Lint: fix errcheck issue

Signed-off-by: Xiang Dai <long0dai@foxmail.com>

5 files changed, 58 insertions, 17 deletions

diff --git a/edgemesh/pkg/dns/dns.go b/edgemesh/pkg/dns/dns.go
index 57d4bf00b..5782e3c09 100644
--- a/edgemesh/pkg/dns/dns.go
+++ b/edgemesh/pkg/dns/dns.go
@@ -125,7 +125,9 @@ func startDNS() {
 			klog.Warningf("[EdgeMesh] failed to resolve dns: %v", err)
 			continue
 		}
-		dnsConn.WriteTo(rsp, from)
+		if _, err = dnsConn.WriteTo(rsp, from); err != nil {
+			klog.Warningf("[EdgeMesh] failed to write: %v", err)
+		}
 	}
 }
 
@@ -330,7 +332,10 @@ func getFromRealDNS(req []byte, from *net.UDPAddr) {
 
 		if n > 0 {
 			rsp = append(rsp, buf[:n]...)
-			dnsConn.WriteToUDP(rsp, from)
+			if _, err = dnsConn.WriteToUDP(rsp, from); err != nil {
+				klog.Errorf("[EdgeMesh] failed to wirte to udp, err: %v", err)
+				continue
+			}
 			break
 		}
 	}
diff --git a/edgemesh/pkg/listener/listener.go b/edgemesh/pkg/listener/listener.go
index 3a4d88a66..e1a90db23 100644
--- a/edgemesh/pkg/listener/listener.go
+++ b/edgemesh/pkg/listener/listener.go
@@ -256,7 +256,9 @@ func realServerAddress(conn *net.Conn) (string, int, error) {
 	}
 
 	port := int(addr.data[0])<<8 + int(addr.data[1])
-	syscall.SetNonblock(int(fd), true)
+	if err := syscall.SetNonblock(int(fd), true); err != nil {
+		return "", -1, nil
+	}
 
 	return ip.String(), port, nil
 }
diff --git a/edgemesh/pkg/plugin/plugin.go b/edgemesh/pkg/plugin/plugin.go
index 0d2eeee3c..5202836d8 100644
--- a/edgemesh/pkg/plugin/plugin.go
+++ b/edgemesh/pkg/plugin/plugin.go
@@ -1,6 +1,8 @@
 package plugin
 
 import (
+	"k8s.io/klog"
+
 	"github.com/go-chassis/go-archaius"
 	"github.com/go-chassis/go-chassis/control"
 	"github.com/go-chassis/go-chassis/core/config"
@@ -43,7 +45,11 @@ func Install() {
 		Infra:   config.GlobalDefinition.Panel.Infra,
 		Address: config.GlobalDefinition.Panel.Settings["address"],
 	}
-	control.Init(opts)
+	if err := control.Init(opts); err != nil {
+		klog.Errorf("failed to init control: %v", err)
+	}
 	// init archaius
-	archaius.Init()
+	if err := archaius.Init(); err != nil {
+		klog.Errorf("failed to init arahaius: %v", err)
+	}
 }
diff --git a/edgemesh/pkg/protocol/http/http.go b/edgemesh/pkg/protocol/http/http.go
index 9e84921f3..cbec2632b 100644
--- a/edgemesh/pkg/protocol/http/http.go
+++ b/edgemesh/pkg/protocol/http/http.go
@@ -97,7 +97,9 @@ func (p *HTTP) responseCallback(data *invocation.Response) error {
 					klog.Errorf("[EdgeMesh] convert http response to bytes err: %v", err)
 				} else {
 					// send response back
-					p.Conn.Write(respBytes)
+					if _, err := p.Conn.Write(respBytes); err != nil {
+						klog.Errorf("[EdgeMesh] write err: %v", err)
+					}
 					return nil
 				}
 			}
@@ -113,8 +115,10 @@ func (p *HTTP) responseCallback(data *invocation.Response) error {
 	}
 	respBytes, _ = httpResponseToBytes(resp)
 	// send error response back
-	p.Conn.Write(respBytes)
-	return err
+	if _, err = p.Conn.Write(respBytes); err != nil {
+		return err
+	}
+	return nil
 }
 
