WIP instance sync

cmd/root.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"math"
+	"net"
 	"os"
 	"os/signal"
 	"strconv"
@@ -23,6 +24,8 @@ import (
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
 	"github.com/thediveo/enumflag/v2"
+
+	"github.com/hashicorp/memberlist"
 )
 
 var cfg config.Config
@@ -247,6 +250,8 @@ func RootCmd() *cobra.Command {
 	rootCmd.PersistentFlags().StringArrayVar(&amqpAppProperties, "amqp-app-property", []string{}, "AMQP application properties, eg. key1=val1,val2")
 	rootCmd.PersistentFlags().StringArrayVar(&amqpAppPropertyFilters, "amqp-app-property-filter", []string{}, "AMQP application property filters, eg. key1=$p:prefix")
 	rootCmd.PersistentFlags().StringArrayVar(&amqpPropertyFilters, "amqp-property-filter", []string{}, "AMQP property filters, eg. key1=$p:prefix")
+	rootCmd.PersistentFlags().IntVar(&cfg.ExpectedInstances, "expected-instances", 1, "The number of instances to synchronize")
+	rootCmd.PersistentFlags().StringVar(&cfg.SyncName, "expected-instances-dns", "", "The DNS name that will return members to synchronize with")
 
 	rootCmd.AddCommand(amqp_amqp)
 	rootCmd.AddCommand(amqp_stomp)
@@ -263,6 +268,8 @@ func RootCmd() *cobra.Command {
 }
 
 func start(cfg config.Config) {
+	join_cluster(cfg.ExpectedInstances, cfg.SyncName)
+
 	if cfg.ConsumerLatency != 0 && cfg.ConsumerProto == config.MQTT {
 		fmt.Printf("Consumer latency is not supported for MQTT consumers")
 		os.Exit(1)
@@ -340,6 +347,45 @@ func start(cfg config.Config) {
 	wg.Wait()
 }
 
+func join_cluster(expectedInstance int, serviceName string) {
+	list, err := memberlist.Create(memberlist.DefaultLANConfig())
+	if err != nil {
+		panic("Failed to create memberlist: " + err.Error())
+	}
+
+	// keep trying to retrieve IPs for the DNS name in serviceName
+	// until there's no error
+	var ips []net.IP
+	for {
+		ips, err = net.LookupIP(serviceName)
+		if err == nil && len(ips) > 0 {
+			hosts := make([]string, len(ips))
+			for i, ip := range ips {
+				hosts[i] = ip.String()
+			}
+			// Join an existing cluster by specifying at least one known member.
+			_, err = list.Join(hosts)
+			if err == nil {
+				break
+			} else {
+				log.Info("failed to join cluster", "error", err)
+			}
+		} else {
+			log.Info("failed to lookup the service name", "error", err)
+		}
+		time.Sleep(time.Second)
+	}
+	for {
+		members := list.Members()
+		if len(members) >= expectedInstance {
+			break
+		}
+		log.Info("Waiting for more instances to join the cluster", "expected instances", expectedInstance, "current cluster size", len(members))
+		time.Sleep(time.Second)
+	}
+
+}
+
 func startConsumers(ctx context.Context, consumerProto config.Protocol, wg *sync.WaitGroup) {
 	for i := 1; i <= cfg.Consumers; i++ {
 		subscribed := make(chan bool)

go.mod

@@ -20,27 +20,39 @@ require (
 )
 
 require (
+	github.com/armon/go-metrics v0.0.0-20180917152333-f0300d1749da // indirect
 	github.com/aymanbagabas/go-osc52/v2 v2.0.1 // indirect
 	github.com/charmbracelet/lipgloss v1.0.0 // indirect
 	github.com/charmbracelet/x/ansi v0.5.0 // indirect
 	github.com/go-logfmt/logfmt v0.6.0 // indirect
 	github.com/go-logr/logr v1.4.2 // indirect
 	github.com/go-task/slim-sprig/v3 v3.0.0 // indirect
+	github.com/google/btree v0.0.0-20180813153112-4030bb1f1f0c // indirect
 	github.com/google/go-cmp v0.6.0 // indirect
 	github.com/google/pprof v0.0.0-20241101162523-b92577c0c142 // indirect
 	github.com/google/uuid v1.6.0 // indirect
 	github.com/gorilla/websocket v1.5.3 // indirect
+	github.com/hashicorp/errwrap v1.0.0 // indirect
+	github.com/hashicorp/go-immutable-radix v1.0.0 // indirect
+	github.com/hashicorp/go-msgpack/v2 v2.1.1 // indirect
+	github.com/hashicorp/go-multierror v1.0.0 // indirect
+	github.com/hashicorp/go-sockaddr v1.0.0 // indirect
+	github.com/hashicorp/golang-lru v0.5.0 // indirect
+	github.com/hashicorp/memberlist v0.5.1 // indirect
 	github.com/kr/pretty v0.3.1 // indirect
 	github.com/lucasb-eyer/go-colorful v1.2.0 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect
 	github.com/mattn/go-runewidth v0.0.16 // indirect
+	github.com/miekg/dns v1.1.26 // indirect
 	github.com/muesli/termenv v0.15.2 // indirect
 	github.com/onsi/ginkgo v1.16.5 // indirect
 	github.com/rivo/uniseg v0.4.7 // indirect
 	github.com/rogpeppe/go-internal v1.11.0 // indirect
+	github.com/sean-/seed v0.0.0-20170313163322-e2103e2c3529 // indirect
 	github.com/streadway/amqp v1.1.0 // indirect
 	github.com/valyala/fastrand v1.1.0 // indirect
 	github.com/valyala/histogram v1.2.0 // indirect
+	golang.org/x/crypto v0.29.0 // indirect
 	golang.org/x/exp v0.0.0-20241108190413-2d47ceb2692f // indirect
 	golang.org/x/net v0.31.0 // indirect
 	golang.org/x/sync v0.9.0 // indirect

