fix(lint):err check rules and fix config

.golangci.yml

@@ -1,11 +1,11 @@
-version: 2
+version: "2"
 
 run:
   timeout: 5m
   tests: true
 
 linters:
-    disable-all: true
+  default: none
   enable:
     - errcheck
     - govet
@@ -18,18 +18,26 @@ linters:
     - ineffassign
     - unconvert
     - bidichk
-
+  settings:
-linters-settings:
     errcheck:
       check-type-assertions: true
-        check-blank: true
+      check-blank: false
-
+      exclude-functions:
+        - fmt.Print
+        - fmt.Println
+        - fmt.Printf
+        - fmt.Fprint
+        - fmt.Fprintln
+        - fmt.Fprintf
     govet:
       enable-all: true
       disable:
         - fieldalignment
+  exclusions:
+    rules:
+      - linters: [errcheck]
+        source: "^\\s*defer "
 
 issues:
-    exclude-use-default: false
   max-issues-per-linter: 0
   max-same-issues: 0

ipc/server.go

@@ -24,7 +24,10 @@ func NewServer() (*Server, error) {
 		return nil, err
 	}
 
-	localAddr := conn.LocalAddr().(*net.UDPAddr)
+	localAddr, ok := conn.LocalAddr().(*net.UDPAddr)
+	if !ok {
+		return nil, net.InvalidAddrError("not a UDP address")
+	}
 
 	s := &Server{
 		conn:       conn,