gke

Documentation

Index

• Variables

Variables

var CheckEnableAutoRepair = rules.Register(
	scan.Rule{
		AVDID:       "AVD-GCP-0063",
		Provider:    providers.GoogleProvider,
		Service:     "gke",
		ShortCode:   "enable-auto-repair",
		Summary:     "Kubernetes should have 'Automatic repair' enabled",
		Impact:      "Failing nodes will require manual repair.",
		Resolution:  "Enable automatic repair",
		Explanation: `Automatic repair will monitor nodes and attempt repair when a node fails multiple subsequent health checks`,
		Links:       []string{},
		Terraform: &scan.EngineMetadata{
			GoodExamples:        terraformEnableAutoRepairGoodExamples,
			BadExamples:         terraformEnableAutoRepairBadExamples,
			Links:               terraformEnableAutoRepairLinks,
			RemediationMarkdown: terraformEnableAutoRepairRemediationMarkdown,
		},
		Severity: severity.Low,
	},
	func(s *state.State) (results scan.Results) {
		for _, cluster := range s.Google.GKE.Clusters {
			for _, nodePool := range cluster.NodePools {
				if nodePool.Management.EnableAutoRepair.IsFalse() {
					results.Add(
						"Node pool does not have auto-repair enabled.",
						nodePool.Management.EnableAutoRepair,
					)
				} else {
					results.AddPassed(&nodePool)
				}
			}
		}
		return
	},
)

var CheckEnableAutoUpgrade = rules.Register(
	scan.Rule{
		AVDID:       "AVD-GCP-0058",
		Provider:    providers.GoogleProvider,
		Service:     "gke",
		ShortCode:   "enable-auto-upgrade",
		Summary:     "Kubernetes should have 'Automatic upgrade' enabled",
		Impact:      "Nodes will need the cluster master version manually updating",
		Resolution:  "Enable automatic upgrades",
		Explanation: `Automatic updates keep nodes updated with the latest cluster master version.`,
		Links:       []string{},
		Terraform: &scan.EngineMetadata{
			GoodExamples:        terraformEnableAutoUpgradeGoodExamples,
			BadExamples:         terraformEnableAutoUpgradeBadExamples,
			Links:               terraformEnableAutoUpgradeLinks,
			RemediationMarkdown: terraformEnableAutoUpgradeRemediationMarkdown,
		},
		Severity: severity.Low,
	},
	func(s *state.State) (results scan.Results) {
		for _, cluster := range s.Google.GKE.Clusters {
			for _, nodePool := range cluster.NodePools {
				if nodePool.Management.EnableAutoUpgrade.IsFalse() {
					results.Add(
						"Node pool does not have auto-upgraade enabled.",
						nodePool.Management.EnableAutoUpgrade,
					)
				} else {
					results.AddPassed(&nodePool)
				}

			}
		}
		return
	},
)

var CheckEnableIpAliasing = rules.Register(
	scan.Rule{
		AVDID:       "AVD-GCP-0049",
		Provider:    providers.GoogleProvider,
		Service:     "gke",
		ShortCode:   "enable-ip-aliasing",
		Summary:     "Clusters should have IP aliasing enabled",
		Impact:      "Nodes need a NAT gateway to access local services",
		Resolution:  "Enable IP aliasing",
		Explanation: `IP aliasing allows the reuse of public IPs internally, removing the need for a NAT gateway.`,
		Links:       []string{},
		Terraform: &scan.EngineMetadata{
			GoodExamples:        terraformEnableIpAliasingGoodExamples,
			BadExamples:         terraformEnableIpAliasingBadExamples,
			Links:               terraformEnableIpAliasingLinks,
			RemediationMarkdown: terraformEnableIpAliasingRemediationMarkdown,
		},
		Severity: severity.Low,
	},
	func(s *state.State) (results scan.Results) {
		for _, cluster := range s.Google.GKE.Clusters {
			if cluster.Metadata.IsUnmanaged() {
				continue
			}
			if cluster.IPAllocationPolicy.Enabled.IsFalse() {
				results.Add(
					"Cluster has IP aliasing disabled.",
					cluster.IPAllocationPolicy.Enabled,
				)
			} else {
				results.AddPassed(&cluster)
			}

