configauditreport_controller.go

/*
Copyright 2021.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package configauditreport

import (
	"context"
	"fmt"

	aqua "github.com/aquasecurity/trivy-operator/pkg/apis/aquasecurity/v1alpha1"
	"github.com/go-logr/logr"
	"github.com/pkg/errors"
	"github.com/prometheus/client_golang/prometheus"
	apierrors "k8s.io/apimachinery/pkg/api/errors"
	"k8s.io/apimachinery/pkg/runtime"
	apitypes "k8s.io/apimachinery/pkg/types"
	ctrl "sigs.k8s.io/controller-runtime"
	"sigs.k8s.io/controller-runtime/pkg/client"
	ctrlutil "sigs.k8s.io/controller-runtime/pkg/controller/controllerutil"
	"sigs.k8s.io/controller-runtime/pkg/log"

	"github.com/giantswarm/starboard-exporter/controllers"
	"github.com/giantswarm/starboard-exporter/utils"
)

const (
	ConfigAuditReportFinalizer = "starboard-exporter.giantswarm.io/configauditreport"
)

// ConfigAuditReportReconciler reconciles a ConfigAuditReport object
type ConfigAuditReportReconciler struct {
	client.Client
	Log    logr.Logger
	Scheme *runtime.Scheme

	MaxJitterPercent int
	ShardHelper      *utils.ShardHelper
}

// +kubebuilder:rbac:groups=aquasecurity.github.io.giantswarm,resources=configauditreports,verbs=get;list;watch;create;update;patch;delete
// +kubebuilder:rbac:groups=aquasecurity.github.io.giantswarm,resources=configauditreports/status,verbs=get;update;patch
// +kubebuilder:rbac:groups=aquasecurity.github.io.giantswarm,resources=configauditreports/finalizers,verbs=update
func (r *ConfigAuditReportReconciler) Reconcile(ctx context.Context, req ctrl.Request) (ctrl.Result, error) {
	_ = log.FromContext(ctx)
	_ = r.Log.WithValues("configauditreport", req.NamespacedName)

	deletedSummaries := ConfigAuditSummary.DeletePartialMatch(prometheus.Labels{"report_name": req.NamespacedName.String()})

	shouldOwn := r.ShardHelper.ShouldOwn(req.NamespacedName.String())
	if shouldOwn {

		// Try to get the report. It might not exist anymore, in which case we don't need to do anything.
		report := &aqua.ConfigAuditReport{}
		if err := r.Client.Get(ctx, req.NamespacedName, report); err != nil {
			if apierrors.IsNotFound(err) {
				// Most likely the report was deleted.
				return ctrl.Result{}, nil
			}

			// Error reading the object.
			r.Log.Error(err, "Unable to read report")
			return ctrl.Result{}, err
		}

		r.Log.Info(fmt.Sprintf("Reconciled %s || Found (C/H/M/L): %d/%d/%d/%d",
			req.NamespacedName,
			report.Report.Summary.CriticalCount,
			report.Report.Summary.HighCount,
			report.Report.Summary.MediumCount,
			report.Report.Summary.LowCount,
		))

		// Publish summary and CVE metrics for this report.
		publishSummaryMetrics(report)

		if utils.SliceContains(report.GetFinalizers(), ConfigAuditReportFinalizer) {
			// Remove the finalizer if we're the shard owner.
			ctrlutil.RemoveFinalizer(report, ConfigAuditReportFinalizer)
			if err := r.Update(ctx, report); err != nil {
				return ctrl.Result{}, err
			}
		}

		// Add a label to this report so any previous owners will reconcile and drop the metric.
		report.Labels[controllers.ShardOwnerLabel] = r.ShardHelper.PodIP
		err := r.Client.Update(ctx, report, &client.UpdateOptions{})
		if err != nil {
			r.Log.Error(err, "unable to add shard owner label")
		}
	} else {
		if deletedSummaries > 0 {
			r.Log.Info(fmt.Sprintf("cleared %d summary metrics", deletedSummaries))
		}
	}

	return utils.JitterRequeue(controllers.DefaultRequeueDuration, r.MaxJitterPercent, r.Log), nil
}

// SetupWithManager sets up the controller with the Manager.
func (r *ConfigAuditReportReconciler) SetupWithManager(mgr ctrl.Manager) error {
	err := ctrl.NewControllerManagedBy(mgr).
		For(&aqua.ConfigAuditReport{}).
		Complete(r)
	if err != nil {
		return errors.Wrap(err, "failed setting up controller with controller manager")
	}

	return nil
}

func RequeueReportsForPod(c client.Client, log logr.Logger, podIP string) {
	reportList := &aqua.ConfigAuditReportList{}
	opts := []client.ListOption{
		client.MatchingLabels{controllers.ShardOwnerLabel: podIP},
	}

	// Get the list of reports with our label.
	err := c.List(context.Background(), reportList, opts...)
	if err != nil {
		log.Error(err, "unable to fetch configauditreport")
	}

	for _, r := range reportList.Items {
		// Retrieve the individual report.
		log.Info(fmt.Sprintf("re-queueing configauditreport %s", r.Name))
		report := &aqua.ConfigAuditReport{}
		err := c.Get(context.Background(), client.ObjectKey{Name: r.Name, Namespace: r.Namespace}, report)
		if err != nil {
			log.Error(err, "unable to fetch configauditreport")
		}

		// Clear the shard-owner label if it still has our label
		if r.Labels[controllers.ShardOwnerLabel] == podIP {
			r.Labels[controllers.ShardOwnerLabel] = ""
			err = c.Update(context.Background(), report, &client.UpdateOptions{})
			if err != nil {
				log.Error(err, fmt.Sprintf("unable to remove %s label", controllers.ShardOwnerLabel))
			}
		}
	}
}

func getCountPerSeverity(report *aqua.ConfigAuditReport) map[string]float64 {
	// Format is e.g. {CRITICAL: 10}.
	return map[string]float64{
		string(aqua.SeverityCritical): float64(report.Report.Summary.CriticalCount),
		string(aqua.SeverityHigh):     float64(report.Report.Summary.HighCount),
		string(aqua.SeverityMedium):   float64(report.Report.Summary.MediumCount),
		string(aqua.SeverityLow):      float64(report.Report.Summary.LowCount),
	}
}

func publishSummaryMetrics(report *aqua.ConfigAuditReport) {
	summaryValues := valuesForReport(report, metricLabels)

	// Add the severity label after the standard labels and expose each severity metric.
	for severity, count := range getCountPerSeverity(report) {
		v := summaryValues
		v["severity"] = severity

		// Expose the metric.
		ConfigAuditSummary.With(
			v,
		).Set(count)
	}
}

func valuesForReport(report *aqua.ConfigAuditReport, labels []string) map[string]string {
	result := map[string]string{}
	for _, label := range labels {
		result[label] = reportValueFor(label, report)
	}
	return result
}

func reportValueFor(field string, report *aqua.ConfigAuditReport) string {
	switch field {
	case "report_name":
		return apitypes.NamespacedName{Name: report.Name, Namespace: report.Namespace}.String()
	case "resource_name":
		return report.Name
	case "resource_namespace":
		return report.Namespace
	case "severity":
		return "" // this value will be overwritten in publishSummaryMetrics
	default:
		// Error?
		return ""
	}
}