extract trusted node sync trigger into separate function (#5544)

To prepare for calling trusted node sync from the main Nimbus startup
logic, extract the trusted node sync trigger into a separate function.
Further allow passing a pre-opened database, as that will be needed to
check whether trusted node sync needs to be called during regular start.

beacon_chain/nimbus_beacon_node.nim

@@ -114,6 +114,57 @@ declareGauge next_action_wait,
 
 logScope: topics = "beacnde"
 
+proc doRunTrustedNodeSync(
+    db: BeaconChainDB,
+    metadata: Eth2NetworkMetadata,
+    databaseDir: string,
+    eraDir: string,
+    restUrl: string,
+    stateId: Option[string],
+    trustedBlockRoot: Option[Eth2Digest],
+    backfill: bool,
+    reindex: bool,
+    downloadDepositSnapshot: bool) {.async.} =
+  let
+    cfg = metadata.cfg
+    syncTarget =
+      if stateId.isSome:
+        if trustedBlockRoot.isSome:
+          warn "Ignoring `trustedBlockRoot`, `stateId` is set",
+            stateId, trustedBlockRoot
+        TrustedNodeSyncTarget(
+          kind: TrustedNodeSyncKind.StateId,
+          stateId: stateId.get)
+      elif trustedBlockRoot.isSome:
+        TrustedNodeSyncTarget(
+          kind: TrustedNodeSyncKind.TrustedBlockRoot,
+          trustedBlockRoot: trustedBlockRoot.get)
+      else:
+        TrustedNodeSyncTarget(
+          kind: TrustedNodeSyncKind.StateId,
+          stateId: "finalized")
+    genesis =
+      if metadata.hasGenesis:
+        let genesisBytes = try: await metadata.fetchGenesisBytes()
+        except CatchableError as err:
+          error "Failed to obtain genesis state",
+                source = metadata.genesis.sourceDesc,
+                err = err.msg
+          quit 1
+        newClone(readSszForkedHashedBeaconState(cfg, genesisBytes))
+      else: nil
+
+  await db.doTrustedNodeSync(
+    cfg,
+    databaseDir,
+    eraDir,
+    restUrl,
+    syncTarget,
+    backfill,
+    reindex,
+    downloadDepositSnapshot,
+    genesis)
+
 func getVanityLogs(stdoutKind: StdoutLogKind): VanityLogs =
   case stdoutKind
   of StdoutLogKind.Auto: raiseAssert "inadmissable here"
@@ -2143,51 +2194,24 @@ proc handleStartUpCmd(config: var BeaconNodeConf) {.raises: [CatchableError].} =
   of BNStartUpCmd.web3: doWeb3Cmd(config, rng[])
   of BNStartUpCmd.slashingdb: doSlashingInterchange(config)
   of BNStartUpCmd.trustedNodeSync:
-    let
-      network = loadEth2Network(config)
-      cfg = network.cfg
-      syncTarget =
-        if config.stateId.isSome:
-          if config.lcTrustedBlockRoot.isSome:
-            warn "Ignoring `trustedBlockRoot`, `stateId` is set",
-              stateId = config.stateId,
-              trustedBlockRoot = config.lcTrustedBlockRoot
-          TrustedNodeSyncTarget(
-            kind: TrustedNodeSyncKind.StateId,
-            stateId: config.stateId.get)
-        elif config.lcTrustedBlockRoot.isSome:
-          TrustedNodeSyncTarget(
-            kind: TrustedNodeSyncKind.TrustedBlockRoot,
-            trustedBlockRoot: config.lcTrustedBlockRoot.get)
-        else:
-          TrustedNodeSyncTarget(
-            kind: TrustedNodeSyncKind.StateId,
-            stateId: "finalized")
-      genesis =
-        if network.hasGenesis:
-          let genesisBytes = try: waitFor network.fetchGenesisBytes()
-          except CatchableError as err:
-            error "Failed to obtain genesis state",
-                  source = network.genesis.sourceDesc,
-                  err = err.msg
-            quit 1
-          newClone(readSszForkedHashedBeaconState(cfg, genesisBytes))
-        else: nil
-
     if config.blockId.isSome():
       error "--blockId option has been removed - use --state-id instead!"
       quit 1
 
-    waitFor doTrustedNodeSync(
-      cfg,
+    let
+      metadata = loadEth2Network(config)
+      db = BeaconChainDB.new(config.databaseDir, metadata.cfg, inMemory = false)
+    waitFor db.doRunTrustedNodeSync(
+      metadata,
       config.databaseDir,
       config.eraDir,
       config.trustedNodeUrl,
-      syncTarget,
+      config.stateId,
+      config.lcTrustedBlockRoot,
       config.backfillBlocks,
       config.reindex,
-      config.downloadDepositSnapshot,
-      genesis)
+      config.downloadDepositSnapshot)
+    db.close()
 
 {.pop.} # TODO moduletests exceptions
 

beacon_chain/trusted_node_sync.nim

@@ -68,6 +68,7 @@ func shortLog*(v: TrustedNodeSyncTarget): auto =
 chronicles.formatIt(TrustedNodeSyncTarget): shortLog(it)
 
 proc doTrustedNodeSync*(
+    db: BeaconChainDB,
     cfg: RuntimeConfig,
     databaseDir: string,
     eraDir: string,
@@ -89,11 +90,6 @@ proc doTrustedNodeSync*(
       error "Cannot connect to server", error = error
       quit 1
 
-  let
-    db = BeaconChainDB.new(databaseDir, cfg, inMemory = false)
-  defer:
-    db.close()
-
   # If possible, we'll store the genesis state in the database - this is not
   # strictly necessary but renders the resulting database compatible with
   # versions prior to 22.11 and makes reindexing possible
@@ -551,7 +547,8 @@ when isMainModule:
       kind: TrustedNodeSyncKind.StateId,
       stateId: os.paramStr(5))
     backfill = os.paramCount() > 5 and os.paramStr(6) == "true"
-
-  waitFor doTrustedNodeSync(
+    db = BeaconChainDB.new(databaseDir, cfg, inMemory = false)
+  waitFor db.doTrustedNodeSync(
     getRuntimeConfig(some os.paramStr(1)), os.paramStr(2), os.paramStr(3),
     os.paramStr(4), syncTarget, backfill, false, true)
+  db.close()