go.sum

@@ -1,5 +1,7 @@
 github.com/VictoriaMetrics/metrics v1.35.1 h1:o84wtBKQbzLdDy14XeskkCZih6anG+veZ1SwJHFGwrU=
 github.com/VictoriaMetrics/metrics v1.35.1/go.mod h1:r7hveu6xMdUACXvB8TYdAj8WEsKzWB0EkpJN+RDtOf8=
+github.com/armon/go-metrics v0.0.0-20180917152333-f0300d1749da h1:8GUt8eRujhVEGZFFEjBj46YV4rDjvGrNxb0KMWYkL2I=
+github.com/armon/go-metrics v0.0.0-20180917152333-f0300d1749da/go.mod h1:Q73ZrmVTwzkszR9V5SSuryQ31EELlFMUz1kKyl939pY=
 github.com/aymanbagabas/go-osc52/v2 v2.0.1 h1:HwpRHbFMcZLEVr42D4p7XBqjyuxQH5SMiErDT4WkJ2k=
 github.com/aymanbagabas/go-osc52/v2 v2.0.1/go.mod h1:uYgXzlJ7ZpABp8OJ+exZzJJhRNQ2ASbcXHWsFqH8hp8=
 github.com/charmbracelet/lipgloss v1.0.0 h1:O7VkGDvqEdGi93X+DeqsQ7PKHDgtQfF8j8/O2qFMQNg=
@@ -51,6 +53,8 @@ github.com/golang/protobuf v1.4.0-rc.2/go.mod h1:LlEzMj4AhA7rCAGe4KMBDvJI+AwstrU
 github.com/golang/protobuf v1.4.0-rc.4.0.20200313231945-b860323f09d0/go.mod h1:WU3c8KckQ9AFe+yFwt9sWVRKCVIyN9cPHBJSNnbL67w=
 github.com/golang/protobuf v1.4.0/go.mod h1:jodUvKwWbYaEsadDk5Fwe5c77LiNKVO9IDvqG2KuDX0=
 github.com/golang/protobuf v1.4.2/go.mod h1:oDoupMAO8OvCJWAcko0GGGIgR6R6ocIYbsSw735rRwI=
+github.com/google/btree v0.0.0-20180813153112-4030bb1f1f0c h1:964Od4U6p2jUkFxvCydnIczKteheJEzHRToSGK3Bnlw=
+github.com/google/btree v0.0.0-20180813153112-4030bb1f1f0c/go.mod h1:lNA+9X1NB3Zf8V7Ke586lFgjr2dZNuvo3lPJSGZ5JPQ=
 github.com/google/go-cmp v0.3.0/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
 github.com/google/go-cmp v0.3.1/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
 github.com/google/go-cmp v0.4.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
@@ -63,6 +67,21 @@ github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
 github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/gorilla/websocket v1.5.3 h1:saDtZ6Pbx/0u+bgYQ3q96pZgCzfhKXGPqt7kZ72aNNg=
 github.com/gorilla/websocket v1.5.3/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
+github.com/hashicorp/errwrap v1.0.0 h1:hLrqtEDnRye3+sgx6z4qVLNuviH3MR5aQ0ykNJa/UYA=
+github.com/hashicorp/errwrap v1.0.0/go.mod h1:YH+1FKiLXxHSkmPseP+kNlulaMuP3n2brvKWEqk/Jc4=
+github.com/hashicorp/go-immutable-radix v1.0.0 h1:AKDB1HM5PWEA7i4nhcpwOrO2byshxBjXVn/J/3+z5/0=
+github.com/hashicorp/go-immutable-radix v1.0.0/go.mod h1:0y9vanUI8NX6FsYoO3zeMjhV/C5i9g4Q3DwcSNZ4P60=
+github.com/hashicorp/go-msgpack/v2 v2.1.1 h1:xQEY9yB2wnHitoSzk/B9UjXWRQ67QKu5AOm8aFp8N3I=
+github.com/hashicorp/go-msgpack/v2 v2.1.1/go.mod h1:upybraOAblm4S7rx0+jeNy+CWWhzywQsSRV5033mMu4=
+github.com/hashicorp/go-multierror v1.0.0 h1:iVjPR7a6H0tWELX5NxNe7bYopibicUzc7uPribsnS6o=
+github.com/hashicorp/go-multierror v1.0.0/go.mod h1:dHtQlpGsu+cZNNAkkCN/P3hoUDHhCYQXV3UM06sGGrk=
+github.com/hashicorp/go-sockaddr v1.0.0 h1:GeH6tui99pF4NJgfnhp+L6+FfobzVW3Ah46sLo0ICXs=
