Added retry delay to registration loops

We added retry delay to loops where it's possible to continue the loop
execution in case of an error. The solution is similiar to the one we added
in #409. If loop execution gets an error for any reason, e.g. problems
with connection to the ethereum API the client ended up in a crazy loop
logging huge amount of errors. This causes disk space drain by the log
file.

pkg/client/registration.go

@@ -3,12 +3,14 @@ package client
 import (
 	"context"
 	"fmt"
+	"time"
 
 	"github.com/ethereum/go-ethereum/common"
 	eth "github.com/keep-network/keep-ecdsa/pkg/chain"
 )
 
 const statusCheckIntervalBlocks = 100
+const retryDelay = 1 * time.Second
 
 // checkStatusAndRegisterForApplication checks whether the operator is
 // registered as a member candidate for keep for the given application.
@@ -37,6 +39,7 @@ RegistrationLoop:
 					application.String(),
 					err,
 				)
+				time.Sleep(retryDelay) // TODO: #413 Replace with backoff.
 				continue RegistrationLoop
 			}
 
@@ -51,6 +54,7 @@ RegistrationLoop:
 			// registered, we can start to monitor the status
 			if err := monitorSignerPoolStatus(ctx, ethereumChain, application); err != nil {
 				logger.Errorf("failed on signer pool status monitoring: [%v]", err)
+				time.Sleep(retryDelay) // TODO: #413 Replace with backoff.
 				continue RegistrationLoop
 			}
 		}
@@ -124,6 +128,7 @@ func registerAsMemberCandidateWhenEligible(
 					application.String(),
 					err,
 				)
+				time.Sleep(retryDelay) // TODO: #413 Replace with backoff.
 				continue
 			}
 
@@ -134,6 +139,7 @@ func registerAsMemberCandidateWhenEligible(
 					"operator is not eligible for application [%s]",
 					application.String(),
 				)
+				time.Sleep(retryDelay) // TODO: #413 Replace with backoff.
 				continue
 			}
 
@@ -149,6 +155,7 @@ func registerAsMemberCandidateWhenEligible(
 					application.String(),
 					err,
 				)
+				time.Sleep(retryDelay) // TODO: #413 Replace with backoff.
 				continue
 			}
 
@@ -180,6 +187,7 @@ func waitUntilRegistered(
 					application.String(),
 					err,
 				)
+				time.Sleep(retryDelay) // TODO: #413 Replace with backoff.
 				continue
 			}