Merge pull request containers#1549 from geichelberger/add-host-gateway-support

libnetwork: Add support for host-gatway

Author: openshift-merge-robot

libnetwork/etchosts/hosts.go

@@ -14,6 +14,7 @@ import (
 
 const (
 	HostContainersInternal = "host.containers.internal"
+	HostGateway            = "host-gateway"
 	localhost              = "localhost"
 )
 
@@ -98,7 +99,7 @@ func Remove(file string, entries HostEntries) error {
 
 // new see comment on New()
 func newHost(params *Params) error {
-	entries, err := parseExtraHosts(params.ExtraHosts)
+	entries, err := parseExtraHosts(params.ExtraHosts, params.HostContainersInternalIP)
 	if err != nil {
 		return err
 	}
@@ -230,7 +231,7 @@ func checkIfEntryExists(current HostEntry, entries HostEntries) bool {
 // parseExtraHosts converts a slice of "name:ip" string to entries.
 // Because podman and buildah both store the extra hosts in this format
 // we convert it here instead of having to this on the caller side.
-func parseExtraHosts(extraHosts []string) (HostEntries, error) {
+func parseExtraHosts(extraHosts []string, hostContainersInternalIP string) (HostEntries, error) {
 	entries := make(HostEntries, 0, len(extraHosts))
 	for _, entry := range extraHosts {
 		values := strings.SplitN(entry, ":", 2)
@@ -243,7 +244,14 @@ func parseExtraHosts(extraHosts []string) (HostEntries, error) {
 		if values[1] == "" {
 			return nil, fmt.Errorf("IP address in host entry %q is empty", entry)
 		}
-		e := HostEntry{IP: values[1], Names: []string{values[0]}}
+		ip := values[1]
+		if values[1] == HostGateway {
+			if hostContainersInternalIP == "" {
+				return nil, fmt.Errorf("unable to replace %q of host entry %q: host containers internal IP address is empty", HostGateway, entry)
+			}
+			ip = hostContainersInternalIP
+		}
+		e := HostEntry{IP: ip, Names: []string{values[0]}}
 		entries = append(entries, e)
 	}
 	return entries, nil

libnetwork/etchosts/hosts_test.go

@@ -218,6 +218,13 @@ func TestNew(t *testing.T) {
 			hostContainersInternal:    "10.0.0.1",
 			expectedTargetFileContent: targetFileContent1 + "10.0.0.1\thost.containers.internal\n",
 		},
+		{
+			name:                      "with host.containers.internal ip and host-gateway",
+			baseFileContent:           baseFileContent1Spaces,
+			extraHosts:                []string{"gatewayname:host-gateway"},
+			hostContainersInternal:    "10.0.0.1",
+			expectedTargetFileContent: "10.0.0.1\tgatewayname\n" + targetFileContent1 + "10.0.0.1\thost.containers.internal\n",
+		},
 		{
 			name:                      "host.containers.internal not added when already present in extra hosts",
 			baseFileContent:           baseFileContent1Spaces,
@@ -267,6 +274,12 @@ func TestNew(t *testing.T) {
 			extraHosts:      []string{"name"},
 			wantErrString:   "unable to parse host entry \"name\": incorrect format",
 		},
+		{
+			name:            "invalid host-gateway",
+			baseFileContent: baseFileContent1Spaces,
+			extraHosts:      []string{"gatewayname:host-gateway"},
+			wantErrString:   "host containers internal IP address is empty",
+		},
 	}
 
 	for _, tt := range tests {