Integrate nim-metrics and add some metrics from the ETH2 spec (#394)

beacon_chain.nimble

@@ -17,19 +17,20 @@ bin           = @[
 
 ### Dependencies
 requires "nim >= 0.19.0",
-  "eth",
-  "nimcrypto",
   "blscurve",
-  "stew",
   "chronicles",
-  "confutils",
-  "serialization",
-  "json_serialization",
-  "json_rpc",
   "chronos",
-  "yaml",
+  "confutils",
+  "eth",
+  "json_rpc",
+  "json_serialization",
   "libp2p",
-  "web3"
+  "metrics",
+  "nimcrypto",
+  "serialization",
+  "stew",
+  "web3",
+  "yaml"
 
 ### Helper functions
 proc buildBinary(name: string, srcDir = "./", params = "", cmdParams = "", lang = "c") =

beacon_chain/beacon_node.nim

@@ -1,7 +1,7 @@
 import
   net, sequtils, options, tables, osproc, random, strutils, times, strformat,
   stew/shims/os, stew/[objects, bitseqs],
-  chronos, chronicles, confutils,
+  chronos, chronicles, confutils, metrics,
   json_serialization/std/sets, serialization/errors,
   eth/trie/db, eth/trie/backends/rocksdb_backend, eth/async_utils,
   spec/[datatypes, digest, crypto, beaconstate, helpers, validator,
@@ -23,6 +23,28 @@ const
   genesisFile = "genesis.json"
   testnetsBaseUrl = "https://serenity-testnets.status.im"
 
+declareGauge beacon_slot, "Latest slot of the beacon chain state"
+declareGauge beacon_head_slot, "Slot of the head block of the beacon chain"
+declareGauge beacon_head_root, "Root of the head block of the beacon chain"
+
+# TODO Implement these additional metrics (some of the them should be moved to different modules):
+declareGauge beacon_finalized_epoch, "Current finalized epoch" # On epoch transition
+declareGauge beacon_finalized_root, "Current finalized root" # On epoch transition
+declareGauge beacon_current_justified_epoch, "Current justified epoch" # On epoch transition
+declareGauge beacon_current_justified_root, "Current justified root" # On epoch transition
+declareGauge beacon_previous_justified_epoch, "Current previously justified epoch" # On epoch transition
+declareGauge beacon_previous_justified_root, "Current previously justified root" # On epoch transition
+
+declareGauge beacon_current_validators, """Number of status="pending|active|exited|withdrawable" validators in current epoch""" # On epoch transition
+declareGauge beacon_previous_validators, """Number of status="pending|active|exited|withdrawable" validators in previous epoch""" # On epoch transition
+declareGauge beacon_current_live_validators, "Number of active validators that successfully included attestation on chain for current epoch" # On block
+declareGauge beacon_previous_live_validators, "Number of active validators that successfully included attestation on chain for previous epoch" # On block
+declareGauge beacon_pending_deposits, "Number of pending deposits (state.eth1_data.deposit_count - state.eth1_deposit_index)" # On block
+declareGauge beacon_processed_deposits_total, "Number of total deposits included on chain" # On block
+declareGauge beacon_pending_exits, "Number of pending voluntary exits in local operation pool" # On slot
+declareGauge beacon_previous_epoch_orphaned_blocks, "Number of blocks orphaned in the previous epoch" # On epoch transition
+declareCounter beacon_reorgs_total, "Total occurrences of reorganizations of the chain" # On fork choice
+
 proc onBeaconBlock*(node: BeaconNode, blck: BeaconBlock) {.gcsafe.}
 
 func localValidatorsDir(conf: BeaconNodeConf): string =
@@ -212,6 +234,12 @@ proc init*(T: type BeaconNode, conf: BeaconNodeConf): Future[BeaconNode] {.async
   result.network.saveConnectionAddressFile(addressFile)
   result.beaconClock = BeaconClock.init(result.stateCache.data.data)
 
+  when useInsecureFeatures:
+    if conf.metricsServer:
+      let metricsAddress = conf.metricsServerAddress
+      info "Starting metrics HTTP server", address = metricsAddress, port = conf.metricsServerPort
+      metrics.startHttpServer(metricsAddress, Port(conf.metricsServerPort))
+
 template withState(
     pool: BlockPool, cache: var StateData, blockSlot: BlockSlot, body: untyped): untyped =
   ## Helper template that updates state to a particular BlockSlot - usage of
@@ -296,6 +324,9 @@ proc updateHead(node: BeaconNode, slot: Slot): BlockRef =
     newHeadBlockRoot = shortLog(newHead.root)
 
   node.blockPool.updateHead(node.stateCache, newHead)
+  beacon_head_slot.set slot.int64
+  beacon_head_root.set newHead.root.toGaugeValue
+
   newHead
 
 proc sendAttestation(node: BeaconNode,
@@ -589,6 +620,8 @@ proc onSlotStart(node: BeaconNode, lastSlot, scheduledSlot: Slot) {.gcsafe, asyn
     slot = wallSlot.slot # afterGenesis == true!
     nextSlot = slot + 1
 