		}
		return
	},
)

var CheckEnableMasterNetworks = rules.Register(
	scan.Rule{
		AVDID:       "AVD-GCP-0061",
		Provider:    providers.GoogleProvider,
		Service:     "gke",
		ShortCode:   "enable-master-networks",
		Summary:     "Master authorized networks should be configured on GKE clusters",
		Impact:      "Unrestricted network access to the master",
		Resolution:  "Enable master authorized networks",
		Explanation: `Enabling authorized networks means you can restrict master access to a fixed set of CIDR ranges`,
		Links:       []string{},
		Terraform: &scan.EngineMetadata{
			GoodExamples:        terraformEnableMasterNetworksGoodExamples,
			BadExamples:         terraformEnableMasterNetworksBadExamples,
			Links:               terraformEnableMasterNetworksLinks,
			RemediationMarkdown: terraformEnableMasterNetworksRemediationMarkdown,
		},
		Severity: severity.High,
	},
	func(s *state.State) (results scan.Results) {
		for _, cluster := range s.Google.GKE.Clusters {
			if cluster.Metadata.IsUnmanaged() {
				continue
			}
			if cluster.MasterAuthorizedNetworks.Enabled.IsFalse() {
				results.Add(
					"Cluster does not have master authorized networks enabled.",
					cluster.MasterAuthorizedNetworks.Enabled,
				)
			} else {
				results.AddPassed(&cluster)
			}

		}
		return
	},
)

var CheckEnableNetworkPolicy = rules.Register(
	scan.Rule{
		AVDID:       "AVD-GCP-0056",
		Provider:    providers.GoogleProvider,
		Service:     "gke",
		ShortCode:   "enable-network-policy",
		Summary:     "Network Policy should be enabled on GKE clusters",
		Impact:      "Unrestricted inter-cluster communication",
		Resolution:  "Enable network policy",
		Explanation: `Enabling a network policy allows the segregation of network traffic by namespace`,
		Links:       []string{},
		Terraform: &scan.EngineMetadata{
			GoodExamples:        terraformEnableNetworkPolicyGoodExamples,
			BadExamples:         terraformEnableNetworkPolicyBadExamples,
			Links:               terraformEnableNetworkPolicyLinks,
			RemediationMarkdown: terraformEnableNetworkPolicyRemediationMarkdown,
		},
		Severity: severity.Medium,
	},
	func(s *state.State) (results scan.Results) {
		for _, cluster := range s.Google.GKE.Clusters {
			if cluster.Metadata.IsUnmanaged() {
				continue
			}
			if cluster.NetworkPolicy.Enabled.IsFalse() {
				results.Add(
					"Cluster does not have a network policy enabled.",
					cluster.NetworkPolicy.Enabled,
				)
			} else {
				results.AddPassed(&cluster)
			}

		}
		return
	},
)

var CheckEnablePrivateCluster = rules.Register(
	scan.Rule{
		AVDID:       "AVD-GCP-0059",
		Provider:    providers.GoogleProvider,
		Service:     "gke",
		ShortCode:   "enable-private-cluster",
		Summary:     "Clusters should be set to private",
		Impact:      "Nodes may be exposed to the public internet",
		Resolution:  "Enable private cluster",
		Explanation: `Enabling private nodes on a cluster ensures the nodes are only available internally as they will only be assigned internal addresses.`,
		Links:       []string{},
		Terraform: &scan.EngineMetadata{
			GoodExamples:        terraformEnablePrivateClusterGoodExamples,
			BadExamples:         terraformEnablePrivateClusterBadExamples,
			Links:               terraformEnablePrivateClusterLinks,
			RemediationMarkdown: terraformEnablePrivateClusterRemediationMarkdown,
		},
		Severity: severity.Medium,
	},
	func(s *state.State) (results scan.Results) {
		for _, cluster := range s.Google.GKE.Clusters {
			if cluster.Metadata.IsUnmanaged() {
				continue
			}
			if cluster.PrivateCluster.EnablePrivateNodes.IsFalse() {
				results.Add(
					"Cluster does not have private nodes.",
					cluster.PrivateCluster.EnablePrivateNodes,
				)
			} else {
				results.AddPassed(&cluster)
			}

