Linkerd as lightweight alternative in Kubernetes - Step-by-Step Execution

Process Flow - Linkerd as lightweight alternative

Start Kubernetes Cluster

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Install Linkerd Control Plane

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Deploy Application with Linkerd Proxy

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Linkerd Proxies Handle Traffic

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Observe Lightweight Service Mesh Features

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Compare Resource Use with Other Meshes

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Decide on Lightweight Mesh Benefits

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End

This flow shows how Linkerd is installed and runs as a lightweight service mesh in Kubernetes, managing traffic with minimal resource use.

Execution Sample

Kubernetes

linkerd install | kubectl apply -f -
linkerd check
kubectl get pods -n linkerd
kubectl annotate deploy myapp linkerd.io/inject=enabled
kubectl rollout restart deploy myapp
linkerd stat deploy

This sequence installs Linkerd, verifies it, injects proxies into an app, restarts it, and checks mesh stats.

Process Table

Step	Command	Action	Result/Output
1	linkerd install | kubectl apply -f -	Install Linkerd control plane	Linkerd control plane components created in 'linkerd' namespace
2	linkerd check	Verify Linkerd installation	All checks passed: control plane is running and healthy
3	kubectl get pods -n linkerd	List Linkerd pods	linkerd-controller, linkerd-proxy-injector, linkerd-web all Running
4	kubectl annotate deploy myapp linkerd.io/inject=enabled	Enable proxy injection on app	Deployment 'myapp' annotated for Linkerd proxy injection
5	kubectl rollout restart deploy myapp	Restart app to inject proxy	Deployment 'myapp' restarted, new pods have Linkerd proxy sidecar
6	linkerd stat deploy	Show service mesh stats	Displays success rates, request rates, and latencies for 'myapp'
7	-	Exit	Linkerd is running as lightweight mesh managing 'myapp' traffic

💡 Linkerd installed and managing traffic with minimal resource overhead

Status Tracker

Component	Before Installation	After Installation	After Proxy Injection	Final State
Linkerd Control Plane	Not present	Running in 'linkerd' namespace	Running	Healthy and managing traffic
Application Pods	No proxy sidecar	No proxy sidecar	Proxy sidecar injected	Pods running with Linkerd proxy
Resource Usage	N/A	Low CPU and memory usage	Slight increase due to proxy	Overall lightweight compared to other meshes

Key Moments - 3 Insights

Why do we need to restart the application deployment after annotating it?

Restarting the deployment creates new pods with the Linkerd proxy sidecar injected, as shown in step 5 of the execution table.

How can we confirm Linkerd is running correctly after installation?

The 'linkerd check' command in step 2 confirms all components are healthy and running.

What makes Linkerd lightweight compared to other service meshes?

Linkerd uses minimal CPU and memory resources as shown in the variable tracker, making it simpler and lighter to run.

Visual Quiz - 3 Questions

Look at the execution table, what command verifies that Linkerd is installed and healthy?

A kubectl get pods -n linkerd

B linkerd check

C kubectl annotate deploy myapp linkerd.io/inject=enabled

D linkerd stat deploy

💡 Hint

Check step 2 in the execution table where the verification happens.

At which step does the application get restarted to include the Linkerd proxy?

A Step 5

B Step 4

C Step 3

D Step 6

💡 Hint

Look at the action 'Restart app to inject proxy' in the execution table.

If the application pods did not restart after annotation, what would be the state of the pods?

A Pods would have the proxy sidecar injected

B Linkerd control plane would stop running

C Pods would remain without the proxy sidecar

D Application would crash immediately

💡 Hint

Refer to variable tracker row 'Application Pods' before and after proxy injection.

Concept Snapshot

Linkerd is a lightweight service mesh for Kubernetes.
Install with 'linkerd install | kubectl apply -f -'.
Verify with 'linkerd check'.
Enable proxy injection by annotating deployments.
Restart deployments to inject proxies.
Use 'linkerd stat' to monitor traffic.
It uses minimal resources compared to other meshes.

Full Transcript

This visual execution shows how to install and use Linkerd as a lightweight alternative service mesh in Kubernetes. First, the Linkerd control plane is installed and verified to be healthy. Then, an application deployment is annotated to enable Linkerd proxy injection. Restarting the deployment creates new pods with the proxy sidecar. Finally, Linkerd monitors traffic with low resource use. Key moments include the need to restart pods after annotation and how to verify installation health. The lightweight nature is confirmed by resource tracking. This step-by-step trace helps beginners see how Linkerd runs and manages traffic simply and efficiently.