Use a directory name that is the hash of the clusterPeers for etcd state

hydra-cluster/src/Hydra/Cluster/Scenarios.hs

@@ -1096,6 +1096,48 @@ threeNodesNoErrorsOnOpen tracer tmpDir node@RunningNode{nodeSocket} hydraScripts
       Right _headIsOpen ->
         pure ()
 
+-- | Hydra nodes ABC run on ABC cluster and connect to each other.
+-- Hydra nodes BC shut down.
+-- Hydra nodes BC run on BC cluster and connect to each other.
+-- Hydra nodes BC shut down.
+-- Hydra nodes BC run and connect ABC cluster again.
+nodeCanSupportMultipleEtcdClusters :: Tracer IO EndToEndLog -> FilePath -> RunningNode -> [TxId] -> IO ()
+nodeCanSupportMultipleEtcdClusters tracer workDir RunningNode{networkId, nodeSocket} hydraScriptsTxId = do
+  let contestationPeriod = UnsafeContestationPeriod 2
+  let depositDeadline = UnsafeDepositDeadline 50
+
+  aliceChainConfig <-
+    chainConfigFor Alice workDir nodeSocket hydraScriptsTxId [Bob, Carol] contestationPeriod depositDeadline
+      <&> setNetworkId networkId
+  bobChainConfig <-
+    chainConfigFor Bob workDir nodeSocket hydraScriptsTxId [Alice, Carol] contestationPeriod depositDeadline
+      <&> setNetworkId networkId
+  carolChainConfig <-
+    chainConfigFor Carol workDir nodeSocket hydraScriptsTxId [Alice, Bob] contestationPeriod depositDeadline
+      <&> setNetworkId networkId
+
+  let hydraTracer = contramap FromHydraNode tracer
+
+  withHydraNode hydraTracer aliceChainConfig workDir 1 aliceSk [bobVk, carolVk] [1, 2, 3] $ \n1 -> do
+    withHydraNode hydraTracer bobChainConfig workDir 2 bobSk [aliceVk, carolVk] [1, 2, 3] $ \n2 -> do
+      withHydraNode hydraTracer carolChainConfig workDir 3 carolSk [aliceVk, bobVk] [1, 2, 3] $ \n3 -> do
+        waitForNodesConnected hydraTracer 30 $ n1 :| [n2, n3]
+
+    bobChainConfig' <-
+      chainConfigFor Bob workDir nodeSocket hydraScriptsTxId [Carol] contestationPeriod depositDeadline
+        <&> setNetworkId networkId
+    carolChainConfig' <-
+      chainConfigFor Carol workDir nodeSocket hydraScriptsTxId [Bob] contestationPeriod depositDeadline
+        <&> setNetworkId networkId
+
+    withHydraNode hydraTracer bobChainConfig' workDir 2 bobSk [carolVk] [2, 3] $ \n2 -> do
+      withHydraNode hydraTracer carolChainConfig' workDir 3 carolSk [bobVk] [2, 3] $ \n3 -> do
+        waitForNodesConnected hydraTracer 30 $ n2 :| [n3]
+
+    withHydraNode hydraTracer bobChainConfig workDir 2 bobSk [aliceVk, carolVk] [1, 2, 3] $ \n2 -> do
+      withHydraNode hydraTracer carolChainConfig workDir 3 carolSk [aliceVk, bobVk] [1, 2, 3] $ \n3 -> do
+        waitForNodesConnected hydraTracer 30 $ n1 :| [n2, n3]
+
 -- | Two hydra node setup where Alice is wrongly configured to use Carol's
 -- cardano keys instead of Bob's which will prevent him to be notified the
 -- `HeadIsInitializing` but he should still receive some notification.

hydra-cluster/test/Test/EndToEndSpec.hs

@@ -60,6 +60,7 @@ import Hydra.Cluster.Scenarios (
   checkFanout,
   headIsInitializingWith,
   initWithWrongKeys,
+  nodeCanSupportMultipleEtcdClusters,
   nodeReObservesOnChainTxs,
   oneOfThreeNodesStopsForAWhile,
   persistenceCanLoadWithEmptyCommit,
@@ -282,6 +283,13 @@ spec = around (showLogsOnFailure "EndToEndSpec") $ do
               publishHydraScriptsAs node Faucet
                 >>= threeNodesNoErrorsOnOpen tracer tmpDir node
 
+      it "node can support multiple etcd clusters" $ \tracer ->
+        failAfter 60 $
+          withClusterTempDir $ \tmpDir -> do
+            withCardanoNodeDevnet (contramap FromCardanoNode tracer) tmpDir $ \node -> do
+              publishHydraScriptsAs node Faucet
+                >>= nodeCanSupportMultipleEtcdClusters tracer tmpDir node
+
       it "inits a Head, processes a single Cardano transaction and closes it again" $ \tracer ->
         failAfter 60 $
           withClusterTempDir $ \tmpDir -> do

hydra-node/src/Hydra/Network/Etcd.hs

@@ -44,6 +44,7 @@ module Hydra.Network.Etcd where
 import Hydra.Prelude
 
 import Cardano.Binary (decodeFull', serialize')
+import Cardano.Crypto.Hash (SHA256, hashToStringAsHex, hashWithSerialiser)
 import Control.Concurrent.Class.MonadSTM (
   modifyTVar',
   newTBQueueIO,
@@ -61,6 +62,7 @@ import Data.Aeson qualified as Aeson
 import Data.Aeson.Types (Value)
 import Data.Bits ((.|.))
 import Data.ByteString qualified as BS
+import Data.ByteString.Char8 qualified as BS8
 import Data.List ((\\))
 import Data.List qualified as List
 import Data.Map qualified as Map
@@ -205,7 +207,7 @@ withEtcdNetwork tracer protocolVersion config callback action = do
       $ concat
         [ -- NOTE: Must be used in clusterPeers
           ["--name", show advertise]
-        , ["--data-dir", persistenceDir </> "etcd"]
+        , ["--data-dir", persistenceDir </> "etcd" </> hashToStringAsHex (hashWithSerialiser @SHA256 toCBOR $ BS8.pack clusterPeers)]
         , ["--listen-peer-urls", httpUrl listen]
         , ["--initial-advertise-peer-urls", httpUrl advertise]
         , ["--listen-client-urls", httpUrl clientHost]

hydra-node/test/Hydra/NetworkSpec.hs

@@ -113,7 +113,7 @@ spec = do
 
       it "emits connectivity events" $ \tracer -> do
         withTempDir "test-etcd" $ \tmp -> do
-          failAfter 20 $ do
+          failAfter 30 $ do
             PeerConfig3{aliceConfig, bobConfig, carolConfig} <- setup3Peers tmp
             -- Record and assert connectivity events from alice's perspective
             (recordReceived, _, waitConnectivity) <- newRecordingCallback