Linkerd is aservice meshfor Kubernetes. It makes running services easier and safer by giving you runtime debugging, observability, reliability, and security—all without requiring any changes to your code.
Installation
Ensure you have access to the Kubernetes cluster and a functioning kubectl, if not, you could set up Kubernetes cluster on your local machine through Minikube, docker desktop, or kind, etc.
Install linked CLIFor Linux
Follow the instructions from the official site:https://linkerd.io/2.14/getting-started/
curl --proto '=https' --tlsv1.2 -sSfL https://run.linkerd.io/install | sh
For Windows
Download the Windows execution file from Github:https://github.com/linkerd/linkerd2/releases/
No need to install, change the file name to linkerd and add it to the Path environment.
Check whether linked cli is running correctly by
linkerd version
Install Linkerd control plane
Check if your cluster is ready for installing Linkerd.
linkerd check --pre
InstallLinkerd’s Custom Resource Definitions (CRDs), it must be installed first.
linkerd install --crds | kubectl apply -f -Install Linkerd control panel.
linkerd install | kubectl apply -f -You may encounter some installation errors, for example, the one below, based on the error message, change the install command accordingly.
linkerd install --set proxyInit.runAsRoot=true | kubectl apply -f -
Check whether the control plane is installed successfully, linkerd control plane will be deployed to your cluster, a couple of images will be pulled, so make sure you have a workable network.
linkerd check
Deploy Linkerd to your application
First, you need an application deployed in your cluster, you can use the emojivoto application inhttps://linkerd.io/2.14/getting-started/.
After the application is deployed, add Linkerd’s data plane proxy to it.
kubectl get -n emojivoto deploy -o yaml | linkerd inject - | kubectl apply -f -
Afteremojivotois ‘meshed’, check the data plane
linkerd -n emojivoto check --proxy
Dashboard
Install Linkerd’s dashboard extension
linkerd viz install | kubectl apply -f -This is the official way to access the dashboard
linkerd viz dashboard &
While this doesn’t work when I using Windows docker desktop Kubernetes, I got this error
Looks like the normal way doesn’t work, so let’s inspect the webservice
kubectl get service web -n linkerd-viz -o yaml
And, got this, service type is ClusterIP and listening at port 8080 port
apiVersion: v1kind: Servicemetadata: annotations: kubectl.kubernetes.io/last-applied-configuration: | {"apiVersion":"v1","kind":"Service","metadata":{"annotations":{"linkerd.io/created-by":"linkerd/helm stable-2.14.7","linkerd.io/inject":"enabled"},"labels":{"component":"web","linkerd.io/extension":"viz","namespace":"linkerd-viz"},"name":"web","namespace":"linkerd-viz"},"spec":{"ports":[{"name":"http","port":8084,"targetPort":8084},{"name":"admin-http","port":9994,"targetPort":9994}],"selector":{"component":"web","linkerd.io/extension":"viz"},"type":"ClusterIP"}} linkerd.io/created-by: linkerd/helm stable-2.14.7 linkerd.io/inject: enabled creationTimestamp: "2023-12-29T05:06:38Z" labels: component: web linkerd.io/extension: viz namespace: linkerd-viz name: web namespace: linkerd-viz resourceVersion: "5396830" uid: ba0b70ec-89f3-4f9a-a407-492744f3f90bspec: clusterIP: 10.106.135.240 clusterIPs: - 10.106.135.240 internalTrafficPolicy: Cluster ipFamilies: - IPv4 ipFamilyPolicy: SingleStack ports: - name: http port: 8084 protocol: TCP targetPort: 8084 - name: admin-http port: 9994 protocol: TCP targetPort: 9994 selector: component: web linkerd.io/extension: viz sessionAffinity: None type: ClusterIPstatus: loadBalancer: {}
Then we can do a workaround, expose the service outside the cluster
kubectl -n linkerd-viz port-forward svc/web 8084Bingo!!!
