source-controller/controllers/helmrepository_controller.go

/*
Copyright 2020 The Flux authors

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 controllers

import (
	"context"
	"errors"
	"fmt"
	"net/url"
	"os"
	"time"

	helmgetter "helm.sh/helm/v3/pkg/getter"
	corev1 "k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/apimachinery/pkg/types"
	kuberecorder "k8s.io/client-go/tools/record"
	ctrl "sigs.k8s.io/controller-runtime"
	"sigs.k8s.io/controller-runtime/pkg/client"
	"sigs.k8s.io/controller-runtime/pkg/controller"
	"sigs.k8s.io/controller-runtime/pkg/controller/controllerutil"
	"sigs.k8s.io/controller-runtime/pkg/predicate"

	"github.com/fluxcd/pkg/apis/meta"
	"github.com/fluxcd/pkg/runtime/conditions"
	helper "github.com/fluxcd/pkg/runtime/controller"
	"github.com/fluxcd/pkg/runtime/events"
	"github.com/fluxcd/pkg/runtime/patch"
	"github.com/fluxcd/pkg/runtime/predicates"

	sourcev1 "github.com/fluxcd/source-controller/api/v1beta2"
	serror "github.com/fluxcd/source-controller/internal/error"
	"github.com/fluxcd/source-controller/internal/helm/getter"
	"github.com/fluxcd/source-controller/internal/helm/repository"
	sreconcile "github.com/fluxcd/source-controller/internal/reconcile"
	"github.com/fluxcd/source-controller/internal/reconcile/summarize"
)

// helmRepositoryReadyCondition contains the information required to summarize a
// v1beta2.HelmRepository Ready Condition.
var helmRepositoryReadyCondition = summarize.Conditions{
	Target: meta.ReadyCondition,
	Owned: []string{
		sourcev1.FetchFailedCondition,
		sourcev1.ArtifactOutdatedCondition,
		meta.ReadyCondition,
		meta.ReconcilingCondition,
		meta.StalledCondition,
	},
	Summarize: []string{
		sourcev1.FetchFailedCondition,
		sourcev1.ArtifactOutdatedCondition,
		meta.StalledCondition,
		meta.ReconcilingCondition,
	},
	NegativePolarity: []string{
		sourcev1.FetchFailedCondition,
		sourcev1.ArtifactOutdatedCondition,
		meta.StalledCondition,
		meta.ReconcilingCondition,
	},
}

// +kubebuilder:rbac:groups=source.toolkit.fluxcd.io,resources=helmrepositories,verbs=get;list;watch;create;update;patch;delete
// +kubebuilder:rbac:groups=source.toolkit.fluxcd.io,resources=helmrepositories/status,verbs=get;update;patch
// +kubebuilder:rbac:groups=source.toolkit.fluxcd.io,resources=helmrepositories/finalizers,verbs=get;create;update;patch;delete
// +kubebuilder:rbac:groups="",resources=events,verbs=create;patch

// HelmRepositoryReconciler reconciles a v1beta2.HelmRepository object.
type HelmRepositoryReconciler struct {
	client.Client
	kuberecorder.EventRecorder
	helper.Metrics

	Getters helmgetter.Providers
	Storage *Storage
}

type HelmRepositoryReconcilerOptions struct {
	MaxConcurrentReconciles int
}

// helmRepositoryReconcileFunc is the function type for all the
// v1beta2.HelmRepository (sub)reconcile functions. The type implementations
// are grouped and executed serially to perform the complete reconcile of the
// object.
type helmRepositoryReconcileFunc func(ctx context.Context, obj *sourcev1.HelmRepository, artifact *sourcev1.Artifact, repo *repository.ChartRepository) (sreconcile.Result, error)

func (r *HelmRepositoryReconciler) SetupWithManager(mgr ctrl.Manager) error {
	return r.SetupWithManagerAndOptions(mgr, HelmRepositoryReconcilerOptions{})
}

func (r *HelmRepositoryReconciler) SetupWithManagerAndOptions(mgr ctrl.Manager, opts HelmRepositoryReconcilerOptions) error {
	return ctrl.NewControllerManagedBy(mgr).
		For(&sourcev1.HelmRepository{}).
		WithEventFilter(predicate.Or(predicate.GenerationChangedPredicate{}, predicates.ReconcileRequestedPredicate{})).
		WithOptions(controller.Options{MaxConcurrentReconciles: opts.MaxConcurrentReconciles}).
		Complete(r)
}

func (r *HelmRepositoryReconciler) Reconcile(ctx context.Context, req ctrl.Request) (result ctrl.Result, retErr error) {
	start := time.Now()
	log := ctrl.LoggerFrom(ctx)

