod
DevOps & Tooling / Knowledge library
Linkerd
service identity encrypted traffic and observability
Why learn Linkerd?
Useful for consistent service communication policies. Mesh installation alone does not establish every application's authorization or reliability requirements.
Where it came from
Linkerd is a service mesh for Kubernetes applications. It adds service communication features such as traffic visibility and identity-based security through mesh components.
Build your understanding
Work through these exercises in order. Try the task before opening a reference.
- Identify control-plane and data-plane components.
- Mesh a disposable test workload.
- Observe traffic between two services.
- Check identity and encryption for a meshed connection.
- Test application behavior when a dependent service becomes unavailable.
Documentation and sources
- Official project documentation (linkerd.io)
Catalog research notes
- Research snapshot: September 9, 2026. This entry summarizes the linked primary documentation; it does not assert a latest release version.
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Real World Example
Securing Inter-Service Communication for Fintech Microservices
A fintech startup managing sensitive user transaction data across a distributed Kubernetes microservices architecture.
The business problem
The organization faces difficulty in verifying service identities and ensuring that all internal traffic is encrypted, leading to potential compliance risks and lack of visibility into inter-service communication patterns.
How this topic solves it
Linkerd provides a service mesh that automatically injects micro-proxies next to each service instance. These proxies handle mutual TLS (mTLS) for encrypted traffic and generate telemetry data for observability, ensuring that service identities are verified without requiring modifications to the application source code.
- Install the Linkerd control plane into the Kubernetes cluster to manage the mesh configuration.
- Inject the Linkerd data plane proxies into the target service pods to intercept network traffic.
- Configure the proxies to automatically establish mTLS connections between all meshed services.
- Utilize the generated telemetry to monitor service-to-service communication patterns and identify anomalies.
This diagram illustrates how traffic is intercepted by the Linkerd data plane proxies to ensure secure communication.
Linkerd micro-proxy
Linkerd micro-proxy
Destination application pod
- Service A → Local traffic → Proxy A
- Proxy A → mTLS encrypted tunnel → Proxy B
- Proxy B → Local traffic → Service B
Expected business outcome
The organization achieves automated, transparent encryption and granular observability of service interactions, significantly reducing the burden of manual security configuration and improving incident response times.
Limitations and checks
The primary limitation is the increased resource overhead introduced by running a sidecar proxy alongside every service instance. This can be monitored by checking the CPU and memory consumption of the linkerd-proxy container within each pod to ensure it remains within acceptable infrastructure limits.