fix golangci-lint warnings

Fix the following issues:

  etcd/etcd.go:39:50: S1002: should omit comparison to bool constant, can be simplified to `match` (gosimple)
  	if match, _ := regexp.Match("0\\.4\\.*", body); match == true {
  etcd/etcd.go:4:2: SA1019: "io/ioutil" has been deprecated since Go 1.19: As of Go 1.16, the same functionality is now provided by package [io] or package [os], and those implementations should be preferred in new code. See the specific function documentation for details. (staticcheck)
  	"io/ioutil"
  zookeeper/zookeeper.go:30:11: Error return value of `c.Create` is not checked (errcheck)
  		c.Create(uri.Path, []byte{}, 0, zk.WorldACL(zk.PermAll))
  bridge/bridge.go:229:6: S1002: should omit comparison to bool constant, can be simplified to `!b.config.Internal` (gosimple)
  		if b.config.Internal != true && port.HostPort == "" {
  bridge/bridge.go:301:5: S1002: should omit comparison to bool constant, can be simplified to `b.config.Internal` (gosimple)
  	if b.config.Internal == true {
  bridge/bridge.go:213:41: composites: github.com/fsouza/go-dockerclient.PortBinding struct literal uses unkeyed fields (govet)
  		published := []dockerapi.PortBinding{ {"0.0.0.0", port.Port()}, }

bridge/bridge.go

@@ -210,7 +210,7 @@ func (b *Bridge) add(containerId string, quiet bool) {
 
 	// Extract configured host port mappings, relevant when using --net=host
 	for port := range container.Config.ExposedPorts {
-		published := []dockerapi.PortBinding{{"0.0.0.0", port.Port()}}
+		published := []dockerapi.PortBinding{{HostIP: "0.0.0.0", HostPort: port.Port()}}
 		ports[string(port)] = servicePort(container, port, published)
 	}
 
@@ -226,7 +226,7 @@ func (b *Bridge) add(containerId string, quiet bool) {
 
 	servicePorts := make(map[string]ServicePort)
 	for key, port := range ports {
-		if b.config.Internal != true && port.HostPort == "" {
+		if !b.config.Internal && port.HostPort == "" {
 			if !quiet {
 				log.Println("ignored:", container.ID[:12], "port", port.ExposedPort, "not published on host")
 			}
@@ -298,7 +298,7 @@ func (b *Bridge) newService(port ServicePort, isgroup bool) *Service {
 	}
 	var p int
 
-	if b.config.Internal == true {
+	if b.config.Internal {
 		service.IP = port.ExposedIP
 		p, _ = strconv.Atoi(port.ExposedPort)
 	} else {

etcd/etcd.go

@@ -1,7 +1,7 @@
 package etcd
 
 import (
-	"io/ioutil"
+	"io"
 	"log"
 	"net"
 	"net/http"
@@ -34,9 +34,9 @@ func (f *Factory) New(uri *url.URL) bridge.RegistryAdapter {
 	}
 
 	defer res.Body.Close()
-	body, _ := ioutil.ReadAll(res.Body)
+	body, _ := io.ReadAll(res.Body)
 
-	if match, _ := regexp.Match("0\\.4\\.*", body); match == true {
+	if match, _ := regexp.Match("0\\.4\\.*", body); match {
 		log.Println("etcd: using v0 client")
 		return &EtcdAdapter{client: etcd.NewClient(urls), path: uri.Path}
 	}

zookeeper/zookeeper.go

@@ -27,7 +27,7 @@ func (f *Factory) New(uri *url.URL) bridge.RegistryAdapter {
 		log.Println("zookeeper: error checking if base path exists:", err)
 	}
 	if !exists {
-		c.Create(uri.Path, []byte{}, 0, zk.WorldACL(zk.PermAll))
+		c.Create(uri.Path, []byte{}, 0, zk.WorldACL(zk.PermAll)) // nolint:errcheck
 	}
 	return &ZkAdapter{client: c, path: uri.Path}
 }