[Feature] Topology Support (#804)

Author: ajanikow

CHANGELOG.md

@@ -5,6 +5,7 @@
 - Add "Short Names" feature
 - Switch ArangoDB Image Discovery process from Headless Service to Pod IP
 - Fix PVC Resize for Single servers
+- Add Topology support
 
 ## [1.2.3](https://github.com/arangodb/kube-arangodb/tree/1.2.3) (2021-09-24)
 - Update UBI Image to 8.4

go.mod

@@ -29,7 +29,7 @@ require (
 	github.com/arangodb/go-driver v0.0.0-20210621075908-e7a6fa0cbd18
 	github.com/arangodb/go-upgrade-rules v0.0.0-20180809110947-031b4774ff21
 	github.com/cenkalti/backoff v2.2.1+incompatible
-	github.com/coreos/go-semver v0.3.0
+	github.com/coreos/go-semver v0.3.0 // indirect
 	github.com/dchest/uniuri v0.0.0-20160212164326-8902c56451e9
 	github.com/evanphx/json-patch v4.9.0+incompatible
 	github.com/ghodss/yaml v1.0.0
@@ -43,7 +43,7 @@ require (
 	github.com/jessevdk/go-assets v0.0.0-20160921144138-4f4301a06e15
 	github.com/jessevdk/go-assets-builder v0.0.0-20130903091706-b8483521738f // indirect
 	github.com/jessevdk/go-flags v1.4.0 // indirect
-	github.com/json-iterator/go v1.1.11
+	github.com/json-iterator/go v1.1.11 // indirect
 	github.com/julienschmidt/httprouter v1.3.0
 	github.com/kevinburke/rest v0.0.0-20210222204520-f7a2e216372f // indirect
 	github.com/magiconair/properties v1.8.0
@@ -62,7 +62,7 @@ require (
 	github.com/ugorji/go/codec v1.2.6 // indirect
 	github.com/voxelbrain/goptions v0.0.0-20180630082107-58cddc247ea2 // indirect
 	github.com/zenazn/goji v0.9.0 // indirect
-	golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4
+	golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4 // indirect
 	golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c
 	golang.org/x/tools v0.1.1-0.20210504181558-0bb7e5c47b1a // indirect
 	google.golang.org/protobuf v1.27.1 // indirect

pkg/apis/deployment/v1/conditions.go

@@ -83,6 +83,8 @@ const (
 	ConditionTypeUpdating ConditionType = "Updating"
 	// ConditionTypeUpdateFailed indicates that runtime update failed
 	ConditionTypeUpdateFailed ConditionType = "UpdateFailed"
+	// ConditionTypeTopologyAware indicates that the member is deployed with TopologyAwareness.
+	ConditionTypeTopologyAware ConditionType = "TopologyAware"
 )
 
 // Condition represents one current condition of a deployment or deployment member.

pkg/apis/deployment/v1/deployment_spec.go

@@ -163,6 +163,9 @@ type DeploymentSpec struct {
 
 	// CommunicationMethod define communication method used in deployment
 	CommunicationMethod *DeploymentCommunicationMethod `json:"communicationMethod,omitempty"`
+
+	// Topology define topology adjustment details, Enterprise only
+	Topology *TopologySpec `json:"topology,omitempty"`
 }
 
 // GetAllowMemberRecreation returns member recreation policy based on group and settings

pkg/apis/deployment/v1/deployment_status.go

@@ -81,6 +81,8 @@ type DeploymentStatus struct {
 
 	// Agency keeps information about agency
 	Agency *DeploymentStatusAgencyInfo `json:"agency,omitempty"`
+
+	Topology *TopologyStatus `json:"topology,omitempty"`
 }
 
 // Equal checks for equality

pkg/apis/deployment/v1/list.go

@@ -0,0 +1,55 @@
+//
+// DISCLAIMER
+//
+// Copyright 2020 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
+//
+
+package v1
+
+import "sort"
+
+type List []string
+
+func (l List) Contains(v string) bool {
+	for _, z := range l {
+		if z == v {
+			return true
+		}
+	}
+
+	return false
+}
+
+func (l List) Sort() {
+	sort.Strings(l)
+}
+
+func (l List) Remove(values ...string) List {
+	var m List
+
+	toRemove := List(values)
+
+	for _, v := range l {
+		if toRemove.Contains(v) {
+			continue
+		}
+
+		m = append(m, v)
+	}
+
+	return m
+}

