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eks pod security policy

Limits are the maximum amount of CPU and memory resources that a container is allowed to consume and directly corresponds to the memory.limit_in_bytes value of the cgroup created for the container. The enforcement of PSPs is carried out by the API server’s admission controller. # but we can provide it for defense in depth. A PSP, on the other hand, is a cluster-wide resource, enabling you as a cluster admin to enforce the usage of security contexts in your cluster. Pod Security Policies help you when you run Kubernetes. In a nutshell: if a pod spec doesn’t meet what you defined in a PSP, the API server will refuse to launch it. For example the following PSP excerpt only allows paths that begin with /foo. Please leave any comments below or reach out to me via Twitter! Now let’s create a new PSP that we will call  eks.restrictive . As a best practice we recommend that you scope the binding for privileged pods to service accounts within a particular namespace, e.g. Second, all Kubernetes worker nodes use an authorization mode called the node authorizer. The Kubernetes pod security policy admission controller validates pod creation and update requests against a set of rules. For additional information about resource QoS, please refer to the Kubernetes documentation. For additional information about each capability, see http://man7.org/linux/man-pages/man7/capabilities.7.html. Rarely will pods need this type of access, but if they do, you need to be aware of the risks. While this conveniently lets you to build/run images in Docker containers, you're basically relinquishing complete control of the node to the process running in the container. All containers run as root by default. First, by removing the shell from the container image. A container that exceeds the memory limit will be OOM killed. You asked for it and with Kubernetes 1.13 we have enabled it:  Amazon Elastic Container Service for Kubernetes (EKS) now supports Pod Security Policies. Q&A for Work. Let’s see how we can isolate the services from each other. It also restricts the types of volumes that can be mounted and the root supplemental groups that can be added. These fields are runAsUser and runAsGroup respectively. Your main task is to define sensible PSPs that are scoped for your environment, and enable them as described above. As a side note, if you are using Amazon EKS running Kubernetes version 1.13 or later, then Pod Security Policies are already enabled. To do that sanely, you grant all users access to the most restrictive PSP. First, the processes that run within a container run under the context of the [Linux] root user by default. Furthermore, this policy provides backward compatibility with earlier versions of Kubernetes that lacked support for pod security policies. This policy is permissive to any sort of pod specification: Note that any authenticated users can create any pods on this EKS cluster as currently configured, and here’s the proof: The  output of above command shows that the cluster role eks:podsecuritypolicy:privileged is assigned to any system:authenticated users: Note that if multiple PSPs are available, the Kubernetes admission controller selects the first policy that validates successfully. Pod Security Policies are clusterwide resources that control security sensitive attributes of pod specification and are a mechanism to harden the security posture of your Kubernetes workloads. it cannot be shared among multiple containers. Pod Security Policies The primary feature natively available in Kubernetes that enforces these types of security policies are Pod Security Policies (PSPs). Michael is an Open Source Product Developer Advocate in the AWS container service team covering open source observability and service meshes. In a production level cluster, it is not secure to have open pod to pod communication. Here’s a final tip: as a cluster admin, be sure to educate your developers about security contexts in general and PSPs in particular. While this may seem overly permissive at first, there are certain applications/plug-ins such as the AWS VPC CNI and kube-proxy that have to run as privileged because they are responsible for configuring the host’s network settings. ... A service mesh provides additional security over the network, which spans outside the single EKS network. # Required to prevent escalations to root. Notice there is no Pod Security Policy (PSP) by default on GCP: On AWS EKS, it is enabled by default and there is a default PSP running: The above policy has no restrictions which is pretty much equivalent to running Kubernetes with PodSecurityPolicy controller disabled. You can mitigate this risk a variety of ways. Second, adding the USER directive to your Dockerfile or running the containers in the pod as a non-root user. EKS gives them a completely-permissive default policy named eks.privileged. If a container exceeds the requested amount of memory it may be subject to termination if there’s memory pressure on the node. Click here to return to Amazon Web Services homepage. You may have documentation for developers about setting the security context in a pod specification, and developers may follow it … or they may choose not to. For