Use CurrentImage field in status to prevent unintended upgrades

Author: ewoutp

pkg/apis/deployment/v1alpha/deployment_status.go

@@ -38,6 +38,8 @@ type DeploymentStatus struct {
 
 	// Images holds a list of ArangoDB images with their ID and ArangoDB version.
 	Images ImageInfoList `json:"arangodb-images,omitempty"`
+	// Image that is currently being used when new pods are created
+	CurrentImage *ImageInfo `json:"current-image,omitempty"`
 
 	// Members holds the status for all members in all server groups
 	Members DeploymentStatusMembers `json:"members"`

pkg/apis/deployment/v1alpha/plan.go

@@ -49,6 +49,8 @@ const (
 	ActionTypeRenewTLSCertificate ActionType = "RenewTLSCertificate"
 	// ActionTypeRenewTLSCACertificate causes the TLS CA certificate of the entire deployment to be renewed.
 	ActionTypeRenewTLSCACertificate ActionType = "RenewTLSCACertificate"
+	// ActionTypeSetCurrentImage causes status.CurrentImage to be updated to the image given in the action.
+	ActionTypeSetCurrentImage ActionType = "SetCurrentImage"
 )
 
 const (
@@ -73,6 +75,8 @@ type Action struct {
 	StartTime *metav1.Time `json:"startTime,omitempty"`
 	// Reason for this action
 	Reason string `json:"reason,omitempty"`
+	// Image used in can of a SetCurrentImage action.
+	Image string `json:"image,omitempty"`
 }
 
 // NewAction instantiates a new Action.
@@ -90,6 +94,13 @@ func NewAction(actionType ActionType, group ServerGroup, memberID string, reason
 	return a
 }
 
+// SetImage sets the Image field to the given value and returns the modified
+// action.
+func (a Action) SetImage(image string) Action {
+	a.Image = image
+	return a
+}
+
 // Plan is a list of actions that will be taken to update a deployment.
 // Only 1 action is in progress at a time. The operator will wait for that
 // action to be completely and then remove the action.

pkg/apis/deployment/v1alpha/zz_generated.deepcopy.go

@@ -295,6 +295,15 @@ func (in *DeploymentStatus) DeepCopyInto(out *DeploymentStatus) {
 		*out = make(ImageInfoList, len(*in))
 		copy(*out, *in)
 	}
+	if in.CurrentImage != nil {
+		in, out := &in.CurrentImage, &out.CurrentImage
+		if *in == nil {
+			*out = nil
+		} else {
+			*out = new(ImageInfo)
+			**out = **in
+		}
+	}
 	in.Members.DeepCopyInto(&out.Members)
 	if in.Conditions != nil {
 		in, out := &in.Conditions, &out.Conditions

pkg/deployment/reconcile/action_context.go

@@ -78,6 +78,12 @@ type ActionContext interface {
 	DeleteTLSKeyfile(group api.ServerGroup, member api.MemberStatus) error
 	// DeleteTLSCASecret removes the Secret containing the TLS CA certificate.
 	DeleteTLSCASecret() error
+	// GetImageInfo returns the image info for an image with given name.
+	// Returns: (info, infoFound)
+	GetImageInfo(imageName string) (api.ImageInfo, bool)
+	// SetCurrentImage changes the CurrentImage field in the deployment
+	// status to the given image.
+	SetCurrentImage(imageInfo api.ImageInfo) error
 }
 
 // newActionContext creates a new ActionContext implementation.
@@ -260,3 +266,21 @@ func (ac *actionContext) DeleteTLSCASecret() error {
 	}
 	return nil
 }
+
+// GetImageInfo returns the image info for an image with given name.
+// Returns: (info, infoFound)
+func (ac *actionContext) GetImageInfo(imageName string) (api.ImageInfo, bool) {
+	status, _ := ac.context.GetStatus()
+	return status.Images.GetByImage(imageName)
+}
+
+// SetCurrentImage changes the CurrentImage field in the deployment
+// status to the given image.
+func (ac *actionContext) SetCurrentImage(imageInfo api.ImageInfo) error {
+	status, lastVersion := ac.context.GetStatus()
+	status.CurrentImage = &imageInfo
+	if err := ac.context.UpdateStatus(status, lastVersion); err != nil {
+		return maskAny(err)
+	}
+	return nil
+}