+github.com/hashicorp/go-sockaddr v1.0.0/go.mod h1:7Xibr9yA9JjQq1JpNB2Vw7kxv8xerXegt+ozgdvDeDU=
+github.com/hashicorp/go-uuid v1.0.0/go.mod h1:6SBZvOh/SIDV7/2o3Jml5SYk/TvGqwFJ/bN7x4byOro=
+github.com/hashicorp/golang-lru v0.5.0 h1:CL2msUPvZTLb5O648aiLNJw3hnBxN2+1Jq8rCOH9wdo=
+github.com/hashicorp/golang-lru v0.5.0/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
+github.com/hashicorp/memberlist v0.5.1 h1:mk5dRuzeDNis2bi6LLoQIXfMH7JQvAzt3mQD0vNZZUo=
+github.com/hashicorp/memberlist v0.5.1/go.mod h1:zGDXV6AqbDTKTM6yxW0I4+JtFzZAJVoIPvss4hV8F24=
 github.com/hpcloud/tail v1.0.0/go.mod h1:ab1qPbhIpdTxEkNHXyeSf5vhxWSCs/tWer42PpOxQnU=
 github.com/ianlancetaylor/demangle v0.0.0-20230524184225-eabc099b10ab/go.mod h1:gx7rwoVhcfuVKG5uya9Hs3Sxj7EIvldVofAWIUtGouw=
 github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
@@ -85,6 +104,8 @@ github.com/mattn/go-runewidth v0.0.16 h1:E5ScNMtiwvlvB5paMFdw9p4kSQzbXFikJ5SQO6T
 github.com/mattn/go-runewidth v0.0.16/go.mod h1:Jdepj2loyihRzMpdS35Xk/zdY8IAYHsh153qUoGf23w=
 github.com/michaelklishin/rabbit-hole v1.5.0 h1:Bex27BiFDsijCM9D0ezSHqyy0kehpYHuNKaPqq/a4RM=
 github.com/michaelklishin/rabbit-hole v1.5.0/go.mod h1:vvI1uOitYZi0O5HEGXhaWC1XT80Gy+HvFheJ+5Krlhk=
+github.com/miekg/dns v1.1.26 h1:gPxPSwALAeHJSjarOs00QjVdV9QoBvc1D2ujQUr5BzU=
+github.com/miekg/dns v1.1.26/go.mod h1:bPDLeHnStXmXAq1m/Ch/hvfNHr14JKNPMBo3VZKjuso=
 github.com/mkuratczyk/go-amqp v0.0.0-20241014095613-d9376f5f2d9f h1:WVdm43rq1NhTOuRrxn73Tw4j9rrrC/ilOEKWTYxFWqo=
 github.com/mkuratczyk/go-amqp v0.0.0-20241014095613-d9376f5f2d9f/go.mod h1:vZAogwdrkbyK3Mla8m/CxSc/aKdnTZ4IbPxl51Y5WZE=
 github.com/muesli/termenv v0.15.2 h1:GohcuySI0QmI3wN8Ok9PtKGkgkFIk7y6Vpb5PvrY+Wo=
@@ -117,6 +138,8 @@ github.com/rogpeppe/go-internal v1.9.0/go.mod h1:WtVeX8xhTBvf0smdhujwtBcq4Qrzq/f
 github.com/rogpeppe/go-internal v1.11.0 h1:cWPaGQEPrBb5/AsnsZesgZZ9yb1OQ+GOISoDNXVBh4M=
 github.com/rogpeppe/go-internal v1.11.0/go.mod h1:ddIwULY96R17DhadqLgMfk9H9tvdUzkipdSkR5nkCZA=
 github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
+github.com/sean-/seed v0.0.0-20170313163322-e2103e2c3529 h1:nn5Wsu0esKSJiIVhscUtVbo7ada43DJhG55ua/hjS5I=
+github.com/sean-/seed v0.0.0-20170313163322-e2103e2c3529/go.mod h1:DxrIzT+xaE7yg65j358z/aeFdxmN0P9QXhEzd20vsDc=
 github.com/sirupsen/logrus v1.9.3 h1:dueUQJ1C2q9oE3F7wvmSGAaVtTmUizReu6fjN8uqzbQ=
 github.com/sirupsen/logrus v1.9.3/go.mod h1:naHLuLoDiP4jHNo9R0sCBMtWGeIprob74mVsIT4qYEQ=
 github.com/spf13/cobra v1.8.1 h1:e5/vxKd/rZsfSJMUX1agtjeTDf+qv1/JdBF8gg5k9ZM=
@@ -145,15 +168,19 @@ github.com/yuin/goldmark v1.3.5/go.mod h1:mwnBkeHKe2W/ZEtQ+71ViKU8L12m81fl3OWwC1
 go.uber.org/goleak v1.2.1 h1:NBol2c7O1ZokfZ0LEU9K6Whx/KnwvepVetCUhtKja4A=
