Security ======== .. raw:: html This section contains information about security for CloudNativePG, that are analyzed at 3 different layers: Code, Container and Cluster. .. Warning:: The information contained in this page must not exonerate you from performing regular InfoSec duties on your Kubernetes cluster. Please familiarize yourself with the `Overview of Cloud Native Security `_ page from the Kubernetes documentation. 　 .. Note:: Please refer to `The 4C’s Security Model in Kubernetes `_ blog article to get a better understanding and context of the approach EDB has taken with security in CloudNativePG. 　 Code ---- CloudNativePG’s source code undergoes systematic static analysis, including checks for security vulnerabilities, using the popular open-source linter for Go, `GolangCI-Lint `_ , directly integrated into the CI/CD pipeline. GolangCI-Lint can run multiple linters on the same source code. The following tools are used to identify security issues: - \*\* `Golang Security Checker `_ (``gosec`` ):\*\* A linter that scans the abstract syntax tree of the source code against a set of rules designed to detect known vulnerabilities, threats, and weaknesses, such as hard-coded credentials, integer overflows, and SQL injections. GolangCI-Lint runs ``gosec`` as part of its suite. - \*\* `govulncheck `_ :\*\* This tool runs in the CI/CD pipeline and reports known vulnerabilities affecting Go code or the compiler. If the operator is built with a version of the Go compiler containing a known vulnerability, ``govulncheck`` will detect it. - \*\* `CodeQL `_ :\*\* Provided by GitHub, this tool scans for security issues and blocks any pull request with detected vulnerabilities. CodeQL is configured to review only Go code, excluding other languages in the repository such as Python or Bash. - \*\* `Snyk `_ :\*\* Conducts nightly code scans in a scheduled job and generates weekly reports highlighting any new findings related to code security and licensing issues. The CloudNativePG repository has the *“Private vulnerability reporting”* option enabled in the `Security section `_ . This feature allows users to safely report security issues that require careful handling before being publicly disclosed. If you discover any security bug, please use this medium to report it. .. Note:: A failure in the static code analysis phase of the CI/CD pipeline will block the entire delivery process of CloudNativePG. Every commit must pass all the linters defined by GolangCI-Lint. 　 Container --------- Every container image in CloudNativePG is automatically built via CI/CD pipelines after every commit. These images include not only the operator’s image but also the operands’ images, specifically for every supported PostgreSQL version. .. Note:: All operand images are automatically and regularly rebuilt by our pipelines to incorporate the latest security updates at both the base image and package levels. This ensures that container images distributed to the community receive **patch-level updates** regularly. 　 During the CI/CD process, images are scanned using the following tools: - \*\* `Dockle `_ :\*\* Ensures best practices in the container build process. - \*\* `Snyk `_ :\*\* Detects security issues within the container and reports findings via the GitHub interface. Image Signatures ^^^^^^^^^^^^^^^^ The operator and `operandimages `_ are cryptographically signed using `cosign `_ , a signature tool from `sigstore `_ . This process is automated via GitHub Actions and leverages `short-lived tokens issued through OpenID Connect `_ . The token issuer is ``https://token.actions.githubusercontent.com`` , and the signing identity corresponds to a GitHub workflow executed under the `cloudnative-pg `_ repository. This workflow uses the `cosign-installer action `_ to streamline the signing process. To verify the authenticity of an operator image, use the following ``cosign`` command with the image digest: .. code:: shell cosign verify ghcr.io/cloudnative-pg/cloudnative-pg@sha256: \ --certificate-identity-regexp="^https://github.com/cloudnative-pg/cloudnative-pg/" \ --certificate-oidc-issuer="https://token.actions.githubusercontent.com" Attestations ^^^^^^^^^^^^ Container images include the following attestations for transparency and traceability: - \*\* `Software Bill of Materials (SBOM) `_ :\*\* A comprehensive list of software artifacts included in the image or used during its build process, formatted using the `in-toto SPDX predicate standard `_ . - \*\* `Provenance `_ :\*\* Metadata detailing how the image was built, following the `SLSA Provenance `_ framework. You can retrieve the SBOM for a specific image and platform using the following command: .. code:: shell docker buildx imagetools inspect \ --format {{ json (index .SBOM "").SPDX }} This