		}
		return
	},
)

var CheckEnableStackdriverLogging = rules.Register(
	scan.Rule{
		AVDID:       "AVD-GCP-0060",
		Provider:    providers.GoogleProvider,
		Service:     "gke",
		ShortCode:   "enable-stackdriver-logging",
		Summary:     "Stackdriver Logging should be enabled",
		Impact:      "Visibility will be reduced",
		Resolution:  "Enable StackDriver logging",
		Explanation: `StackDriver logging provides a useful interface to all of stdout/stderr for each container and should be enabled for moitoring, debugging, etc.`,
		Links:       []string{},
		Terraform: &scan.EngineMetadata{
			GoodExamples:        terraformEnableStackdriverLoggingGoodExamples,
			BadExamples:         terraformEnableStackdriverLoggingBadExamples,
			Links:               terraformEnableStackdriverLoggingLinks,
			RemediationMarkdown: terraformEnableStackdriverLoggingRemediationMarkdown,
		},
		Severity: severity.Low,
	},
	func(s *state.State) (results scan.Results) {
		for _, cluster := range s.Google.GKE.Clusters {
			if cluster.Metadata.IsUnmanaged() {
				continue
			}
			if cluster.LoggingService.NotEqualTo("logging.googleapis.com/kubernetes") {
				results.Add(
					"Cluster does not use the logging.googleapis.com/kubernetes StackDriver logging service.",
					cluster.LoggingService,
				)
			} else {
				results.AddPassed(&cluster)
			}

		}
		return
	},
)

var CheckEnableStackdriverMonitoring = rules.Register(
	scan.Rule{
		AVDID:       "AVD-GCP-0052",
		Provider:    providers.GoogleProvider,
		Service:     "gke",
		ShortCode:   "enable-stackdriver-monitoring",
		Summary:     "Stackdriver Monitoring should be enabled",
		Impact:      "Visibility will be reduced",
		Resolution:  "Enable StackDriver monitoring",
		Explanation: `StackDriver monitoring aggregates logs, events, and metrics from your Kubernetes environment on GKE to help you understand your application's behavior in production.`,
		Links:       []string{},
		Terraform: &scan.EngineMetadata{
			GoodExamples:        terraformEnableStackdriverMonitoringGoodExamples,
			BadExamples:         terraformEnableStackdriverMonitoringBadExamples,
			Links:               terraformEnableStackdriverMonitoringLinks,
			RemediationMarkdown: terraformEnableStackdriverMonitoringRemediationMarkdown,
		},
		Severity: severity.Low,
	},
	func(s *state.State) (results scan.Results) {
		for _, cluster := range s.Google.GKE.Clusters {
			if cluster.Metadata.IsUnmanaged() {
				continue
			}
			if cluster.MonitoringService.NotEqualTo("monitoring.googleapis.com/kubernetes") {
				results.Add(
					"Cluster does not use the monitoring.googleapis.com/kubernetes StackDriver monitoring service.",
					cluster.MonitoringService,
				)
			} else {
				results.AddPassed(&cluster)
			}

		}
		return
	},
)

var CheckMetadataEndpointsDisabled = rules.Register(
	scan.Rule{
		AVDID:      "AVD-GCP-0048",
		Provider:   providers.GoogleProvider,
		Service:    "gke",
		ShortCode:  "metadata-endpoints-disabled",
		Summary:    "Legacy metadata endpoints enabled.",
		Impact:     "Legacy metadata endpoints don't require metadata headers",
		Resolution: "Disable legacy metadata endpoints",
		Explanation: `The Compute Engine instance metadata server exposes legacy v0.1 and v1beta1 endpoints, which do not enforce metadata query headers. 