pkg/apis/deployment/v1/member_status.go

@@ -41,6 +41,9 @@ type MemberStatus struct {
 	// ID holds the unique ID of the member.
 	// This id is also used within the ArangoDB cluster to identify this server.
 	ID string `json:"id"`
+	// UID holds the unique UID of the member.
+	// UID is created once member run in AddMember action.
+	UID types.UID `json:"uid,omitempty"`
 	// RID holds the ID of the member run.
 	// Value is updated in Pending Phase.
 	RID types.UID `json:"rid,omitempty"`
@@ -80,11 +83,14 @@ type MemberStatus struct {
 	Upgrade bool `json:"upgrade,omitempty"`
 	// Endpoint definition how member should be reachable
 	Endpoint *string `json:"endpoint,omitempty"`
+	// Topology define topology member status assignment
+	Topology *TopologyMemberStatus `json:"topology,omitempty"`
 }
 
 // Equal checks for equality
 func (s MemberStatus) Equal(other MemberStatus) bool {
 	return s.ID == other.ID &&
+		s.UID == other.UID &&
 		s.RID == other.RID &&
 		s.Phase == other.Phase &&
 		util.TimeCompareEqual(s.CreatedAt, other.CreatedAt) &&

pkg/apis/deployment/v1/member_status_list.go

@@ -138,10 +138,12 @@ func (l *MemberStatusList) removeByID(id string) error {
 	return errors.WithStack(errors.Wrapf(NotFoundError, "Member '%s' is not a member", id))
 }
 
+type MemberToRemoveSelector func(m MemberStatusList) (string, error)
+
 // SelectMemberToRemove selects a member from the given list that should
 // be removed in a scale down action.
 // Returns an error if the list is empty.
-func (l MemberStatusList) SelectMemberToRemove() (MemberStatus, error) {
+func (l MemberStatusList) SelectMemberToRemove(selectors ...MemberToRemoveSelector) (MemberStatus, error) {
 	if len(l) > 0 {
 		// Try to find member with phase to be removed
 		for _, m := range l {
@@ -165,6 +167,20 @@ func (l MemberStatusList) SelectMemberToRemove() (MemberStatus, error) {
 				return m, nil
 			}
 		}
+
+		// Run conditional picker
+		for _, selector := range selectors {
+			if m, err := selector(l); err != nil {
+				return MemberStatus{}, err
+			} else if m != "" {
+				if member, ok := l.ElementByID(m); ok {
+					return member, nil
+				} else {
+					return MemberStatus{}, errors.Newf("Unable to find member with id %s", m)
+				}
+			}
+		}
+
 		// Pick a random member that is in created state
 		perm := rand.Perm(len(l))
 		for _, idx := range perm {

pkg/apis/deployment/v1/plan.go

@@ -171,6 +171,11 @@ const (
 	ActionTypeRuntimeContainerImageUpdate ActionType = "RuntimeContainerImageUpdate"
 	// ActionTypeRuntimeContainerArgsLogLevelUpdate updates the container's executor arguments.
 	ActionTypeRuntimeContainerArgsLogLevelUpdate ActionType = "RuntimeContainerArgsLogLevelUpdate"
+
+	// Topology
+	ActionTypeTopologyEnable           ActionType = "TopologyEnable"
+	ActionTypeTopologyDisable          ActionType = "TopologyDisable"
+	ActionTypeTopologyMemberAssignment ActionType = "TopologyMemberAssignment"
 )
 
 const (
@@ -346,3 +351,45 @@ func (p Plan) Wrap(before, after Action) Plan {
 
 	return n
 }
+
+// AfterFirst adds actions when condition will return false
+func (p Plan) AfterFirst(condition func(a Action) bool, actions ...Action) Plan {
+	var r Plan
+	c := p
+	for {
+		if len(c) == 0 {
+			break
+		}
+
+		if !condition(c[0]) {
+			r = append(r, actions...)
+
+			r = append(r, c...)
+
+			break
+		}
+
+		r = append(r, c[0])
+
+		if len(c) == 1 {
+			break
+		}
+
+		c = c[1:]
+	}
+
+	return r
+}
+
+// Filter filter list of the actions
+func (p Plan) Filter(condition func(a Action) bool) Plan {
+	var r Plan
+
+	for _, a := range p {
+		if condition(a) {
+			r = append(r, a)
+		}
+	}
+
+	return r
+}

pkg/apis/deployment/v1/topology_member_status.go

@@ -0,0 +1,28 @@
+//
+// DISCLAIMER
+//
+// Copyright 2020 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
+//
+
+package v1
+
+import "k8s.io/apimachinery/pkg/types"
+
+type TopologyMemberStatus struct {
+	ID   types.UID `json:"id"`
+	Zone int       `json:"rack"`
+}