+  beacon_slot.set slot.int64
+
   if slot > lastSlot + SLOTS_PER_EPOCH:
     # We've fallen behind more than an epoch - there's nothing clever we can
     # do here really, except skip all the work and try again later.

beacon_chain/beacon_node_types.nim

@@ -1,6 +1,6 @@
 import
   sets, deques, tables,
-  eth/keys, stew/bitseqs,
+  eth/keys, stew/[bitseqs, endians2],
   spec/[datatypes, crypto, digest],
   beacon_chain_db, conf, mainchain_monitor, eth2_network, time
 
@@ -270,3 +270,10 @@ proc userValidatorsRange*(d: NetworkMetadata): HSlice[int, int] =
   0 .. d.lastUserValidator.int
 
 proc shortLog*(v: AttachedValidator): string = shortLog(v.pubKey)
+
+proc toGaugeValue*(hash: Eth2Digest): int64 =
+  # Only the last 8 bytes are taken into consideration in accordance
+  # to the ETH2 metrics spec:
+  # https://github.com/ethereum/eth2.0-metrics/blob/6a79914cb31f7d54858c7dd57eee75b6162ec737/metrics.md#interop-metrics
+  cast[int64](uint64.fromBytes(hash.data[24..31], littleEndian))
+

beacon_chain/conf.nim

@@ -86,6 +86,18 @@ type
               "If you set this to 'auto', a persistent automatically generated ID will be seleceted for each --dataDir folder"
         defaultValue: ""}: string
 
+      metricsServer* {.
+        desc: "Enable the metrics server"
+        defaultValue: false.}: bool
+
+      metricsServerAddress* {.
+        desc: "Listening address of the metrics server"
+        defaultValue: "0.0.0.0".}: string # TODO: use a validated type here
+
+      metricsServerPort* {.
+        desc: "Listening HTTP port of the metrics server"
+        defaultValue: 8008 .}: uint16
+
     of createTestnet:
       networkId* {.
         desc: "An unique numeric identifier for the network".}: uint8

beacon_chain/sync_protocol.nim

@@ -1,6 +1,6 @@
 import
   options, tables, sequtils, algorithm, sets, macros,
-  chronicles, chronos, stew/ranges/bitranges,
+  chronicles, chronos, metrics, stew/ranges/bitranges,
   spec/[datatypes, crypto, digest, helpers], eth/rlp,
   beacon_node_types, eth2_network, beacon_chain_db, block_pool, time, ssz
 
@@ -8,6 +8,8 @@ when networkBackend == rlpxBackend:
   import eth/rlp/options as rlpOptions
   template libp2pProtocol*(name: string, version: int) {.pragma.}
 
+declareGauge libp2p_peers, "Number of libp2p peers"
+
 type
   ValidatorSetDeltaFlags {.pure.} = enum
     Activation = 0
@@ -108,6 +110,7 @@ p2pProtocol BeaconSync(version = 1,
     # where it needs to sync and it should execute the sync algorithm with a certain
     # number of randomly selected peers. The algorithm itself must be extracted in a proc.
     try:
+      libp2p_peers.set peer.network.peers.len.int64
       debug "Peer connected. Initiating sync", peer, bestSlot, remoteBestSlot = m.bestSlot
 
       let bestDiff = cmp((latestFinalizedEpoch, bestSlot), (m.latestFinalizedEpoch, m.bestSlot))
@@ -140,6 +143,9 @@ p2pProtocol BeaconSync(version = 1,
     except CatchableError:
       warn "Failed to sync with peer", peer, err = getCurrentExceptionMsg()
 
+  onPeerDisconnected do (peer: Peer):
+    libp2p_peers.set peer.network.peers.len.int64
+
   handshake:
     proc hello(
             peer: Peer,

beacon_chain/version.nim

@@ -20,6 +20,11 @@ const
     # Clients having different semantic versions won't be able
     # to join the same testnets.
 
+  useInsecureFeatures* = true # defined(insecure)
+    # TODO This is temporarily set to true, so it's easier for other teams to
+    # launch the beacon_node with metrics enabled during the interop lock-in.
+    # We'll disable it once the lock-in is over.
+
 template versionAsStr*: string =
   $versionMajor & "." & $versionMinor & "." & $versionBuild
 

vendor/nim-eth

@@ -1 +1 @@
-Subproject commit bef28a18e58f52f24bcc50f0cadefac0224d4630
+Subproject commit 44adb2a70a7a6d5720652029f722960eeec400de