This is a feature in the v1 APIs that makes it more difficult for a potential attacker to retrieve instance metadata. 

Unless specifically required, we recommend you disable these legacy APIs.

When setting the <code>metadata</code> block, the default value for <code>disable-legacy-endpoints</code> is set to true, they should not be explicitly enabled.`,
		Links: []string{
			"https://cloud.google.com/kubernetes-engine/docs/how-to/hardening-your-cluster#protect_node_metadata_default_for_112",
		},
		Terraform: &scan.EngineMetadata{
			GoodExamples:        terraformMetadataEndpointsDisabledGoodExamples,
			BadExamples:         terraformMetadataEndpointsDisabledBadExamples,
			Links:               terraformMetadataEndpointsDisabledLinks,
			RemediationMarkdown: terraformMetadataEndpointsDisabledRemediationMarkdown,
		},
		Severity: severity.High,
	},
	func(s *state.State) (results scan.Results) {
		for _, cluster := range s.Google.GKE.Clusters {
			if cluster.Metadata.IsUnmanaged() {
				continue
			}
			if cluster.RemoveDefaultNodePool.IsTrue() {
				for _, pool := range cluster.NodePools {
					if pool.NodeConfig.EnableLegacyEndpoints.IsTrue() {
						results.Add(
							"Cluster has legacy metadata endpoints enabled.",
							pool.NodeConfig.EnableLegacyEndpoints,
						)
					}
				}
			} else if cluster.NodeConfig.EnableLegacyEndpoints.IsTrue() {
				results.Add(
					"Cluster has legacy metadata endpoints enabled.",
					cluster.NodeConfig.EnableLegacyEndpoints,
				)
			} else {
				results.AddPassed(&cluster)
			}

		}
		return
	},
)

var CheckNoLegacyAuthentication = rules.Register(
	scan.Rule{
		AVDID:      "AVD-GCP-0064",
		Provider:   providers.GoogleProvider,
		Service:    "gke",
		ShortCode:  "no-legacy-authentication",
		Summary:    "Legacy client authentication methods utilized.",
		Impact:     "Username/password or certificate authentication methods are less secure",
		Resolution: "Use service account or OAuth for authentication",
		Explanation: `It is recommended to use Service Accounts and OAuth as authentication methods for accessing the master in the container cluster. 

Basic authentication should be disabled by explicitly unsetting the <code>username</code> and <code>password</code> on the <code>master_auth</code> block.`,
		Links: []string{
			"https://cloud.google.com/kubernetes-engine/docs/how-to/hardening-your-cluster#restrict_authn_methods",
		},
		Terraform: &scan.EngineMetadata{
			GoodExamples:        terraformNoLegacyAuthenticationGoodExamples,
			BadExamples:         terraformNoLegacyAuthenticationBadExamples,
			Links:               terraformNoLegacyAuthenticationLinks,
			RemediationMarkdown: terraformNoLegacyAuthenticationRemediationMarkdown,
		},
		Severity: severity.High,
	},
	func(s *state.State) (results scan.Results) {
		for _, cluster := range s.Google.GKE.Clusters {
			if cluster.Metadata.IsUnmanaged() {
				continue
			}
			if cluster.MasterAuth.ClientCertificate.IssueCertificate.IsTrue() {
				results.Add(
					"Cluster allows the use of certificates for master authentication.",
					cluster.MasterAuth.ClientCertificate.IssueCertificate,
				)
			} else if cluster.MasterAuth.Username.NotEqualTo("") {
				results.Add(
					"Cluster allows the use of basic auth for master authentication.",
					cluster.MasterAuth.Username,
				)
			} else {
				results.AddPassed(&cluster)
			}