	// Fetch the HelmRepository
	obj := &sourcev1.HelmRepository{}
	if err := r.Get(ctx, req.NamespacedName, obj); err != nil {
		return ctrl.Result{}, client.IgnoreNotFound(err)
	}

	// Record suspended status metric
	r.RecordSuspend(ctx, obj, obj.Spec.Suspend)

	// Return early if the object is suspended
	if obj.Spec.Suspend {
		log.Info("reconciliation is suspended for this object")
		return ctrl.Result{}, nil
	}

	// Initialize the patch helper with the current version of the object.
	patchHelper, err := patch.NewHelper(obj, r.Client)
	if err != nil {
		return ctrl.Result{}, err
	}

	// recResult stores the abstracted reconcile result.
	var recResult sreconcile.Result

	// Always attempt to patch the object after each reconciliation.
	// NOTE: The final runtime result and error are set in this block.
	defer func() {
		summarizeHelper := summarize.NewHelper(r.EventRecorder, patchHelper)
		summarizeOpts := []summarize.Option{
			summarize.WithConditions(helmRepositoryReadyCondition),
			summarize.WithReconcileResult(recResult),
			summarize.WithReconcileError(retErr),
			summarize.WithIgnoreNotFound(),
			summarize.WithProcessors(
				summarize.RecordContextualError,
				summarize.RecordReconcileReq,
			),
			summarize.WithResultBuilder(sreconcile.AlwaysRequeueResultBuilder{RequeueAfter: obj.GetRequeueAfter()}),
		}
		result, retErr = summarizeHelper.SummarizeAndPatch(ctx, obj, summarizeOpts...)

		// Always record readiness and duration metrics
		r.Metrics.RecordReadiness(ctx, obj)
		r.Metrics.RecordDuration(ctx, obj, start)
	}()

	// Add finalizer first if not exist to avoid the race condition
	// between init and delete
	if !controllerutil.ContainsFinalizer(obj, sourcev1.SourceFinalizer) {
		controllerutil.AddFinalizer(obj, sourcev1.SourceFinalizer)
		recResult = sreconcile.ResultRequeue
		return
	}

	// Examine if the object is under deletion
	if !obj.ObjectMeta.DeletionTimestamp.IsZero() {
		recResult, retErr = r.reconcileDelete(ctx, obj)
		return
	}

	// Reconcile actual object
	reconcilers := []helmRepositoryReconcileFunc{
		r.reconcileStorage,
		r.reconcileSource,
		r.reconcileArtifact,
	}
	recResult, retErr = r.reconcile(ctx, obj, reconcilers)
	return
}

// reconcile iterates through the gitRepositoryReconcileFunc tasks for the
// object. It returns early on the first call that returns
// reconcile.ResultRequeue, or produces an error.
func (r *HelmRepositoryReconciler) reconcile(ctx context.Context, obj *sourcev1.HelmRepository, reconcilers []helmRepositoryReconcileFunc) (sreconcile.Result, error) {
	if obj.Generation != obj.Status.ObservedGeneration {
		conditions.MarkReconciling(obj, "NewGeneration", "reconciling new object generation (%d)", obj.Generation)
	}

	var chartRepo repository.ChartRepository
	var artifact sourcev1.Artifact

	// Run the sub-reconcilers and build the result of reconciliation.
	var res sreconcile.Result
	var resErr error
	for _, rec := range reconcilers {
		recResult, err := rec(ctx, obj, &artifact, &chartRepo)
		// Exit immediately on ResultRequeue.
		if recResult == sreconcile.ResultRequeue {
			return sreconcile.ResultRequeue, nil
		}
		// If an error is received, prioritize the returned results because an
		// error also means immediate requeue.
		if err != nil {
			resErr = err
			res = recResult
			break
		}
		// Prioritize requeue request in the result for successful results.
		res = sreconcile.LowestRequeuingResult(res, recResult)
	}
	return res, resErr
}

