Kyverno Policies vs. Gatekeeper Policies in Big Bang📜

The following table shows the policies implemented in Big Bang under Gatekeeper and the corresponding policy in Kyverno.

GK = Gatekeeper KY = Kyverno

Name	Category	Description	Gatekeeper	Kyverno	Notes
AppArmor	Pod Security Standards (Baseline)	Restrict AppArmor profiles to allowed list	`allowedAppArmorProfiles`	`restrict-apparmor`	Disabled in GK
Default Service Account	Unknown	Disallow use of default service account	`noDefaultServiceAccount`	Will not implement	Kubernetes assigns the default service account to all pods that do not specify a service account. Policy value is below threshold for implementation. KY policy `update-token-automount` likely covers what this policy was intended to do.
Docker Registries	Best Practices (Security)	Restrict image registries to allowed list	`allowedDockerRegistries`	`restrict-image-registries`
External IPs	Vulnerability Mitigation	Restrict service’s external IPs to allowed list	`allowedIPs`	`restrict-external-ips`	GK uses CIDR range. KY uses regex.
Group IDs - Non-root	Pod Security Standards (Restricted)	Require groups to be non-root	`allowedUsers`	`require-non-root-group`
Group IDs - Range	Best Practices (Security)	Restrict group IDs to a specified range	`allowedUsers`	`restrict-group-id`
Host Namespace	Pod Security Standards (Baseline)	Disallow access to the host PID and IPC	`noHostNamespace`	`disallow-host-namespaces`
Host Networking	Pod Security Standards (Baseline)	Disallow sharing the host network	`hostNetworking`	`disallow-host-namespaces`
Host Path	Best Practices (Security)	Restrict volumes that map host paths to allowed list and require the volume mount to be read-only	`allowedHostFilesystem`	`restrict-host-path-mount`; `restrict-host-path-write`
Host Ports	Pod Security Standards (Baseline)	Restrict host ports to a specified range	`hostNetworking`	`restrict-host-ports`
Image Digest	Best Practices (Security)	Require images to use image digests instead of tags	`imageDigest`	Will not implement	Iron Bank images require tags for nightly image builds. Policy value is below threshold for implementation.
Image Tags	Best Practices	Allow image tags not on banned list	`bannedImageTags`	`disallow-image-tags`
Ingress - HTTPS Only	Best Practices (Security)	Require ingresses to be HTTPS only	`httpsOnly`	Will not implement	Big Bang uses Istio instead of Ingresses. Policy value is below threshold for implementation.
Ingress - Unique	Best Practice	Disallows multiple Ingresses with the same host	`uniqueIngressHost`	Will not implement	Big Bang uses Istio instead of Ingresses. Policy value is below threshold for implementation.
Istio Sidecar Injection - Namespace	Best Practices	Require namespaces to be annotated for automatic Istio sidecar injection	`namespacesHaveIstio`	`require-istio-on-namespaces`
Istio Sidecar Injection - Pod	Best Practices	Require pods don’t disable automatic Istio sidecar injection	`podsHaveIstio`	`disallow-istio-injection-bypass`
Labels	Best Practices	Require specified labels to be on resources	`requiredLabels`	`require-labels`	KY removed `component`, `part-of`, and `managed-by` from default required list.
Linux Capabilities	Pod Security Standards (Restricted)	Require all capabilities to be dropped and restrict added capabilities to allowed list	`allowedCapabilities`	`require-drop-all-capabilities`; `restrict-capabilities`	KY adds `NET_BIND_SERVICE` to the default allowed list
Node Ports	Best Practices (Security)	Disallow NodePort services	`blockNodePort`	`disallow-nodeport-services`
Privileged Containers	Pod Security Standards (Baseline)	Disallow containers that run as privileged	`noPrivilegedContainers`	`disallow-privileged-containers`
Privileged Escalation	Pod Security Standards (Restricted)	Disallow privilege escalation permissions	`noPrivilegedEscalation`	`disallow-privilege-escalation`
Probes	Best Practices	Require probes on pods	`requiredProbes`	`require-probes`	KY removes validation of probe types (e.g. `tcpSocket`, `httpGet`, `exec`)
Proc Mount	Pod Security Standards (Baseline)	Restrict proc mount to allowed list	`allowedProcMount`	`restrict-proc-mount`
Read-only Root Filesystem	Best Practices (Security)	Require root file systems to be read only	`readOnlyRoot`	`require-ro-rootfs`
Resources - Large	Best Practices	Require CPU and memory limits and disallow extremely large values	`noBigContainers`	`require-cpu-limit; require-memory-limit`
Resources - Ratio	Best Practices	Ensure CPU and memory limits are not disproportionate to requests	`containerRatio`	Will not implement	No use case. Policy value is below threshold for implementation.
SecComp	Pod Security Standards (Baseline)	Restrict SecComp profiles to allowed list	`allowedSecCompProfiles`	`restrict-seccomp`	KY adds `Localhost` to the default allowed list
SELinux	Pod Security Standards (Baseline)	Restrict SELinux options to allowed list	`seLinuxPolicy`	`disallow-selinux-options`; `restrict-selinux-type`	KY adds additional allowed values to the default allowed list
SysCtl	Pod Security Standards (Baseline)	Restrict SysCtls to allowed list	`noSysctls`	`restrict-sysctls`	KY adds additional sysctl values to the default allowed list
Tolerations	Best Practices (Security)	Tolerations must not match specified list of taints	`restrictedTaint`	`disallow-tolerations`	KY also prevents tolerations on `RuntimeClasses`
User IDs - Non-root	Pod Security Standards (Restricted)	Require user to run as non-root	`allowedUsers`	`require-non-root-user`
User IDs - Range	Best Practices (Security)	Restrict user IDs to a specified range	`allowedUsers`	`restrict-user-id`
Volumes - Flex	Historical	Restrict flex volume drivers to allowed list	`allowedFlexVolumes`	`restrict-volume-types`	Flex Volume drivers are deprecated. In KY, Flex Volumes are not allowed.
Volumes - Types	Pod Security Standards (Restricted)	Restrict volume types to allowed list	`volumeTypes`	`restrict-volume-types`	KY adds `csi`and `ephemeral` to the default allowed list.