WIP

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

go.mod

@@ -13,10 +13,12 @@ require (
 	darvaza.org/slog/handlers/discard v0.4.5
 	github.com/gofrs/uuid/v5 v5.0.0
 	github.com/hack-pad/hackpadfs v0.2.1
+	github.com/libdns/cloudflare v0.1.0
 	github.com/libdns/libdns v0.2.1
 	github.com/mgechev/revive v1.3.3
 	github.com/spf13/cobra v1.7.0
 	golang.org/x/crypto v0.12.0
+	golang.org/x/net v0.14.0
 	gopkg.in/yaml.v3 v3.0.1
 )
 
@@ -41,7 +43,6 @@ require (
 	github.com/rs/zerolog v1.30.0 // indirect
 	github.com/spf13/pflag v1.0.5 // indirect
 	golang.org/x/mod v0.12.0 // indirect
-	golang.org/x/net v0.14.0 // indirect
 	golang.org/x/sys v0.12.0 // indirect
 	golang.org/x/text v0.13.0 // indirect
 	golang.org/x/tools v0.12.0 // indirect

go.sum

@@ -34,6 +34,9 @@ github.com/hack-pad/hackpadfs v0.2.1 h1:FelFhIhv26gyjujoA/yeFO+6YGlqzmc9la/6iKMI
 github.com/hack-pad/hackpadfs v0.2.1/go.mod h1:khQBuCEwGXWakkmq8ZiFUvUZz84ZkJ2KNwKvChs4OrU=
 github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
 github.com/inconshreveable/mousetrap v1.1.0/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
+github.com/libdns/cloudflare v0.1.0 h1:93WkJaGaiXCe353LHEP36kAWCUw0YjFqwhkBkU2/iic=
+github.com/libdns/cloudflare v0.1.0/go.mod h1:a44IP6J1YH6nvcNl1PverfJviADgXUnsozR3a7vBKN8=
+github.com/libdns/libdns v0.2.0/go.mod h1:yQCXzk1lEZmmCPa857bnk4TsOiqYasqpyOEeSObbb40=
 github.com/libdns/libdns v0.2.1 h1:Wu59T7wSHRgtA0cfxC+n1c/e+O3upJGWytknkmFEDis=
 github.com/libdns/libdns v0.2.1/go.mod h1:yQCXzk1lEZmmCPa857bnk4TsOiqYasqpyOEeSObbb40=
 github.com/mattn/go-colorable v0.1.12/go.mod h1:u5H1YNBxpqRaxsYJYSkiCWKzEfiAb1Gb520KVy5xxl4=

pkg/cluster/regions.go

@@ -9,6 +9,15 @@ type Region struct {
 	Regions []string `json:",omitempty" yaml:",omitempty"`
 }
 
+// Zones ...
+func (r *Region) Zones() []string {
+	out := make([]string, len(r.zones))
+	for i := range r.zones {
+		out[i] = r.zones[i].Name
+	}
+	return out
+}
+
 func (m *Cluster) initRegions(_ *ScanOptions) error {
 	regions := make(map[string][]*Zone)
 

pkg/dns/dns.go

@@ -1,2 +1,34 @@
 // Package dns manages DNS entries for the cluster
 package dns
+
+import "net/netip"
+
+// // A Config defines a Region
+//
+//	type Config struct {
+//		// Name is the identifier of this Region
+//		Name string
+//		// Regions are a list of (sub)regions that belong to this Region
+//		Regions []string
+//		// Zones are a list of Zones that directly belong to this Region
+//		Zones []string
+//	}
+//
+//	type Region struct {
+//		Name string
+//	}
+
+// Zone represents a set of machines with high affinity
+type Zone struct {
+	Name string
+
+	Machines map[int]*Machine
+}
+
+// Machine represents a member of the cluster
+type Machine struct {
+	ID int
+
+	Active bool
+	Addrs  []netip.Addr
+}

