Strengthen WAN IP address retrieval and validation

Author: crazy-max

.res/compose/docker-compose.yml

@@ -9,6 +9,7 @@ services:
     environment:
       - "TZ=Europe/Paris"
       - "SCHEDULE=*/30 * * * *"
+      - "MAX_RETRIES=3"
       - "LOG_LEVEL=info"
       - "LOG_JSON=false"
     restart: always

CHANGELOG.md

@@ -1,5 +1,12 @@
 # Changelog
 
+## 1.6.0 (2019/12/20)
+
+* Strengthen WAN IP address retrieval and validation
+* Move ident.me client to pkg
+* Add `--max-retries` flag
+* Go 1.13.5
+
 ## 1.5.0 (2019/11/11)
 
 * Seconds field is now optional

cmd/main.go

@@ -23,6 +23,7 @@ func main() {
 	// Parse command line
 	kingpin.Flag("config", "ddns-route53 configuration file.").Envar("CONFIG").Required().StringVar(&flags.Cfgfile)
 	kingpin.Flag("schedule", "CRON expression format.").Envar("SCHEDULE").StringVar(&flags.Schedule)
+	kingpin.Flag("max-retries", "Number of retries in case of WAN IP retrieval failure.").Envar("MAX_RETRIES").Default("3").IntVar(&flags.MaxRetries)
 	kingpin.Flag("timezone", "Timezone assigned to ddns-route53.").Envar("TZ").Default("UTC").StringVar(&flags.Timezone)
 	kingpin.Flag("log-level", "Set log level.").Envar("LOG_LEVEL").Default("info").StringVar(&flags.LogLevel)
 	kingpin.Flag("log-json", "Enable JSON logging output.").Envar("LOG_JSON").Default("false").BoolVar(&flags.LogJson)

doc/configuration.md

@@ -25,7 +25,7 @@ route53:
   * `secret_access_key`: AWS Secret Key.
 * `route53`
   * `hosted_zone_id`: AWS Route53 hosted zone ID.
-  * `records_set`: Map of records set.
+  * `records_set`: Slice of records set.
     * `name`: AWS Route53 record set name (don't forget to add a dot at the end).
     * `type`: AWS Route53 record set type, can be `A` or `AAAA`.
     * `ttl`: AWS Route53 record TTL (time to live) in seconds.

doc/install/binary.md

@@ -18,14 +18,15 @@ After getting the binary, it can be tested with `./ddns-route53 --help` or moved
 $ ./ddns-route53 --help
 usage: ddns-route53 --config=CONFIG [<flags>]
 
-Dynamic DNS for Amazon Route 53‎ on a time-based schedule. More info on
+Dynamic DNS for Amazon Route 53‎ on a time-based schedule. More info:
 https://github.com/crazy-max/ddns-route53
 
 Flags:
   --help               Show context-sensitive help (also try --help-long and
                        --help-man).
   --config=CONFIG      ddns-route53 configuration file.
   --schedule=SCHEDULE  CRON expression format.
+  --max-retries=3      Number of retries in case of WAN IP retrieval failure.
   --timezone="UTC"     Timezone assigned to ddns-route53.
   --log-level="info"   Set log level.
   --log-json           Enable JSON logging output.

doc/install/docker.md

@@ -22,6 +22,7 @@ Environment variables can be used within your container:
 
 * `TZ` : Timezone assigned to ddns-route53
 * `SCHEDULE` : [CRON expression](https://godoc.org/github.com/robfig/cron#hdr-CRON_Expression_Format) to schedule ddns-route53
+* `MAX_RETRIES` : Number of retries in case of WAN IP retrieval failure (default `3`)
 * `LOG_LEVEL` : Log level output (default `info`)
 * `LOG_JSON`: Enable JSON logging output (default `false`)
 