		}
		return
	},
)

var CheckNoPublicControlPlane = rules.Register(
	scan.Rule{
		AVDID:       "AVD-GCP-0053",
		Provider:    providers.GoogleProvider,
		Service:     "gke",
		ShortCode:   "no-public-control-plane",
		Summary:     "GKE Control Plane should not be publicly accessible",
		Impact:      "GKE control plane exposed to public internet",
		Resolution:  "Use private nodes and master authorised networks to prevent exposure",
		Explanation: `The GKE control plane is exposed to the public internet by default.`,
		Links:       []string{},
		Terraform: &scan.EngineMetadata{
			GoodExamples:        terraformNoPublicControlPlaneGoodExamples,
			BadExamples:         terraformNoPublicControlPlaneBadExamples,
			Links:               terraformNoPublicControlPlaneLinks,
			RemediationMarkdown: terraformNoPublicControlPlaneRemediationMarkdown,
		},
		Severity: severity.High,
	},
	func(s *state.State) (results scan.Results) {
		for _, cluster := range s.Google.GKE.Clusters {
			if cluster.Metadata.IsUnmanaged() {
				continue
			}
			for _, block := range cluster.MasterAuthorizedNetworks.CIDRs {
				if cidr.IsPublic(block.Value()) {
					results.Add(
						"Cluster exposes control plane to the public internet.",
						block,
					)
				} else {
					results.AddPassed(&cluster)
				}

			}
		}
		return
	},
)

var CheckNodeMetadataSecurity = rules.Register(
	scan.Rule{
		AVDID:      "AVD-GCP-0057",
		Provider:   providers.GoogleProvider,
		Service:    "gke",
		ShortCode:  "node-metadata-security",
		Summary:    "Node metadata value disables metadata concealment.",
		Impact:     "Metadata that isn't concealed potentially risks leakage of sensitive data",
		Resolution: "Set node metadata to SECURE or GKE_METADATA_SERVER",
		Explanation: `If the <code>workload_metadata_config</code> block within <code>node_config</code> is included, the <code>node_metadata</code> attribute should be configured securely.

The attribute should be set to <code>SECURE</code> to use metadata concealment, or <code>GKE_METADATA_SERVER</code> if workload identity is enabled. This ensures that the VM metadata is not unnecessarily exposed to pods.`,
		Links: []string{
			"https://cloud.google.com/kubernetes-engine/docs/how-to/protecting-cluster-metadata#create-concealed",
		},
		Terraform: &scan.EngineMetadata{
			GoodExamples:        terraformNodeMetadataSecurityGoodExamples,
			BadExamples:         terraformNodeMetadataSecurityBadExamples,
			Links:               terraformNodeMetadataSecurityLinks,
			RemediationMarkdown: terraformNodeMetadataSecurityRemediationMarkdown,
		},
		Severity: severity.High,
	},
	func(s *state.State) (results scan.Results) {
		for _, cluster := range s.Google.GKE.Clusters {
			if cluster.Metadata.IsManaged() {
				metadata := cluster.NodeConfig.WorkloadMetadataConfig.NodeMetadata
				if metadata.EqualTo("UNSPECIFIED") || metadata.EqualTo("EXPOSE") {
					results.Add(
						"Cluster exposes node metadata of pools by default.",
						metadata,
					)
				} else {
					results.AddPassed(&cluster)
				}

			}
			for _, pool := range cluster.NodePools {
				metadata := pool.NodeConfig.WorkloadMetadataConfig.NodeMetadata
				if metadata.EqualTo("UNSPECIFIED") || metadata.EqualTo("EXPOSE") {
					results.Add(
						"Node pool exposes node metadata.",
						metadata,
					)
				} else {
					results.AddPassed(&pool)
				}

			}
		}
		return
	},
)

