From 708b455960c5bb29e521cf7c546040e0fecee158 Mon Sep 17 00:00:00 2001
From: Tomasz Mielech <informal.ict@gmail.com>
Date: Thu, 16 Sep 2021 12:14:28 +0200
Subject: [PATCH 01/14] change log.level on the fly

---
 pkg/apis/deployment/v1/plan.go                |   2 +
 pkg/deployment/reconcile/action_helper.go     |   2 +-
 .../action_runtime_container_args_udpate.go   | 289 ++++++++++++++++++
 pkg/deployment/reconcile/plan_executor.go     |   2 +-
 pkg/deployment/rotation/arangod_containers.go |  26 +-
 .../rotation/arangod_containers_test.go       |   2 +
 pkg/deployment/rotation/check.go              |   1 +
 pkg/util/k8sutil/pair.go                      |  14 +
 pkg/util/strings.go                           |  17 ++
 9 files changed, 351 insertions(+), 4 deletions(-)
 create mode 100644 pkg/deployment/reconcile/action_runtime_container_args_udpate.go

diff --git a/pkg/apis/deployment/v1/plan.go b/pkg/apis/deployment/v1/plan.go
index f7b66b076..a689ec3a5 100644
--- a/pkg/apis/deployment/v1/plan.go
+++ b/pkg/apis/deployment/v1/plan.go
@@ -169,6 +169,8 @@ const (
 	// Runtime Updates
 	// ActionTypeRuntimeContainerImageUpdate updates container image in runtime
 	ActionTypeRuntimeContainerImageUpdate ActionType = "RuntimeContainerImageUpdate"
+	// ActionTypeRuntimeContainerArgsLogLevelUpdate updates the container's executor arguments.
+	ActionTypeRuntimeContainerArgsLogLevelUpdate ActionType = "RuntimeContainerArgsLogLevelUpdate"
 )
 
 const (
diff --git a/pkg/deployment/reconcile/action_helper.go b/pkg/deployment/reconcile/action_helper.go
index 8ce21d571..7c90373d9 100644
--- a/pkg/deployment/reconcile/action_helper.go
+++ b/pkg/deployment/reconcile/action_helper.go
@@ -102,7 +102,7 @@ func (a actionImpl) Timeout(deploymentSpec api.DeploymentSpec) time.Duration {
 	return a.timeout(deploymentSpec)
 }
 
-// Return the MemberID used / created in this action
+// MemberID returns the member ID used / created in the current action.
 func (a actionImpl) MemberID() string {
 	return *a.memberIDRef
 }
diff --git a/pkg/deployment/reconcile/action_runtime_container_args_udpate.go b/pkg/deployment/reconcile/action_runtime_container_args_udpate.go
new file mode 100644
index 000000000..56da29dd0
--- /dev/null
+++ b/pkg/deployment/reconcile/action_runtime_container_args_udpate.go
@@ -0,0 +1,289 @@
+//
+// DISCLAIMER
+//
+// Copyright 2021 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 Tomasz Mielech
+//
+
+package reconcile
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	"github.com/pkg/errors"
+	"github.com/rs/zerolog"
+	core "k8s.io/api/core/v1"
+
+	api "github.com/arangodb/kube-arangodb/pkg/apis/deployment/v1"
+	"github.com/arangodb/kube-arangodb/pkg/deployment/rotation"
+	"github.com/arangodb/kube-arangodb/pkg/util/arangod"
+	"github.com/arangodb/kube-arangodb/pkg/util/k8sutil"
+)
+
+func init() {
+	registerAction(api.ActionTypeRuntimeContainerArgsLogLevelUpdate, runtimeContainerArgsUpdate)
+}
+
+func runtimeContainerArgsUpdate(log zerolog.Logger, action api.Action, actionCtx ActionContext) Action {
+	a := &actionRuntimeContainerArgsUpdate{}
+
+	a.actionImpl = newActionImplDefRef(log, action, actionCtx, defaultTimeout)
+
+	return a
+}
+
+var _ ActionReloadCachedStatus = &actionRuntimeContainerArgsUpdate{}
+var _ ActionPost = &actionRuntimeContainerArgsUpdate{}
+
+type actionRuntimeContainerArgsUpdate struct {
+	// actionImpl implement timeout and member id functions
+	actionImpl
+}
+
+// Post updates arguments for the specific Arango member.
+func (a actionRuntimeContainerArgsUpdate) Post(ctx context.Context) error {
+
+	a.log.Info().Msgf("Updating container args")
+
+	m, ok := a.actionCtx.GetMemberStatusByID(a.action.MemberID)
+	if !ok {
+		a.log.Info().Msg("member is gone already")
+		return nil
+	}
+
+	memberName := m.ArangoMemberName(a.actionCtx.GetName(), a.action.Group)
+	member, ok := a.actionCtx.GetCachedStatus().ArangoMember(memberName)
+	if !ok {
+		return errors.Errorf("ArangoMember %s not found", memberName)
+	}
+
+	containerName, ok := a.action.GetParam(rotation.ContainerName)
+	if !ok {
+		a.log.Warn().Msgf("Unable to find action's param %s", rotation.ContainerName)
+		return nil
+	}
+
+	updateMemberStatusArgs := func(obj *api.ArangoMember, s *api.ArangoMemberStatus) bool {
+		if obj.Spec.Template == nil || s.Template == nil ||
+			obj.Spec.Template.PodSpec == nil || s.Template.PodSpec == nil {
+			a.log.Info().Msgf("Nil Member definition")
+			return false
+		}
+
+		if len(obj.Spec.Template.PodSpec.Spec.Containers) != len(s.Template.PodSpec.Spec.Containers) {
+			a.log.Info().Msgf("Invalid size of containers")
+			return false
+		}
+
+		for id := range obj.Spec.Template.PodSpec.Spec.Containers {
+			if obj.Spec.Template.PodSpec.Spec.Containers[id].Name == containerName {
+				if s.Template.PodSpec.Spec.Containers[id].Name != containerName {
+					a.log.Info().Msgf("Invalid order of containers")
+					return false
+				}
+
+				// TODO what if additional log level was added in the meantime
+				s.Template.PodSpec.Spec.Containers[id].Args = obj.Spec.Template.PodSpec.Spec.Containers[id].Args
+				return true
+			}
+		}
+
+		a.log.Info().Msgf("can not find the container")
+
+		return false
+	}
+
+	err := a.actionCtx.WithArangoMemberStatusUpdate(ctx, member.GetNamespace(), member.GetName(), updateMemberStatusArgs)
+	if err != nil {
+		return errors.WithMessage(err, "Error while updating member status")
+	}
+
+	return nil
+}
+
+// ReloadCachedStatus reloads the inspector cache when the action is done.
+func (a actionRuntimeContainerArgsUpdate) ReloadCachedStatus() bool {
+	return true
+}
+
+// Start starts the action for changing conditions on the provided member.
+func (a actionRuntimeContainerArgsUpdate) Start(ctx context.Context) (bool, error) {
+
+	m, ok := a.actionCtx.GetMemberStatusByID(a.action.MemberID)
+	if !ok {
+		a.log.Info().Msg("member is gone already")
+		return true, nil
+	}
+
+	if !m.Phase.IsReady() {
+		a.log.Info().Msg("Member is not ready, unable to run update operation")
+		return true, nil
+	}
+
+	containerName, ok := a.action.GetParam(rotation.ContainerName)
+	if !ok {
+		return true, nil
+	}
+
+	memberName := m.ArangoMemberName(a.actionCtx.GetName(), a.action.Group)
+	member, ok := a.actionCtx.GetCachedStatus().ArangoMember(memberName)
+	if !ok {
+		// TODO only event is created on the top of that func.
+		return false, errors.Errorf("ArangoMember %s not found", memberName)
+	}
+
+	pod, ok := a.actionCtx.GetCachedStatus().Pod(m.PodName)
+	if !ok {
+		a.log.Info().Str("podName", m.PodName).Msg("pod is not present")
+		return true, nil
+	}
+
+	var op cmpContainer = func(containerSpec core.Container, containerStatus core.Container) error {
+		//diff := util.GetDifference(containerSpec.Args, containerStatus.Args)
+		topicsLogLevel := map[string]string{}
+
+		for _, arg := range containerSpec.Args {
+			if !strings.HasPrefix(strings.TrimLeft(arg, " "), "--log.level") {
+				continue
+			}
+
+			// TODO
+			a.log.Info().Str("arg", arg).Msg("TEST TODO the arg has changed")
+
+			logLevelOption := k8sutil.ExtractStringToOptionPair(arg)
+			if len(logLevelOption.Value) > 0 {
+				logValueOption := k8sutil.ExtractStringToOptionPair(logLevelOption.Value)
+				if len(logValueOption.Value) > 0 {
+					// It is the topic log, e.g.: --log.level=request=INFO.
+					topicsLogLevel[logValueOption.Key] = logValueOption.Value
+				} else {
+					// It is the general log, e.g.: --log.level=INFO.
+					topicsLogLevel["general"] = logLevelOption.Value
+				}
+			}
+		}
+
+		// TODO how to disable old log topics?
+		// TODO how to set the general log level
+
+		if err := a.setLogLevel(ctx, topicsLogLevel); err != nil {
+			return errors.WithMessage(err, "can not set log level")
+		}
+
+		return nil
+	}
+
+	if err := checkContainer(member, pod, containerName, op); err != nil && err != api.NotFoundError {
+		return false, errors.WithMessagef(err, "can not check the container %s", containerName)
+	}
+
+	return true, nil
+}
+
+type cmpContainer func(spec core.Container, status core.Container) error
+
+func checkContainer(member *api.ArangoMember, pod *core.Pod, containerName string, action cmpContainer) error {
+	spec, status, err := validateMemberAndPod(member, pod)
+	if err != nil {
+		return err
+	}
+
+	ok, id := getIndexContainer(pod, spec, status, containerName)
+	if !ok {
+		return api.NotFoundError
+	}
+
+	return action(spec.Spec.Containers[id], status.Spec.Containers[id])
+}
+
+// getIndexContainer returns the index of the container from the list of containers.
+func getIndexContainer(pod *core.Pod, spec *core.PodTemplateSpec, status *core.PodTemplateSpec,
+	containerName string) (bool, int) {
+
+	for id := range pod.Spec.Containers {
+		if pod.Spec.Containers[id].Name != spec.Spec.Containers[id].Name ||
+			pod.Spec.Containers[id].Name != status.Spec.Containers[id].Name ||
+			pod.Spec.Containers[id].Name != containerName {
+
+			return true, id
+		}
+	}
+
+	return false, 0
+}
+
+func validateMemberAndPod(member *api.ArangoMember, pod *core.Pod) (*core.PodTemplateSpec, *core.PodTemplateSpec, error) {
+
+	if member.Spec.Template == nil || member.Spec.Template.PodSpec == nil {
+		return nil, nil, fmt.Errorf("member spec is not present")
+	}
+
+	if member.Status.Template == nil || member.Status.Template.PodSpec == nil {
+		return nil, nil, fmt.Errorf("member status is not present")
+	}
+
+	if len(pod.Spec.Containers) != len(member.Spec.Template.PodSpec.Spec.Containers) {
+		return nil, nil, fmt.Errorf("spec container count is not equal")
+	}
+
+	if len(pod.Spec.Containers) != len(member.Status.Template.PodSpec.Spec.Containers) {
+		return nil, nil, fmt.Errorf("status container count is not equal")
+	}
+
+	return member.Spec.Template.PodSpec, member.Status.Template.PodSpec, nil
+}
+
+// CheckProgress returns always true because it does not have to wait for any result.
+func (a actionRuntimeContainerArgsUpdate) CheckProgress(_ context.Context) (bool, bool, error) {
+	return true, false, nil
+}
+
+// setLogLevel sets the log's levels for the specific server.
+func (a actionRuntimeContainerArgsUpdate) setLogLevel(ctx context.Context, logLevels map[string]string) error {
+	if len(logLevels) == 0 {
+		return nil
+	}
+
+	ctxChild, cancel := context.WithTimeout(ctx, arangod.GetRequestTimeout())
+	defer cancel()
+	cli, err := a.actionCtx.GetServerClient(ctxChild, a.action.Group, a.action.MemberID)
+	if err != nil {
+		return err
+	}
+	conn := cli.Connection()
+
+	req, err := conn.NewRequest("PUT", "_admin/log/level")
+	if err != nil {
+		return err
+	}
+
+	if _, err := req.SetBody(logLevels); err != nil {
+		return err
+	}
+
+	ctxChild, cancel = context.WithTimeout(ctx, arangod.GetRequestTimeout())
+	defer cancel()
+	resp, err := conn.Do(ctxChild, req)
+	if err != nil {
+		return err
+	}
+
+	return resp.CheckStatus(200)
+}
diff --git a/pkg/deployment/reconcile/plan_executor.go b/pkg/deployment/reconcile/plan_executor.go
index 93a3c3ff2..7a0c6240b 100644
--- a/pkg/deployment/reconcile/plan_executor.go
+++ b/pkg/deployment/reconcile/plan_executor.go
@@ -188,7 +188,7 @@ func (d *Reconciler) executePlan(ctx context.Context, cachedStatus inspectorInte
 