pkg/deployment/reconcile/action_upgrade_current_image.go

@@ -0,0 +1,85 @@
+//
+// DISCLAIMER
+//
+// Copyright 2018 ArangoDB GmbH, Cologne, Germany
+//
+// 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.
+//
+// Copyright holder is ArangoDB GmbH, Cologne, Germany
+//
+// Author Ewout Prangsma
+//
+
+package reconcile
+
+import (
+	"context"
+	"time"
+
+	api "github.com/arangodb/kube-arangodb/pkg/apis/deployment/v1alpha"
+	"github.com/rs/zerolog"
+)
+
+// NewSetCurrentImageAction creates a new Action that implements the given
+// planned SetCurrentImage action.
+func NewSetCurrentImageAction(log zerolog.Logger, action api.Action, actionCtx ActionContext) Action {
+	return &setCurrentImageAction{
+		log:       log,
+		action:    action,
+		actionCtx: actionCtx,
+	}
+}
+
+// setCurrentImageAction implements an SetCurrentImage.
+type setCurrentImageAction struct {
+	log       zerolog.Logger
+	action    api.Action
+	actionCtx ActionContext
+}
+
+// Start performs the start of the action.
+// Returns true if the action is completely finished, false in case
+// the start time needs to be recorded and a ready condition needs to be checked.
+func (a *setCurrentImageAction) Start(ctx context.Context) (bool, error) {
+	ready, _, err := a.CheckProgress(ctx)
+	if err != nil {
+		return false, maskAny(err)
+	}
+	return ready, nil
+}
+
+// CheckProgress checks the progress of the action.
+// Returns true if the action is completely finished, false otherwise.
+func (a *setCurrentImageAction) CheckProgress(ctx context.Context) (bool, bool, error) {
+	log := a.log
+
+	imageInfo, found := a.actionCtx.GetImageInfo(a.action.Image)
+	if !found {
+		return false, false, nil
+	}
+	if err := a.actionCtx.SetCurrentImage(imageInfo); err != nil {
+		return false, false, maskAny(err)
+	}
+	log.Info().Str("image", a.action.Image).Msg("Changed current image")
+	return true, false, nil
+}
+
+// Timeout returns the amount of time after which this action will timeout.
+func (a *setCurrentImageAction) Timeout() time.Duration {
+	return upgradeMemberTimeout
+}
+
+// Return the MemberID used / created in this action
+func (a *setCurrentImageAction) MemberID() string {
+	return ""
+}

pkg/deployment/reconcile/plan_builder.go

@@ -149,33 +149,51 @@ func createPlan(log zerolog.Logger, apiObject k8sutil.APIObject,
 			}
 			return nil
 		}
-		status.Members.ForeachServerGroup(func(group api.ServerGroup, members api.MemberStatusList) error {
-			for _, m := range members {
-				if len(plan) > 0 {
-					// Only 1 change at a time
-					continue
-				}
-				if m.Phase != api.MemberPhaseCreated {
-					// Only rotate when phase is created
-					continue
-				}
-				if podName := m.PodName; podName != "" {
-					if p := getPod(podName); p != nil {
-						// Got pod, compare it with what it should be
-						decision := podNeedsUpgrading(*p, spec, status.Images)
-						if decision.UpgradeNeeded && decision.UpgradeAllowed {
-							plan = append(plan, createUpgradeMemberPlan(log, m, group, "Version upgrade")...)
-						} else {
-							rotNeeded, reason := podNeedsRotation(log, *p, apiObject, spec, group, status.Members.Agents, m.ID, context)
-							if rotNeeded {
-								plan = append(plan, createRotateMemberPlan(log, m, group, reason)...)
+		// createRotateOrUpgradePlan goes over all pods to check if an upgrade or rotate
+		// is needed. If an upgrade is needed but not allowed, the second return value
+		// will be true.
+		// Returns: (newPlan, upgradeNotAllowed)
+		createRotateOrUpgradePlan := func() (api.Plan, bool) {
+			var newPlan api.Plan
+			upgradeNotAllowed := false
+			status.Members.ForeachServerGroup(func(group api.ServerGroup, members api.MemberStatusList) error {
+				for _, m := range members {
+					if m.Phase != api.MemberPhaseCreated {
+						// Only rotate when phase is created
+						continue
+					}
+					if podName := m.PodName; podName != "" {
+						if p := getPod(podName); p != nil {
+							// Got pod, compare it with what it should be
+							decision := podNeedsUpgrading(*p, spec, status.Images)
+							if decision.UpgradeNeeded && !decision.UpgradeAllowed {
+								// Oops, upgrade is not allowed
+								upgradeNotAllowed = true
+								return nil
+							} else if len(newPlan) == 0 {
+								// Only rotate/upgrade 1 pod at a time
+								if decision.UpgradeNeeded && decision.UpgradeAllowed {
+									newPlan = createUpgradeMemberPlan(log, m, group, "Version upgrade", spec.GetImage(), status)
+								} else {
+									rotNeeded, reason := podNeedsRotation(log, *p, apiObject, spec, group, status.Members.Agents, m.ID, context)
+									if rotNeeded {
+										newPlan = createRotateMemberPlan(log, m, group, reason)
+									}
+								}
 							}
 						}
 					}
 				}
-			}
-			return nil
-		})
+				return nil
+			})
+			return newPlan, upgradeNotAllowed
+		}
+		if newPlan, upgradeNotAllowed := createRotateOrUpgradePlan(); upgradeNotAllowed {
+			// TODO create event
+		} else {
+			// Use the new plan
+			plan = newPlan
+		}
 	}
 
