Add gosimple check

Add the gosimple tool check in the Makefile
Fix all the issues identified

Signed-off-by: Flavio Crisciani <flavio.crisciani@docker.com>

Dockerfile.build

@@ -6,4 +6,5 @@ RUN go get github.com/tools/godep \
 		golang.org/x/tools/cmd/cover \
 		github.com/mattn/goveralls \
 		github.com/gordonklaus/ineffassign \
-		github.com/client9/misspell/cmd/misspell
+		github.com/client9/misspell/cmd/misspell \
+		honnef.co/go/tools/cmd/gosimple

Makefile

@@ -1,4 +1,4 @@
-.PHONY: all all-local build build-local clean cross cross-local vet lint misspell check check-code check-format run-tests integration-tests check-local coveralls circle-ci-cross circle-ci-build circle-ci-check circle-ci
+.PHONY: all all-local build build-local clean cross cross-local gosimple vet lint misspell check check-code check-format run-tests integration-tests check-local coveralls circle-ci-cross circle-ci-build circle-ci-check circle-ci
 SHELL=/bin/bash
 build_image=libnetworkbuild
 dockerargs = --privileged -v $(shell pwd):/go/src/github.com/docker/libnetwork -w /go/src/github.com/docker/libnetwork
@@ -64,7 +64,7 @@ cross-local:
 check: ${build_image}.created
 	@${docker} ./wrapmake.sh check-local
 
-check-code: lint vet ineffassign
+check-code: lint gosimple vet ineffassign
 
 check-format: fmt misspell
 
@@ -153,6 +153,10 @@ ineffassign: ## run ineffassign
 	@echo "🐳 $@"
 	@test -z "$$(ineffassign . | grep -v vendor/ | grep -v ".pb.go:" | grep -v ".mock.go" | tee /dev/stderr)"
 
+gosimple: ## run gosimple
+	@echo "🐳 $@"
+	@test -z "$$(gosimple . | grep -v vendor/ | grep -v ".pb.go:" | grep -v ".mock.go" | tee /dev/stderr)"
+
 # CircleCI's Docker fails when cleaning up using the --rm flag
 # The following targets are a workaround for this
 circle-ci-cross: ${build_image}.created

agent.go

@@ -383,15 +383,11 @@ func (c *controller) agentClose() {
 
 	agent.Lock()
 	for _, cancelFuncs := range agent.driverCancelFuncs {
-		for _, cancel := range cancelFuncs {
-			cancelList = append(cancelList, cancel)
-		}
+		cancelList = append(cancelList, cancelFuncs...)
 	}
 
 	// Add also the cancel functions for the network db
-	for _, cancel := range agent.coreCancelFuncs {
-		cancelList = append(cancelList, cancel)
-	}
+	cancelList = append(cancelList, agent.coreCancelFuncs...)
 	agent.Unlock()
 
 	for _, cancel := range cancelList {

endpoint_info.go

@@ -154,9 +154,7 @@ func (epi *endpointInterface) CopyTo(dstEpi *endpointInterface) error {
 	dstEpi.v6PoolID = epi.v6PoolID
 	if len(epi.llAddrs) != 0 {
 		dstEpi.llAddrs = make([]*net.IPNet, 0, len(epi.llAddrs))
-		for _, ll := range epi.llAddrs {
-			dstEpi.llAddrs = append(dstEpi.llAddrs, ll)
-		}
+		dstEpi.llAddrs = append(dstEpi.llAddrs, epi.llAddrs...)
 	}
 
 	for _, route := range epi.routes {

libnetwork_linux_test.go

@@ -903,9 +903,7 @@ func runParallelTests(t *testing.T, thrNumber int) {
 	}
 
 	if thrNumber != first {
-		select {
-		case <-start:
-		}
+		<-start
 
 		thrdone := make(chan struct{})
 		done <- thrdone
@@ -972,9 +970,7 @@ func runParallelTests(t *testing.T, thrNumber int) {
 	}
 	if thrNumber == first {
 		for thrdone := range done {
-			select {
-			case <-thrdone:
-			}
+			<-thrdone
 		}
 
 		testns.Close()

libnetwork_test.go

@@ -64,11 +64,7 @@ func createController() error {
 		return err
 	}
 	controller, err = libnetwork.New(append(cfgOptions, config.OptionDriverConfig(bridgeNetType, genericOption))...)
-	if err != nil {
-		return err
-	}
-
-	return nil
+	return err
 }
 
 func createTestNetwork(networkType, networkName string, netOption options.Generic, ipamV4Configs, ipamV6Configs []*libnetwork.IpamConf) (libnetwork.Network, error) {