command outputs the SBOM in JSON format, providing a detailed view of the software components and build dependencies. For the provenance, use: .. code:: shell docker buildx imagetools inspect \ --format {{ json (index .Provenance "").SLSA }} Guidelines and Frameworks for Container Security ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ The following guidelines and frameworks have been considered for ensuring container-level security: - \*\* `Container Image Creation and Deployment Guide `_ :\*\* Developed by the Defense Information Systems Agency (DISA) of the United States Department of Defense (DoD). - \*\* `CIS Benchmark for Docker `_ :\*\* Developed by the Center for Internet Security (CIS). .. Note:: For more information on the approach that EDB has taken regarding security at the container level in CloudNativePG, please refer to the blog article `Security and Containers in CloudNativePG `_ . 　 Cluster ------- Security at the cluster level takes into account all Kubernetes components that form both the control plane and the nodes, as well as the applications that run in the cluster (PostgreSQL included). Role Based Access Control (RBAC) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ The operator interacts with the Kubernetes API server using a dedicated service account named ``cnpg-manager`` . This service account is typically installed in the operator namespace, commonly ``cnpg-system`` . However, the namespace may vary based on the deployment method (see the subsection below). In the same namespace, there is a binding between the ``cnpg-manager`` service account and a role. The specific name and type of this role (either ``Role`` or ``ClusterRole`` ) also depend on the deployment method. This role defines the necessary permissions required by the operator to function correctly. To learn more about these roles, you can use the ``kubectl describe clusterrole`` or ``kubectl describe role`` commands, depending on the deployment method. .. Note:: The above permissions are exclusively reserved for the operator's service account to interact with the Kubernetes API server. They are not directly accessible by the users of the operator that interact only with `Cluster` , `Pooler` , `Backup` , `ScheduledBackup` , `Database` , `Publication` , `Subscription` , `ImageCatalog` and `ClusterImageCatalog` resources. 　 Below we provide some examples and, most importantly, the reasons why CloudNativePG requires full or partial management of standard Kubernetes namespaced or non-namespaced resources. ``configmaps`` The operator needs to create and manage default config maps for the Prometheus exporter monitoring metrics. ``deployments`` The operator needs to manage a PgBouncer connection pooler using a standard Kubernetes ``Deployment`` resource. ``jobs`` The operator needs to handle jobs to manage different ``Cluster`` ’s phases. ``persistentvolumeclaims`` The volume where the ``PGDATA`` resides is the central element of a PostgreSQL ``Cluster`` resource; the operator needs to interact with the selected storage class to dynamically provision the requested volumes, based on the defined scheduling policies. ``pods`` The operator needs to manage ``Cluster`` ’s instances. ``secrets`` Unless you provide certificates and passwords to your ``Cluster`` objects, the operator adopts the “convention over configuration” paradigm by self-provisioning random generated passwords and TLS certificates, and by storing them in secrets. ``serviceaccounts`` The operator needs to create a service account that enables the instance manager (which is the *PID 1* process of the container that controls the PostgreSQL server) to safely communicate with the Kubernetes API server to coordinate actions and continuously provide a reliable status of the ``Cluster`` . ``services`` The operator needs to control network access to the PostgreSQL cluster (or the connection pooler) from applications, and properly manage failover/switchover operations in an automated way (by assigning, for example, the correct end-point of a service to the proper primary PostgreSQL instance). ``validatingwebhookconfigurations`` and ``mutatingwebhookconfigurations`` The operator injects its self-signed webhook CA into both webhook configurations, which are needed to validate and mutate all the resources it manages. For more details, please see the `Kubernetes documentation `_ . ``volumesnapshots`` The operator needs to generate ``VolumeSnapshots`` objects in order to take backups of a PostgreSQL server. VolumeSnapshots are read too in order to validate them before starting the restore process. ``nodes`` The operator needs to get the labels for Affinity and AntiAffinity so it can decide in which nodes a pod can be scheduled. This is useful, for example, to prevent the