Merge pull request #989 from input-output-hk/endpoint-to-return-proto…

…col-params

Ability to read protocol parameters via REST

CHANGELOG.md

@@ -12,6 +12,9 @@ changes.
 
 - `Greetings` message now contains also the hydra-node version.
 
+- New HTTP endpoint (`GET /protocol-parameters`) which provides the current protocol parameters
+  used by the hydra-node when validating transactions.
+
 - *Fixed bugs* in `hydra-node`:
   + Multisignature verification would silently ignore certain keys in case the
   list of verification keys is not of same length as the list of signatures.

hydra-node/exe/hydra-node/Main.hs

@@ -105,12 +105,12 @@ main = do
         withDirectChain (contramap DirectChain tracer) chainConfig ctx wallet (getChainState hs) (putEvent . OnChainEvent) $ \chain -> do
           let RunOptions{host, port, peers, nodeId} = opts
               putNetworkEvent (Authenticated msg otherParty) = putEvent $ NetworkEvent defaultTTL otherParty msg
-              RunOptions{apiHost, apiPort} = opts
+              RunOptions{apiHost, apiPort, ledgerConfig} = opts
+          protocolParams <- readJsonFileThrow protocolParametersFromJson (cardanoLedgerProtocolParametersFile ledgerConfig)
           apiPersistence <- createPersistenceIncremental $ persistenceDir <> "/server-output"
-          withAPIServer apiHost apiPort party apiPersistence (contramap APIServer tracer) chain (putEvent . ClientEvent) $ \server -> do
+          withAPIServer apiHost apiPort party apiPersistence (contramap APIServer tracer) chain protocolParams (putEvent . ClientEvent) $ \server -> do
             withNetwork tracer server signingKey otherParties host port peers nodeId putNetworkEvent $ \hn -> do
-              let RunOptions{ledgerConfig} = opts
-              withCardanoLedger ledgerConfig chainConfig $ \ledger ->
+              withCardanoLedger chainConfig protocolParams $ \ledger ->
                 runHydraNode (contramap Node tracer) $
                   HydraNode{eq, hn = contramap (`Authenticated` party) hn, nodeState, oc = chain, server, ledger, env, persistence}
 
@@ -127,13 +127,10 @@ main = do
           Disconnected nodeid -> sendOutput $ PeerDisconnected nodeid
      in withAuthentication (contramap Authentication tracer) signingKey parties $ withHeartbeat nodeId connectionMessages $ withOuroborosNetwork (contramap Network tracer) localhost peers
 
-  withCardanoLedger ledgerConfig chainConfig action = do
+  withCardanoLedger chainConfig protocolParams action = do
     let DirectChainConfig{networkId, nodeSocket} = chainConfig
     globals <- newGlobals =<< queryGenesisParameters networkId nodeSocket QueryTip
-    ledgerEnv <-
-      newLedgerEnv
-        <$> readJsonFileThrow protocolParametersFromJson (cardanoLedgerProtocolParametersFile ledgerConfig)
-
+    let ledgerEnv = newLedgerEnv protocolParams
     action (Ledger.cardanoLedger globals ledgerEnv)
 
   -- check if hydra-node parameters are matching with the hydra-node state.

hydra-node/hydra-node.cabal

@@ -336,6 +336,7 @@ test-suite tests
     , hspec
     , hspec-core
     , hspec-golden-aeson
+    , hspec-wai
     , HUnit
     , hydra-cardano-api
     , hydra-node

hydra-node/json-schemas/api.yaml

@@ -141,6 +141,20 @@ channels:
           type: request
           method: POST
           bindingVersion: '0.1.0'
+  /protocol-parameters:
+    description: Endpoint to obtain protocol parameters used by the internal ledger of a hydra-node.
+    servers:
+      - localhost-http
+    subscribe:
+      summary: Get cardano protocol parameters.
+      operationId: getProtocolParameters
+      message:
+        $ref: "#/components/messages/ProtocolParameters"
+      bindings:
+        http:
+          type: response
+          method: GET
+          bindingVersion: '0.1.0'
 components:
   messages:
     ########
@@ -787,6 +801,13 @@ components:
       payload:
         $ref: "api.yaml#/components/schemas/TextEnvelopeTransaction"
 
