Hands-on Lab·Certified Kubernetes Security Specialist
Managing Kubernetes Secrets
Encryption at rest protects the datastore. This guide is about everything above it: how a Secret is consumed, where it ends up, what immutability buys, and the Role that looks like it restricts access and does not.
Microservice Vulnerabilities Guide 21 of 40 Intermediate
- Kubernetesapiserver v1.36.4, kubelet v1.36.3
- Runtimecontainerd 2.2.6
- CNICilium 1.18.1 - tunnel/VXLAN, with Hubble relay and UI
- Host OSUbuntu 26.04 LTS, kernel 7.0.0-29
- Built withkubeadm v1.36.3 - podSubnet 10.244.0.0/16, serviceSubnet 10.96.0.0/12
- TimeAbout 16 min
- Reviewed25 August 2026
Written against the versions above. Secret volumes are tmpfs on Linux nodes and mounted read-only when the Pod asks for it. `immutable: true` cannot be reversed - the Secret has to be replaced.
| Server Name | IP Address | OS | Roles | CPU | RAM | HDD |
|---|---|---|---|---|---|---|
| CKA6001 | 192.168.0.46 | Ubuntu 26.04 LTS | Control Plane Node (tainted NoSchedule) | 2 Core | 4 GB | 50 GB |
| CKA6001-NODE01 | 192.168.0.47 | Ubuntu 26.04 LTS | Worker Node | 2 Core | 4 GB | 50 GB |
| CKA6001-NODE02 | 192.168.0.48 | Ubuntu 26.04 LTS | Worker Node | 2 Core | 4 GB | 50 GB |
Before you start
- guide 11 - the other credential in a Pod.
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The same Secret, consumed two ways
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The parts that are not about mounting
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What the node sees