return an error on `show_validator` (#3316)

* return a command error prior to init

* add a pending log entry

* Update CHANGELOG_PENDING.md

Co-Authored-By: alexanderbez <alexanderbez@users.noreply.github.com>

closes: #3314

CHANGELOG_PENDING.md

@@ -21,5 +21,9 @@ Special thanks to external contributors on this release:
 ### IMPROVEMENTS:
 
 ### BUG FIXES:
-- [consensus] \#3297 Flush WAL on stop to prevent data corruption during
+
+* [consensus] \#3297 Flush WAL on stop to prevent data corruption during
   graceful shutdown
+* [cmd] \#3314 Return an
+  error on `show_validator` when the private validator file does not exist.
+  

cmd/tendermint/commands/show_node_id.go

@@ -16,12 +16,11 @@ var ShowNodeIDCmd = &cobra.Command{
 }
 
 func showNodeID(cmd *cobra.Command, args []string) error {
-
 	nodeKey, err := p2p.LoadNodeKey(config.NodeKeyFile())
 	if err != nil {
 		return err
 	}
-	fmt.Println(nodeKey.ID())
 
+	fmt.Println(nodeKey.ID())
 	return nil
 }

cmd/tendermint/commands/show_validator.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/spf13/cobra"
 
+	cmn "github.com/tendermint/tendermint/libs/common"
 	"github.com/tendermint/tendermint/privval"
 )
 
@@ -12,11 +13,21 @@ import (
 var ShowValidatorCmd = &cobra.Command{
 	Use:   "show_validator",
 	Short: "Show this node's validator info",
-	Run:   showValidator,
+	RunE:  showValidator,
 }
 
-func showValidator(cmd *cobra.Command, args []string) {
-	privValidator := privval.LoadOrGenFilePV(config.PrivValidatorKeyFile(), config.PrivValidatorStateFile())
-	pubKeyJSONBytes, _ := cdc.MarshalJSON(privValidator.GetPubKey())
-	fmt.Println(string(pubKeyJSONBytes))
+func showValidator(cmd *cobra.Command, args []string) error {
+	keyFilePath := config.PrivValidatorKeyFile()
+	if !cmn.FileExists(keyFilePath) {
+		return fmt.Errorf("private validator file %s does not exist", keyFilePath)
+	}
+
+	pv := privval.LoadFilePV(keyFilePath, config.PrivValidatorStateFile())
+	bz, err := cdc.MarshalJSON(pv.GetPubKey())
+	if err != nil {
+		return err
+	}
+
+	fmt.Println(string(bz))
+	return nil
 }