dump-snap.go

package main

import (
	"fmt"
	"io"
	"os"

	"github.com/hashicorp/consul/agent/structs"
	"github.com/hashicorp/go-msgpack/codec"
)

// snapshotHeader is the first entry in our snapshot
type snapshotHeader struct {
	// LastIndex is the last index that affects the data.
	// This is used when we do the restore for watchers.
	LastIndex uint64
}

func main() {

	// msgpackHandle is a shared handle for encoding/decoding msgpack payloads
	var msgpackHandle = &codec.MsgpackHandle{
		RawToString: true,
	}

	old := os.Stdin

	dec := codec.NewDecoder(old, msgpackHandle)

	// Read in the header
	var header snapshotHeader
	if err := dec.Decode(&header); err != nil {
		panic(err)
	}

	// Populate the new state
	msgType := make([]byte, 1)
	for {
		// Read the message type
		_, err := old.Read(msgType)
		if err == io.EOF {
			break
		} else if err != nil {
			panic(err)
		}

		// Decode
		msg := structs.MessageType(msgType[0])
		fmt.Printf("Message Type %d\n", msg)

		var val interface{}

		err = dec.Decode(&val)
		if err != nil {
			panic(err)
		}

		fmt.Println(val)
	}
}

example.txt

$ # Note message type 15 is connect CA config and is usually near the end.
$ cat /tmp/consul-corrupt/raft/snapshots/3-7136-1544044771131/state.bin  | go run dump-snap.go
Message Type 0
map[Check:<nil> Checks:<nil> ID:d101a112-0598-5581-33db-4382a01017c5 Token: SkipNodeUpdate:false TaggedAddresses:map[lan:127.0.0.1 wan:127.0.0.1] Address:127.0.0.1 Datacenter:dc1 Node:Evariste.local NodeMeta:map[consul-network-segment:] Service:<nil>]
Message Type 0
map[Datacenter:dc1 TaggedAddresses:map[lan:127.0.0.1 wan:127.0.0.1] Checks:<nil> Check:<nil> ID:d101a112-0598-5581-33db-4382a01017c5 Node:Evariste.local NodeMeta:map[consul-network-segment:] Service:map[Proxy:map[Config:<nil> DestinationServiceID: DestinationServiceName: LocalServiceAddress: LocalServicePort:0 Upstreams:<nil>] Kind: LocallyRegisteredAsSidecar:false ModifyIndex:2564 ProxyDestination: Tags:<nil> Address: Connect:map[Native:false Proxy:<nil> SidecarService:<nil>] EnableTagOverride:false ID:consul Service:consul Weights:map[Warning:1 Passing:1] CreateIndex:2564 Meta:<nil> Port:8300] SkipNodeUpdate:false Token: Address:127.0.0.1]
...
Message Type 15
map[Provider: ClusterID: Config:<nil> CreateIndex:0 ModifyIndex:0]