 			if err := getActionPost(action, ctx); err != nil {
 				log.Err(err).Msgf("Post action failed")
-				return nil, true, errors.WithStack(err)
+				return nil, false, errors.WithStack(err)
 			}
 		} else {
 			if plan[0].StartTime.IsZero() {
diff --git a/pkg/deployment/rotation/arangod_containers.go b/pkg/deployment/rotation/arangod_containers.go
index 1883d76a4..1b891e328 100644
--- a/pkg/deployment/rotation/arangod_containers.go
+++ b/pkg/deployment/rotation/arangod_containers.go
@@ -1,7 +1,7 @@
 //
 // DISCLAIMER
 //
-// Copyright 2020 ArangoDB GmbH, Cologne, Germany
+// Copyright 2020-2021 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.
@@ -17,10 +17,17 @@
 //
 // Copyright holder is ArangoDB GmbH, Cologne, Germany
 //
+// Author Adam Janikowski
+// Author Tomasz Mielech
+//
 
 package rotation
 
 import (
+	"strings"
+
+	"github.com/arangodb/kube-arangodb/pkg/util"
+
 	api "github.com/arangodb/kube-arangodb/pkg/apis/deployment/v1"
 	"github.com/arangodb/kube-arangodb/pkg/util"
 	"github.com/arangodb/kube-arangodb/pkg/util/k8sutil"
@@ -42,7 +49,22 @@ func containersCompare(deploymentSpec api.DeploymentSpec, group api.ServerGroup,
 
 		for id := range a {
 			if ac, bc := &a[id], &b[id]; ac.Name == k8sutil.ServerContainerName && ac.Name == bc.Name {
-				// Nothing to do
+				foundLogLevelDifference := false
+				for _, arg := range util.GetDifference(ac.Args, bc.Args) {
+					if strings.HasPrefix(strings.TrimLeft(arg, " "), "--log.level") {
+						foundLogLevelDifference = true
+					}
+				}
+
+				if !foundLogLevelDifference {
+					continue
+				}
+
+				plan = append(plan, builder.NewAction(api.ActionTypeRuntimeContainerArgsLogLevelUpdate).
+					AddParam(ContainerName, ac.Name))
+
+				bc.Args = ac.Args
+				mode = mode.And(InPlaceRotation)
 			} else if ac.Name == bc.Name {
 				if ac.Image != bc.Image {
 					// Image changed
diff --git a/pkg/deployment/rotation/arangod_containers_test.go b/pkg/deployment/rotation/arangod_containers_test.go
index f788a82e0..e83bacdf7 100644
--- a/pkg/deployment/rotation/arangod_containers_test.go
+++ b/pkg/deployment/rotation/arangod_containers_test.go
@@ -144,3 +144,5 @@ func Test_InitContainers(t *testing.T) {
 		runTestCases(t)(testCases...)
 	})
 }
+
+// TODO unit tests for changed args
diff --git a/pkg/deployment/rotation/check.go b/pkg/deployment/rotation/check.go
index 628c2f149..df2312e14 100644
--- a/pkg/deployment/rotation/check.go
+++ b/pkg/deployment/rotation/check.go
@@ -41,6 +41,7 @@ const (
 	EnforcedRotation
 )
 
+// And returns the higher value of the rotation mode.
 func (m Mode) And(b Mode) Mode {
 	if m > b {
 		return m
diff --git a/pkg/util/k8sutil/pair.go b/pkg/util/k8sutil/pair.go
index 406294387..39abf3489 100644
--- a/pkg/util/k8sutil/pair.go
+++ b/pkg/util/k8sutil/pair.go
@@ -162,3 +162,17 @@ func (o OptionPair) CompareTo(other OptionPair) int {
 func NewOptionPair(pairs ...OptionPair) OptionPairs {
 	return pairs
 }
+
+// TODO test desc
+func ExtractStringToOptionPair(arg string) OptionPair {
+	trimmed := strings.Trim(arg, " ")
+	index := strings.Index(trimmed, "=")
+	if index < 0 {
+		return OptionPair{Key: trimmed}
+	}
+
+	return OptionPair{
+		Key:   trimmed[0:index],
+		Value: trimmed[index:],
+	}
+}
diff --git a/pkg/util/strings.go b/pkg/util/strings.go
index 20a5446a9..52bc76126 100644
--- a/pkg/util/strings.go
+++ b/pkg/util/strings.go
@@ -63,3 +63,20 @@ func PrefixStringArray(a []string, prefix string) []string {
 
 	return b
 }
+
+// GetDifference returns the elements in `compareWhat` that are not in `compareTo`.
+func GetDifference(compareWhat, compareTo []string) []string {
+	mb := make(map[string]struct{}, len(compareTo))
+	for _, x := range compareTo {
+		mb[x] = struct{}{}
+	}
+
+	var diff []string
+	for _, x := range compareWhat {
+		if _, found := mb[x]; !found {
+			diff = append(diff, x)
+		}
+	}
+
+	return diff
+}

From 5e17927e2536212efe7b69de8acd959b5de5f0cd Mon Sep 17 00:00:00 2001
From: Tomasz Mielech <informal.ict@gmail.com>
Date: Thu, 16 Sep 2021 20:32:27 +0200
Subject: [PATCH 02/14] fix checking the container name

---
 .../action_runtime_container_args_udpate.go   | 21 ++++++++-----------
 pkg/deployment/reconcile/plan_executor.go     |  3 +--
 pkg/deployment/rotation/arangod_containers.go |  4 +---
 3 files changed, 11 insertions(+), 17 deletions(-)

diff --git a/pkg/deployment/reconcile/action_runtime_container_args_udpate.go b/pkg/deployment/reconcile/action_runtime_container_args_udpate.go
index 56da29dd0..f4e9d8aa0 100644
--- a/pkg/deployment/reconcile/action_runtime_container_args_udpate.go
+++ b/pkg/deployment/reconcile/action_runtime_container_args_udpate.go
@@ -145,7 +145,6 @@ func (a actionRuntimeContainerArgsUpdate) Start(ctx context.Context) (bool, erro
 	memberName := m.ArangoMemberName(a.actionCtx.GetName(), a.action.Group)
 	member, ok := a.actionCtx.GetCachedStatus().ArangoMember(memberName)
 	if !ok {
-		// TODO only event is created on the top of that func.
 		return false, errors.Errorf("ArangoMember %s not found", memberName)
 	}
 
@@ -164,9 +163,6 @@ func (a actionRuntimeContainerArgsUpdate) Start(ctx context.Context) (bool, erro
 				continue
 			}
 
