Risks

Each time a pod is created or updated, it requires one or more container images. Depending on the policy, the pod may use the containers residing on the host VM or may need to ignore the images on the host VM and pull the images from a registry. Container images are typically provisioned from a container registry. The images are downloaded (pulled) locally to the machine on which the container is launched when the container is created. In the registry, the images are administered and are the central place for managing images. Thus, it is crucial to start each container with the correct image.

In each YAML file that specifies images, the entry for ImagePullPolicy should be set as follows:

spec:

  containers:

  - image: <Imagename>

    imagePullPolicy: Always

Risks and Best Practices for Container Image Management

Risks of Untrusted or Non-Verified Registries: Pulling images from untrusted or non-verified registries can introduce vulnerabilities or malicious code into the environment. Malicious or compromised images can contain backdoors, malware, or other security threats that could compromise the entire cluster.

Image Signatures and Verification: To ensure the integrity and authenticity of container images, it is essential to use image signatures. Image signing tools, such as Notary or Cosign, can be used to verify the integrity and authenticity of images. This ensures that only trusted images are pulled and executed.

Monitoring and Alerting: Implement monitoring and alerting to detect and mitigate potential risks associated with namespace misconfigurations. Tools like Prometheus, Grafana, and Kubernetes-native solutions can help monitor the cluster and alert administrators to any suspicious activity or misconfigurations.