 	// Check for the need to rotate TLS certificate of a members
@@ -343,7 +361,7 @@ func createRotateMemberPlan(log zerolog.Logger, member api.MemberStatus,
 // createUpgradeMemberPlan creates a plan to upgrade (stop-recreateWithAutoUpgrade-stop-start) an existing
 // member.
 func createUpgradeMemberPlan(log zerolog.Logger, member api.MemberStatus,
-	group api.ServerGroup, reason string) api.Plan {
+	group api.ServerGroup, reason string, imageName string, status api.DeploymentStatus) api.Plan {
 	log.Debug().
 		Str("id", member.ID).
 		Str("role", group.AsRole()).
@@ -353,6 +371,11 @@ func createUpgradeMemberPlan(log zerolog.Logger, member api.MemberStatus,
 		api.NewAction(api.ActionTypeUpgradeMember, group, member.ID, reason),
 		api.NewAction(api.ActionTypeWaitForMemberUp, group, member.ID),
 	}
+	if status.CurrentImage == nil || status.CurrentImage.Image != imageName {
+		plan = append(api.Plan{
+			api.NewAction(api.ActionTypeSetCurrentImage, group, "", reason).SetImage(imageName),
+		}, plan...)
+	}
 	return plan
 }
 

pkg/deployment/reconcile/plan_executor.go

@@ -181,6 +181,8 @@ func (d *Reconciler) createAction(ctx context.Context, log zerolog.Logger, actio
 		return NewRenewTLSCertificateAction(log, action, actionCtx)
 	case api.ActionTypeRenewTLSCACertificate:
 		return NewRenewTLSCACertificateAction(log, action, actionCtx)
+	case api.ActionTypeSetCurrentImage:
+		return NewSetCurrentImageAction(log, action, actionCtx)
 	default:
 		panic(fmt.Sprintf("Unknown action type '%s'", action.Type))
 	}

pkg/deployment/resources/pod_creator.go

@@ -459,13 +459,23 @@ func (r *Resources) createPodForMember(spec api.DeploymentSpec, memberID string,
 	podSuffix := createPodSuffix(spec)
 	m.PodName = k8sutil.CreatePodName(apiObject.GetName(), roleAbbr, m.ID, podSuffix)
 	newPhase := api.MemberPhaseCreated
-	// Find image ID
-	imageInfo, imageFound := status.Images.GetByImage(spec.GetImage())
-	if !imageFound {
-		imageNotFoundOnce.Do(func() {
-			log.Debug().Str("image", spec.GetImage()).Msg("Image ID is not known yet for image")
-		})
-		return nil
+	// Select image
+	var imageInfo api.ImageInfo
+	if current := status.CurrentImage; current != nil {
+		// Use current image
+		imageInfo = *current
+	} else {
+		// Find image ID
+		info, imageFound := status.Images.GetByImage(spec.GetImage())
+		if !imageFound {
+			imageNotFoundOnce.Do(func() {
+				log.Debug().Str("image", spec.GetImage()).Msg("Image ID is not known yet for image")
+			})
+			return nil
+		}
+		imageInfo = info
+		// Save image as current image
+		status.CurrentImage = &info
 	}
 	// Create pod
 	if group.IsArangod() {

pkg/deployment/server_api.go

@@ -218,17 +218,15 @@ func (d *Deployment) DatabaseURL() string {
 // DatabaseVersion returns the version used by the deployment
 // Returns versionNumber, licenseType
 func (d *Deployment) DatabaseVersion() (string, string) {
-	image := d.GetSpec().GetImage()
 	status, _ := d.GetStatus()
-	info, found := status.Images.GetByImage(image)
-	if !found {
-		return "", ""
-	}
-	license := "community"
-	if info.Enterprise {
-		license = "enterprise"
+	if current := status.CurrentImage; current != nil {
+		license := "community"
+		if current.Enterprise {
+			license = "enterprise"
+		}
+		return string(current.ArangoDBVersion), license
 	}
-	return string(info.ArangoDBVersion), license
+	return "", ""
 }
 
 // Members returns all members of the deployment by role.