network.go

@@ -434,15 +434,11 @@ func (n *network) applyConfigurationTo(to *network) error {
 	}
 	if len(n.ipamV4Config) > 0 {
 		to.ipamV4Config = make([]*IpamConf, 0, len(n.ipamV4Config))
-		for _, v4conf := range n.ipamV4Config {
-			to.ipamV4Config = append(to.ipamV4Config, v4conf)
-		}
+		to.ipamV4Config = append(to.ipamV4Config, n.ipamV4Config...)
 	}
 	if len(n.ipamV6Config) > 0 {
 		to.ipamV6Config = make([]*IpamConf, 0, len(n.ipamV6Config))
-		for _, v6conf := range n.ipamV6Config {
-			to.ipamV6Config = append(to.ipamV6Config, v6conf)
-		}
+		to.ipamV6Config = append(to.ipamV6Config, n.ipamV6Config...)
 	}
 	if len(n.generic) > 0 {
 		to.generic = options.Generic{}
@@ -873,8 +869,7 @@ func (n *network) resolveDriver(name string, load bool) (driverapi.Driver, *driv
 	d, cap := c.drvRegistry.Driver(name)
 	if d == nil {
 		if load {
-			var err error
-			err = c.loadDriver(name)
+			err := c.loadDriver(name)
 			if err != nil {
 				return nil, nil, err
 			}
@@ -1451,11 +1446,7 @@ func (n *network) ipamAllocate() error {
 	}
 
 	err = n.ipamAllocateVersion(6, ipam)
-	if err != nil {
-		return err
-	}
-
-	return nil
+	return err
 }
 
 func (n *network) requestPoolHelper(ipam ipamapi.Ipam, addressSpace, preferredPool, subPool string, options map[string]string, v6 bool) (string, *net.IPNet, map[string]string, error) {
@@ -1654,9 +1645,7 @@ func (n *network) getIPInfo(ipVer int) []*IpamInfo {
 	}
 	l := make([]*IpamInfo, 0, len(info))
 	n.Lock()
-	for _, d := range info {
-		l = append(l, d)
-	}
+	l = append(l, info...)
 	n.Unlock()
 	return l
 }
@@ -1870,7 +1859,7 @@ func (n *network) ResolveName(req string, ipType int) ([]net.IP, bool) {
 		// the docker network domain. If the network is not v6 enabled
 		// set ipv6Miss to filter the DNS query from going to external
 		// resolvers.
-		if ok && n.enableIPv6 == false {
+		if ok && !n.enableIPv6 {
 			ipv6Miss = true
 		}
 		ipSet, ok = sr.svcIPv6Map.Get(req)

resolver.go

@@ -446,7 +446,7 @@ func (r *resolver) ServeDNS(w dns.ResponseWriter, query *dns.Msg) {
 			defer co.Close()
 
 			// limits the number of outstanding concurrent queries.
-			if r.forwardQueryStart() == false {
+			if !r.forwardQueryStart() {
 				old := r.tStamp
 				r.tStamp = time.Now()
 				if r.tStamp.Sub(old) > logInterval {

sandbox.go

@@ -621,7 +621,7 @@ func (sb *sandbox) resolveName(req string, networkName string, epList []*endpoin
 func (sb *sandbox) SetKey(basePath string) error {
 	start := time.Now()
 	defer func() {
-		logrus.Debugf("sandbox set key processing took %s for container %s", time.Now().Sub(start), sb.ContainerID())
+		logrus.Debugf("sandbox set key processing took %s for container %s", time.Since(start), sb.ContainerID())
 	}()
 
 	if basePath == "" {
@@ -773,9 +773,7 @@ func (sb *sandbox) restoreOslSandbox() error {
 		}
 		Ifaces[fmt.Sprintf("%s+%s", i.srcName, i.dstPrefix)] = ifaceOptions
 		if joinInfo != nil {
-			for _, r := range joinInfo.StaticRoutes {
-				routes = append(routes, r)
-			}
+			routes = append(routes, joinInfo.StaticRoutes...)
 		}
 		if ep.needResolver() {
 			sb.startResolver(true)
@@ -789,11 +787,7 @@ func (sb *sandbox) restoreOslSandbox() error {
 
 	// restore osl sandbox
 	err := sb.osSbox.Restore(Ifaces, routes, gwep.joinInfo.gw, gwep.joinInfo.gw6)
-	if err != nil {
-		return err
-	}
-
-	return nil
+	return err
 }
 
 func (sb *sandbox) populateNetworkResources(ep *endpoint) error {
@@ -958,9 +952,7 @@ func (sb *sandbox) joinLeaveStart() {
 		joinLeaveDone := sb.joinLeaveDone
 		sb.Unlock()
 
-		select {
-		case <-joinLeaveDone:
-		}
+		<-joinLeaveDone
 
 		sb.Lock()
 	}

sandbox_externalkey_unix.go

@@ -52,7 +52,6 @@ func processSetKeyReexec() {
 	controllerID := os.Args[2]
 
 	err = SetExternalKey(controllerID, containerID, fmt.Sprintf("/proc/%d/ns/net", state.Pid))
-	return
 }
 
 // SetExternalKey provides a convenient way to set an External key to a sandbox

sandbox_store.go

@@ -115,9 +115,7 @@ func (sbs *sbState) CopyTo(o datastore.KVObject) error {
 	dstSbs.dbExists = sbs.dbExists
 	dstSbs.EpPriority = sbs.EpPriority
 
-	for _, eps := range sbs.Eps {
-		dstSbs.Eps = append(dstSbs.Eps, eps)
-	}
+	dstSbs.Eps = append(dstSbs.Eps, sbs.Eps...)
 
 	if len(sbs.ExtDNS2) > 0 {
 		for _, dns := range sbs.ExtDNS2 {