metrics: HTTP server disabled by default

- metric logging added
- new Nimbus options: --metricsServer, --metricsServerPort:<value>,
  --logMetrics, --logMetricsInterval:<value>

nimbus/config.nim

@@ -135,7 +135,8 @@ type
     staticNodes*: seq[ENode]      ## List of static nodes to connect to
     bindPort*: uint16             ## Main TCP bind port
     discPort*: uint16             ## Discovery UDP bind port
-    metricsPort*: uint16          ## metrics HTTP server port
+    metricsServer*: bool           ## Enable metrics server
+    metricsServerPort*: uint16    ## metrics HTTP server port
     maxPeers*: int                ## Maximum allowed number of peers
     maxPendingPeers*: int         ## Maximum allowed pending peers
     networkId*: uint              ## Network ID as integer
@@ -150,6 +151,8 @@ type
     flags*: set[DebugFlags]       ## Debug flags
     logLevel*: LogLevel           ## Log level
     logFile*: string              ## Log file
+    logMetrics*: bool             ## Enable metrics logging
+    logMetricsInterval*: int      ## Metrics logging interval
 
   PruneMode* {.pure.} = enum
     Full
@@ -494,11 +497,13 @@ proc processNetArguments(key, value: string): ConfigStatus =
     result = processInteger(value, res)
     if result == Success:
       config.net.discPort = uint16(res and 0xFFFF)
-  elif skey == "metricsport":
+  elif skey == "metricsserver":
+    config.net.metricsServer = true
+  elif skey == "metricsserverport":
     var res = 0
     result = processInteger(value, res)
     if result == Success:
-      config.net.metricsPort = uint16(res and 0xFFFF)
+      config.net.metricsServerPort = uint16(res and 0xFFFF)
   elif skey == "maxpeers":
     var res = 0
     result = processInteger(value, res)
@@ -590,6 +595,13 @@ proc processDebugArguments(key, value: string): ConfigStatus =
       result = ErrorIncorrectOption
     else:
       config.debug.logFile = value
+  elif skey == "logmetrics":
+    config.debug.logMetrics = true
+  elif skey == "logmetricsinterval":
+    var res = 0
+    result = processInteger(value, res)
+    if result == Success:
+      config.debug.logMetricsInterval = res
 
 proc dumpConfiguration*(): string =
   ## Dumps current configuration as string
@@ -632,7 +644,8 @@ proc initConfiguration(): NimbusConfiguration =
   result.net.maxPendingPeers = 0
   result.net.bindPort = 30303'u16
   result.net.discPort = 30303'u16
-  result.net.metricsPort = 9093'u16
+  result.net.metricsServer = false
+  result.net.metricsServerPort = 9093'u16
   result.net.ident = NimbusIdent
   result.net.nat = NatAny
   result.net.protocols = defaultProtocols
@@ -651,6 +664,8 @@ proc initConfiguration(): NimbusConfiguration =
   ## Debug defaults
   result.debug.flags = {}
   result.debug.logLevel = defaultLogLevel
+  result.debug.logMetrics = false
+  result.debug.logMetricsInterval = 10
 
 proc getConfiguration*(): NimbusConfiguration =
   ## Retreive current configuration object `NimbusConfiguration`.
@@ -682,7 +697,8 @@ NETWORKING OPTIONS:
   --staticnodes:<value>   Comma separated enode URLs to connect with
   --port:<value>          Network listening TCP port (default: 30303)
   --discport:<value>      Network listening UDP port (defaults to --port argument)
-  --metricsport:<value>   Metrics HTTP server port on localhost (defaults to 9093, set to 0 to disable)
+  --metricsServer         Enable the metrics HTTP server
+  --metricsServerPort:<value> Metrics HTTP server port on localhost (default: 9093)
   --maxpeers:<value>      Maximum number of network peers (default: 25)
   --maxpendpeers:<value>  Maximum number of pending connection attempts (default: 0)
   --nat:<value>           NAT port mapping mechanism (any|none|upnp|pmp|<external IP>) (default: "any")
@@ -711,6 +727,8 @@ API AND CONSOLE OPTIONS:
 LOGGING AND DEBUGGING OPTIONS:
   --log-level:<value>     One of: $2 (default: $3)
   --log-file:<value>      Optional log file, replacing stdout
+  --logMetrics            Enable metrics logging
+  --logMetricsInterval:<value> Interval at which to log metrics, in seconds (default: 10)
   --debug                 Enable debug mode
   --test:<value>          Perform specified test
 """ % [

nimbus/nimbus.nim

@@ -15,7 +15,7 @@ import
   eth/p2p/rlpx_protocols/[eth_protocol, les_protocol, whisper_protocol],
   eth/p2p/blockchain_sync, eth/net/nat, eth/p2p/peer_pool,
   config, genesis, rpc/[common, p2p, debug, whisper], p2p/chain,
-  eth/trie/db, metrics
+  eth/trie/db, metrics, metrics/chronicles_support
 
 ## TODO:
 ## * No IPv6 support
@@ -59,6 +59,15 @@ proc start() =
     defaultChroniclesStream.output.outFile = nil # to avoid closing stdout
     discard defaultChroniclesStream.output.open(conf.debug.logFile, fmAppend)
 
+  # metrics logging
+  if conf.debug.logMetrics:
+    proc logMetrics(udata: pointer) {.closure, gcsafe.} =
+      {.gcsafe.}:
+        let registry = defaultRegistry
+      info "metrics", registry
+      addTimer(Moment.fromNow(conf.debug.logMetricsInterval.seconds), logMetrics)
+    addTimer(Moment.fromNow(conf.debug.logMetricsInterval.seconds), logMetrics)
+
   ## Creating RPC Server
   if RpcFlags.Enabled in conf.rpc.flags:
     nimbus.rpcServer = newRpcHttpServer(conf.rpc.binds)
@@ -136,11 +145,11 @@ proc start() =
       result = "EXITING"
     nimbus.rpcServer.start()
 
-  # metrics
+  # metrics server
-  if conf.net.metricsPort > 0.uint16:
+  if conf.net.metricsServer:
     let metricsAddress = "127.0.0.1"
-    info "Starting metrics HTTP server", address = metricsAddress, port = conf.net.metricsPort
+    info "Starting metrics HTTP server", address = metricsAddress, port = conf.net.metricsServerPort
-    metrics.startHttpServer(metricsAddress, Port(conf.net.metricsPort))
+    metrics.startHttpServer(metricsAddress, Port(conf.net.metricsServerPort))
 
   # Connect directly to the static nodes
   for enode in conf.net.staticNodes: