Platform Engineers

Securing FluxCD Deployments with Role-Based Access Control (RBAC)

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Platform Engineers
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3 min read

FluxCD is a popular tool for automating the deployment of applications in Kubernetes environments. It provides a robust and efficient way to manage the lifecycle of applications, ensuring that they are always up-to-date and running as expected. However, as with any powerful tool, it is essential to ensure that FluxCD deployments are properly secured to prevent unauthorized access and potential security breaches.

One effective way to secure FluxCD deployments is by implementing Role-Based Access Control (RBAC). RBAC is a widely adopted security model that restricts access to resources based on the roles assigned to users or groups. In this blog, we will explore how to implement RBAC for FluxCD deployments, ensuring that only authorized users can manage and access the deployed applications.

Understanding FluxCD Components

Before diving into the implementation of RBAC, it is essential to understand the key components involved in a FluxCD deployment:

  • GitRepository: This is the source of truth for the application configuration. It contains the YAML files that define the application's components, such as deployments, services, and ingress resources.

  • GitOps: This is the core component of FluxCD that automates the deployment of applications based on the configuration in the GitRepository.

  • Kustomization: This is a set of YAML files that define the customization of the application components, such as environment variables, resource requests, and other settings.

Creating Roles and RoleBindings

To implement RBAC for FluxCD deployments, we need to create roles and role bindings that define the permissions and access levels for users or groups. Here is an example of how to create a role and role binding using Kubernetes YAML files:

# Role definition
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  name: fluxcd-deployer
rules:
  - apiGroups:
      - ""
    resources:
      - deployments
      - services
      - ingress
    verbs:
      - get
      - list
      - watch
      - create
      - update
      - delete

# RoleBinding definition
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: fluxcd-deployer-binding
roleRef:
  name: fluxcd-deployer
  kind: Role
subjects:
  - kind: User
    name: fluxcd-user
    apiGroup: rbac.authorization.k8s.io

In this example, we create a role named fluxcd-deployer that grants permissions to manage deployments, services, and ingress resources. We then create a role binding named fluxcd-deployer-binding that assigns this role to a user named fluxcd-user.

Configuring FluxCD with RBAC

Once the roles and role bindings are created, we need to configure FluxCD to use these roles for authentication and authorization. This involves updating the FluxCD configuration to specify the role and role binding:

apiVersion: fluxcd.io/v1beta2
kind: GitRepository
metadata:
  name: fluxcd-repo
spec:
  url: https://github.com/myorg/myrepo
  secretRef:
    name: fluxcd-credentials
  timeout: 1m
  interval: 1m
  roleRef:
    name: fluxcd-deployer
    kind: Role

In this example, we update the GitRepository configuration to specify the fluxcd-deployer role, which ensures that only users with this role can access and manage the GitRepository.

Implementing Kustomization with RBAC

Kustomization is an essential component of FluxCD that allows for customization of application components. To ensure that only authorized users can modify the kustomization, we need to create a separate role and role binding for kustomization:

# Role definition for kustomization
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  name: fluxcd-kustomizer
rules:
  - apiGroups:
      - ""
    resources:
      - kustomizations
    verbs:
      - get
      - list
      - watch
      - create
      - update
      - delete

# RoleBinding definition for kustomization
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: fluxcd-kustomizer-binding
roleRef:
  name: fluxcd-kustomizer
  kind: Role
subjects:
  - kind: User
    name: fluxcd-kustomizer
    apiGroup: rbac.authorization.k8s.io

We then update the kustomization configuration to specify the fluxcd-kustomizer role:

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
metadata:
  name: fluxcd-kustomization
spec:
  interval: 1m
  path: ./kustomize
  roleRef:
    name: fluxcd-kustomizer
    kind: Role

Conclusion

Implementing Role-Based Access Control (RBAC) for FluxCD deployments is a crucial step in ensuring the security and integrity of the deployed applications. By creating roles and role bindings that define the permissions and access levels for users or groups, we can restrict unauthorized access and prevent potential security breaches. This approach is particularly important in Platform Engineering, where multiple teams and users may be involved in managing and deploying applications.