doc/usage.md

@@ -8,6 +8,7 @@
 * `--version` : Show version and exit. _Optional_.
 * `--config <path>` : ddns-route53 YAML configuration file. **Required**. (example: `ddns-route53.yml`).
 * `--schedule <cron expression>` : [CRON expression](https://godoc.org/github.com/robfig/cron#hdr-CRON_Expression_Format) to schedule ddns-route53. _Optional_. (example: `*/30 * * * *`).
+* `--max-retries <nb of retries>` : Number of retries in case of WAN IP retrieval failure. _Optional_. (example: `3`).
 * `--timezone <timezone>` : Timezone assigned to ddns-route53. _Optional_. (default: `UTC`).
 * `--log-level <level>` : Log level output. _Optional_. (default: `info`).
 * `--log-json` : Enable JSON logging output. _Optional_. (default: `false`).

go.mod

@@ -6,6 +6,8 @@ require (
 	github.com/alecthomas/kingpin v0.0.0-20190816080609-dce89ec0b9f1
 	github.com/aws/aws-sdk-go v1.26.6
 	github.com/hako/durafmt v0.0.0-20190612201238-650ed9f29a84
+	github.com/jpillora/backoff v1.0.0
+	github.com/pkg/errors v0.8.1
 	github.com/robfig/cron/v3 v3.0.0
 	github.com/rs/zerolog v1.17.2
 	gopkg.in/yaml.v3 v3.0.0-20190924164351-c8b7dadae555

go.sum

@@ -13,6 +13,9 @@ github.com/hako/durafmt v0.0.0-20190612201238-650ed9f29a84 h1:RvcDqcKLua4b/jtXez
 github.com/hako/durafmt v0.0.0-20190612201238-650ed9f29a84/go.mod h1:5Scbynm8dF1XAPwIwkGPqzkM/shndPm79Jd1003hTjE=
 github.com/jmespath/go-jmespath v0.0.0-20180206201540-c2b33e8439af h1:pmfjZENx5imkbgOkpRUYLnmbU7UEFbjtDA2hxJ1ichM=
 github.com/jmespath/go-jmespath v0.0.0-20180206201540-c2b33e8439af/go.mod h1:Nht3zPeWKUH0NzdCt2Blrr5ys8VGpn0CEB0cQHVjt7k=
+github.com/jpillora/backoff v1.0.0 h1:uvFg412JmmHBHw7iwprIxkPMI+sGQ4kzOWsMeHnm2EA=
+github.com/jpillora/backoff v1.0.0/go.mod h1:J/6gKK9jxlEcS3zixgDgUAsiuZ7yrSoa/FX5e0EB2j4=
+github.com/pkg/errors v0.8.1 h1:iURUrRGxPUNPdy5/HRSm+Yj6okJ6UtLINN0Q9M4+h3I=
 github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=

internal/app/app.go internal/app/ddnsr53.gointernal/app/app.go renamed to internal/app/ddnsr53.go

@@ -2,6 +2,9 @@ package app
 
 import (
 	"fmt"
+	"net"
+	"runtime"
+	"strings"
 	"sync/atomic"
 	"time"
 
@@ -10,7 +13,7 @@ import (
 	"github.com/aws/aws-sdk-go/aws/session"
 	"github.com/aws/aws-sdk-go/service/route53"
 	"github.com/crazy-max/ddns-route53/internal/config"
-	"github.com/crazy-max/ddns-route53/internal/utl"
+	"github.com/crazy-max/ddns-route53/pkg/identme"
 	"github.com/hako/durafmt"
 	"github.com/robfig/cron/v3"
 	"github.com/rs/zerolog/log"
@@ -22,9 +25,10 @@ type Client struct {
 	loc      *time.Location
 	cron     *cron.Cron
 	r53      *route53.Route53
+	im       *identme.Client
 	jobID    cron.EntryID
-	lastIPv4 string
-	lastIPv6 string
+	lastIPv4 net.IP
+	lastIPv6 net.IP
 	locker   uint32
 }
 
