doc(indexer): more clarity for ChainIndexer configuration setup (#12701)

Author: rvagg

documentation/en/default-lotus-config.toml

@@ -223,6 +223,7 @@
 [Fevm]
   # EnableEthRPC enables eth_ RPC methods.
   # Note: Setting this to true will also require that ChainIndexer is enabled, otherwise it will cause an error at startup.
+  # Set EnableIndexer in the ChainIndexer section of the config to true to enable the ChainIndexer.
   #
   # type: bool
   # env var: LOTUS_FEVM_ENABLEETHRPC
@@ -249,6 +250,7 @@
   # EnableActorEventsAPI enables the Actor events API that enables clients to consume events
   # emitted by (smart contracts + built-in Actors).
   # Note: Setting this to true will also require that ChainIndexer is enabled, otherwise it will cause an error at startup.
+  # Set EnableIndexer in the ChainIndexer section of the config to true to enable the ChainIndexer.
   #
   # type: bool
   # env var: LOTUS_EVENTS_ENABLEACTOREVENTSAPI
@@ -294,6 +296,9 @@
   # 
   # Setting this to true will enable the indexer, which will significantly improve RPC performance.
   # It is strongly recommended to keep this set to true if you are an RPC provider.
+  # 
+  # If EnableEthRPC or EnableActorEventsAPI are set to true, the ChainIndexer must be enabled using
+  # this option to avoid errors at startup.
   #
   # type: bool
   # env var: LOTUS_CHAININDEXER_ENABLEINDEXER

node/builder_chain.go

@@ -180,10 +180,10 @@ func ConfigFullNode(c interface{}) Option {
 	}
 
 	if cfg.Fevm.EnableEthRPC && !cfg.ChainIndexer.EnableIndexer {
-		return Error(xerrors.New("chain indexer must be enabled if ETH RPC is enabled"))
+		return Error(xerrors.New("EnableIndexer in the ChainIndexer configuration section must be set to true when setting EnableEthRPC to true"))
 	}
 	if cfg.Events.EnableActorEventsAPI && !cfg.ChainIndexer.EnableIndexer {
-		return Error(xerrors.New("chain indexer must be enabled if actor events API is enabled"))
+		return Error(xerrors.New("EnableIndexer in the ChainIndexer configuration section must be set to true when setting EnableActorEventsAPI to true"))
 	}
 
 	return Options(

node/config/doc_gen.go

@@ -540,6 +540,7 @@ type FeeConfig struct {
 type FevmConfig struct {
 	// EnableEthRPC enables eth_ RPC methods.
 	// Note: Setting this to true will also require that ChainIndexer is enabled, otherwise it will cause an error at startup.
+	// Set EnableIndexer in the ChainIndexer section of the config to true to enable the ChainIndexer.
 	EnableEthRPC bool
 
 	// EthTraceFilterMaxResults sets the maximum results returned per request by trace_filter
@@ -557,6 +558,7 @@ type EventsConfig struct {
 	// EnableActorEventsAPI enables the Actor events API that enables clients to consume events
 	// emitted by (smart contracts + built-in Actors).
 	// Note: Setting this to true will also require that ChainIndexer is enabled, otherwise it will cause an error at startup.
+	// Set EnableIndexer in the ChainIndexer section of the config to true to enable the ChainIndexer.
 	EnableActorEventsAPI bool
 
 	// FilterTTL specifies the time to live for actor event filters. Filters that haven't been accessed longer than
@@ -587,6 +589,9 @@ type ChainIndexerConfig struct {
 	//
 	// Setting this to true will enable the indexer, which will significantly improve RPC performance.
 	// It is strongly recommended to keep this set to true if you are an RPC provider.
+	//
+	// If EnableEthRPC or EnableActorEventsAPI are set to true, the ChainIndexer must be enabled using
+	// this option to avoid errors at startup.
 	EnableIndexer bool
 
 	// GCRetentionEpochs specifies the number of epochs for which data is retained in the Indexer.