-			// TODO
-			a.log.Info().Str("arg", arg).Msg("TEST TODO the arg has changed")
-
 			logLevelOption := k8sutil.ExtractStringToOptionPair(arg)
 			if len(logLevelOption.Value) > 0 {
 				logValueOption := k8sutil.ExtractStringToOptionPair(logLevelOption.Value)
@@ -180,6 +176,7 @@ func (a actionRuntimeContainerArgsUpdate) Start(ctx context.Context) (bool, erro
 			}
 		}
 
+		// TODO
 		// TODO how to disable old log topics?
 		// TODO how to set the general log level
 
@@ -205,8 +202,8 @@ func checkContainer(member *api.ArangoMember, pod *core.Pod, containerName strin
 		return err
 	}
 
-	ok, id := getIndexContainer(pod, spec, status, containerName)
-	if !ok {
+	id := getIndexContainer(pod, spec, status, containerName)
+	if id < 0 {
 		return api.NotFoundError
 	}
 
@@ -215,18 +212,18 @@ func checkContainer(member *api.ArangoMember, pod *core.Pod, containerName strin
 
 // getIndexContainer returns the index of the container from the list of containers.
 func getIndexContainer(pod *core.Pod, spec *core.PodTemplateSpec, status *core.PodTemplateSpec,
-	containerName string) (bool, int) {
+	containerName string) int {
 
 	for id := range pod.Spec.Containers {
-		if pod.Spec.Containers[id].Name != spec.Spec.Containers[id].Name ||
-			pod.Spec.Containers[id].Name != status.Spec.Containers[id].Name ||
-			pod.Spec.Containers[id].Name != containerName {
+		if pod.Spec.Containers[id].Name == spec.Spec.Containers[id].Name ||
+			pod.Spec.Containers[id].Name == status.Spec.Containers[id].Name ||
+			pod.Spec.Containers[id].Name == containerName {
 
-			return true, id
+			return id
 		}
 	}
 
-	return false, 0
+	return -1
 }
 
 func validateMemberAndPod(member *api.ArangoMember, pod *core.Pod) (*core.PodTemplateSpec, *core.PodTemplateSpec, error) {
diff --git a/pkg/deployment/reconcile/plan_executor.go b/pkg/deployment/reconcile/plan_executor.go
index 7a0c6240b..ddb61afdb 100644
--- a/pkg/deployment/reconcile/plan_executor.go
+++ b/pkg/deployment/reconcile/plan_executor.go
@@ -206,8 +206,7 @@ func (d *Reconciler) executeAction(ctx context.Context, log zerolog.Logger, plan
 		// Not started yet
 		ready, err := action.Start(ctx)
 		if err != nil {
-			log.Debug().Err(err).
-				Msg("Failed to start action")
+			log.Error().Err(err).Msg("Failed to start action")
 			return false, false, false, errors.WithStack(err)
 		}
 
diff --git a/pkg/deployment/rotation/arangod_containers.go b/pkg/deployment/rotation/arangod_containers.go
index 1b891e328..aea681b56 100644
--- a/pkg/deployment/rotation/arangod_containers.go
+++ b/pkg/deployment/rotation/arangod_containers.go
@@ -26,8 +26,6 @@ package rotation
 import (
 	"strings"
 
-	"github.com/arangodb/kube-arangodb/pkg/util"
-
 	api "github.com/arangodb/kube-arangodb/pkg/apis/deployment/v1"
 	"github.com/arangodb/kube-arangodb/pkg/util"
 	"github.com/arangodb/kube-arangodb/pkg/util/k8sutil"
@@ -39,7 +37,7 @@ const (
 	ContainerImage = "image"
 )
 
-func containersCompare(deploymentSpec api.DeploymentSpec, group api.ServerGroup, spec, status *core.PodSpec) compareFunc {
+func containersCompare(_ api.DeploymentSpec, _ api.ServerGroup, spec, status *core.PodSpec) compareFunc {
 	return func(builder api.ActionBuilder) (mode Mode, plan api.Plan, err error) {
 		a, b := spec.Containers, status.Containers
 

From d8b53828be710b39ee7b4a09529be3aa7895d49d Mon Sep 17 00:00:00 2001
From: Tomasz Mielech <informal.ict@gmail.com>
Date: Fri, 17 Sep 2021 14:58:06 +0200
Subject: [PATCH 03/14] use commands instead of args

---
 .../action_runtime_container_args_udpate.go   | 11 ++----
 pkg/deployment/rotation/arangod_containers.go | 13 ++++---
 .../rotation/arangod_containers_test.go       | 34 ++++++++++++++++---
 pkg/deployment/rotation/compare.go            | 24 ++++++-------
 pkg/deployment/rotation/utils_test.go         |  6 ++++
 pkg/util/k8sutil/pair.go                      |  4 +--
 6 files changed, 60 insertions(+), 32 deletions(-)

diff --git a/pkg/deployment/reconcile/action_runtime_container_args_udpate.go b/pkg/deployment/reconcile/action_runtime_container_args_udpate.go
index f4e9d8aa0..0ad91b92a 100644
--- a/pkg/deployment/reconcile/action_runtime_container_args_udpate.go
+++ b/pkg/deployment/reconcile/action_runtime_container_args_udpate.go
@@ -99,8 +99,7 @@ func (a actionRuntimeContainerArgsUpdate) Post(ctx context.Context) error {
 					return false
 				}
 
-				// TODO what if additional log level was added in the meantime
-				s.Template.PodSpec.Spec.Containers[id].Args = obj.Spec.Template.PodSpec.Spec.Containers[id].Args
+				s.Template.PodSpec.Spec.Containers[id].Command = obj.Spec.Template.PodSpec.Spec.Containers[id].Command
 				return true
 			}
 		}
@@ -155,10 +154,9 @@ func (a actionRuntimeContainerArgsUpdate) Start(ctx context.Context) (bool, erro
 	}
 
 	var op cmpContainer = func(containerSpec core.Container, containerStatus core.Container) error {
-		//diff := util.GetDifference(containerSpec.Args, containerStatus.Args)
 		topicsLogLevel := map[string]string{}
 
-		for _, arg := range containerSpec.Args {
+		for _, arg := range containerSpec.Command {
 			if !strings.HasPrefix(strings.TrimLeft(arg, " "), "--log.level") {
 				continue
 			}
@@ -176,14 +174,11 @@ func (a actionRuntimeContainerArgsUpdate) Start(ctx context.Context) (bool, erro
 			}
 		}
 
-		// TODO
-		// TODO how to disable old log topics?
-		// TODO how to set the general log level
-
 		if err := a.setLogLevel(ctx, topicsLogLevel); err != nil {
 			return errors.WithMessage(err, "can not set log level")
 		}
 
+		a.log.Info().Interface("topics", topicsLogLevel).Msg("send log level to the ArangoDB")
 		return nil
 	}
 
diff --git a/pkg/deployment/rotation/arangod_containers.go b/pkg/deployment/rotation/arangod_containers.go
index aea681b56..ded68f755 100644
--- a/pkg/deployment/rotation/arangod_containers.go
+++ b/pkg/deployment/rotation/arangod_containers.go
@@ -47,21 +47,24 @@ func containersCompare(_ api.DeploymentSpec, _ api.ServerGroup, spec, status *co
 
 		for id := range a {
 			if ac, bc := &a[id], &b[id]; ac.Name == k8sutil.ServerContainerName && ac.Name == bc.Name {
-				foundLogLevelDifference := false
-				for _, arg := range util.GetDifference(ac.Args, bc.Args) {
+				onlyLogLevelArgsChanged := false
+				for _, arg := range util.GetDifference(ac.Command, bc.Command) {
 					if strings.HasPrefix(strings.TrimLeft(arg, " "), "--log.level") {
-						foundLogLevelDifference = true
+						onlyLogLevelArgsChanged = true
+					} else {
+						onlyLogLevelArgsChanged = false
+						break
 					}
 				}
 
-				if !foundLogLevelDifference {
+				if !onlyLogLevelArgsChanged {
 					continue
 				}
 
 				plan = append(plan, builder.NewAction(api.ActionTypeRuntimeContainerArgsLogLevelUpdate).
 					AddParam(ContainerName, ac.Name))
 
-				bc.Args = ac.Args
+				bc.Command = ac.Command
 				mode = mode.And(InPlaceRotation)
 			} else if ac.Name == bc.Name {
 				if ac.Image != bc.Image {
diff --git a/pkg/deployment/rotation/arangod_containers_test.go b/pkg/deployment/rotation/arangod_containers_test.go
index e83bacdf7..09d12987d 100644
--- a/pkg/deployment/rotation/arangod_containers_test.go
+++ b/pkg/deployment/rotation/arangod_containers_test.go
@@ -23,11 +23,10 @@ package rotation
 import (
 	"testing"
 