replicas from being scheduled in the same node - especially important if nodes are in different availability zones. This permission is also used to determine whether a node is scheduled, preventing the creation of pods on unscheduled nodes, or triggering a switchover if the primary lives in an unscheduled node. Deployments and ``ClusterRole`` Resources ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ As mentioned above, each deployment method may have variations in the namespace location of the service account, as well as the names and types of role bindings and respective roles. Via Kubernetes Manifest ''''''''''''''''''''''' When installing CloudNativePG using the Kubernetes manifest, permissions are set to ``ClusterRoleBinding`` by default. You can inspect the permissions required by the operator by running: .. code:: sh kubectl describe clusterrole cnpg-manager Via OLM ''''''' From a security perspective, the Operator Lifecycle Manager (OLM) provides a more flexible deployment method. It allows you to configure the operator to watch either all namespaces or specific namespaces, enabling more granular permission management. .. Note:: OLM allows you to deploy the operator in its own namespace and configure it to watch specific namespaces used for CloudNativePG clusters. This setup helps to contain permissions and restrict access more effectively. 　 Why Are ClusterRole Permissions Needed? ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ The operator currently requires ``ClusterRole`` permissions to read ``nodes`` and ``ClusterImageCatalog`` objects. All other permissions can be namespace-scoped (i.e., ``Role`` ) or cluster-wide (i.e., ``ClusterRole`` ). Even with these permissions, if someone gains access to the ``ServiceAccount`` , they will only have ``get`` , ``list`` , and ``watch`` permissions, which are limited to viewing resources. However, if an unauthorized user gains access to the ``ServiceAccount`` , it indicates a more significant security issue. Therefore, it’s crucial to prevent users from accessing the operator’s ``ServiceAccount`` and any other ``ServiceAccount`` with elevated permissions. Calls to the API server made by the instance manager ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ The instance manager, which is the entry point of the operand container, needs to make some calls to the Kubernetes API server to ensure that the status of some resources is correctly updated and to access the config maps and secrets that are associated with that Postgres cluster. Such calls are performed through a dedicated ``ServiceAccount`` created by the operator that shares the same PostgreSQL ``Cluster`` resource name. .. Note:: The operand can only access a specific and limited subset of resources through the API server. A service account is the `recommended way to access the API server from within a Pod `_ . 　 For transparency, the permissions associated with the service account are defined in the `roles.go `_ file. For example, to retrieve the permissions of a generic ``mypg`` cluster in the ``myns`` namespace, you can type the following command: .. code:: bash kubectl get role -n myns mypg -o yaml Then verify that the role is bound to the service account: .. code:: bash kubectl get rolebinding -n myns mypg -o yaml .. Note:: Remember that **roles are limited to a given namespace**. 　 Below we provide a quick summary of the permissions associated with the service account for generic Kubernetes resources. ``configmaps`` The instance manager can only read config maps that are related to the same cluster, such as custom monitoring queries ``secrets`` The instance manager can only read secrets that are related to the same cluster, namely: streaming replication user, application user, super user, LDAP authentication user, client CA, server CA, server certificate, backup credentials, custom monitoring queries ``events`` The instance manager can create an event for the cluster, informing the API server about a particular aspect of the PostgreSQL instance lifecycle Here instead, we provide the same summary for resources specific to CloudNativePG. ``clusters`` The instance manager requires read-only permissions, namely ``get`` , ``list`` and ``watch`` , just for its own ``Cluster`` resource ``clusters/status`` The instance manager requires to ``update`` and ``patch`` the status of just its own ``Cluster`` resource ``backups`` The instance manager requires ``get`` and ``list`` permissions to read any ``Backup`` resource in the namespace. Additionally, it requires the ``delete`` permission to clean up the Kubernetes cluster by removing the ``Backup`` objects that do not have a counterpart in the object store - typically because of retention policies ``backups/status`` The instance manager requires