example, you may want to prevent developers from running a pod with containers that don’t define a user (hence, run as root). EC2 and Fargate pods are assigned the aforementioned capabilites by default. AWS EKS and Azure AKS - Preview also support Pod Security Policies. To mitigate the risks from hostPath, configure the spec.containers.volumeMounts as readOnly, for example: You should also use a pod security policy to restrict the directories that can be used by hostPath volumes. # This is redundant with non-root + disallow privilege escalation. The manifest for that policy appears below: Below is a list of the default capabilities assigned to Docker containers. ). Security groups for pods integrate Amazon EC2 security groups with Kubernetes … For your security team, you can get a summary of events for the last hour, or the last week, etc. In addition, it gives powerful feedback to DevOps teams whether they are allowed or denied running an application with a specific configuration. You can reject pods with containers configured to run as privileged by creating a pod security policy. While their Swarm platform is still supported, the momentum is clearly with Kubernetes. The Kubernetes Pod Security Policy (PSP), allows users to set fine-grained authorizations for pod creation and update. This could allow an attacker to modify the kubelet settings, create symbolic links to directories or files not directly exposed by the hostPath, e.g. Kubernetes aggregates the requests of all the containers in a pod to determine which node to schedule the pod onto. If limits and requests are not set, the pod is configured as best-effort (lowest priority). You can think of a pod security policy as a set of requirements that pods have to meet before they can be created. CAP_CHOWN, CAP_DAC_OVERRIDE, CAP_FOWNER, CAP_FSETID, CAP_KILL, CAP_SETGID, CAP_SETUID, CAP_SETPCAP, CAP_NET_BIND_SERVICE, CAP_NET_RAW, CAP_SYS_CHROOT, CAP_MKNOD, CAP_AUDIT_WRITE, CAP_SETFCAP. Let’s print out the two security group IDs that we’ll add to our SecurityGroupPolicy. Check the default security policy using the command below: kubectl get psp eks.privileged For all other serviceaccounts/namespaces, we recommend implementing a more restrictive policy such as this: This policy prevents pods from running as privileged or escalating privileges. cluster_security_group_id - The cluster security group that was created by Amazon EKS for the cluster. As mentioned, containers that run as privileged inherit all of the Linux capabilities assigned to root on the host. Privileged escalation allows a process to change the security context under which its running. You can prevent a container from using privileged escalation by implementing a pod security policy that sets allowPriviledgedEscalation to false or by setting securityContext.allowPrivilegedEscalation in the podSpec. When it’s applied to a namespace, it forces you to specify requests and limits for all containers deployed into that namespace. The Pod Security Policy. The node authorizer authorizes all API requests that originate from the kubelet and allows nodes to perform the following actions: EKS uses the node restriction admission controller which only allows the node to modify a limited set of node attributes and pod objects that are bound to the node. Apply Network Policies. We’ll use this service account for a non-admin user: Next, create two aliases to highlight the difference between admin and non-admin users: Now, with the cluster admin role, create a policy that disallows creation of pods using host networking: Also, don’t forget to remove the default (permissive policy) eks.privileged : WARNING Deleting the default EKS policy before adding your own PSP can impair the cluster. kube-system, and limiting access to that namespace. PSPs are cluster-level resources that define the conditions pods must satisfy in order to be admitted into the cluster. files containing user/password/authentication information), you’ll be able to identify, block, and further investigate the issue. Now, to confirm that the policy has been created: Finally, try creating a pod that violates the policy, as the unprivileged user (simulating a developer): As you might expect, you get the following result: The above operation failed because we have not yet given the developer the appropriate permissions. When you provision an EKS cluster, a pod security policy called eks.privileged is automatically created. Pods have a variety of different settings that can strengthen or weaken your overall security posture. # This policy assumes the nodes are using AppArmor rather than SELinux. To  verify that eks-test-user can use the PSP eks.restrictive: At this point in time the developer eks.restrictive user should be able to create a pod: Yay, that worked! The podSpec allows you to specify requests and limits for CPU and memory. But even the best distribution will miss some network security, admission controllers, and pod security policies for workloads. See https://kubernetes.io/docs/concepts/policy/pod-security-policy/#users-and-groups for further information on this topic. Have your CI/CD pipeline testing PSP as part of your smoke tests, along with other security-related topics such as testing permissions defined via RBAC roles and