feat: fix linting errors, and add golangci-lint config

.circleci/continue_config.yml

@@ -227,7 +227,11 @@ jobs:
       - run:
           name: run lint
           command: |
+             if [ -f .golangci.yml ]; then
+              golangci-lint run -c .golangci.yml -E goimports,sqlclosecheck,bodyclose,asciicheck,misspell,errorlint -e "errors.As" -e "errors.Is" --timeout "3m0s" ./...
+             else
               golangci-lint run -E goimports,sqlclosecheck,bodyclose,asciicheck,misspell,errorlint -e "errors.As" -e "errors.Is" --timeout "3m0s" ./...
+             fi
           working_directory: <<parameters.module>>
 
   go-test:

op-ufm/.golangci.yml

@@ -0,0 +1,10 @@
+linters-settings:
+  staticcheck:
+    checks: ["all"]
+
+issues:
+  exclude-rules:
+    - path: "pkg/provider/roundtrip.go"
+      linters:
+        - staticcheck
+      text: "SA4006"

op-ufm/pkg/provider/roundtrip.go

@@ -37,6 +37,7 @@ func (p *Provider) RoundTrip(ctx context.Context) {
 	p.txPool.ExclusiveSend.Lock()
 	defer p.txPool.ExclusiveSend.Unlock()
 
+	// lint:ignore SA4006 txHash is set and used within tx sending loop
 	txHash := common.Hash{}
 	attempt := 0
 	nonce := uint64(0)

op-ufm/pkg/service/healthz_server.go

@@ -6,6 +6,8 @@ import (
 
 	"github.com/gorilla/mux"
 	"github.com/rs/cors"
+
+	"github.com/ethereum/go-ethereum/log"
 )
 
 type HealthzServer struct {
@@ -33,5 +35,8 @@ func (h *HealthzServer) Shutdown() error {
 }
 
 func (h *HealthzServer) Handle(w http.ResponseWriter, r *http.Request) {
-	w.Write([]byte("OK"))
+	_, err := w.Write([]byte("OK"))
+	if err != nil {
+		log.Error("error handling HealthzServer response")
+	}
 }

op-ufm/pkg/service/service.go

@@ -91,11 +91,15 @@ func (s *Service) Start(ctx context.Context) {
 func (s *Service) Shutdown() {
 	log.Info("service shutting down")
 	if s.Config.Healthz.Enabled {
-		s.Healthz.Shutdown()
+		if err := s.Healthz.Shutdown(); err != nil {
+			log.Error("Error shutting down healthz server", err)
+		}
 		log.Info("healthz stopped")
 	}
 	if s.Config.Metrics.Enabled {
-		s.Metrics.Shutdown()
+		if err := s.Metrics.Shutdown(); err != nil {
+			log.Error("Error shutting down metrics server", err)
+		}
 		log.Info("metrics stopped")
 	}
 	for name, provider := range s.Providers {

op-ufm/tools/kmstool/main.go

@@ -57,7 +57,7 @@ func resolveAddr(ctx context.Context, client *kms.KeyManagementClient, keyName s
 	}
 	_, err = asn1.Unmarshal(block.Bytes, &info)
 	if err != nil {
-		return common.Address{}, fmt.Errorf("google kms public key %q pem block %q: %v", keyName, block.Type, err)
+		return common.Address{}, fmt.Errorf("google kms public key %q pem block %q: %w", keyName, block.Type, err)
 	}
 
 	return pubKeyAddr(info.Key.Bytes), nil