// reconcileStorage ensures the current state of the storage matches the
// desired and previously observed state.
//
// All Artifacts for the object except for the current one in the Status are
// garbage collected from the Storage.
// If the Artifact in the Status of the object disappeared from the Storage,
// it is removed from the object.
// If the object does not have an Artifact in its Status, a Reconciling
// condition is added.
// The hostname of any URL in the Status of the object are updated, to ensure
// they match the Storage server hostname of current runtime.
func (r *HelmRepositoryReconciler) reconcileStorage(ctx context.Context, obj *sourcev1.HelmRepository, _ *sourcev1.Artifact, _ *repository.ChartRepository) (sreconcile.Result, error) {
	// Garbage collect previous advertised artifact(s) from storage
	_ = r.garbageCollect(ctx, obj)

	// Determine if the advertised artifact is still in storage
	if artifact := obj.GetArtifact(); artifact != nil && !r.Storage.ArtifactExist(*artifact) {
		obj.Status.Artifact = nil
		obj.Status.URL = ""
	}

	// Record that we do not have an artifact
	if obj.GetArtifact() == nil {
		conditions.MarkReconciling(obj, "NoArtifact", "no artifact for resource in storage")
		return sreconcile.ResultSuccess, nil
	}

	// Always update URLs to ensure hostname is up-to-date
	// TODO(hidde): we may want to send out an event only if we notice the URL has changed
	r.Storage.SetArtifactURL(obj.GetArtifact())
	obj.Status.URL = r.Storage.SetHostname(obj.Status.URL)

	return sreconcile.ResultSuccess, nil
}

// reconcileSource attempts to fetch the Helm repository index using the
// specified configuration on the v1beta2.HelmRepository object.
//
// When the fetch fails, it records v1beta2.FetchFailedCondition=True and
// returns early.
// If successful and the index is valid, any previous
// v1beta2.FetchFailedCondition is removed, and the repository.ChartRepository
// pointer is set to the newly fetched index.
func (r *HelmRepositoryReconciler) reconcileSource(ctx context.Context, obj *sourcev1.HelmRepository, artifact *sourcev1.Artifact, chartRepo *repository.ChartRepository) (sreconcile.Result, error) {
	// Configure Helm client to access repository
	clientOpts := []helmgetter.Option{
		helmgetter.WithTimeout(obj.Spec.Timeout.Duration),
		helmgetter.WithURL(obj.Spec.URL),
		helmgetter.WithPassCredentialsAll(obj.Spec.PassCredentials),
	}

	// Configure any authentication related options
	if obj.Spec.SecretRef != nil {
		// Attempt to retrieve secret
		name := types.NamespacedName{
			Namespace: obj.GetNamespace(),
			Name:      obj.Spec.SecretRef.Name,
		}
		var secret corev1.Secret
		if err := r.Client.Get(ctx, name, &secret); err != nil {
			e := &serror.Event{
				Err:    fmt.Errorf("failed to get secret '%s': %w", name.String(), err),
				Reason: sourcev1.AuthenticationFailedReason,
			}
			conditions.MarkTrue(obj, sourcev1.FetchFailedCondition, sourcev1.AuthenticationFailedReason, e.Err.Error())
			return sreconcile.ResultEmpty, e
		}

		// Get client options from secret
		tmpDir, err := os.MkdirTemp("", fmt.Sprintf("%s-%s-auth-", obj.Name, obj.Namespace))
		if err != nil {
			return sreconcile.ResultEmpty, &serror.Event{
				Err:    fmt.Errorf("failed to create temporary directory for credentials: %w", err),
				Reason: sourcev1.StorageOperationFailedReason,
			}
		}
		defer func() {
			if err = os.RemoveAll(tmpDir); err != nil {
				ctrl.LoggerFrom(ctx).Error(err, "failed to remove temporary directory for credentials")
			}
		}()

		// Construct actual options
		opts, err := getter.ClientOptionsFromSecret(tmpDir, secret)
		if err != nil {
			e := &serror.Event{
				Err:    fmt.Errorf("failed to configure Helm client with secret data: %w", err),
				Reason: sourcev1.AuthenticationFailedReason,
			}
			conditions.MarkTrue(obj, sourcev1.FetchFailedCondition, sourcev1.AuthenticationFailedReason, e.Err.Error())
			// Return err as the content of the secret may change.
			return sreconcile.ResultEmpty, e
		}
		clientOpts = append(clientOpts, opts...)
	}

