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Getting Started

Before you Begin

You need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. If you do not already have a cluster, you can create one by installing minikube or kind, or you can use one of these Kubernetes playgrounds:

You also need the Starboard Operator to be installed in the starboard-system namespace, e.g. with kubectl or Helm.

Workloads Scanning

Assuming that you installed the operator in the starboard-system namespace, and it's configured to discover Kubernetes workloads in the default namespace, let's create the nginx Deployment that we know is vulnerable:

kubectl create deployment nginx --image nginx:1.16

When the first ReplicaSet controlled by the nginx Deployment is created, the operator immediately detects that and creates the Kubernetes Job in the starboard-system namespace to scan the nginx:1.16 image for vulnerabilities. It also creates the Job to audit the Deployment's configuration for common pitfalls such as running the nginx container as root:

kubectl get job -n starboard-operator
Result
NAME                                 COMPLETIONS   DURATION   AGE
scan-configauditreport-c4956cb9d     0/1           1s         1s
scan-vulnerabilityreport-c4956cb9d   0/1           1s         1s

If everything goes fine, the scan Jobs are deleted, and the operator saves scan reports as custom resources in the default namespace, named after the Deployment's active ReplicaSet. For image vulnerability scans, the operator creates a VulnerabilityReport for each different container defined in the active ReplicaSet. In this example there is just one container image called nginx:

kubectl get vulnerabilityreports -o wide
Result
NAME                                REPOSITORY      TAG    SCANNER   AGE   CRITICAL   HIGH   MEDIUM   LOW   UNKNOWN
replicaset-nginx-7ff78f74b9-nginx   library/nginx   1.16   Trivy     12s   4          40     26       90    0

Similarly, the operator creates a ConfigAuditReport holding the result of auditing the configuration of the active ReplicaSet controlled by the nginx Deployment:

kubectl get configauditreports -o wide
Result
NAME                          SCANNER   AGE   DANGER   WARNING   PASS
replicaset-nginx-7ff78f74b9   Polaris   33s   1        9         7

Notice that scan reports generated by the operator are controlled by Kubernetes workloads. In our example, VulnerabilityReport and ConfigAuditReport objects are controlled by the active ReplicaSet of the nginx Deployment:

kubectl tree deploy nginx
Result
NAMESPACE  NAME                                                       READY  REASON  AGE
default    Deployment/nginx                                           -              51s
default    └─ReplicaSet/nginx-6d4cf56db6                              -              51s
default      ├─ConfigAuditReport/replicaset-nginx-6d4cf56db6          -              46s
default      ├─VulnerabilityReport/replicaset-nginx-6d4cf56db6-nginx  -              31s
default      └─Pod/nginx-6d4cf56db6-fhbm9                             True           51s

Note

The tree command is a kubectl plugin to browse Kubernetes object hierarchies as a tree.

Moving forward, let's update the container image of the nginx Deployment from nginx:1.16 to nginx:1.17. This will trigger a rolling update of the Deployment and eventually create another ReplicaSet.

kubectl set image deployment nginx nginx=nginx:1.17

Even this time the operator will pick up changes and rescan our Deployment with updated configuration:

kubectl tree deploy nginx
Result
NAMESPACE  NAME                                                       READY  REASON  AGE
default    Deployment/nginx                                           -              86s
default    ├─ReplicaSet/nginx-6d4cf56db6                              -              86s
default    │ ├─ConfigAuditReport/replicaset-nginx-6d4cf56db6          -              81s
default    │ └─VulnerabilityReport/replicaset-nginx-6d4cf56db6-nginx  -              66s
default    └─ReplicaSet/nginx-db749865c                               -              19s
default      ├─ConfigAuditReport/replicaset-nginx-db749865c           -              17s
default      ├─VulnerabilityReport/replicaset-nginx-db749865c-nginx   -              9s
default      └─Pod/nginx-db749865c-lfcp5                              True           19s

By following this guide you could realize that the operator knows how to attach VulnerabilityReport and ConfigAuditReport objects to build-in Kubernetes objects so that looking them up is easy. What's more, in this approach where a custom resource inherits a life cycle of the built-in resource we could leverage Kubernetes garbage collection. For example, when the previous ReplicaSet named nginx-6d4cf56db6 is deleted the VulnerabilityReport named replicaset-nginx-6d4cf56db6-nginx as well as the ConfigAuditReport named replicaset-nginx-6d4cf56db6 are automatically garbage collected.