-	"github.com/arangodb/kube-arangodb/pkg/util/k8sutil"
-
 	v1 "k8s.io/api/core/v1"
 
 	api "github.com/arangodb/kube-arangodb/pkg/apis/deployment/v1"
+	"github.com/arangodb/kube-arangodb/pkg/util/k8sutil"
 )
 
 func Test_ArangoDContainers_SidecarImages(t *testing.T) {
@@ -52,6 +51,35 @@ func Test_ArangoDContainers_SidecarImages(t *testing.T) {
 				api.NewAction(api.ActionTypeRuntimeContainerImageUpdate, 0, ""),
 			},
 		},
+		{
+			name: "Only log level arguments of the ArangoDB server have been changed",
+			spec: buildPodSpec(addContainerWithArgs(k8sutil.ServerContainerName,
+				[]string{"--log.level=INFO", "--log.level=requests=error"})),
+			status:       buildPodSpec(addContainerWithArgs(k8sutil.ServerContainerName, []string{"--log.level=INFO"})),
+			expectedMode: InPlaceRotation,
+			expectedPlan: api.Plan{
+				api.NewAction(api.ActionTypeRuntimeContainerArgsLogLevelUpdate, 0, ""),
+			},
+		},
+		{
+			name: "Only log level arguments of the Sidecar have been changed",
+			spec: buildPodSpec(addContainerWithArgs("sidecar",
+				[]string{"--log.level=INFO", "--log.level=requests=error"})),
+			status:       buildPodSpec(addContainerWithArgs("sidecar", []string{"--log.level=INFO"})),
+			expectedMode: GracefulRotation,
+		},
+		{
+			name:   "ArangoDB server arguments have not been changed",
+			spec:   buildPodSpec(addContainerWithArgs(k8sutil.ServerContainerName, []string{"--log.level=INFO"})),
+			status: buildPodSpec(addContainerWithArgs(k8sutil.ServerContainerName, []string{"--log.level=INFO"})),
+		},
+		{
+			name: "Not only log level arguments of the ArangoDB server have been changed",
+			spec: buildPodSpec(addContainerWithArgs(k8sutil.ServerContainerName, []string{"--log.level=INFO",
+				"--server.endpoint=localhost"})),
+			status:       buildPodSpec(addContainerWithArgs(k8sutil.ServerContainerName, []string{"--log.level=INFO"})),
+			expectedMode: GracefulRotation,
+		},
 	}
 
 	runTestCases(t)(testCases...)
@@ -144,5 +172,3 @@ func Test_InitContainers(t *testing.T) {
 		runTestCases(t)(testCases...)
 	})
 }
-
-// TODO unit tests for changed args
diff --git a/pkg/deployment/rotation/compare.go b/pkg/deployment/rotation/compare.go
index 71c01db8f..0c1632885 100644
--- a/pkg/deployment/rotation/compare.go
+++ b/pkg/deployment/rotation/compare.go
@@ -21,8 +21,6 @@
 package rotation
 
 import (
-	"encoding/json"
-
 	api "github.com/arangodb/kube-arangodb/pkg/apis/deployment/v1"
 	"github.com/arangodb/kube-arangodb/pkg/deployment/resources"
 	"github.com/rs/zerolog"
@@ -51,7 +49,9 @@ func compareFuncs(builder api.ActionBuilder, f ...compareFunc) (mode Mode, plan
 	return
 }
 
-func compare(log zerolog.Logger, deploymentSpec api.DeploymentSpec, member api.MemberStatus, group api.ServerGroup, spec, status *api.ArangoMemberPodTemplate) (mode Mode, plan api.Plan, err error) {
+func compare(log zerolog.Logger, deploymentSpec api.DeploymentSpec, member api.MemberStatus, group api.ServerGroup,
+	spec, status *api.ArangoMemberPodTemplate) (mode Mode, plan api.Plan, err error) {
+
 	if spec.Checksum == status.Checksum {
 		return SkippedRotation, nil, nil
 	}
@@ -79,21 +79,19 @@ func compare(log zerolog.Logger, deploymentSpec api.DeploymentSpec, member api.M
 		return SkippedRotation, nil, err
 	}
 
-	newSpec, err := api.GetArangoMemberPodTemplate(podStatus, checksum)
+	newStatus, err := api.GetArangoMemberPodTemplate(podStatus, checksum)
 	if err != nil {
 		log.Err(err).Msg("Error while getting template")
 		return SkippedRotation, nil, err
 	}
 
-	if spec.RotationNeeded(newSpec) {
-		l := log.Info().Str("id", member.ID).Str("Before", spec.PodSpecChecksum)
-		if d, err := json.Marshal(status); err == nil {
-			l = l.Str("status", string(d))
-		}
-		if d, err := json.Marshal(newSpec); err == nil {
-			l = l.Str("spec", string(d))
-		}
-		l.Msgf("Pod needs rotation - templates does not match")
+	if spec.RotationNeeded(newStatus) {
+		log.Info().Str("before", spec.PodSpecChecksum).
+			Str("id", member.ID).
+			Interface("spec", spec).
+			Interface("status", newStatus).
+			Msg("Pod needs rotation - templates does not match")
+
 		return GracefulRotation, nil, nil
 	}
 
diff --git a/pkg/deployment/rotation/utils_test.go b/pkg/deployment/rotation/utils_test.go
index 14c82d8f3..0556bac24 100644
--- a/pkg/deployment/rotation/utils_test.go
+++ b/pkg/deployment/rotation/utils_test.go
@@ -127,6 +127,12 @@ func addSidecarWithImage(name, image string) podSpecBuilder {
 	})
 }
 
+func addContainerWithArgs(name string, args []string) podSpecBuilder {
+	return addContainer(name, func(c *core.Container) {
+		c.Args = args
+	})
+}
+
 type deploymentBuilder func(depl *api.DeploymentSpec)
 
 func buildDeployment(b ...deploymentBuilder) api.DeploymentSpec {
diff --git a/pkg/util/k8sutil/pair.go b/pkg/util/k8sutil/pair.go
index 39abf3489..79cfc4d47 100644
--- a/pkg/util/k8sutil/pair.go
+++ b/pkg/util/k8sutil/pair.go
@@ -163,7 +163,7 @@ func NewOptionPair(pairs ...OptionPair) OptionPairs {
 	return pairs
 }
 
-// TODO test desc
+// TODO test desc + UT
 func ExtractStringToOptionPair(arg string) OptionPair {
 	trimmed := strings.Trim(arg, " ")
 	index := strings.Index(trimmed, "=")
@@ -173,6 +173,6 @@ func ExtractStringToOptionPair(arg string) OptionPair {
 
 	return OptionPair{
 		Key:   trimmed[0:index],
-		Value: trimmed[index:],
+		Value: trimmed[index+1:],
 	}
 }

From 12e657fb7ea0ac28d1ffda9752145b33437119d1 Mon Sep 17 00:00:00 2001
From: Tomasz Mielech <informal.ict@gmail.com>
Date: Fri, 17 Sep 2021 15:43:40 +0200
Subject: [PATCH 04/14] add unit tests

---
 pkg/util/k8sutil/pair.go      |  8 ++--
 pkg/util/k8sutil/pair_test.go | 78 +++++++++++++++++++++++++++++++++++
 2 files changed, 82 insertions(+), 4 deletions(-)
 create mode 100644 pkg/util/k8sutil/pair_test.go

diff --git a/pkg/util/k8sutil/pair.go b/pkg/util/k8sutil/pair.go
index 79cfc4d47..12938d2e4 100644
--- a/pkg/util/k8sutil/pair.go
+++ b/pkg/util/k8sutil/pair.go
@@ -163,16 +163,16 @@ func NewOptionPair(pairs ...OptionPair) OptionPairs {
 	return pairs
 }
 
-// TODO test desc + UT
+// ExtractStringToOptionPair extracts command line argument into the OptionPair.
 func ExtractStringToOptionPair(arg string) OptionPair {
-	trimmed := strings.Trim(arg, " ")
+	trimmed := strings.TrimLeft(arg, " ")
 	index := strings.Index(trimmed, "=")
 	if index < 0 {
-		return OptionPair{Key: trimmed}
+		return OptionPair{Key: strings.TrimRight(trimmed, " ")}
 	}
 
 	return OptionPair{
-		Key:   trimmed[0:index],
+		Key:   strings.Trim(trimmed[0:index], " "),
 		Value: trimmed[index+1:],
 	}
 }
diff --git a/pkg/util/k8sutil/pair_test.go b/pkg/util/k8sutil/pair_test.go
new file mode 100644
index 000000000..94dec5017
--- /dev/null
+++ b/pkg/util/k8sutil/pair_test.go
@@ -0,0 +1,78 @@
+//
+// DISCLAIMER
+//
+// Copyright 2021 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 Tomasz Mielech
+//
+
+package k8sutil
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestExtractStringToOptionPair(t *testing.T) {
+	tests := map[string]struct {
+		arg  string
+		want OptionPair
+	}{
+		"empty argument": {},
+		"not trimmed key argument on the left side": {
+			arg: "           --log.level=requests=debug",
+			want: OptionPair{
+				Key:   "--log.level",
+				Value: "requests=debug",
+			},
+		},
+		"key argument not trimmed on the both sides": {
+			arg: "           --log.level   =requests=debug",
+			want: OptionPair{
+				Key:   "--log.level",
+				Value: "requests=debug",
+			},
+		},
+		"key argument not trimmed on the both sides without value": {
+			arg: "  --log.level  ",
+			want: OptionPair{
+				Key: "--log.level",
+			},
+		},
+		"key argument not trimmed on the both sides without value with equal": {
+			arg: "  --log.level =",
+			want: OptionPair{
+				Key: "--log.level",
+			},
+		},
+		"key argument not trimmed on the right side with some value": {
+			arg: "--log.level =  value   ",
+			want: OptionPair{
+				Key:   "--log.level",
+				Value: "  value   ",
+			},
+		},
+	}
+
+	for testName, testCase := range tests {
+		t.Run(testName, func(t *testing.T) {
+			got := ExtractStringToOptionPair(testCase.arg)
+			assert.Equal(t, testCase.want, got)
+		})
+	}
+}

From acedcb2b06c84f43103fe04c87c78728f253566d Mon Sep 17 00:00:00 2001
From: Tomasz Mielech <informal.ict@gmail.com>
Date: Sat, 18 Sep 2021 22:00:34 +0200
Subject: [PATCH 05/14] turn off removed log levels topics

---
 .../action_runtime_container_args_udpate.go   | 45 +++++++++++++------
 1 file changed, 32 insertions(+), 13 deletions(-)

diff --git a/pkg/deployment/reconcile/action_runtime_container_args_udpate.go b/pkg/deployment/reconcile/action_runtime_container_args_udpate.go
index 0ad91b92a..68fb9072f 100644
--- a/pkg/deployment/reconcile/action_runtime_container_args_udpate.go
+++ b/pkg/deployment/reconcile/action_runtime_container_args_udpate.go
@@ -33,6 +33,7 @@ import (
 
 	api "github.com/arangodb/kube-arangodb/pkg/apis/deployment/v1"
 	"github.com/arangodb/kube-arangodb/pkg/deployment/rotation"
+	"github.com/arangodb/kube-arangodb/pkg/util"
 	"github.com/arangodb/kube-arangodb/pkg/util/arangod"
 	"github.com/arangodb/kube-arangodb/pkg/util/k8sutil"
 )
@@ -156,21 +157,18 @@ func (a actionRuntimeContainerArgsUpdate) Start(ctx context.Context) (bool, erro
 	var op cmpContainer = func(containerSpec core.Container, containerStatus core.Container) error {
 		topicsLogLevel := map[string]string{}
 
