cluster: assign valid rings.RegionID to each primary region

Signed-off-by: Alejandro Mery <amery@jpi.io>

pkg/cluster/env.go

@@ -53,7 +53,7 @@ func (m *Env) Regions() []string {
 	var regions []string
 
 	m.ForEachRegion(func(r *Region) bool {
-		if r.Cluster != nil {
+		if r.IsPrimary() {
 			regions = append(regions, r.Name)
 		}
 
@@ -166,7 +166,7 @@ func genEnvZoneRegion(z *Zone) string {
 	var region string
 
 	z.ForEachRegion(func(r *Region) bool {
-		if r.Cluster != nil {
+		if r.IsPrimary() {
 			region = r.Name
 			return true
 		}

pkg/cluster/regions.go

@@ -3,6 +3,8 @@ package cluster
 import (
 	"bytes"
 	"path/filepath"
+
+	"git.jpi.io/amery/jpictl/pkg/rings"
 )
 
 var (
@@ -24,10 +26,17 @@ type Region struct {
 	zones []*Zone
 
 	Name    string
+	ID      rings.RegionID `json:",omitempty" yaml:",omitempty"`
 	Cluster *string        `json:",omitempty" yaml:",omitempty"`
 	Regions []string       `json:",omitempty" yaml:",omitempty"`
 }
 
+// IsPrimary indicates the region is primary and corresponds
+// to a kubernetes cluster.
+func (r *Region) IsPrimary() bool {
+	return r != nil && r.Cluster != nil
+}
+
 // ForEachRegion calls a function for each Region of the cluster
 // until instructed to terminate the loop
 func (m *Cluster) ForEachRegion(fn func(r *Region) bool) {
@@ -92,6 +101,7 @@ func (m *Cluster) initRegions(_ *ScanOptions) error {
 	}
 
 	m.sortRegions()
+	m.scanRegionID()
 	return nil
 }
 
@@ -210,6 +220,63 @@ func (m *Cluster) finishRegion(r *Region) {
 	r.Regions = sub
 }
 
+// revive:disable:cognitive-complexity
+func (m *Cluster) scanRegionID() {
+	// revive:enable:cognitive-complexity
+	var max rings.RegionID
+	var missing bool
+
+	// check IDs
+	ids := make(map[rings.RegionID]bool)
+	fn := func(r *Region) bool {
+		var term bool
+
+		switch {
+		case !r.IsPrimary():
+			// secondary, no ID.
+			r.ID = 0
+		case !r.ID.Valid():
+			// primary without ID
+			missing = true
+		case ids[r.ID]:
+			// duplicate
+			m.error(nil).WithField("region", r.Name).Print("duplicate ID")
+			missing = true
+			r.ID = 0
+		default:
+			ids[r.ID] = true
+
+			if r.ID > max {
+				max = r.ID
+			}
+		}
+
+		return term
+	}
+	m.ForEachRegion(fn)
+
+	if missing {
+		// assign missing IDs
+		fn := func(r *Region) bool {
+			var term bool
+
+			switch {
+			case !r.IsPrimary():
+				// ignore secondary
+			case r.ID.Valid():
+				// already has an ID
+			default:
+				r.ID = max + 1
+				max = r.ID
+			}
+
+			return term
+		}
+
+		m.ForEachRegion(fn)
+	}
+}
+
 func (m *Cluster) getRegion(name string) (*Region, bool) {
 	for i := range m.Regions {
 		r := &m.Regions[i]