Tip

If you only want the latest ReplicaSet in your Deployment to be scanned for vulnerabilities you can set the value of the OPERATOR_VULNERABILITY_SCANNER_SCAN_ONLY_CURRENT_REVISIONS environment variable to true in the operator's deployment descriptor. This is useful to identify vulnerabilities that impact only the running workloads.

Tip

You can get and describe vulnerabilityreports and configauditreports as built-in Kubernetes objects:

kubectl get vulnerabilityreport replicaset-nginx-db749865c-nginx -o json
kubectl describe configauditreport replicaset-nginx-db749865c

Notice that scaling up the nginx Deployment will not schedule new scan Jobs because all replica Pods refer to the same Pod templated defined by the nginx-db749865c ReplicaSet.

kubectl scale deploy nginx --replicas 3
kubectl tree deploy nginx
Result
NAMESPACE  NAME                                                       READY  REASON  AGE
default    Deployment/nginx                                           -              2m22s
default    ├─ReplicaSet/nginx-6d4cf56db6                              -              2m22s
default    │ ├─ConfigAuditReport/replicaset-nginx-6d4cf56db6          -              2m17s
default    │ └─VulnerabilityReport/replicaset-nginx-6d4cf56db6-nginx  -              2m2s
default    └─ReplicaSet/nginx-db749865c                               -              75s
default      ├─ConfigAuditReport/replicaset-nginx-db749865c           -              73s
default      ├─VulnerabilityReport/replicaset-nginx-db749865c-nginx   -              65s
default      ├─Pod/nginx-db749865c-lfcp5                              True           75s
default      ├─Pod/nginx-db749865c-tn5k7                              True           12s
default      └─Pod/nginx-db749865c-vjlr9                              True           12s

Finally, when you delete the nginx Deployment, orphaned security reports will be deleted in the background by the Kubernetes garbage collection controller.

kubectl delete deploy nginx
kubectl get vuln,configaudit
Result
No resources found in default namespace.

Tip

Use vuln and configaudit as short names for vulnerabilityreports and configauditreports resources.

Note

You can define the validity period for VulnerabilityReports by setting the duration as the value of the OPERATOR_VULNERABILITY_SCANNER_REPORT_TTL environment variable. For example, setting the value to 24h would delete reports after 24 hours. When a VulnerabilityReport gets deleted Starboard Operator will automatically rescan the underlying workload. Assuming that the vulnerability scanner has updated its vulnerability database, new VulnerabilityReports will contain the latest vulnerabilities.

Infrastructure Scanning

The operator discovers also Kubernetes nodes and runs CIS Kubernetes Benchmark checks on each of them. The results are stored as CISKubeBenchReport objects. In other words, for a cluster with 3 nodes the operator will eventually create 3 benchmark reports:

kubectl get node
Result
NAME                 STATUS   ROLES    AGE     VERSION
kind-control-plane   Ready    master   3h27m   v1.18.8
kind-worker          Ready    <none>   3h26m   v1.18.8
kind-worker2         Ready    <none>   3h26m   v1.18.8
kubectl get ciskubebenchreports -o wide
Result
NAME                 SCANNER      AGE   FAIL   WARN   INFO   PASS
kind-control-plane   kube-bench   8s    12     40     0      70
kind-worker          kube-bench   9s    2      27     0      18
kind-worker2         kube-bench   9s    2      27     0      18

Notice that each CISKubeBenchReport is named after a node and is controlled by that node to inherit its life cycle:

kubectl tree node kind-control-plane -A
Result
NAMESPACE        NAME                                              READY  REASON        AGE
                 Node/kind-control-plane                           True   KubeletReady  48m
                 ├─CISKubeBenchReport/kind-control-plane           -                    44m
                 ├─CSINode/kind-control-plane                      -                    48m
kube-node-lease  ├─Lease/kind-control-plane                        -                    48m
kube-system      ├─Pod/etcd-kind-control-plane                     True                 48m
kube-system      ├─Pod/kube-apiserver-kind-control-plane           True                 48m
kube-system      ├─Pod/kube-controller-manager-kind-control-plane  True                 48m
kube-system      └─Pod/kube-scheduler-kind-control-plane           True                 48m

What's Next?