Add tx signing metrics (#1659)

Monitor the rate at which we sign channel txs and the duration of the
signing operations.

eclair-core/src/main/scala/fr/acinq/eclair/crypto/Monitoring.scala

@@ -22,10 +22,21 @@ object Monitoring {
 
   object Metrics {
     val OnionPayloadFormat = Kamon.counter("crypto.sphinx.onion-payload-format")
+    val SignTxCount = Kamon.counter("crypto.keymanager.sign.count")
+    val SignTxDuration = Kamon.timer("crypto.keymanager.sign.duration")
   }
 
   object Tags {
     val LegacyOnion = "legacy"
+    val TxOwner = "txOwner"
+    val TxType = "txType"
+
+    object TxTypes {
+      val CommitTx = "commit"
+      val HtlcTx = "htlc"
+      val RevokedTx = "revoked"
+    }
+
   }
 
 }

eclair-core/src/main/scala/fr/acinq/eclair/crypto/keymanager/ChannelKeyManager.scala

@@ -16,16 +16,16 @@
 
 package fr.acinq.eclair.crypto.keymanager
 
-import java.io.ByteArrayInputStream
-import java.nio.ByteOrder
-
 import fr.acinq.bitcoin.Crypto.{PrivateKey, PublicKey}
 import fr.acinq.bitcoin.DeterministicWallet.ExtendedPublicKey
 import fr.acinq.bitcoin.{ByteVector64, Crypto, DeterministicWallet, Protocol}
 import fr.acinq.eclair.channel.{ChannelVersion, LocalParams}
 import fr.acinq.eclair.transactions.Transactions.{CommitmentFormat, TransactionWithInputInfo, TxOwner}
 import scodec.bits.ByteVector
 
+import java.io.ByteArrayInputStream
+import java.nio.ByteOrder
+
 trait ChannelKeyManager {
   def fundingPublicKey(keyPath: DeterministicWallet.KeyPath): ExtendedPublicKey
 
@@ -62,8 +62,7 @@ trait ChannelKeyManager {
    * @param publicKey        extended public key
    * @param txOwner          owner of the transaction (local/remote)
    * @param commitmentFormat format of the commitment tx
-   * @return a signature generated with the private key that matches the input
-   *         extended public key
+   * @return a signature generated with the private key that matches the input extended public key
    */
   def sign(tx: TransactionWithInputInfo, publicKey: ExtendedPublicKey, txOwner: TxOwner, commitmentFormat: CommitmentFormat): ByteVector64
 
@@ -75,8 +74,7 @@ trait ChannelKeyManager {
    * @param remotePoint      remote point
    * @param txOwner          owner of the transaction (local/remote)
    * @param commitmentFormat format of the commitment tx
-   * @return a signature generated with a private key generated from the input keys's matching
-   *         private key and the remote point.
+   * @return a signature generated with a private key generated from the input key's matching private key and the remote point.
    */
   def sign(tx: TransactionWithInputInfo, publicKey: ExtendedPublicKey, remotePoint: PublicKey, txOwner: TxOwner, commitmentFormat: CommitmentFormat): ByteVector64
 
@@ -88,8 +86,7 @@ trait ChannelKeyManager {
    * @param remoteSecret     remote secret
    * @param txOwner          owner of the transaction (local/remote)
    * @param commitmentFormat format of the commitment tx
-   * @return a signature generated with a private key generated from the input keys's matching
-   *         private key and the remote secret.
+   * @return a signature generated with a private key generated from the input key's matching private key and the remote secret.
    */
   def sign(tx: TransactionWithInputInfo, publicKey: ExtendedPublicKey, remoteSecret: PrivateKey, txOwner: TxOwner, commitmentFormat: CommitmentFormat): ByteVector64
 
@@ -105,7 +102,7 @@ trait ChannelKeyManager {
 object ChannelKeyManager {
   /**
    * Create a BIP32 path from a public key. This path will be used to derive channel keys.
-   * Having channel keys derived from the funding public keys makes it very easy to retrieve your funds when've you've lost your data:
+   * Having channel keys derived from the funding public keys makes it very easy to retrieve your funds when you've lost your data:
    * - connect to your peer and use DLP to get them to publish their remote commit tx
    * - retrieve the commit tx from the bitcoin network, extract your funding pubkey from its witness data
    * - recompute your channel keys and spend your output

eclair-core/src/main/scala/fr/acinq/eclair/crypto/keymanager/LocalChannelKeyManager.scala