-		for _, arg := range containerSpec.Command {
-			if !strings.HasPrefix(strings.TrimLeft(arg, " "), "--log.level") {
-				continue
+		// Set log levels to INFO for topics which were removed from the spec.
+		statusDiff := util.GetDifference(containerStatus.Command, containerSpec.Command)
+		for _, arg := range statusDiff {
+			if ok, topic, _ := getTopicAndLevel(arg); ok {
+				topicsLogLevel[topic] = "INFO"
 			}
+		}
 
-			logLevelOption := k8sutil.ExtractStringToOptionPair(arg)
-			if len(logLevelOption.Value) > 0 {
-				logValueOption := k8sutil.ExtractStringToOptionPair(logLevelOption.Value)
-				if len(logValueOption.Value) > 0 {
-					// It is the topic log, e.g.: --log.level=request=INFO.
-					topicsLogLevel[logValueOption.Key] = logValueOption.Value
-				} else {
-					// It is the general log, e.g.: --log.level=INFO.
-					topicsLogLevel["general"] = logLevelOption.Value
-				}
+		// Set log levels from the provided spec.
+		for _, arg := range containerSpec.Command {
+			if ok, topic, value := getTopicAndLevel(arg); ok {
+				topicsLogLevel[topic] = value
 			}
 		}
 
@@ -279,3 +277,24 @@ func (a actionRuntimeContainerArgsUpdate) setLogLevel(ctx context.Context, logLe
 
 	return resp.CheckStatus(200)
 }
+
+// getTopicAndLevel returns topics and log level from the argument.
+func getTopicAndLevel(arg string) (bool, string, string) {
+	if !strings.HasPrefix(strings.TrimLeft(arg, " "), "--log.level") {
+		return false, "", ""
+	}
+
+	logLevelOption := k8sutil.ExtractStringToOptionPair(arg)
+	if len(logLevelOption.Value) > 0 {
+		logValueOption := k8sutil.ExtractStringToOptionPair(logLevelOption.Value)
+		if len(logValueOption.Value) > 0 {
+			// It is the topic log, e.g.: --log.level=request=INFO.
+			return true, logValueOption.Key, logValueOption.Value
+		} else {
+			// It is the general log, e.g.: --log.level=INFO.
+			return true, "general", logLevelOption.Value
+		}
+	}
+
+	return false, "", ""
+}

From 10d5706b454e7707b881e0ec1852a88c63f76a68 Mon Sep 17 00:00:00 2001
From: Tomasz Mielech <informal.ict@gmail.com>
Date: Sun, 19 Sep 2021 13:10:47 +0200
Subject: [PATCH 06/14] compare status args to the spec args

---
 pkg/deployment/rotation/arangod_containers.go | 36 +++++++++++++------
 pkg/util/strings.go                           |  6 ++--
 2 files changed, 28 insertions(+), 14 deletions(-)

diff --git a/pkg/deployment/rotation/arangod_containers.go b/pkg/deployment/rotation/arangod_containers.go
index ded68f755..7c48715fd 100644
--- a/pkg/deployment/rotation/arangod_containers.go
+++ b/pkg/deployment/rotation/arangod_containers.go
@@ -47,17 +47,7 @@ func containersCompare(_ api.DeploymentSpec, _ api.ServerGroup, spec, status *co
 
 		for id := range a {
 			if ac, bc := &a[id], &b[id]; ac.Name == k8sutil.ServerContainerName && ac.Name == bc.Name {
-				onlyLogLevelArgsChanged := false
-				for _, arg := range util.GetDifference(ac.Command, bc.Command) {
-					if strings.HasPrefix(strings.TrimLeft(arg, " "), "--log.level") {
-						onlyLogLevelArgsChanged = true
-					} else {
-						onlyLogLevelArgsChanged = false
-						break
-					}
-				}
-
-				if !onlyLogLevelArgsChanged {
+				if !IsOnlyLogLevelChanged(ac.Command, bc.Command) {
 					continue
 				}
 
@@ -123,3 +113,27 @@ func initContainersCompare(deploymentSpec api.DeploymentSpec, group api.ServerGr
 		return
 	}
 }
+
+// IsOnlyLogLevelChanged returns true when status and spec log level arguments are different.
+// If any other argument than --log.level is different false is returned.
+func IsOnlyLogLevelChanged(specArgs, statusArgs []string) bool {
+	diffSpec := util.GetDifference(specArgs, statusArgs)
+	for _, arg := range diffSpec {
+		if !strings.HasPrefix(strings.TrimLeft(arg, " "), "--log.level") {
+			return false
+		}
+	}
+
+	diffStatus := util.GetDifference(statusArgs, specArgs)
+	for _, arg := range diffStatus {
+		if !strings.HasPrefix(strings.TrimLeft(arg, " "), "--log.level") {
+			return false
+		}
+	}
+
+	if len(diffSpec) == 0 && len(diffStatus) == 0 {
+		return false
+	}
+
+	return true
+}
diff --git a/pkg/util/strings.go b/pkg/util/strings.go
index 52bc76126..310746f6d 100644
--- a/pkg/util/strings.go
+++ b/pkg/util/strings.go
@@ -66,14 +66,14 @@ func PrefixStringArray(a []string, prefix string) []string {
 
 // GetDifference returns the elements in `compareWhat` that are not in `compareTo`.
 func GetDifference(compareWhat, compareTo []string) []string {
-	mb := make(map[string]struct{}, len(compareTo))
+	compareToMap := make(map[string]struct{}, len(compareTo))
 	for _, x := range compareTo {
-		mb[x] = struct{}{}
+		compareToMap[x] = struct{}{}
 	}
 
 	var diff []string
 	for _, x := range compareWhat {
-		if _, found := mb[x]; !found {
+		if _, found := compareToMap[x]; !found {
 			diff = append(diff, x)
 		}
 	}

From e5ea22f712b878c4f444a0facdc96b421039020f Mon Sep 17 00:00:00 2001
From: Tomasz Mielech <informal.ict@gmail.com>
Date: Sun, 19 Sep 2021 21:15:52 +0200
Subject: [PATCH 07/14] update checksum for the status

---
 .../action_runtime_container_args_udpate.go   | 27 ++++++++++++++-----
 1 file changed, 21 insertions(+), 6 deletions(-)

diff --git a/pkg/deployment/reconcile/action_runtime_container_args_udpate.go b/pkg/deployment/reconcile/action_runtime_container_args_udpate.go
index 68fb9072f..e8868f1f6 100644
--- a/pkg/deployment/reconcile/action_runtime_container_args_udpate.go
+++ b/pkg/deployment/reconcile/action_runtime_container_args_udpate.go
@@ -32,6 +32,7 @@ import (
 	core "k8s.io/api/core/v1"
 
 	api "github.com/arangodb/kube-arangodb/pkg/apis/deployment/v1"
+	"github.com/arangodb/kube-arangodb/pkg/deployment/resources"
 	"github.com/arangodb/kube-arangodb/pkg/deployment/rotation"
 	"github.com/arangodb/kube-arangodb/pkg/util"
 	"github.com/arangodb/kube-arangodb/pkg/util/arangod"
@@ -61,8 +62,6 @@ type actionRuntimeContainerArgsUpdate struct {
 // Post updates arguments for the specific Arango member.
 func (a actionRuntimeContainerArgsUpdate) Post(ctx context.Context) error {
 
-	a.log.Info().Msgf("Updating container args")
-
 	m, ok := a.actionCtx.GetMemberStatusByID(a.action.MemberID)
 	if !ok {
 		a.log.Info().Msg("member is gone already")
@@ -81,31 +80,47 @@ func (a actionRuntimeContainerArgsUpdate) Post(ctx context.Context) error {
 		return nil
 	}
 
+	log := a.log.With().Str("containerName", containerName).Logger()
 	updateMemberStatusArgs := func(obj *api.ArangoMember, s *api.ArangoMemberStatus) bool {
 		if obj.Spec.Template == nil || s.Template == nil ||
 			obj.Spec.Template.PodSpec == nil || s.Template.PodSpec == nil {
-			a.log.Info().Msgf("Nil Member definition")
+			log.Info().Msgf("Nil Member definition")
 			return false
 		}
 
 		if len(obj.Spec.Template.PodSpec.Spec.Containers) != len(s.Template.PodSpec.Spec.Containers) {
-			a.log.Info().Msgf("Invalid size of containers")
+			log.Info().Msgf("Invalid size of containers")
 			return false
 		}
 
 		for id := range obj.Spec.Template.PodSpec.Spec.Containers {
 			if obj.Spec.Template.PodSpec.Spec.Containers[id].Name == containerName {
 				if s.Template.PodSpec.Spec.Containers[id].Name != containerName {
-					a.log.Info().Msgf("Invalid order of containers")
+					log.Info().Msgf("Invalid order of containers")
 					return false
 				}
 
 				s.Template.PodSpec.Spec.Containers[id].Command = obj.Spec.Template.PodSpec.Spec.Containers[id].Command
+				groupSpec := a.actionCtx.GetSpec().GetServerGroupSpec(a.action.Group)
+				checksum, err := resources.ChecksumArangoPod(groupSpec,
+					resources.CreatePodFromTemplate(obj.Spec.Template.PodSpec))
+				if err != nil {
+					log.Error().Err(err).Msg("Error while getting pod checksum")
+					return false
+				}
+
+				newStatus, err := api.GetArangoMemberPodTemplate(s.Template.PodSpec, checksum)
+				if err != nil {
+					log.Error().Err(err).Msg("Error while getting template")
+					return false
+				}
+				s.Template = newStatus
+				log.Info().Msgf("Updating container args")
 				return true
 			}
 		}
 
-		a.log.Info().Msgf("can not find the container")
+		log.Info().Msgf("can not find the container")
 
 		return false
 	}

From a9a006e12dd632813c83eaa205b1c51661fa7447 Mon Sep 17 00:00:00 2001
From: Tomasz Mielech <informal.ict@gmail.com>
Date: Mon, 20 Sep 2021 15:48:12 +0200
Subject: [PATCH 08/14] use default silent rotation

---
 .../action_runtime_container_args_udpate.go   | 31 +++++--------------
 pkg/deployment/rotation/arangod_containers.go |  4 +--
 pkg/deployment/rotation/compare.go            |  4 ++-
 pkg/util/strings.go                           |  4 +--
 4 files changed, 15 insertions(+), 28 deletions(-)

diff --git a/pkg/deployment/reconcile/action_runtime_container_args_udpate.go b/pkg/deployment/reconcile/action_runtime_container_args_udpate.go
index e8868f1f6..3ea6eb034 100644
--- a/pkg/deployment/reconcile/action_runtime_container_args_udpate.go
+++ b/pkg/deployment/reconcile/action_runtime_container_args_udpate.go
@@ -32,9 +32,7 @@ import (
 	core "k8s.io/api/core/v1"
 
 	api "github.com/arangodb/kube-arangodb/pkg/apis/deployment/v1"
-	"github.com/arangodb/kube-arangodb/pkg/deployment/resources"
 	"github.com/arangodb/kube-arangodb/pkg/deployment/rotation"
-	"github.com/arangodb/kube-arangodb/pkg/util"
 	"github.com/arangodb/kube-arangodb/pkg/util/arangod"
 	"github.com/arangodb/kube-arangodb/pkg/util/k8sutil"
 )
@@ -101,20 +99,6 @@ func (a actionRuntimeContainerArgsUpdate) Post(ctx context.Context) error {
 				}
 
 				s.Template.PodSpec.Spec.Containers[id].Command = obj.Spec.Template.PodSpec.Spec.Containers[id].Command
-				groupSpec := a.actionCtx.GetSpec().GetServerGroupSpec(a.action.Group)
-				checksum, err := resources.ChecksumArangoPod(groupSpec,
-					resources.CreatePodFromTemplate(obj.Spec.Template.PodSpec))
-				if err != nil {
-					log.Error().Err(err).Msg("Error while getting pod checksum")
-					return false
-				}
-
-				newStatus, err := api.GetArangoMemberPodTemplate(s.Template.PodSpec, checksum)
-				if err != nil {
-					log.Error().Err(err).Msg("Error while getting template")
-					return false
-				}
-				s.Template = newStatus
 				log.Info().Msgf("Updating container args")
 				return true
 			}
@@ -172,13 +156,14 @@ func (a actionRuntimeContainerArgsUpdate) Start(ctx context.Context) (bool, erro
 	var op cmpContainer = func(containerSpec core.Container, containerStatus core.Container) error {
 		topicsLogLevel := map[string]string{}
 
-		// Set log levels to INFO for topics which were removed from the spec.
-		statusDiff := util.GetDifference(containerStatus.Command, containerSpec.Command)
-		for _, arg := range statusDiff {
-			if ok, topic, _ := getTopicAndLevel(arg); ok {
-				topicsLogLevel[topic] = "INFO"
-			}
-		}
+		// The below code can be used to set default log level when it is removed from the spec.
+		// The list of default log levels exists, but it is hardcoded in ArangoDB, and it is not possible to fetch it.
+		//statusDiff := util.Diff(containerStatus.Command, containerSpec.Command)
+		//for _, arg := range statusDiff {
+		//	if ok, topic, _ := getTopicAndLevel(arg); ok {
+		//		topicsLogLevel[topic] = "INFO" // Each topic has its own default log level. It is INFO for most of them.
+		//	}
+		//}
 
 		// Set log levels from the provided spec.
 		for _, arg := range containerSpec.Command {
diff --git a/pkg/deployment/rotation/arangod_containers.go b/pkg/deployment/rotation/arangod_containers.go
index 7c48715fd..d42c854c2 100644
--- a/pkg/deployment/rotation/arangod_containers.go
+++ b/pkg/deployment/rotation/arangod_containers.go
@@ -117,14 +117,14 @@ func initContainersCompare(deploymentSpec api.DeploymentSpec, group api.ServerGr
 // IsOnlyLogLevelChanged returns true when status and spec log level arguments are different.
 // If any other argument than --log.level is different false is returned.
 func IsOnlyLogLevelChanged(specArgs, statusArgs []string) bool {
-	diffSpec := util.GetDifference(specArgs, statusArgs)
+	diffSpec := util.Diff(specArgs, statusArgs)
 	for _, arg := range diffSpec {
 		if !strings.HasPrefix(strings.TrimLeft(arg, " "), "--log.level") {
 			return false
 		}
 	}
 
-	diffStatus := util.GetDifference(statusArgs, specArgs)
+	diffStatus := util.Diff(statusArgs, specArgs)
 	for _, arg := range diffStatus {
 		if !strings.HasPrefix(strings.TrimLeft(arg, " "), "--log.level") {
 			return false
diff --git a/pkg/deployment/rotation/compare.go b/pkg/deployment/rotation/compare.go
index 0c1632885..036409164 100644
--- a/pkg/deployment/rotation/compare.go
+++ b/pkg/deployment/rotation/compare.go
@@ -56,7 +56,9 @@ func compare(log zerolog.Logger, deploymentSpec api.DeploymentSpec, member api.M
 		return SkippedRotation, nil, nil
 	}
 
-	mode = SkippedRotation
+	// If checksums are different and rotation is not needed and there are no changes between containers
+	// then silent rotation must be applied to adjust status checksum.
+	mode = SilentRotation
 
 	podStatus := status.PodSpec.DeepCopy()
 
diff --git a/pkg/util/strings.go b/pkg/util/strings.go
index 310746f6d..7c4d36cbd 100644
--- a/pkg/util/strings.go
+++ b/pkg/util/strings.go
@@ -64,8 +64,8 @@ func PrefixStringArray(a []string, prefix string) []string {
 	return b
 }
 
-// GetDifference returns the elements in `compareWhat` that are not in `compareTo`.
-func GetDifference(compareWhat, compareTo []string) []string {
+// Diff returns the elements in `compareWhat` that are not in `compareTo`.
+func Diff(compareWhat, compareTo []string) []string {
 	compareToMap := make(map[string]struct{}, len(compareTo))
 	for _, x := range compareTo {
 		compareToMap[x] = struct{}{}

From c2a31fd445a19a8afe7e202db3457b8406dcbcd5 Mon Sep 17 00:00:00 2001
From: Tomasz Mielech <informal.ict@gmail.com>
Date: Mon, 20 Sep 2021 16:36:25 +0200
Subject: [PATCH 09/14] fix unit tests

---
 .../rotation/arangod_containers_test.go       | 65 ++++++++++---------
 pkg/deployment/rotation/utils_test.go         |  4 +-
 pkg/util/strings_test.go                      | 65 +++++++++++++++++++
 3 files changed, 103 insertions(+), 31 deletions(-)
 create mode 100644 pkg/util/strings_test.go

diff --git a/pkg/deployment/rotation/arangod_containers_test.go b/pkg/deployment/rotation/arangod_containers_test.go
index 09d12987d..11eadf4bb 100644
--- a/pkg/deployment/rotation/arangod_containers_test.go
+++ b/pkg/deployment/rotation/arangod_containers_test.go
@@ -51,35 +51,6 @@ func Test_ArangoDContainers_SidecarImages(t *testing.T) {
 				api.NewAction(api.ActionTypeRuntimeContainerImageUpdate, 0, ""),
 			},
 		},
-		{
-			name: "Only log level arguments of the ArangoDB server have been changed",
-			spec: buildPodSpec(addContainerWithArgs(k8sutil.ServerContainerName,
-				[]string{"--log.level=INFO", "--log.level=requests=error"})),
-			status:       buildPodSpec(addContainerWithArgs(k8sutil.ServerContainerName, []string{"--log.level=INFO"})),
-			expectedMode: InPlaceRotation,
-			expectedPlan: api.Plan{
-				api.NewAction(api.ActionTypeRuntimeContainerArgsLogLevelUpdate, 0, ""),
-			},
-		},
-		{
-			name: "Only log level arguments of the Sidecar have been changed",
-			spec: buildPodSpec(addContainerWithArgs("sidecar",
-				[]string{"--log.level=INFO", "--log.level=requests=error"})),
-			status:       buildPodSpec(addContainerWithArgs("sidecar", []string{"--log.level=INFO"})),
-			expectedMode: GracefulRotation,
-		},
-		{
-			name:   "ArangoDB server arguments have not been changed",
-			spec:   buildPodSpec(addContainerWithArgs(k8sutil.ServerContainerName, []string{"--log.level=INFO"})),
-			status: buildPodSpec(addContainerWithArgs(k8sutil.ServerContainerName, []string{"--log.level=INFO"})),
-		},
-		{
-			name: "Not only log level arguments of the ArangoDB server have been changed",
-			spec: buildPodSpec(addContainerWithArgs(k8sutil.ServerContainerName, []string{"--log.level=INFO",
-				"--server.endpoint=localhost"})),
-			status:       buildPodSpec(addContainerWithArgs(k8sutil.ServerContainerName, []string{"--log.level=INFO"})),
-			expectedMode: GracefulRotation,
-		},
 	}
 