var CheckNodePoolUsesCos = rules.Register(
	scan.Rule{
		AVDID:       "AVD-GCP-0054",
		Provider:    providers.GoogleProvider,
		Service:     "gke",
		ShortCode:   "node-pool-uses-cos",
		Summary:     "Ensure Container-Optimized OS (cos) is used for Kubernetes Engine Clusters Node image",
		Impact:      "COS is the recommended OS image to use on cluster nodes",
		Resolution:  "Use the COS image type",
		Explanation: `GKE supports several OS image types but COS is the recommended OS image to use on cluster nodes for enhanced security`,
		Links:       []string{},
		Terraform: &scan.EngineMetadata{
			GoodExamples:        terraformNodePoolUsesCosGoodExamples,
			BadExamples:         terraformNodePoolUsesCosBadExamples,
			Links:               terraformNodePoolUsesCosLinks,
			RemediationMarkdown: terraformNodePoolUsesCosRemediationMarkdown,
		},
		Severity: severity.Low,
	},
	func(s *state.State) (results scan.Results) {
		for _, cluster := range s.Google.GKE.Clusters {
			if cluster.Metadata.IsManaged() {
				if cluster.NodeConfig.ImageType.NotEqualTo("") && cluster.NodeConfig.ImageType.NotEqualTo("COS_CONTAINERD", types.IgnoreCase) && cluster.NodeConfig.ImageType.NotEqualTo("COS", types.IgnoreCase) {
					results.Add(
						"Cluster is not configuring node pools to use the COS containerd image type by default.",
						cluster.NodeConfig.ImageType,
					)
				} else {
					results.AddPassed(&cluster)
				}
			}
			for _, pool := range cluster.NodePools {
				if pool.NodeConfig.ImageType.NotEqualTo("COS_CONTAINERD", types.IgnoreCase) && pool.NodeConfig.ImageType.NotEqualTo("COS", types.IgnoreCase) {
					results.Add(
						"Node pool is not using the COS containerd image type.",
						pool.NodeConfig.ImageType,
					)
				} else {
					results.AddPassed(&pool)
				}

			}
		}
		return
	},
)

var CheckNodeShieldingEnabled = rules.Register(
	scan.Rule{
		AVDID:      "AVD-GCP-0055",
		Provider:   providers.GoogleProvider,
		Service:    "gke",
		ShortCode:  "node-shielding-enabled",
		Summary:    "Shielded GKE nodes not enabled.",
		Impact:     "Node identity and integrity can't be verified without shielded GKE nodes",
		Resolution: "Enable node shielding",
		Explanation: `CIS GKE Benchmark Recommendation: 6.5.5. Ensure Shielded GKE Nodes are Enabled

Shielded GKE Nodes provide strong, verifiable node identity and integrity to increase the security of GKE nodes and should be enabled on all GKE clusters.`,
		Links: []string{
			"https://cloud.google.com/kubernetes-engine/docs/how-to/hardening-your-cluster#shielded_nodes",
		},
		Terraform: &scan.EngineMetadata{
			GoodExamples:        terraformNodeShieldingEnabledGoodExamples,
			BadExamples:         terraformNodeShieldingEnabledBadExamples,
			Links:               terraformNodeShieldingEnabledLinks,
			RemediationMarkdown: terraformNodeShieldingEnabledRemediationMarkdown,
		},
		Severity: severity.High,
	},
	func(s *state.State) (results scan.Results) {
		for _, cluster := range s.Google.GKE.Clusters {
			if cluster.Metadata.IsUnmanaged() {
				continue
			}
			if cluster.EnableShieldedNodes.IsFalse() {
				results.Add(
					"Cluster has shielded nodes disabled.",
					cluster.EnableShieldedNodes,
				)
			} else {
				results.AddPassed(&cluster)
			}

		}
		return
	},
)

var CheckUseClusterLabels = rules.Register(
	scan.Rule{
		AVDID:       "AVD-GCP-0051",
		Provider:    providers.GoogleProvider,
		Service:     "gke",
		ShortCode:   "use-cluster-labels",
		Summary:     "Clusters should be configured with Labels",
		Impact:      "Asset management can be limited/more difficult",
		Resolution:  "Set cluster resource labels",
		Explanation: `Labels make it easier to manage assets and differentiate between clusters and environments, allowing the mapping of computational resources to the wider organisational structure.`,
		Links:       []string{},
		Terraform: &scan.EngineMetadata{
			GoodExamples:        terraformUseClusterLabelsGoodExamples,
			BadExamples:         terraformUseClusterLabelsBadExamples,
			Links:               terraformUseClusterLabelsLinks,
			RemediationMarkdown: terraformUseClusterLabelsRemediationMarkdown,
		},
		Severity: severity.Low,
	},
	func(s *state.State) (results scan.Results) {
		for _, cluster := range s.Google.GKE.Clusters {
			if cluster.Metadata.IsUnmanaged() {
				continue
			}
			if cluster.ResourceLabels.Len() == 0 {
				results.Add(
					"Cluster does not use GCE resource labels.",
					cluster.ResourceLabels,
				)
			} else {
				results.AddPassed(&cluster)
			}
		}
		return
	},
)