@@ -21,11 +21,13 @@ import fr.acinq.bitcoin.Crypto.{PrivateKey, PublicKey}
 import fr.acinq.bitcoin.DeterministicWallet.{derivePrivateKey, _}
 import fr.acinq.bitcoin.{Block, ByteVector32, ByteVector64, Crypto, DeterministicWallet}
 import fr.acinq.eclair.crypto.Generators
+import fr.acinq.eclair.crypto.Monitoring.{Metrics, Tags}
 import fr.acinq.eclair.router.Announcements
-import fr.acinq.eclair.secureRandom
 import fr.acinq.eclair.transactions.Transactions
 import fr.acinq.eclair.transactions.Transactions.{CommitmentFormat, TransactionWithInputInfo, TxOwner}
+import fr.acinq.eclair.{KamonExt, secureRandom}
 import grizzled.slf4j.Logging
+import kamon.tag.TagSet
 import scodec.bits.ByteVector
 
 object LocalChannelKeyManager {
@@ -97,12 +99,16 @@ class LocalChannelKeyManager(seed: ByteVector, chainHash: ByteVector32) extends
    * @param publicKey        extended public key
    * @param txOwner          owner of the transaction (local/remote)
    * @param commitmentFormat format of the commitment tx
-   * @return a signature generated with the private key that matches the input
-   *         extended public key
+   * @return a signature generated with the private key that matches the input extended public key
    */
   override def sign(tx: TransactionWithInputInfo, publicKey: ExtendedPublicKey, txOwner: TxOwner, commitmentFormat: CommitmentFormat): ByteVector64 = {
-    val privateKey = privateKeys.get(publicKey.path)
-    Transactions.sign(tx, privateKey.privateKey, txOwner, commitmentFormat)
+    // NB: not all those transactions are actually commit txs (especially during closing), but this is good enough for monitoring purposes
+    val tags = TagSet.Empty.withTag(Tags.TxOwner, txOwner.toString).withTag(Tags.TxType, Tags.TxTypes.CommitTx)
+    Metrics.SignTxCount.withTags(tags).increment()
+    KamonExt.time(Metrics.SignTxDuration.withTags(tags)) {
+      val privateKey = privateKeys.get(publicKey.path)
+      Transactions.sign(tx, privateKey.privateKey, txOwner, commitmentFormat)
+    }
   }
 
   /**
@@ -113,13 +119,17 @@ class LocalChannelKeyManager(seed: ByteVector, chainHash: ByteVector32) extends
    * @param remotePoint      remote point
    * @param txOwner          owner of the transaction (local/remote)
    * @param commitmentFormat format of the commitment tx
-   * @return a signature generated with a private key generated from the input keys's matching
-   *         private key and the remote point.
+   * @return a signature generated with a private key generated from the input key's matching private key and the remote point.
    */
   override def sign(tx: TransactionWithInputInfo, publicKey: ExtendedPublicKey, remotePoint: PublicKey, txOwner: TxOwner, commitmentFormat: CommitmentFormat): ByteVector64 = {
-    val privateKey = privateKeys.get(publicKey.path)
-    val currentKey = Generators.derivePrivKey(privateKey.privateKey, remotePoint)
-    Transactions.sign(tx, currentKey, txOwner, commitmentFormat)
+    // NB: not all those transactions are actually htlc txs (especially during closing), but this is good enough for monitoring purposes
+    val tags = TagSet.Empty.withTag(Tags.TxOwner, txOwner.toString).withTag(Tags.TxType, Tags.TxTypes.HtlcTx)
+    Metrics.SignTxCount.withTags(tags).increment()
+    KamonExt.time(Metrics.SignTxDuration.withTags(tags)) {
+      val privateKey = privateKeys.get(publicKey.path)
+      val currentKey = Generators.derivePrivKey(privateKey.privateKey, remotePoint)
+      Transactions.sign(tx, currentKey, txOwner, commitmentFormat)
+    }
   }
 
   /**
@@ -130,13 +140,16 @@ class LocalChannelKeyManager(seed: ByteVector, chainHash: ByteVector32) extends
    * @param remoteSecret     remote secret
    * @param txOwner          owner of the transaction (local/remote)
    * @param commitmentFormat format of the commitment tx
-   * @return a signature generated with a private key generated from the input keys's matching
-   *         private key and the remote secret.
+   * @return a signature generated with a private key generated from the input key's matching private key and the remote secret.
    */
   override def sign(tx: TransactionWithInputInfo, publicKey: ExtendedPublicKey, remoteSecret: PrivateKey, txOwner: TxOwner, commitmentFormat: CommitmentFormat): ByteVector64 = {
-    val privateKey = privateKeys.get(publicKey.path)
-    val currentKey = Generators.revocationPrivKey(privateKey.privateKey, remoteSecret)
-    Transactions.sign(tx, currentKey, txOwner, commitmentFormat)
+    val tags = TagSet.Empty.withTag(Tags.TxOwner, txOwner.toString).withTag(Tags.TxType, Tags.TxTypes.RevokedTx)
+    Metrics.SignTxCount.withTags(tags).increment()
+    KamonExt.time(Metrics.SignTxDuration.withTags(tags)) {
+      val privateKey = privateKeys.get(publicKey.path)
+      val currentKey = Generators.revocationPrivKey(privateKey.privateKey, remoteSecret)
+      Transactions.sign(tx, currentKey, txOwner, commitmentFormat)
+    }
   }
 
   override def signChannelAnnouncement(witness: ByteVector, fundingKeyPath: KeyPath): ByteVector64 =