	// Construct Helm chart repository with options and download index
	newChartRepo, err := repository.NewChartRepository(obj.Spec.URL, "", r.Getters, clientOpts)
	if err != nil {
		switch err.(type) {
		case *url.Error:
			e := &serror.Stalling{
				Err:    fmt.Errorf("invalid Helm repository URL: %w", err),
				Reason: sourcev1.URLInvalidReason,
			}
			conditions.MarkTrue(obj, sourcev1.FetchFailedCondition, sourcev1.URLInvalidReason, e.Err.Error())
			return sreconcile.ResultEmpty, e
		default:
			e := &serror.Stalling{
				Err:    fmt.Errorf("failed to construct Helm client: %w", err),
				Reason: meta.FailedReason,
			}
			conditions.MarkTrue(obj, sourcev1.FetchFailedCondition, meta.FailedReason, e.Err.Error())
			return sreconcile.ResultEmpty, e
		}
	}
	checksum, err := newChartRepo.CacheIndex()
	if err != nil {
		e := &serror.Event{
			Err:    fmt.Errorf("failed to fetch Helm repository index: %w", err),
			Reason: meta.FailedReason,
		}
		conditions.MarkTrue(obj, sourcev1.FetchFailedCondition, meta.FailedReason, e.Err.Error())
		// Coin flip on transient or persistent error, return error and hope for the best
		return sreconcile.ResultEmpty, e
	}
	*chartRepo = *newChartRepo

	// Load the cached repository index to ensure it passes validation.
	if err := chartRepo.LoadFromCache(); err != nil {
		e := &serror.Event{
			Err:    fmt.Errorf("failed to load Helm repository from cache: %w", err),
			Reason: sourcev1.FetchFailedCondition,
		}
		conditions.MarkTrue(obj, sourcev1.FetchFailedCondition, sourcev1.IndexationFailedReason, e.Err.Error())
		return sreconcile.ResultEmpty, e
	}
	defer chartRepo.Unload()

	// Mark observations about the revision on the object.
	if !obj.GetArtifact().HasRevision(checksum) {
		message := fmt.Sprintf("new index revision '%s'", checksum)
		conditions.MarkTrue(obj, sourcev1.ArtifactOutdatedCondition, "NewRevision", message)
		conditions.MarkReconciling(obj, "NewRevision", message)
	}

	conditions.Delete(obj, sourcev1.FetchFailedCondition)

	// Create potential new artifact.
	*artifact = r.Storage.NewArtifactFor(obj.Kind,
		obj.ObjectMeta.GetObjectMeta(),
		chartRepo.Checksum,
		fmt.Sprintf("index-%s.yaml", checksum))

	return sreconcile.ResultSuccess, nil
}

// reconcileArtifact archives a new Artifact to the Storage, if the current
// (Status) data on the object does not match the given.
//
// The inspection of the given data to the object is differed, ensuring any
// stale observations like v1beta2.ArtifactOutdatedCondition are removed.
// If the given Artifact does not differ from the object's current, it returns
// early.
// On a successful archive, the Artifact in the Status of the object is set,
// and the symlink in the Storage is updated to its path.
func (r *HelmRepositoryReconciler) reconcileArtifact(ctx context.Context, obj *sourcev1.HelmRepository, artifact *sourcev1.Artifact, chartRepo *repository.ChartRepository) (sreconcile.Result, error) {
	// Always restore the Ready condition in case it got removed due to a transient error.
	defer func() {
		if obj.GetArtifact().HasRevision(artifact.Revision) {
			conditions.Delete(obj, sourcev1.ArtifactOutdatedCondition)
			conditions.MarkTrue(obj, meta.ReadyCondition, meta.SucceededReason,
				"stored artifact for revision '%s'", artifact.Revision)
		}

		if err := chartRepo.RemoveCache(); err != nil {
			ctrl.LoggerFrom(ctx).Error(err, "failed to remove temporary cached index file")
		}
	}()

	if obj.GetArtifact().HasRevision(artifact.Revision) {
		ctrl.LoggerFrom(ctx).Info("artifact up-to-date", "revision", artifact.Revision)
		return sreconcile.ResultSuccess, nil
	}

	// Mark reconciling because the artifact and remote source are different.
	// and they have to be reconciled.
	conditions.MarkReconciling(obj, "NewRevision", "new index revision '%s'", artifact.Revision)

	// Create artifact dir
	if err := r.Storage.MkdirAll(*artifact); err != nil {
		return sreconcile.ResultEmpty, &serror.Event{
			Err:    fmt.Errorf("failed to create artifact directory: %w", err),
			Reason: sourcev1.StorageOperationFailedReason,
		}
	}

	// Acquire lock.
	unlock, err := r.Storage.Lock(*artifact)
	if err != nil {
		return sreconcile.ResultEmpty, &serror.Event{
			Err:    fmt.Errorf("failed to acquire lock for artifact: %w", err),
			Reason: meta.FailedReason,
		}
	}
	defer unlock()

	// Save artifact to storage.
	if err = r.Storage.CopyFromPath(artifact, chartRepo.CachePath); err != nil {
		return sreconcile.ResultEmpty, &serror.Event{
			Err:    fmt.Errorf("unable to save artifact to storage: %w", err),
			Reason: sourcev1.StorageOperationFailedReason,
		}
	}

	r.AnnotatedEventf(obj, map[string]string{
		"revision": artifact.Revision,
		"checksum": artifact.Checksum,
	}, corev1.EventTypeNormal, "NewArtifact", "stored artifact for revision '%s'", artifact.Revision)

	// Record it on the object.
	obj.Status.Artifact = artifact.DeepCopy()

	// Update index symlink.
	indexURL, err := r.Storage.Symlink(*artifact, "index.yaml")
	if err != nil {
		r.eventLogf(ctx, obj, corev1.EventTypeWarning, sourcev1.StorageOperationFailedReason,
			"failed to update status URL symlink: %s", err)
	}
	if indexURL != "" {
		obj.Status.URL = indexURL
	}

	return sreconcile.ResultSuccess, nil
}

// reconcileDelete handles the deletion of the object.
// It first garbage collects all Artifacts for the object from the Storage.
// Removing the finalizer from the object if successful.
func (r *HelmRepositoryReconciler) reconcileDelete(ctx context.Context, obj *sourcev1.HelmRepository) (sreconcile.Result, error) {
	// Garbage collect the resource's artifacts
	if err := r.garbageCollect(ctx, obj); err != nil {
		// Return the error so we retry the failed garbage collection
		return sreconcile.ResultEmpty, err
	}

	// Remove our finalizer from the list
	controllerutil.RemoveFinalizer(obj, sourcev1.SourceFinalizer)

	// Stop reconciliation as the object is being deleted
	return sreconcile.ResultEmpty, nil
}

// garbageCollect performs a garbage collection for the given object.
//
// It removes all but the current Artifact from the Storage, unless the
// deletion timestamp on the object is set. Which will result in the
// removal of all Artifacts for the objects.
func (r *HelmRepositoryReconciler) garbageCollect(ctx context.Context, obj *sourcev1.HelmRepository) error {
	if !obj.DeletionTimestamp.IsZero() {
		if deleted, err := r.Storage.RemoveAll(r.Storage.NewArtifactFor(obj.Kind, obj.GetObjectMeta(), "", "*")); err != nil {
			return &serror.Event{
				Err:    fmt.Errorf("garbage collection for deleted resource failed: %w", err),
				Reason: "GarbageCollectionFailed",
			}
		} else if deleted != "" {
			r.eventLogf(ctx, obj, events.EventTypeTrace, "GarbageCollectionSucceeded",
				"garbage collected artifacts for deleted resource")
		}
		obj.Status.Artifact = nil
		return nil
	}
	if obj.GetArtifact() != nil {
		if deleted, err := r.Storage.RemoveAllButCurrent(*obj.GetArtifact()); err != nil {
			return &serror.Event{
				Err:    fmt.Errorf("garbage collection of old artifacts failed: %w", err),
				Reason: "GarbageCollectionFailed",
			}
		} else if len(deleted) > 0 {
			r.eventLogf(ctx, obj, events.EventTypeTrace, "GarbageCollectionSucceeded",
				"garbage collected old artifacts")
		}
	}
	return nil
}

// eventLogf records event and logs at the same time.
//
// This log is different from the debug log in the EventRecorder, in the sense
// that this is a simple log. While the debug log contains complete details
// about the event.
func (r *HelmRepositoryReconciler) eventLogf(ctx context.Context, obj runtime.Object, eventType string, reason string, messageFmt string, args ...interface{}) {
	msg := fmt.Sprintf(messageFmt, args...)
	// Log and emit event.
	if eventType == corev1.EventTypeWarning {
		ctrl.LoggerFrom(ctx).Error(errors.New(reason), msg)
	} else {
		ctrl.LoggerFrom(ctx).Info(msg)
	}
	r.Eventf(obj, eventType, reason, msg)
}