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AKS clusters should collect security-based audit logs#

Security · Azure Kubernetes Service · Azure.AKS.AuditLogs

AKS clusters should collect security-based audit logs to assess and monitor the compliance status of workloads.

Description#

To capture security-based audit logs from AKS clusters, the following diagnostic log categories should be enabled:

  • kube-audit or kube-audit-admin, or both.
    • kube-audit - Contains all audit log data for every audit event, including get, list, create, update, delete, patch, and post.
    • kube-audit-admin - Is a subset of the kube-audit log category. kube-audit-admin reduces the number of logs significantly by excluding the get and list audit events from the log.
  • guard - Contains logs for Azure Active Directory (AAD) authorization integration. For managed Azure AD, this includes token in and user info out. For Azure RBAC, this includes access reviews in and out.

Recommendation#

Consider configuring diagnostic settings to capture security-based audit logs from AKS clusters.

Examples#

Configure with Azure template#

To deploy AKS clusters that pass this rule:

  • Deploy a diagnostic settings sub-resource.
  • Enable logging for the kube-audit/kube-audit-admin and guard categories.

For example:

{
    "comments": "Azure Kubernetes Cluster",
    "apiVersion": "2020-12-01",
    "dependsOn": [
        "[resourceId('Microsoft.ManagedIdentity/userAssignedIdentities', parameters('identityName'))]"
    ],
    "type": "Microsoft.ContainerService/managedClusters",
    "location": "[parameters('location')]",
    "name": "[parameters('clusterName')]",
    "identity": {
        "type": "UserAssigned",
        "userAssignedIdentities": {
            "[resourceId('Microsoft.ManagedIdentity/userAssignedIdentities', parameters('identityName'))]": {}
        }
    },
    "properties": {
        "kubernetesVersion": "[parameters('kubernetesVersion')]",
        "disableLocalAccounts": true,
        "enableRBAC": true,
        "dnsPrefix": "[parameters('dnsPrefix')]",
        "agentPoolProfiles": [
            {
                "name": "system",
                "osDiskSizeGB": 32,
                "count": 3,
                "minCount": 3,
                "maxCount": 10,
                "enableAutoScaling": true,
                "maxPods": 50,
                "vmSize": "Standard_D2s_v3",
                "osType": "Linux",
                "type": "VirtualMachineScaleSets",
                "vnetSubnetID": "[variables('clusterSubnetId')]",
                "mode": "System",
                "osDiskType": "Ephemeral",
                "scaleSetPriority": "Regular"
            }
        ],
        "aadProfile": {
            "managed": true,
            "enableAzureRBAC": true,
            "adminGroupObjectIDs": "[parameters('clusterAdmins')]",
            "tenantID": "[subscription().tenantId]"
        },
        "networkProfile": {
            "networkPlugin": "azure",
            "networkPolicy": "azure",
            "loadBalancerSku": "Standard",
            "serviceCidr": "192.168.0.0/16",
            "dnsServiceIP": "192.168.0.4",
            "dockerBridgeCidr": "172.17.0.1/16"
        },
        "autoUpgradeProfile": {
            "upgradeChannel": "stable"
        },
        "addonProfiles": {
            "azurepolicy": {
                "enabled": true,
                "config": {
                    "version": "v2"
                }
            },
            "omsagent": {
                "enabled": true,
                "config": {
                    "logAnalyticsWorkspaceResourceID": "[parameters('workspaceId')]"
                }
            },
            "kubeDashboard": {
                "enabled": false
            }
        }
    },
    "resources": [
        {
            "apiVersion": "2016-09-01",
            "type": "Microsoft.ContainerService/managedClusters/providers/diagnosticSettings",
            "name": "[concat(parameters('clusterName'), '/Microsoft.Insights/service')]",
            "properties": {
                "workspaceId": "[parameters('workspaceId')]",
                "logs": [
                    {
                        "category": "kube-audit",
                        "enabled": true,
                        "retentionPolicy": {
                            "days": 0,
                            "enabled": false
                        }
                    },
                    {
                        "category": "kube-audit-admin",
                        "enabled": true,
                        "retentionPolicy": {
                            "days": 0,
                            "enabled": false
                        }
                    },
                    {
                        "category": "guard",
                        "enabled": true,
                        "retentionPolicy": {
                            "days": 0,
                            "enabled": false
                        }
                    }
                ],
                "metrics": []
            }
        }
    ]
}

Last update: 2021-10-19