 // httpResponseToBytes transforms http.Response to bytes
diff --git a/edgemesh/pkg/proxy/proxy.go b/edgemesh/pkg/proxy/proxy.go
index 05d630fae..217a94b22 100644
--- a/edgemesh/pkg/proxy/proxy.go
+++ b/edgemesh/pkg/proxy/proxy.go
@@ -150,13 +150,25 @@ func (p *Proxier) readAndCleanRule() {
 	for scan.Scan() {
 		serverString := scan.Text()
 		if strings.Contains(serverString, "-o") {
-			p.iptables.DeleteRule(utiliptables.TableNAT, utiliptables.ChainOutput, strings.Split(serverString, " ")...)
+			if err := p.iptables.DeleteRule(utiliptables.TableNAT, utiliptables.ChainOutput, strings.Split(serverString, " ")...); err != nil {
+				klog.Errorf("[EdgeMesh] failed to delete iptables rule, err: %v", err)
+				return
+			}
 		} else if strings.Contains(serverString, "-i") {
-			p.iptables.DeleteRule(utiliptables.TableNAT, utiliptables.ChainPrerouting, strings.Split(serverString, " ")...)
+			if err := p.iptables.DeleteRule(utiliptables.TableNAT, utiliptables.ChainPrerouting, strings.Split(serverString, " ")...); err != nil {
+				klog.Errorf("[EdgeMesh] failed to delete iptables rule, err: %v", err)
+				return
+			}
 		}
 	}
-	p.iptables.FlushChain(utiliptables.TableNAT, meshChain)
-	p.iptables.DeleteChain(utiliptables.TableNAT, meshChain)
+	if err := p.iptables.FlushChain(utiliptables.TableNAT, meshChain); err != nil {
+		klog.Errorf("[EdgeMesh] failed to flush iptables chain, err: %v", err)
+		return
+	}
+	if err := p.iptables.DeleteChain(utiliptables.TableNAT, meshChain); err != nil {
+		klog.Errorf("[EdgeMesh] failed to delete iptables chain, err: %v", err)
+		return
+	}
 }
 
 // ensureResolvForHost adds edgemesh dns server to the head of /etc/resolv.conf
@@ -170,7 +182,9 @@ func ensureResolvForHost() {
 	resolv := strings.Split(string(bs), "\n")
 	if resolv == nil {
 		nameserver := "nameserver " + config.Config.ListenIP.String()
-		ioutil.WriteFile(hostResolv, []byte(nameserver), 0600)
+		if err := ioutil.WriteFile(hostResolv, []byte(nameserver), 0600); err != nil {
+			klog.Errorf("[EdgeMesh] write file %s err: %v", hostResolv, err)
+		}
 		return
 	}
 
@@ -193,7 +207,10 @@ func ensureResolvForHost() {
 	if configured {
 		if dnsIdx != startIdx && dnsIdx > startIdx {
 			nameserver := sortNameserver(resolv, dnsIdx, startIdx)
-			ioutil.WriteFile(hostResolv, []byte(nameserver), 0600)
+			if err := ioutil.WriteFile(hostResolv, []byte(nameserver), 0600); err != nil {
+				klog.Errorf("[EdgeMesh] failed to write file %s, err: %v", hostResolv, err)
+				return
+			}
 		}
 		return
 	}
@@ -209,7 +226,10 @@ func ensureResolvForHost() {
 		idx++
 	}
 
-	ioutil.WriteFile(hostResolv, []byte(nameserver), 0600)
+	if err := ioutil.WriteFile(hostResolv, []byte(nameserver), 0600); err != nil {
+		klog.Errorf("[EdgeMesh] failed to write file %s, err: %v", hostResolv, err)
+		return
+	}
 }
 
 func sortNameserver(resolv []string, dnsIdx, startIdx int) string {
@@ -232,7 +252,9 @@ func sortNameserver(resolv []string, dnsIdx, startIdx int) string {
 
 func Clean() {
 	proxier.readAndCleanRule()
-	netlink.RouteDel(&route)
+	if err := netlink.RouteDel(&route); err != nil {
+		klog.Warningf("[EdgeMesh] delete route err: %v", err)
+	}
 	bs, err := ioutil.ReadFile(hostResolv)
 	if err != nil {
 		klog.Warningf("[EdgeMesh] read file %s err: %v", hostResolv, err)
@@ -249,5 +271,7 @@ func Clean() {
 		}
 		nameserver = nameserver + item + "\n"
 	}
-	ioutil.WriteFile(hostResolv, []byte(nameserver), 0600)
+	if err := ioutil.WriteFile(hostResolv, []byte(nameserver), 0600); err != nil {
+		klog.Errorf("[EdgeMesh] failed to write nameserver to file %s, err: %v", hostResolv, err)
+	}
 }