pkg/dns/host.go

@@ -0,0 +1,41 @@
+package dns
+
+import (
+	"context"
+	"io/fs"
+	"net/netip"
+)
+
+// AddHost registers a machine
+func (mgr *Manager) AddHost(_ context.Context, zone string, id int,
+	active bool, addrs ...netip.Addr) error {
+	//
+	if zone == "" || id <= 0 {
+		return fs.ErrInvalid
+	}
+
+	z, ok := mgr.zones[zone]
+	if !ok {
+		z = &Zone{
+			Name:     zone,
+			Machines: make(map[int]*Machine),
+		}
+
+		mgr.zones[zone] = z
+	}
+
+	z.Machines[id] = &Machine{
+		ID:     id,
+		Active: active,
+		Addrs:  SortAddrSlice(addrs),
+	}
+
+	return nil
+}
+
+// AddRegion specifies a new region and the zones it contains
+func (mgr *Manager) AddRegion(_ context.Context, region string, zones ...string) error {
+	mgr.l.Debug().WithField("region", region).WithField("zones", zones).Print()
+	mgr.regions[region] = append(mgr.regions[region], zones...)
+	return nil
+}

pkg/dns/manager.go

@@ -0,0 +1,124 @@
+package dns
+
+import (
+	"errors"
+	"strings"
+	"sync"
+
+	"darvaza.org/core"
+	"darvaza.org/slog"
+	"git.jpi.io/amery/jpictl/pkg/cluster"
+	"golang.org/x/net/publicsuffix"
+)
+
+// Manager is a DNS Manager instance
+type Manager struct {
+	mu sync.Mutex
+
+	domain  string
+	suffix  string
+	zones   map[string]*Zone
+	regions map[string][]string
+
+	p Provider
+	l slog.Logger
+}
+
+// ManagerOption configures a Manager
+type ManagerOption func(*Manager) error
+
+func newErrorManagerOption(err error, hint string) ManagerOption {
+	return func(*Manager) error {
+		if hint != "" {
+			err = core.Wrap(err, hint)
+		}
+		return err
+	}
+}
+
+// WithProvider attaches a libdns Provider to the Manager
+func WithProvider(p Provider) ManagerOption {
+	var err error
+
+	if p == nil {
+		p, err = DefaultDNSProvider()
+	}
+
+	if err != nil {
+		return newErrorManagerOption(err, "WithProvider")
+	}
+
+	return func(mgr *Manager) error {
+		mgr.p = p
+		return nil
+	}
+}
+
+// WithLogger attaches a logger to the Manager
+func WithLogger(log slog.Logger) ManagerOption {
+	if log == nil {
+		log = cluster.DefaultLogger()
+	}
+
+	return func(mgr *Manager) error {
+		mgr.l = log
+		return nil
+	}
+}
+
+func (mgr *Manager) setDefaults() error {
+	var opts []ManagerOption
+
+	if mgr.l == nil {
+		opts = append(opts, WithLogger(nil))
+	}
+
+	if mgr.domain == "" || mgr.suffix == "" {
+		return errors.New("domain not specified")
+	}
+
+	mgr.zones = make(map[string]*Zone)
+	mgr.regions = make(map[string][]string)
+
+	for _, opt := range opts {
+		if err := opt(mgr); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// WithDomain specifies where the manager operates
+func WithDomain(domain string) ManagerOption {
+	base, err := publicsuffix.EffectiveTLDPlusOne(domain)
+	if err != nil {
+		return newErrorManagerOption(err, "publicsuffix")
+	}
+
+	suffix := strings.TrimSuffix(domain, base)
+	if suffix != "" {
+		suffix = "." + suffix[:len(suffix)-1]
+	}
+
+	return func(mgr *Manager) error {
+		mgr.domain = base
+		mgr.suffix = suffix
+		return nil
+	}
+}
+
+// NewManager creates a DNS manager with the
+func NewManager(opts ...ManagerOption) (*Manager, error) {
+	mgr := new(Manager)
+
+	for _, opt := range opts {
+		if err := opt(mgr); err != nil {
+			return nil, err
+		}
+	}
+
+	if err := mgr.setDefaults(); err != nil {
+		return nil, err
+	}
+	return mgr, nil
+}

pkg/dns/provider.go

@@ -0,0 +1,36 @@
+package dns
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/libdns/cloudflare"
+	"github.com/libdns/libdns"
+)
+
+const (
+	// CloudflareAPIToken is the environment variable
+	// containing the API Token
+	CloudflareAPIToken = "CLOUDFLARE_DNS_API_TOKEN"
+)
+
+// Provider manages DNS entries
+type Provider interface {
+	libdns.RecordGetter
+	libdns.RecordDeleter
+}
+
+// DefaultDNSProvider returns a cloudflare DNS provider
+// using an API Token from env [CloudflareAPIToken]
+func DefaultDNSProvider() (*cloudflare.Provider, error) {
+	s := os.Getenv(CloudflareAPIToken)
+	if s == "" {
+		return nil, fmt.Errorf("%q: %s", CloudflareAPIToken, "not found")
+	}
+
+	p := &cloudflare.Provider{
+		APIToken: s,
+	}
+
+	return p, nil
+}

pkg/dns/record.go

@@ -1,6 +1,7 @@
 package dns
 
 import (
+	"fmt"
 	"net/netip"
 	"sort"
 	"time"
@@ -9,6 +10,14 @@ import (
 	"github.com/libdns/libdns"
 )
 