 go.uber.org/goleak v1.2.1/go.mod h1:qlT2yGI9QafXHhZZLxlSuNsMw3FFLxBr+tBRlmO1xH4=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20190923035154-9ee001bba392/go.mod h1:/lpIB1dKB+9EgE3H3cr1v9wB50oz8l4C4h62xy7jSTY=
 golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
+golang.org/x/crypto v0.29.0 h1:L5SG1JTTXupVV3n6sUqMTeWbjAyfPwoda2DLX8J8FrQ=
+golang.org/x/crypto v0.29.0/go.mod h1:+F4F4N5hv6v38hfeYwTdx20oUvLLc+QfrE9Ax9HtgRg=
 golang.org/x/exp v0.0.0-20241108190413-2d47ceb2692f h1:XdNn9LlyWAhLVp6P/i8QYBW+hlyhrhei9uErw2B5GJo=
 golang.org/x/exp v0.0.0-20241108190413-2d47ceb2692f/go.mod h1:D5SMRVC3C2/4+F/DB1wZsLRnSNimn2Sp/NPsCrsv8ak=
 golang.org/x/mod v0.3.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/mod v0.4.2/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/net v0.0.0-20180906233101-161cd47e91fd/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20190923162816-aa69164e4478/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/net v0.0.0-20200520004742-59133d7f0dd7/go.mod h1:qpuaurCH72eLCgpAm/N6yyVIVM9cpaDIP3A8BGJEC5A=
 golang.org/x/net v0.0.0-20201021035429-f5854403a974/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
 golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4/go.mod h1:p54w0d4576C0XHj96bSt6lcn1PtDYWL6XObtHCRCNQM=
@@ -169,6 +196,8 @@ golang.org/x/sys v0.0.0-20180909124046-d0be0721c37e/go.mod h1:STP8DvDyc/dI5b8T5h
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190904154756-749cb33beabd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20190922100055-0a153f010e69/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20190924154521-2837fb4f24fe/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20191005200804-aed5e4c7ecf9/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20191120155948-bd437916bb0e/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200323222414-85ca7c5b95cd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
@@ -183,10 +212,12 @@ golang.org/x/sys v0.27.0 h1:wBqf8DvsY9Y/2P8gAfPDEYNuS30J4lPHJxXSb/nJZ+s=
 golang.org/x/sys v0.27.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.20.0 h1:gK/Kv2otX8gz+wn7Rmb3vT96ZwuoxnQlY+HlJVj7Qug=
 golang.org/x/text v0.20.0/go.mod h1:D4IsuqiFMhST5bX19pQ9ikHC2GsaKyk/oF+pn3ducp4=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/tools v0.0.0-20190907020128-2ca718005c18/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools v0.0.0-20201224043029-2b0845dc783e/go.mod h1:emZCQorbCU4vsT4fOWvOPXz4eW1wZW4PmDk9uLelYpA=
 golang.org/x/tools v0.1.1/go.mod h1:o0xws9oXOQQZyjljx8fwUC0k7L1pTE6eaCbjGeHmOkk=

pkg/config/config.go

@@ -63,6 +63,8 @@ type MqttOptions struct {
 }
 
 type Config struct {
+	ExpectedInstances    int
+	SyncName             string
 	ConsumerProto        Protocol
 	PublisherProto       Protocol
 	PublisherId          string