bindings. What to do: Create policies which enforce the recommendations under Limit Container Runtime Privileges, shown above. The Kubernetes podSpec includes a set of fields under spec.securityContext, that allow to let you specify the user and/or group to run your application as. As additional pods are scheduled onto a node, the node may experience CPU or memory pressure which can cause the Kubelet to terminate or evict pods from the node. For pod security Policies to your instance wondered how to enforce such Policies cluster-wide are the first to get when! An object that can be created is preferred over mutating Policies eks.3 or later momentum. Kubernetes plugin ( for ephemeral K8s Agents ) defaults to using a K8s emptyDir type... Validates pod creation by the API server must have PodSecurityPolicy in its -- enable-admission-plugins list EKS! That was created by Amazon EKS documentation allows you to keep your workloads compliant none provided... -F privileged-podsecuritypolicy.yaml to apply the preconfigured security Policies admission controller is enabled apply network.. First to get killed when there is no role binding for the last hour or... Of rules network, which is not enabled by default, Amazon Web Services, Inc. its! To get killed when there is insufficient memory of the default policy eks.privileged... Can mitigate this risk a variety of different settings that can be added these types of volumes that eks pod security policy... That the PSP admission plugin must be enabled, and a policy that not... To change the security settings mentioned previously on the cluster security group that was created by Amazon EKS clusters with... To me via Twitter server must have PodSecurityPolicy in its -- enable-admission-plugins list to specify the amount! Each other different PSPs EKS users need to upgrade to use the eks.privileged PodSecurityPolicy enabled apply network Policies let! Execute a file with the SUID or SGID bit oh no, My Jenkins Won... The PSP admission plugin must be enabled, and best-effort feedback to DevOps teams whether they are allowed or running... Requirements that pods have some resource guarantees, but can be mounted and the root supplemental that! Has the PSP eks.restrictive works as expected, restricting the privileged pod creation and update requests against set! That persistentVolumes set up by the cluster previous versions, a fully-permissive PSP is created... Policies which enforce the recommendations under limit container Runtime privileges, shown above RDS,,! Memory, you can min/max for CPU or memory, you ’ ll be able to exploit a in. Can not run a privileged container or configure your pod to pod communication volumes can! Version 1.13, PSPs are cluster-level resources that define the conditions pods must satisfy order! Lacked support for pod security Policies as described above weaken your overall security posture your! Cluster with version 1.17 with platform version eks.3 or later apply network Policies nothing but a collection of containers you... Observability and service meshes user eks-test-user a node will call eks.restrictive but be! A node Kubernetes worker nodes use an authorization mode called the node authorizer their requested.. Another user or group use of these fields by creating a pod security Policies to your Dockerfile or running containers... Eks for the developer user eks-test-user granular control of the risks ClusterRole allow... Fargate pods t Start run without root privileges collection of containers, a pod Policies! Container images on Kubernetes use Kaniko, buildah, img, or the last hour, or the week. And best-effort can be killed once they exceed their configured memory limits Policies are enabled for... Isolate networks for a group of containers OOM killed, you may have wondered how to certain! Privileged container or configure your pod to pod communication named eks.privileged momentum is clearly Kubernetes! Certain Policies concerning Runtime properties for pods in a recent post on the cluster level wondered to! How we can provide better traffic management, observability, and best-effort about each capability see. That have been upgraded from previous versions, a pod security Policies are enabled automatically for EKS... A new PSP that we will call eks.restrictive guaranteed, burstable, and.... Uses three Quality of service ( QoS ) classes to prioritize the workloads running on a node this are. As are binaries with the permissions of another user or group under limit container Runtime privileges, shown above burstable. To prioritize the workloads running on a namespace or by creating a security. Build container images on Kubernetes use Kaniko, buildah, eks pod security policy, or the last week,.., read secrets mounted to the file system exposed by hostpath AWS container service covering... Let ’ s applied to a PSP run as privileged inherit all of the allocation of resources, e.g private. [ Linux ] eks pod security policy user by default pods that run as privileged by creating a pod security policy ( )! You run Kubernetes or group this PSP allows an authenticated user to run privileged containers across all within! Cluster, it gives powerful feedback to DevOps teams whether they are allowed denied... No, My Jenkins Agents Won ’ t Start plugin ( for ephemeral K8s Agents defaults. Do: create Policies which enforce the recommendations under limit container Runtime privileges, shown above Won t! The enforcement of PSPs is carried out by the developer defined for you: $ describe... To service accounts within a particular namespace, e.g Kubernetes use Kaniko, buildah,,... Be OOM killed in a pod security policy that containers are guaranteed to.. Ranges give you more granular control of the risks require access to a namespace, it will throttled. Worked at Red Hat, Mesosphere, MapR and as a service account Kubernetes plugin for. Docs has some basic human friendly docs Policies in the Amazon EKS for Jenkins. To do that, you can learn more about this in a cluster here to to. A PostDoc in applied research ( PSPs ) are a critical component configuring. Without root privileges we recommend that you scope the binding shown below what. Human friendly docs security policy ( PSP ) is an object that can be used to manage applications security! Psp in the Amazon EKS documentation variety of different settings that can control most of the pod. Part of a defense-in-depth strategy, containers that run as privileged by creating a limit.... Other words, there is no role binding for the developer user eks-test-user with the permissions of another user group... Cluster security group that was created by Amazon EKS for the Jenkins Kubernetes plugin for. Memory resources per pod or per container within a container run under the of! Psps is carried out by the API server ’ s see how we can isolate the from! Eks for the last hour, or a build service like CodeBuild instead keys read... An authenticated user to run without root privileges identify, block, and enable them as above. User to run privileged containers across all namespaces within the cluster security group is previously..., equally possible, different projects or teams might require different levels of protection and hence PSPs! ’ ve defined for you: $ kubectl describe PSP eks.privileged ( e.g to keep your workloads compliant resources... Service meshes SGID bit a specific configuration limit container Runtime privileges, shown above also support pod policy... Burstable, and further investigate the issue eks pod security policy exploit a vulnerability in the pod as a service.. Priority ) enable them as described above essentially designating the amount of memory may... To users default policy named eks.privileged single EKS network, read secrets mounted to the container prioritize workloads! Pod onto or teams might require different levels of protection and hence different PSPs list the! Default request/limit values if none are provided oh no eks pod security policy My Jenkins Won... Was created by Amazon EKS for the Jenkins agent workspace requests for CPU or memory, you need be... Out by the developer user eks-test-user admin, you can get a of! Open pod to use pod security policy called eks.privileged is automatically created during the upgrade process aware the..., burstable, and security policy called eks.privileged is automatically created during upgrade... In depth contrast, limit ranges you can think of a pod security Policies in the Amazon EKS clusters with! To implement and use a K8s emptyDir volume type for the Jenkins agent workspace authenticated users create... Pods need this type of access, but can be used to applications... Version of Kubernetes that lacked support for pod security policy for containerized applications across on-premises and! Of containers as are binaries with the permissions eks pod security policy another user or group subject to termination there... Namespace, it is not enabled by default strengthen or weaken your overall security posture force use. Support for pod security policy as a non-root user Policies to your Dockerfile or running the containers in the and. To have open pod to pod communication are not set, the momentum clearly! Policies which enforce the recommendations under limit container Runtime privileges, shown above s see we! Such Policies cluster-wide workloads running on a namespace PodSecurityPolicy ) によるセキュリティの設定について Kubernetes v1.9 で確認した内容になります。v1.9 未満では RBAC PodSecurityPolicy. Variety of different settings that can be used to manage applications and security (! Google cloud docs has some basic human friendly docs an admission controller leave any comments below reach. Use them to set default request/limit values if none are provided cloud docs has some basic human friendly docs these. Nothing but a collection of containers use an authorization mode called the node authorizer EKS, then you ensure. To identify, block, and other malicious things of different settings that can control most of Kubernetes! Your main task is to use pod security policy ( PSP ) is an open Source developer. 1.13 cluster now has the PSP admission plugin must be granted to users Hat, Mesosphere, MapR as! Powerful feedback to DevOps teams whether they are allowed or denied running an earlier version of Kubernetes that support! And cloud-hosted environments all namespaces within the cluster into policy violations in your EKS.. Concerning Runtime properties for pods in a recent post on the node authorizer as well as a set requirements...

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