inspect: add inspect mode for debugging crashed tendermint node (#6785)

EDIT: Updated, see [comment below]( https://github.com/tendermint/tendermint/pull/6785#issuecomment-897793175)

This change adds a sketch of the `Debug` mode. 

This change adds a `Debug` struct to the node package. This `Debug` struct is intended to be created and started by a command in the `cmd` directory. The `Debug` struct runs the RPC server on the data directories: both the state store and the block store.

This change required a good deal of refactoring. Namely, a new `rpc.go` file was added to the `node` package. This file encapsulates functions for starting RPC servers used by nodes. A potential additional change is to further factor this code into shared code _in_ the `rpc` package. 

Minor API tweaks were also made that seemed appropriate such as the mechanism for fetching routes from the `rpc/core` package.

Additional work is required to register the `Debug` service as a command in the `cmd` directory but I am looking for feedback on if this direction seems appropriate before diving much further.

closes: #5908

node/node.go

@@ -441,22 +441,23 @@ func makeNode(config *cfg.Config,
 			ProxyAppQuery:   proxyApp.Query(),
 			ProxyAppMempool: proxyApp.Mempool(),
 
-			StateStore:       stateStore,
-			BlockStore:       blockStore,
-			EvidencePool:     evPool,
-			ConsensusState:   csState,
+			StateStore:     stateStore,
+			BlockStore:     blockStore,
+			EvidencePool:   evPool,
+			ConsensusState: csState,
+
+			ConsensusReactor: csReactor,
 			BlockSyncReactor: bcReactor.(cs.BlockSyncReactor),
 
 			P2PPeers:    sw,
 			PeerManager: peerManager,
 
-			GenDoc:           genDoc,
-			EventSinks:       eventSinks,
-			ConsensusReactor: csReactor,
-			EventBus:         eventBus,
-			Mempool:          mp,
-			Logger:           logger.With("module", "rpc"),
-			Config:           *config.RPC,
+			GenDoc:     genDoc,
+			EventSinks: eventSinks,
+			EventBus:   eventBus,
+			Mempool:    mp,
+			Logger:     logger.With("module", "rpc"),
+			Config:     *config.RPC,
 		},
 	}
 
@@ -825,7 +826,7 @@ func (n *nodeImpl) startRPC() ([]net.Listener, error) {
 		rpcserver.RegisterRPCFuncs(mux, routes, rpcLogger)
 		listener, err := rpcserver.Listen(
 			listenAddr,
-			config,
+			config.MaxOpenConnections,
 		)
 		if err != nil {
 			return nil, err
@@ -883,7 +884,7 @@ func (n *nodeImpl) startRPC() ([]net.Listener, error) {
 		if config.WriteTimeout <= n.config.RPC.TimeoutBroadcastTxCommit {
 			config.WriteTimeout = n.config.RPC.TimeoutBroadcastTxCommit + 1*time.Second
 		}
-		listener, err := rpcserver.Listen(grpcListenAddr, config)
+		listener, err := rpcserver.Listen(grpcListenAddr, config.MaxOpenConnections)
 		if err != nil {
 			return nil, err
 		}

node/setup.go

@@ -8,7 +8,6 @@ import (
 	"math"
 	"net"
 	_ "net/http/pprof" // nolint: gosec // securely exposed on separate, optional port
-	"strings"
 	"time"
 
 	dbm "github.com/tendermint/tm-db"
@@ -33,9 +32,7 @@ import (
 	"github.com/tendermint/tendermint/proxy"
 	sm "github.com/tendermint/tendermint/state"
 	"github.com/tendermint/tendermint/state/indexer"
-	kv "github.com/tendermint/tendermint/state/indexer/sink/kv"
-	null "github.com/tendermint/tendermint/state/indexer/sink/null"
-	psql "github.com/tendermint/tendermint/state/indexer/sink/psql"
+	"github.com/tendermint/tendermint/state/indexer/sink"
 	"github.com/tendermint/tendermint/store"
 	"github.com/tendermint/tendermint/types"
 	"github.com/tendermint/tendermint/version"
@@ -78,56 +75,9 @@ func createAndStartIndexerService(
 	logger log.Logger,
 	chainID string,
 ) (*indexer.Service, []indexer.EventSink, error) {
-
-	eventSinks := []indexer.EventSink{}
-
-	// check for duplicated sinks
-	sinks := map[string]bool{}
-	for _, s := range config.TxIndex.Indexer {
-		sl := strings.ToLower(s)
-		if sinks[sl] {
-			return nil, nil, errors.New("found duplicated sinks, please check the tx-index section in the config.toml")
-		}
-
-		sinks[sl] = true
-	}
-
-loop:
-	for k := range sinks {
-		switch k {
-		case string(indexer.NULL):
-			// When we see null in the config, the eventsinks will be reset with the
-			// nullEventSink.
-			eventSinks = []indexer.EventSink{null.NewEventSink()}
-			break loop
-
-		case string(indexer.KV):
-			store, err := dbProvider(&cfg.DBContext{ID: "tx_index", Config: config})
-			if err != nil {
-				return nil, nil, err
-			}
-
-			eventSinks = append(eventSinks, kv.NewEventSink(store))
-
-		case string(indexer.PSQL):
-			conn := config.TxIndex.PsqlConn
-			if conn == "" {
-				return nil, nil, errors.New("the psql connection settings cannot be empty")
-			}
-
-			es, _, err := psql.NewEventSink(conn, chainID)
-			if err != nil {
-				return nil, nil, err
-			}
-			eventSinks = append(eventSinks, es)
-
-		default:
-			return nil, nil, errors.New("unsupported event sink type")
-		}
-	}
-
-	if len(eventSinks) == 0 {
-		eventSinks = []indexer.EventSink{null.NewEventSink()}
+	eventSinks, err := sink.EventSinksFromConfig(config, dbProvider, chainID)
+	if err != nil {
+		return nil, nil, err
 	}
 
 	indexerService := indexer.NewIndexerService(eventSinks, eventBus)