Preflight is a tool to automatically perform Kubernetes cluster configuration checks using Open Policy Agent (OPA).
This repository hosts the agent part of Preflight. It sends data to the Preflight SaaS platform.
Table of Contents
Preflight was originally designed to automate Jetstack's production readiness assessments. These are consulting sessions in which a Jetstack engineer inspects a customer's cluster to suggest improvements and identify configuration issues. The product of this assessment is a report which describes any problems and offers remediation advice.
While these assessments have provided a lot of value to many customers, with a complex system like Kubernetes it's hard to thoroughly check everything. Automating the checks allows them to be more comprehensive and much faster.
The automation also allows the checks to be run repeatedly, meaning they can be deployed in-cluster to provide continuous configuration checking. This enables new interesting use cases as policy compliance audits.
The Preflight agent uses data gatherers to collect required data from Kubernetes and cloud provider APIs before formatting it as JSON for analysis. Once data has been collected, it is sent to the configured backend.
To run the Agent locally you can run:
preflight agent --agent-config-file ./path/to/agent/config/file.yaml
Or, to build and run a version from master:
go run main.go agent --agent-config-file ./path/to/agent/config/file.yaml
You can find the example agent file here.
You might also want to run a local echo server to monitor requests the agent sends:
go run main.go echo
Policies for cluster configuration are encoded into Preflight packages. Each
package focuses on a different infrastructure component, for example the
package provides rules for the configuration of a GKE cluster.
Preflight packages are implemented using Open Policy Agent with evaluation taking place in the SaaS backend.
The following instructions walk through the installation of the Preflight agent to gather data about cluster pods and send them to the backend for analysis.
To complete the secret manifest below, you will need to have a Preflight token.
First create a namespace for the preflight components:
apiVersion: v1 kind: Namespace metadata: name: preflight
Next create a secret like the following, substituting your token:
apiVersion: v1 kind: Secret metadata: name: agent-config namespace: preflight type: Opaque stringData: config.yaml: | schedule: "* * * * *" token: # enter your token here endpoint: protocol: https host: preflight.jetstack.io path: /api/v1/datareadings data-gatherers: - name: "pods" kind: "k8s" config: resource-type: resource: pods version: v1
Now create a service account with permissions to read cluster resources:
apiVersion: v1 kind: ServiceAccount metadata: name: agent namespace: preflight --- apiVersion: rbac.authorization.k8s.io/v1 kind: ClusterRoleBinding metadata: name: preflight-agent-cluster-viewer roleRef: apiGroup: rbac.authorization.k8s.io kind: ClusterRole # will be able to view all resources, but not rbac and secrets name: view subjects: - kind: ServiceAccount name: agent namespace: preflight
Finally deploy the agent:
apiVersion: apps/v1 kind: Deployment metadata: name: agent namespace: preflight spec: replicas: 1 selector: matchLabels: app.kubernetes.io/name: agent template: metadata: labels: app.kubernetes.io/name: agent spec: serviceAccountName: agent volumes: - name: config secret: secretName: agent-config containers: - name: agent image: quay.io/jetstack/preflight:7d4fa467258b7592d68fd660f1fd1d42e7332231 args: - "agent" - "-c" - "/etc/secrets/preflight/agent/config.yaml" volumeMounts: - name: config mountPath: "/etc/secrets/preflight/agent" readOnly: true resources: requests: memory: "200Mi" cpu: "200m" limits: memory: "200Mi" cpu: "200m"