 	runTestCases(t)(testCases...)
@@ -172,3 +143,39 @@ func Test_InitContainers(t *testing.T) {
 		runTestCases(t)(testCases...)
 	})
 }
+
+func Test_Container_Args(t *testing.T) {
+	testCases := []TestCase{
+		{
+			name: "Only log level arguments of the ArangoDB server have been changed",
+			spec: buildPodSpec(addContainerWithCommand(k8sutil.ServerContainerName,
+				[]string{"--log.level=INFO", "--log.level=requests=error"})),
+			status:       buildPodSpec(addContainerWithCommand(k8sutil.ServerContainerName, []string{"--log.level=INFO"})),
+			expectedMode: InPlaceRotation,
+			expectedPlan: api.Plan{
+				api.NewAction(api.ActionTypeRuntimeContainerArgsLogLevelUpdate, 0, ""),
+			},
+		},
+		{
+			name: "Only log level arguments of the Sidecar have been changed",
+			spec: buildPodSpec(addContainerWithCommand("sidecar",
+				[]string{"--log.level=INFO", "--log.level=requests=error"})),
+			status:       buildPodSpec(addContainerWithCommand("sidecar", []string{"--log.level=INFO"})),
+			expectedMode: GracefulRotation,
+		},
+		{
+			name:   "ArangoDB server arguments have not been changed",
+			spec:   buildPodSpec(addContainerWithCommand(k8sutil.ServerContainerName, []string{"--log.level=INFO"})),
+			status: buildPodSpec(addContainerWithCommand(k8sutil.ServerContainerName, []string{"--log.level=INFO"})),
+		},
+		{
+			name: "Not only log level arguments of the ArangoDB server have been changed",
+			spec: buildPodSpec(addContainerWithCommand(k8sutil.ServerContainerName, []string{"--log.level=INFO",
+				"--server.endpoint=localhost"})),
+			status:       buildPodSpec(addContainerWithCommand(k8sutil.ServerContainerName, []string{"--log.level=INFO"})),
+			expectedMode: GracefulRotation,
+		},
+	}
+
+	runTestCases(t)(testCases...)
+}
diff --git a/pkg/deployment/rotation/utils_test.go b/pkg/deployment/rotation/utils_test.go
index 0556bac24..61886aa9f 100644
--- a/pkg/deployment/rotation/utils_test.go
+++ b/pkg/deployment/rotation/utils_test.go
@@ -127,9 +127,9 @@ func addSidecarWithImage(name, image string) podSpecBuilder {
 	})
 }
 
-func addContainerWithArgs(name string, args []string) podSpecBuilder {
+func addContainerWithCommand(name string, command []string) podSpecBuilder {
 	return addContainer(name, func(c *core.Container) {
-		c.Args = args
+		c.Command = command
 	})
 }
 
diff --git a/pkg/util/strings_test.go b/pkg/util/strings_test.go
new file mode 100644
index 000000000..670ad2c8e
--- /dev/null
+++ b/pkg/util/strings_test.go
@@ -0,0 +1,65 @@
+package util
+
+import (
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func TestDiff(t *testing.T) {
+	type args struct {
+		compareWhat []string
+		compareTo   []string
+	}
+	tests := map[string]struct {
+		args args
+		want []string
+	}{
+		"two nil slices": {},
+		"source slice is nil": {
+			args: args{
+				compareWhat: nil,
+				compareTo:   []string{"1"},
+			},
+			want: nil,
+		},
+		"destination slice is nil": {
+			args: args{
+				compareWhat: []string{"1"},
+			},
+			want: []string{"1"},
+		},
+		"source slice has more elements": {
+			args: args{
+				compareWhat: []string{"1", "2"},
+				compareTo:   []string{"2"},
+			},
+			want: []string{"1"},
+		},
+		"destination slice has more elements": {
+			args: args{
+				compareWhat: []string{"1", "2"},
+				compareTo:   []string{"1", "2", "3"},
+			},
+		},
+		"destination and source slices have overlapping elements": {
+			args: args{
+				compareWhat: []string{"1", "2", "3", "4", "5", "6", "7", "8", "9", "10"},
+				compareTo:   []string{"1", "3", "5", "7", "9"},
+			},
+			want: []string{"2", "4", "6", "8", "10"},
+		},
+		"destination slice contains source slice": {
+			args: args{
+				compareWhat: []string{"1", "3", "5", "7", "9"},
+				compareTo:   []string{"1", "2", "3", "4", "5", "6", "7", "8", "9", "10"},
+			},
+		},
+	}
+
+	for testName, testCase := range tests {
+		t.Run(testName, func(t *testing.T) {
+			diff := Diff(testCase.args.compareWhat, testCase.args.compareTo)
+			assert.Equal(t, testCase.want, diff)
+		})
+	}
+}

From 5d4bca4ea2e8a286203d653c6d7807e86fbc7f37 Mon Sep 17 00:00:00 2001
From: Tomasz Mielech <informal.ict@gmail.com>
Date: Mon, 20 Sep 2021 19:29:59 +0200
Subject: [PATCH 10/14] add license

---
 pkg/util/strings_test.go | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/pkg/util/strings_test.go b/pkg/util/strings_test.go
index 670ad2c8e..106a1d29d 100644
--- a/pkg/util/strings_test.go
+++ b/pkg/util/strings_test.go
@@ -1,3 +1,25 @@
+//
+// DISCLAIMER
+//
+// Copyright 2021 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 Tomasz Mielech
+//
+
 package util
 
 import (

From 5d0a3ce19244cd4d3274a010a406c4e819792363 Mon Sep 17 00:00:00 2001
From: Tomasz Mielech <informal.ict@gmail.com>
Date: Tue, 21 Sep 2021 08:39:17 +0200
Subject: [PATCH 11/14] adjust find in Makefile to POSIX

---
 Makefile                 | 6 +++---
 pkg/util/strings_test.go | 3 ++-
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/Makefile b/Makefile
index 6ef914743..22c44b913 100644
--- a/Makefile
+++ b/Makefile
@@ -122,10 +122,10 @@ ifdef VERBOSE
 	TESTVERBOSEOPTIONS := -v
 endif
 
-EXCLUDE_DIRS := tests vendor .gobuild deps tools
-SOURCES_QUERY := find $(SRCDIR) -name '*.go' -type f -not -path '$(SRCDIR)/tests/*' -not -path '$(SRCDIR)/vendor/*' -not -path '$(SRCDIR)/.gobuild/*' -not -path '$(SRCDIR)/deps/*' -not -path '$(SRCDIR)/tools/*'
+EXCLUDE_DIRS := tests vendor .gobuild deps
+SOURCES_QUERY := find ./ -type f -name '*.go' $(foreach EXCLUDE_DIR,$(EXCLUDE_DIRS), ! -path "./$(EXCLUDE_DIR)/*") ! -path './tools/*'
 SOURCES := $(shell $(SOURCES_QUERY))
-DASHBOARDSOURCES := $(shell find $(DASHBOARDDIR)/src -name '*.js' -not -path './test/*') $(DASHBOARDDIR)/package.json
+DASHBOARDSOURCES := $(shell find $(DASHBOARDDIR)/src -name '*.js') $(DASHBOARDDIR)/package.json
 
 .DEFAULT_GOAL := all
 .PHONY: all
diff --git a/pkg/util/strings_test.go b/pkg/util/strings_test.go
index 106a1d29d..6a2a5636f 100644
--- a/pkg/util/strings_test.go
+++ b/pkg/util/strings_test.go
@@ -23,8 +23,9 @@
 package util
 
 import (
-	"github.com/stretchr/testify/assert"
 	"testing"
+
+	"github.com/stretchr/testify/assert"
 )
 
 func TestDiff(t *testing.T) {

From c2ee36f8802b1aa0002996b28757c07cba886df7 Mon Sep 17 00:00:00 2001
From: Tomasz Mielech <informal.ict@gmail.com>
Date: Tue, 21 Sep 2021 09:01:19 +0200
Subject: [PATCH 12/14] adjust to v2 version

---
 pkg/apis/deployment/v2alpha1/plan.go | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/pkg/apis/deployment/v2alpha1/plan.go b/pkg/apis/deployment/v2alpha1/plan.go
index b3aa59601..79affd7d1 100644
--- a/pkg/apis/deployment/v2alpha1/plan.go
+++ b/pkg/apis/deployment/v2alpha1/plan.go
@@ -171,6 +171,8 @@ const (
 	// Runtime Updates
 	// ActionTypeRuntimeContainerImageUpdate updates container image in runtime
 	ActionTypeRuntimeContainerImageUpdate ActionType = "RuntimeContainerImageUpdate"
+	// ActionTypeRuntimeContainerArgsLogLevelUpdate updates the container's executor arguments.
+	ActionTypeRuntimeContainerArgsLogLevelUpdate ActionType = "RuntimeContainerArgsLogLevelUpdate"
 )
 
 const (

From 286b2a2f9a0ca968ae9b7e4eafcebfbc3bf8a8bb Mon Sep 17 00:00:00 2001
From: Tomasz Mielech <informal.ict@gmail.com>
Date: Tue, 21 Sep 2021 10:43:54 +0200
Subject: [PATCH 13/14] compare string slices in both ways

---
 Makefile                                      |  4 +-
 .../action_runtime_container_args_udpate.go   |  9 ---
 pkg/deployment/rotation/arangod_containers.go | 15 ++---
 .../rotation/arangod_containers_test.go       | 45 +++++++++++++-
 pkg/util/strings.go                           | 12 +++-
 pkg/util/strings_test.go                      | 62 ++++++++++++++++++-
 6 files changed, 121 insertions(+), 26 deletions(-)

diff --git a/Makefile b/Makefile
index 22c44b913..c1801f603 100644
--- a/Makefile
+++ b/Makefile
@@ -122,8 +122,8 @@ ifdef VERBOSE
 	TESTVERBOSEOPTIONS := -v
 endif
 