+    ProtocolParameters:
+      title: ProtocolParameters
+      payload:
+        type: object
+        additionalProperties: false
+        $ref: "https://raw.githubusercontent.com/CardanoSolutions/cardanonical/main/cardano.json#/definitions/ProtocolParameters<Babbage>"
+
   ########
   #
   # Schemas

hydra-node/src/Hydra/API/Server.hs

@@ -37,6 +37,7 @@ import Hydra.API.ServerOutput (
   projectSnapshotUtxo,
   snapshotUtxo,
  )
+import Hydra.Cardano.Api (ProtocolParameters)
 import Hydra.Chain (
   Chain (..),
   IsChainState,
@@ -56,6 +57,7 @@ import Hydra.Party (Party)
 import Hydra.Persistence (PersistenceIncremental (..))
 import Network.HTTP.Types (Method, status200, status400, status500)
 import Network.Wai (
+  Application,
   Request (pathInfo),
   Response,
   ResponseReceived,
@@ -139,8 +141,9 @@ withAPIServer ::
   PersistenceIncremental (TimedServerOutput tx) IO ->
   Tracer IO APIServerLog ->
   Chain tx IO ->
+  ProtocolParameters ->
   ServerComponent tx IO ()
-withAPIServer host port party PersistenceIncremental{loadAll, append} tracer chain callback action = do
+withAPIServer host port party PersistenceIncremental{loadAll, append} tracer chain pparams callback action = do
   responseChannel <- newBroadcastTChanIO
   timedOutputEvents <- loadAll
 
@@ -153,7 +156,7 @@ withAPIServer host port party PersistenceIncremental{loadAll, append} tracer cha
   history <- newTVarIO (reverse timedOutputEvents)
   (notifyServerRunning, waitForServerRunning) <- setupServerNotification
   race_
-    (runAPIServer host port party tracer history chain callback headStatusP snapshotUtxoP responseChannel notifyServerRunning)
+    (runAPIServer host port party tracer history chain callback headStatusP snapshotUtxoP responseChannel notifyServerRunning pparams)
     ( do
         waitForServerRunning
         action $
@@ -211,13 +214,14 @@ runAPIServer ::
   TChan (TimedServerOutput tx) ->
   -- | Called when the server is listening before entering the main loop.
   NotifyServerRunning ->
+  ProtocolParameters ->
   IO ()
-runAPIServer host port party tracer history chain callback headStatusP snapshotUtxoP responseChannel notifyServerRunning = do
+runAPIServer host port party tracer history chain callback headStatusP snapshotUtxoP responseChannel notifyServerRunning protocolparams = do
   traceWith tracer (APIServerStarted port)
   -- catch and rethrow with more context
   handle onIOException $
     runSettings serverSettings $
-      websocketsOr defaultConnectionOptions wsApp (httpApp chain)
+      websocketsOr defaultConnectionOptions wsApp (httpApp tracer chain protocolparams)
  where
   serverSettings =
     defaultSettings
@@ -248,21 +252,6 @@ runAPIServer host port party tracer history chain callback headStatusP snapshotU
     withPingThread con 30 (pure ()) $
       race_ (receiveInputs con) (sendOutputs chan con outConfig)
 
-  -- Hydra HTTP server
-  httpApp directChain req respond =
-    case (requestMethod req, pathInfo req) of
-      ("POST", ["commit"]) -> do
-        body <- consumeRequestBodyStrict req
-        handleDraftCommitUtxo directChain tracer body (requestMethod req) (pathInfo req) respond
-      _ -> do
-        traceWith tracer $
-          APIRestInputReceived
-            { method = decodeUtf8 $ requestMethod req
-            , paths = pathInfo req
-            , requestInputBody = Nothing
-            }
-        respond $ responseLBS status400 [] "Resource not found"
-
   -- NOTE: We will add a 'Greetings' message on each API server start. This is
   -- important to make sure the latest configured 'party' is reaching the
   -- client.
@@ -360,6 +349,28 @@ data RunServerException = RunServerException
 
 instance Exception RunServerException
 
+-- | Hydra HTTP server
+httpApp ::
+  Tracer IO APIServerLog ->
+  Chain tx IO ->
+  ProtocolParameters ->
+  Application
+httpApp tracer directChain pparams req respond =
+  case (requestMethod req, pathInfo req) of
+    ("POST", ["commit"]) -> do
+      body <- consumeRequestBodyStrict req
+      handleDraftCommitUtxo directChain tracer body (requestMethod req) (pathInfo req) respond
+    ("GET", ["protocol-parameters"]) ->
+      respond $ responseLBS status200 [] (Aeson.encode pparams)
+    _ -> do
+      traceWith tracer $
+        APIRestInputReceived
+          { method = decodeUtf8 $ requestMethod req
+          , paths = pathInfo req
+          , requestInputBody = Nothing
+          }
+      respond $ responseLBS status400 [] "Resource not found"
+
 -- Handle user requests to obtain a draft commit tx
 handleDraftCommitUtxo ::
   Chain tx IO ->

hydra-node/test/Hydra/API/RestServerSpec.hs

@@ -2,29 +2,56 @@
 
 module Hydra.API.RestServerSpec where
 
-import Hydra.Prelude
+import Hydra.Prelude hiding (get)
 import Test.Hydra.Prelude
 