to ``update`` and ``patch`` the status of any ``Backup`` resource in the namespace Pod and Container Security Contexts ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ A `Security Context `_ defines privilege and access control settings for a pod or container. CloudNativePG does not require *privileged* mode for container execution. The PostgreSQL containers run as the ``postgres`` system user. No component whatsoever requires running as ``root`` . Likewise, Volume access does not require *privileged* mode nor ``root`` privileges. Proper permissions must be assigned by the Kubernetes platform and/or administrators. The PostgreSQL containers run with a read-only root filesystem (i.e. no writable layer). The operator manages the setting of security contexts for all pods and containers of a PostgreSQL cluster. The `Seccomp Profile `_ to be used for the PostgreSQL containers can be configured with the ``spec.seccompProfile`` section of the ``Cluster`` resource. If this section is left blank, the containers will use a seccompProfile ``Type`` of ``RuntimeDefault`` , that is, the container runtime default. The security context of PostgreSQL containers using the default ``seccompProfile`` will look like this: :: securityContext: allowPrivilegeEscalation: false capabilities: drop: - ALL privileged: false readOnlyRootFilesystem: true runAsNonRoot: true seccompProfile: type: RuntimeDefault Customizing Security Contexts ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ CloudNativePG provides fine-grained control over security contexts for both pods and containers through the ``spec.podSecurityContext`` and ``spec.securityContext`` fields respectively. .. Note:: Changing security contexts can significantly affect the security posture of your PostgreSQL clusters and may prevent pods from starting or operating correctly. Before making changes, review which fields you will override and how they merge with the operator defaults, test changes in a non-production environment, and apply the minimal, well-documented modifications necessary. 　 **Pod Security Context** (``spec.podSecurityContext`` ): This allows you to override the default ``PodSecurityContext`` applied to all PostgreSQL cluster pods. When specified, it will merge with the operator’s default settings, with your values taking precedence for explicitly set fields. Example: .. code:: yaml apiVersion: postgresql.cnpg.io/v1 kind: Cluster metadata: name: cluster-example spec: instances: 3 podSecurityContext: runAsUser: 26 runAsGroup: 26 fsGroup: 26 supplementalGroups: [2000, 3000] fsGroupChangePolicy: "OnRootMismatch" **Container Security Context** (``spec.securityContext`` ): This allows you to override the default ``SecurityContext`` applied to all containers within the PostgreSQL cluster pods. Like ``podSecurityContext`` , it merges with the operator’s defaults. Example: .. code:: yaml apiVersion: postgresql.cnpg.io/v1 kind: Cluster metadata: name: cluster-example spec: instances: 3 securityContext: allowPrivilegeEscalation: false # Note: capabilities are not merged with operator defaults. # If specified, they fully replace any defaults. capabilities: drop: - ALL add: - NET_BIND_SERVICE readOnlyRootFilesystem: true runAsNonRoot: true .. Note:: For any fields you don't explicitly set, the operator will apply its secure defaults. This ensures that even partial configurations maintain security best practices. 　 .. Note:: These fields are particularly useful when working with the `Pod Security Standards `_ ``restricted`` profile, which has strict requirements for pod and container security contexts. 　 Security Context Constraints ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ When running in an environment that is utilizing `Security Context Constraints (SCC) `_ the operator does not explicitly set the security context of the PostgreSQL cluster pods, but rather allows the pods to inherit the restricted Security Context Constraints that are already defined. Restricting Pod access using AppArmor ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ You can assign an `AppArmor `_ profile to the ``postgres`` , ``initdb`` , ``join`` , ``full-recovery`` and ``bootstrap-controller`` containers inside every ``Cluster`` pod through the ``container.apparmor.security.beta.kubernetes.io`` annotation. .. Note:: 　 :: kind: Cluster metadata: name: cluster-apparmor annotations: container.apparmor.security.beta.kubernetes.io/postgres: runtime/default container.apparmor.security.beta.kubernetes.io/initdb: runtime/default container.apparmor.security.beta.kubernetes.io/join: runtime/default .. Warning:: Using this kind of annotations can result in your cluster to stop working. If this is the case, the annotation can be safely removed from the `Cluster` . 　 The AppArmor configuration must be at Kubernetes node level, meaning that the underlying operating system must have this option enable and properly configured. In case this is not the situation, and the annotations were added at the ``Cluster`` creation time, pods will not be created. On the other hand, if you add the annotations after the ``Cluster`` was created the pods in the cluster will be unable to start and you will get an error like this: :: metadata.annotations[container.apparmor.security.beta.kubernetes.io/postgres]: Forbidden: may not add AppArmor annotations] In such cases, please refer to your Kubernetes administrators and ask for the proper AppArmor profile to use. Network Policies ^^^^^^^^^^^^^^^^ The pods created by the ``Cluster`` resource can be controlled by Kubernetes `network policies `_ to enable/disable inbound and outbound network access at IP and TCP level. You can find more information in the :ref:`networking document ` . .. Note:: The operator needs to communicate to each instance on TCP port 8000 to get information about the status of the PostgreSQL server. Please make sure you keep this in mind in case you add any network policy, and refer to the "Exposed Ports" section below for a list of ports used by CloudNativePG for finer control. 　 Network policies are beyond the scope of this document. Please refer to the `Network policies `_ section of the Kubernetes documentation for further information. Exposed Ports ^^^^^^^^^^^^^ CloudNativePG exposes ports at operator, instance manager and operand levels, as listed in the table below: .. csv-table:: :header: System,Port number,Exposing,Name,TLS,Authentication :widths: auto :align: left :class: longtable operator,9443,webhook server,`webhook-server`,Yes,Yes operator,8080,metrics,`metrics`,No,No instance manager,9187,metrics,`metrics`,Optional,No instance manager,8000,status,`status`,Yes,No operand,5432,PostgreSQL instance,`postgresql`,Optional,Yes PostgreSQL ^^^^^^^^^^ The current implementation of CloudNativePG automatically creates passwords and ``.pgpass`` files for the database owner and, only if requested by setting ``enableSuperuserAccess`` to ``true`` , for the ``postgres`` superuser. .. Warning:: `enableSuperuserAccess` is set to `false` by default to improve the security-by-default posture of the operator, fostering a microservice approach where changes to PostgreSQL are performed in a declarative way through the `spec` of the `Cluster` resource, while providing developers with full powers inside the database through the database owner user. 　 As far as password encryption is concerned, CloudNativePG follows the default behavior of PostgreSQL: starting from PostgreSQL 14, ``password_encryption`` is by default set to ``scram-sha-256`` , while on earlier versions it is set to ``md5`` . .. Note:: Please refer to the `Password authentication `_ section in the PostgreSQL documentation for details. 　 .. Note:: The operator supports toggling the `enableSuperuserAccess` option. When you disable it on a running cluster, the operator will ignore the content of the secret, remove it (if previously generated by the operator) and set the password of the `postgres` user to `NULL` (de facto disabling remote access through password authentication). 　 See the :ref:`Secrets ` for more information. You can use those files to configure application access to the database. By default, every replica is automatically configured to connect in **physical async streaming replication** with the current primary instance, with a special user called ``streaming_replica`` . The connection between nodes is **encrypted** and authentication is via **TLS client certificates** (please refer to the :ref:`Client TLS/SSL connections ` page for details). By default, the operator requires TLS v1.3 connections. Currently, the operator allows administrators to add ``pg_hba.conf`` lines directly in the manifest as part of the ``pg_hba`` section of the ``postgresql`` configuration. The lines defined in the manifest are added to a default ``pg_hba.conf`` . For further detail on how ``pg_hba.conf`` is managed by the operator, see the :ref:`PostgreSQL Configuration ` of the documentation. The administrator can also customize the content of the ``pg_ident.conf`` file that by default only maps the local postgres user to the postgres user in the database. For further detail on how ``pg_ident.conf`` is managed by the operator, see the :ref:`PostgreSQL Configuration ` of the documentation. .. Note:: Examples assume that the Kubernetes cluster runs in a private and secure network. 　 Storage ^^^^^^^ CloudNativePG delegates encryption at rest to the underlying storage class. For data protection in production environments, we highly recommend that you choose a storage class that supports encryption at rest.