@@ -50,6 +54,10 @@ func New(cfg *config.Configuration, loc *time.Location) (*Client, error) {
 			cron.SecondOptional|cron.Minute|cron.Hour|cron.Dom|cron.Month|cron.Dow|cron.Descriptor),
 		)),
 		r53: route53.New(sess, &aws.Config{Credentials: creds}),
+		im: identme.NewClient(
+			fmt.Sprintf("ddns-route53/%s go/%s %s", cfg.App.Version, runtime.Version()[2:], strings.Title(runtime.GOOS)),
+			cfg.Flags.MaxRetries,
+		),
 	}, nil
 }
 
@@ -95,56 +103,57 @@ func (c *Client) Run() {
 			c.cron.Entry(c.jobID).Next)
 	}
 
-	// Get current WAN IP
-	wanIPv4 := ""
+	var wanIPv4 net.IP
 	if c.cfg.Route53.HandleIPv4 {
-		wanIPv4, err = utl.WanIPv4()
+		wanIPv4, err = c.im.IPv4()
 		if err != nil {
-			log.Warn().Err(err).Msg("Cannot get WAN IPv4 address")
+			log.Error().Err(err).Msg("Cannot retrieve WAN IPv4 address")
 		} else {
 			log.Info().Msgf("Current WAN IPv4: %s", wanIPv4)
 		}
-	} else {
-		log.Debug().Msg("")
 	}
 
-	wanIPv6 := ""
+	var wanIPv6 net.IP
 	if c.cfg.Route53.HandleIPv6 {
-		wanIPv6, err = utl.WanIPv6()
+		wanIPv6, err = c.im.IPv6()
 		if err != nil {
-			log.Warn().Err(err).Msg("Cannot get WAN IPv6 address")
+			log.Error().Err(err).Msg("Cannot retrieve WAN IPv6 address")
 		} else {
 			log.Info().Msgf("Current WAN IPv6: %s", wanIPv6)
 		}
 	}
 
-	// Skip if last IP is identical
-	if wanIPv4 == c.lastIPv4 && wanIPv6 == c.lastIPv6 {
-		log.Info().Msg("WAN IPv4/IPv6 addresses have not changed since the last update. Skipping...")
+	if wanIPv4 == nil && wanIPv6 == nil {
+		return
+	}
+
+	// Skip if last IP is identical or empty
+	if wanIPv4.Equal(c.lastIPv4) && wanIPv6.Equal(c.lastIPv6) {
+		log.Info().Msg("WAN IPv4/IPv6 addresses have not changed since last update. Skipping...")
 		return
 	}
 
 	// Create Route53 changes
 	r53Changes := make([]*route53.Change, len(c.cfg.Route53.RecordsSet))
 	for i, rs := range c.cfg.Route53.RecordsSet {
-		if wanIPv4 == "" && rs.Type == route53.RRTypeA {
+		if wanIPv4 == nil && rs.Type == route53.RRTypeA {
 			log.Error().Msgf("No WAN IPv4 address available to update %s record", rs.Name)
 			continue
-		} else if wanIPv6 == "" && rs.Type == route53.RRTypeAaaa {
+		} else if wanIPv6 == nil && rs.Type == route53.RRTypeAaaa {
 			log.Error().Msgf("No WAN IPv6 address available to update %s record", rs.Name)
 			continue
 		}
-		wanIP := wanIPv4
+		recordValue := aws.String(wanIPv4.String())
 		if rs.Type == route53.RRTypeAaaa {
-			wanIP = wanIPv6
+			recordValue = aws.String(wanIPv6.String())
 		}
 		r53Changes[i] = &route53.Change{
 			Action: aws.String("UPSERT"),
 			ResourceRecordSet: &route53.ResourceRecordSet{
 				Name:            aws.String(rs.Name),
 				Type:            aws.String(rs.Type),
 				TTL:             aws.Int64(rs.TTL),
-				ResourceRecords: []*route53.ResourceRecord{{Value: aws.String(wanIP)}},
+				ResourceRecords: []*route53.ResourceRecord{{Value: recordValue}},
 			},
 		}
 	}