-EXCLUDE_DIRS := tests vendor .gobuild deps
-SOURCES_QUERY := find ./ -type f -name '*.go' $(foreach EXCLUDE_DIR,$(EXCLUDE_DIRS), ! -path "./$(EXCLUDE_DIR)/*") ! -path './tools/*'
+EXCLUDE_DIRS := tests vendor .gobuild deps tools
+SOURCES_QUERY := find ./ -type f -name '*.go' $(foreach EXCLUDE_DIR,$(EXCLUDE_DIRS), ! -path "./$(EXCLUDE_DIR)/*")
 SOURCES := $(shell $(SOURCES_QUERY))
 DASHBOARDSOURCES := $(shell find $(DASHBOARDDIR)/src -name '*.js') $(DASHBOARDDIR)/package.json
 
diff --git a/pkg/deployment/reconcile/action_runtime_container_args_udpate.go b/pkg/deployment/reconcile/action_runtime_container_args_udpate.go
index 3ea6eb034..ff3b596b0 100644
--- a/pkg/deployment/reconcile/action_runtime_container_args_udpate.go
+++ b/pkg/deployment/reconcile/action_runtime_container_args_udpate.go
@@ -156,15 +156,6 @@ func (a actionRuntimeContainerArgsUpdate) Start(ctx context.Context) (bool, erro
 	var op cmpContainer = func(containerSpec core.Container, containerStatus core.Container) error {
 		topicsLogLevel := map[string]string{}
 
-		// The below code can be used to set default log level when it is removed from the spec.
-		// The list of default log levels exists, but it is hardcoded in ArangoDB, and it is not possible to fetch it.
-		//statusDiff := util.Diff(containerStatus.Command, containerSpec.Command)
-		//for _, arg := range statusDiff {
-		//	if ok, topic, _ := getTopicAndLevel(arg); ok {
-		//		topicsLogLevel[topic] = "INFO" // Each topic has its own default log level. It is INFO for most of them.
-		//	}
-		//}
-
 		// Set log levels from the provided spec.
 		for _, arg := range containerSpec.Command {
 			if ok, topic, value := getTopicAndLevel(arg); ok {
diff --git a/pkg/deployment/rotation/arangod_containers.go b/pkg/deployment/rotation/arangod_containers.go
index d42c854c2..1d453d91f 100644
--- a/pkg/deployment/rotation/arangod_containers.go
+++ b/pkg/deployment/rotation/arangod_containers.go
@@ -117,23 +117,16 @@ func initContainersCompare(deploymentSpec api.DeploymentSpec, group api.ServerGr
 // IsOnlyLogLevelChanged returns true when status and spec log level arguments are different.
 // If any other argument than --log.level is different false is returned.
 func IsOnlyLogLevelChanged(specArgs, statusArgs []string) bool {
-	diffSpec := util.Diff(specArgs, statusArgs)
-	for _, arg := range diffSpec {
-		if !strings.HasPrefix(strings.TrimLeft(arg, " "), "--log.level") {
-			return false
-		}
+	diff := util.DiffStrings(specArgs, statusArgs)
+	if len(diff) == 0 {
+		return false
 	}
 
-	diffStatus := util.Diff(statusArgs, specArgs)
-	for _, arg := range diffStatus {
+	for _, arg := range diff {
 		if !strings.HasPrefix(strings.TrimLeft(arg, " "), "--log.level") {
 			return false
 		}
 	}
 
-	if len(diffSpec) == 0 && len(diffStatus) == 0 {
-		return false
-	}
-
 	return true
 }
diff --git a/pkg/deployment/rotation/arangod_containers_test.go b/pkg/deployment/rotation/arangod_containers_test.go
index 11eadf4bb..1855e9d6f 100644
--- a/pkg/deployment/rotation/arangod_containers_test.go
+++ b/pkg/deployment/rotation/arangod_containers_test.go
@@ -1,7 +1,7 @@
 //
 // DISCLAIMER
 //
-// Copyright 2020 ArangoDB GmbH, Cologne, Germany
+// Copyright 2020-2021 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.
@@ -17,12 +17,16 @@
 //
 // Copyright holder is ArangoDB GmbH, Cologne, Germany
 //
+// Author Adam Janikowski
+// Author Tomasz Mielech
+//
 
 package rotation
 
 import (
 	"testing"
 
+	"github.com/stretchr/testify/assert"
 	v1 "k8s.io/api/core/v1"
 
 	api "github.com/arangodb/kube-arangodb/pkg/apis/deployment/v1"
@@ -179,3 +183,42 @@ func Test_Container_Args(t *testing.T) {
 
 	runTestCases(t)(testCases...)
 }
+
+func TestIsOnlyLogLevelChanged(t *testing.T) {
+	type args struct {
+		specArgs   []string
+		statusArgs []string
+	}
+	tests := map[string]struct {
+		args args
+		want bool
+	}{
+		"log level not changed": {
+			args: args{
+				specArgs:   []string{"--log.level=INFO"},
+				statusArgs: []string{"--log.level=INFO"},
+			},
+		},
+		"log level changed": {
+			args: args{
+				specArgs:   []string{"--log.level=INFO", "--log.level=requests=DEBUG"},
+				statusArgs: []string{"--log.level=INFO"},
+			},
+			want: true,
+		},
+		"log level and server endpoint changed": {
+			args: args{
+				specArgs:   []string{"--log.level=INFO", "--log.level=requests=DEBUG", "--server.endpoint=localhost"},
+				statusArgs: []string{"--log.level=INFO"},
+			},
+		},
+	}
+
+	for testName, testCase := range tests {
+		t.Run(testName, func(t *testing.T) {
+			got := IsOnlyLogLevelChanged(testCase.args.specArgs, testCase.args.statusArgs)
+
+			assert.Equal(t, testCase.want, got)
+		})
+	}
+}
diff --git a/pkg/util/strings.go b/pkg/util/strings.go
index 7c4d36cbd..b7ac01451 100644
--- a/pkg/util/strings.go
+++ b/pkg/util/strings.go
@@ -64,8 +64,8 @@ func PrefixStringArray(a []string, prefix string) []string {
 	return b
 }
 
-// Diff returns the elements in `compareWhat` that are not in `compareTo`.
-func Diff(compareWhat, compareTo []string) []string {
+// DiffStringsOneWay returns the elements in `compareWhat` that are not in `compareTo`.
+func DiffStringsOneWay(compareWhat, compareTo []string) []string {
 	compareToMap := make(map[string]struct{}, len(compareTo))
 	for _, x := range compareTo {
 		compareToMap[x] = struct{}{}
@@ -80,3 +80,11 @@ func Diff(compareWhat, compareTo []string) []string {
 
 	return diff
 }
+
+// DiffStrings returns the elements in `compareWhat` that are not in `compareTo` and
+// elements in `compareTo` that are not in `compareFrom`.
+func DiffStrings(compareWhat, compareTo []string) []string {
+	diff := DiffStringsOneWay(compareWhat, compareTo)
+
+	return append(diff, DiffStringsOneWay(compareTo, compareWhat)...)
+}
diff --git a/pkg/util/strings_test.go b/pkg/util/strings_test.go
index 6a2a5636f..3d94b6d2d 100644
--- a/pkg/util/strings_test.go
+++ b/pkg/util/strings_test.go
@@ -81,8 +81,68 @@ func TestDiff(t *testing.T) {
 
 	for testName, testCase := range tests {
 		t.Run(testName, func(t *testing.T) {
-			diff := Diff(testCase.args.compareWhat, testCase.args.compareTo)
+			diff := DiffStringsOneWay(testCase.args.compareWhat, testCase.args.compareTo)
 			assert.Equal(t, testCase.want, diff)
 		})
 	}
 }
+
+func TestDiffStrings(t *testing.T) {
+	type args struct {
+		compareWhat []string
+		compareTo   []string
+	}
+	tests := map[string]struct {
+		args args
+		want []string
+	}{
+		"two nil slices": {},
+		"source slice is nil": {
+			args: args{
+				compareTo: []string{"1"},
+			},
+			want: []string{"1"},
+		},
+		"destination slice is nil": {
+			args: args{
+				compareWhat: []string{"1"},
+			},
+			want: []string{"1"},
+		},
+		"source slice has more elements": {
+			args: args{
+				compareWhat: []string{"1", "2"},
+				compareTo:   []string{"2"},
+			},
+			want: []string{"1"},
+		},
+		"destination slice has more elements": {
+			args: args{
+				compareWhat: []string{"1", "2"},
+				compareTo:   []string{"1", "2", "3"},
+			},
+			want: []string{"3"},
+		},
+		"destination and source slices have all different elements": {
+			args: args{
+				compareWhat: []string{"1", "2", "3"},
+				compareTo:   []string{"4", "5", "6"},
+			},
+			want: []string{"1", "2", "3", "4", "5", "6"},
+		},
+		"destination and source slices have some overlapping elements": {
+			args: args{
+				compareWhat: []string{"1", "2", "3", "4"},
+				compareTo:   []string{"3", "4", "5", "6"},
+			},
+			want: []string{"1", "2", "5", "6"},
+		},
+	}
+	for testName, testCase := range tests {
+		t.Run(testName, func(t *testing.T) {
+			got := DiffStrings(testCase.args.compareWhat, testCase.args.compareTo)
+
+			assert.Equal(t, testCase.want, got)
+		})
+	}
+}

From 07488b6d727f3acf9588616bbb26b7a02ec71576 Mon Sep 17 00:00:00 2001
From: Tomasz Mielech <informal.ict@gmail.com>
Date: Tue, 21 Sep 2021 11:06:08 +0200
Subject: [PATCH 14/14] adjust Makefile

---
 Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index c1801f603..ffb98c58f 100644
--- a/Makefile
+++ b/Makefile
@@ -123,7 +123,7 @@ ifdef VERBOSE
 endif
 
 EXCLUDE_DIRS := tests vendor .gobuild deps tools
-SOURCES_QUERY := find ./ -type f -name '*.go' $(foreach EXCLUDE_DIR,$(EXCLUDE_DIRS), ! -path "./$(EXCLUDE_DIR)/*")
+SOURCES_QUERY := find ./ -type f -name '*.go' $(foreach EXCLUDE_DIR,$(EXCLUDE_DIRS), -not -path "./$(EXCLUDE_DIR)/*")
 SOURCES := $(shell $(SOURCES_QUERY))
 DASHBOARDSOURCES := $(shell find $(DASHBOARDDIR)/src -name '*.js') $(DASHBOARDDIR)/package.json