var CheckUseRbacPermissions = rules.Register(
	scan.Rule{
		AVDID:      "AVD-GCP-0062",
		Provider:   providers.GoogleProvider,
		Service:    "gke",
		ShortCode:  "use-rbac-permissions",
		Summary:    "Legacy ABAC permissions are enabled.",
		Impact:     "ABAC permissions are less secure than RBAC permissions",
		Resolution: "Switch to using RBAC permissions",
		Explanation: `You should disable Attribute-Based Access Control (ABAC), and instead use Role-Based Access Control (RBAC) in GKE.

RBAC has significant security advantages and is now stable in Kubernetes, so it’s time to disable ABAC.`,
		Links: []string{
			"https://cloud.google.com/kubernetes-engine/docs/how-to/hardening-your-cluster#leave_abac_disabled_default_for_110",
		},
		Terraform: &scan.EngineMetadata{
			GoodExamples:        terraformUseRbacPermissionsGoodExamples,
			BadExamples:         terraformUseRbacPermissionsBadExamples,
			Links:               terraformUseRbacPermissionsLinks,
			RemediationMarkdown: terraformUseRbacPermissionsRemediationMarkdown,
		},
		Severity: severity.High,
	},
	func(s *state.State) (results scan.Results) {
		for _, cluster := range s.Google.GKE.Clusters {
			if cluster.Metadata.IsUnmanaged() {
				continue
			}
			if cluster.EnableLegacyABAC.IsTrue() {
				results.Add(
					"Cluster has legacy ABAC enabled.",
					cluster.EnableLegacyABAC,
				)
			} else {
				results.AddPassed(&cluster)
			}
		}
		return
	},
)

var CheckUseServiceAccount = rules.Register(
	scan.Rule{
		AVDID:       "AVD-GCP-0050",
		Provider:    providers.GoogleProvider,
		Service:     "gke",
		ShortCode:   "use-service-account",
		Summary:     "Checks for service account defined for GKE nodes",
		Impact:      "Service accounts with wide permissions can increase the risk of compromise",
		Resolution:  "Use limited permissions for service accounts to be effective",
		Explanation: `You should create and use a minimally privileged service account to run your GKE cluster instead of using the Compute Engine default service account.`,
		Links: []string{
			"https://cloud.google.com/kubernetes-engine/docs/how-to/hardening-your-cluster#use_least_privilege_sa",
		},
		Terraform: &scan.EngineMetadata{
			GoodExamples:        terraformUseServiceAccountGoodExamples,
			BadExamples:         terraformUseServiceAccountBadExamples,
			Links:               terraformUseServiceAccountLinks,
			RemediationMarkdown: terraformUseServiceAccountRemediationMarkdown,
		},
		Severity: severity.Medium,
	},
	func(s *state.State) (results scan.Results) {
		for _, cluster := range s.Google.GKE.Clusters {
			if cluster.Metadata.IsManaged() {
				if cluster.RemoveDefaultNodePool.IsFalse() {
					if cluster.NodeConfig.ServiceAccount.IsEmpty() {
						results.Add(
							"Cluster does not override the default service account.",
							cluster.NodeConfig.ServiceAccount,
						)
					}
				} else {
					results.AddPassed(&cluster)
				}
			}
			for _, pool := range cluster.NodePools {
				if pool.NodeConfig.ServiceAccount.IsEmpty() {
					results.Add(
						"Node pool does not override the default service account.",
						pool.NodeConfig.ServiceAccount,
					)
				} else {
					results.AddPassed(&pool)
				}
			}
		}
		return
	},
)