+import Data.Aeson (encode)
 import Data.Aeson.Lens (key)
 import Hydra.API.RestServer (DraftCommitTxRequest, DraftCommitTxResponse)
+import Hydra.API.Server (httpApp)
+import Hydra.API.ServerSpec (dummyChainHandle)
+import Hydra.Chain.Direct.Fixture (defaultPParams)
 import Hydra.Chain.Direct.State ()
 import Hydra.JSONSchema (prop_validateJSONSchema)
+import Hydra.Logging (nullTracer)
 import Test.Aeson.GenericSpecs (roundtripAndGoldenSpecs)
+import Test.Hspec.Wai (MatchBody (..), ResponseMatcher (matchBody), get, shouldRespondWith, with)
 import Test.QuickCheck.Property (property, withMaxSuccess)
 
 spec :: Spec
-spec = parallel $ do
-  roundtripAndGoldenSpecs (Proxy @(ReasonablySized DraftCommitTxResponse))
-  roundtripAndGoldenSpecs (Proxy @(ReasonablySized DraftCommitTxRequest))
-
-  prop "Validate /commit publish api schema" $
-    property $
-      withMaxSuccess 1 $
-        prop_validateJSONSchema @DraftCommitTxRequest "api.json" $
-          key "components" . key "messages" . key "DraftCommitTxRequest" . key "payload"
-
-  prop "Validate /commit subscribe api schema" $
-    property $
-      withMaxSuccess 1 $
-        prop_validateJSONSchema @DraftCommitTxResponse "api.json" $
-          key "components" . key "messages" . key "DraftCommitTxResponse" . key "payload"
+spec = do
+  parallel $ do
+    roundtripAndGoldenSpecs (Proxy @(ReasonablySized DraftCommitTxResponse))
+    roundtripAndGoldenSpecs (Proxy @(ReasonablySized DraftCommitTxRequest))
+
+    prop "Validate /commit publish api schema" $
+      property $
+        withMaxSuccess 1 $
+          prop_validateJSONSchema @DraftCommitTxRequest "api.json" $
+            key "components" . key "messages" . key "DraftCommitTxRequest" . key "payload"
+
+    prop "Validate /commit subscribe api schema" $
+      property $
+        withMaxSuccess 1 $
+          prop_validateJSONSchema @DraftCommitTxResponse "api.json" $
+            key "components" . key "messages" . key "DraftCommitTxResponse" . key "payload"
+
+    apiServerSpec
+
+-- TODO: we should add more tests for other routes here (eg. /commit)
+apiServerSpec :: Spec
+apiServerSpec = do
+  let webServer = httpApp nullTracer dummyChainHandle defaultPParams
+  with (return webServer) $ do
+    describe "API should respond correctly" $
+      it "GET /protocol-parameters works" $
+        get "/protocol-parameters"
+          `shouldRespondWith` 200
+            { matchBody =
+                MatchBody
+                  ( \_ actualBody ->
+                      if actualBody /= encode defaultPParams
+                        then Just "Request body missmatch"
+                        else Nothing
+                  )
+            }

hydra-node/test/Hydra/API/ServerSpec.hs

@@ -36,6 +36,7 @@ import Hydra.Chain (
   draftCommitTx,
   postTx,
  )
+import Hydra.Chain.Direct.Fixture (defaultPParams)
 import Hydra.Ledger (txId)
 import Hydra.Ledger.Simple (SimpleTx)
 import Hydra.Logging (Tracer, showLogsOnFailure)
@@ -433,7 +434,7 @@ withTestAPIServer ::
   (Server SimpleTx IO -> IO ()) ->
   IO ()
 withTestAPIServer port actor persistence tracer =
-  withAPIServer @SimpleTx "127.0.0.1" port actor persistence tracer dummyChainHandle noop
+  withAPIServer @SimpleTx "127.0.0.1" port actor persistence tracer dummyChainHandle defaultPParams noop
 
 withClient :: PortNumber -> String -> (Connection -> IO ()) -> IO ()
 withClient port path action = do