Skip to content

Installing, Testing and Checking Cilium with the Cilium CLI: CCA practice questions

The quick installation guide uses the Cilium CLI for the whole first-day workflow: install, wait for health, then prove that the network works. cilium install installs Cilium into the cluster of the current kubectl context using Helm.

By Ibrahim Yesilay · Published · Updated

Independent community practice, not affiliated with or endorsed by CNCF or The Linux Foundation.

What Installing, Testing and Checking Cilium with the Cilium CLI covers in CCA

The quick installation guide uses the Cilium CLI for the whole first-day workflow: install, wait for health, then prove that the network works. cilium install installs Cilium into the cluster of the current kubectl context using Helm. It detects the environment, such as kind, minikube, EKS, GKE or AKS bring-your-own-CNI, and picks suitable defaults, while --version, --datapath-mode and Helm values let you override them. The cluster must be configured to use CNI and the nodes need Linux 5.10 or newer, or an equivalent such as 4.18 on RHEL 8.10.

Two dry-run flags help before anything is changed. --dry-run writes every resource that would be installed to stdout, and --dry-run-helm-values prints only the non-default Helm values. If pods were already running before Cilium arrived, the installer restarts them and prints lines such as "Restarted unmanaged pod", so that all pods end up with networking provided by Cilium.

After installing, cilium status --wait blocks until the status reports success, which means no errors and no warnings, up to the limit in --wait-duration. --ignore-warnings accepts a state that only has warnings, and -o json gives machine-readable output. The summary covers the cilium DaemonSet, cilium-envoy, the operator, Hubble Relay and Cluster Mesh, with desired, ready and available counts and the image versions in use.

cilium connectivity test then deploys client and echo workloads in a dedicated test namespace and checks pod-to-pod, pod-to-service, pod-to-host and external connectivity. By default it also uses Hubble to validate the flows behind each test, looking for Relay at localhost:4245. When Relay cannot be reached, the README example shows the CLI warning about it, disabling flow validation and running the tests anyway. Useful options include --single-node for one-node clusters, --multi-cluster with a second kubeconfig context to test across a Cluster Mesh, --test to select tests by regular expression, --junit-file for a report and --cleanup to remove the test artifacts without running anything.

Performance is a separate command. cilium connectivity perf runs TCP request-response (TCP_RR) and throughput (TCP_STREAM) tests by default, adds UDP and TCP_CRR tests with --udp and --crr, covers pods on the same node and on different nodes, and prints latency percentiles, transaction rates and throughput.

Key points

  • cilium install uses Helm under the hood and auto-detects the cluster type.
  • cilium status --wait succeeds only with no errors and no warnings, unless --ignore-warnings is set.
  • connectivity test uses Hubble flow validation by default and skips it when Relay is unreachable.
  • --single-node and --multi-cluster adapt the tests to one-node clusters and Cluster Mesh.
  • cilium connectivity perf measures latency and throughput instead of correctness.

Three sample questions

14 CCA questions on Installing, Testing and Checking Cilium with the Cilium CLI, 14 with explanations. How practice works

Question 1

What command installs Cilium with the Cilium CLI?
  1. A.kubectl apply -f cilium.yaml
  2. B.kubectl create -f https://get.cilium.io/install
  3. C.cilium install
  4. D.helm install cilium cilium/cilium

Correct answer: C

The command "cilium install" is used to install Cilium with the CLI. This command automatically detects the Kubernetes environment and applies the appropriate Cilium components.

Question 2

How would you check if all Cilium components are running correctly?
  1. A.kubectl get pods -n kube-system | grep cilium
  2. B.cilium status
  3. C.helm status cilium -n kube-system
  4. D.kubectl describe daemonset cilium -n kube-system

Correct answer: B

The "cilium status" command provides a comprehensive overview of all Cilium components, showing whether they are running correctly and reporting their health status.

Question 3

Which Cilium CLI command would run connectivity tests to verify the cluster's networking?
  1. A.cilium connectivity test
  2. B.cilium test connectivity
  3. C.cilium verify networking
  4. D.cilium network test

Correct answer: A

The "cilium connectivity test" command runs a series of network connectivity tests to verify that the cluster's networking is functioning correctly with Cilium.

Practice this topic

Focus mode keeps every question on Installing, Testing and Checking Cilium with the Cilium CLI until you leave it. 10 free guest answers, then a free account; no credit card.

Or open CCA practice across all topics.

Sources

The explanation above was checked against these official documents.

Frequently asked questions

Does cilium connectivity test touch my own workloads?

No. It creates its own client and echo pods in a separate test namespace and can remove them again with --cleanup.