+// SortAddrSlice ...
+func SortAddrSlice(s []netip.Addr) []netip.Addr {
+	sort.Slice(s, func(i, j int) bool {
+		return s[i].Less(s[j])
+	})
+	return s
+}
+
 // AddrRecord represents an A or AAAA record
 type AddrRecord struct {
 	Name string
@@ -17,9 +26,7 @@ type AddrRecord struct {
 
 // Sort sorts the addresses of the record
 func (rr *AddrRecord) Sort() {
-	sort.Slice(rr.Addr, func(i, j int) bool {
-		return rr.Addr[i].Less(rr.Addr[j])
-	})
+	SortAddrSlice(rr.Addr)
 }
 
 // Export converts the record into libdns.Record
@@ -36,3 +43,79 @@ func (rr *AddrRecord) Export() []libdns.Record {
 
 	return out
 }
+
+func (mgr *Manager) genAllAddrRecords() []AddrRecord {
+	var out []AddrRecord
+
+	cache := make(map[string][]netip.Addr)
+
+	// zones
+	for _, z := range mgr.zones {
+		// machines
+		s := mgr.genZoneMachineRecords(z)
+		out = append(out, s...)
+
+		// zone alias
+		addrs := mgr.genZoneAddresses(z)
+		name := z.Name
+
+		out = append(out, AddrRecord{
+			Name: name + mgr.suffix,
+			Addr: addrs,
+		})
+
+		// and cache for regions
+		cache[name] = addrs
+	}
+
+	// regions
+	for name, zones := range mgr.regions {
+		var addrs []netip.Addr
+
+		for _, z := range zones {
+			addrs = append(addrs, cache[z]...)
+		}
+
+		rec := AddrRecord{
+			Name: name + mgr.suffix,
+			Addr: addrs,
+		}
+		rec.Sort()
+
+		out = append(out, rec)
+	}
+
+	// sort
+	sort.Slice(out, func(i, j int) bool {
+		return out[i].Name < out[j].Name
+	})
+
+	return out
+}
+
+func (*Manager) genZoneAddresses(z *Zone) []netip.Addr {
+	var out []netip.Addr
+
+	for _, p := range z.Machines {
+		if p.Active {
+			out = append(out, p.Addrs...)
+		}
+	}
+
+	SortAddrSlice(out)
+	return out
+}
+
+func (mgr *Manager) genZoneMachineRecords(z *Zone) []AddrRecord {
+	out := make([]AddrRecord, 0, len(z.Machines))
+
+	for _, p := range z.Machines {
+		rec := AddrRecord{
+			Name: fmt.Sprintf("%s-%v%s", z.Name, p.ID, mgr.suffix),
+			Addr: p.Addrs,
+		}
+		out = append(out, rec)
+	}
+
+	return out
+}

pkg/dns/write.go

@@ -0,0 +1,35 @@
+package dns
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"time"
+
+	"github.com/libdns/libdns"
+)
+
+// WriteTo writes the DNS data for the cluster
+func (mgr *Manager) WriteTo(w io.Writer) (int64, error) {
+	var buf bytes.Buffer
+
+	records := mgr.genAllAddrRecords()
+	for i := range records {
+		r := &records[i]
+		r.Name = fmt.Sprintf("%s.%s.", r.Name, mgr.domain)
+	}
+
+	for _, rr1 := range records {
+		for _, rr2 := range rr1.Export() {
+			writeRecord(&buf, rr2)
+		}
+	}
+
+	return buf.WriteTo(w)
+}
+
+func writeRecord(w io.Writer, rr libdns.Record) {
+	_, _ = fmt.Fprintf(w, "%s\t%v\tIN\t%s\t%s\n",
+		rr.Name, int(rr.TTL/time.Second),
+		rr.Type, rr.Value)
+}