Podman CLI --add-host with multiple host for a single IP

Signed-off-by: Jerome degroote <jeromedu59230@gmx.fr>

cmd/podman/parse/net.go

@@ -29,14 +29,23 @@ var (
 )
 
 // validateExtraHost validates that the specified string is a valid extrahost and returns it.
-// ExtraHost is in the form of name:ip where the ip has to be a valid ip (ipv4 or ipv6) or the special string HostGateway.
+// ExtraHost is in the form of name1;name2;name3:ip where the ip has to be a valid ip (ipv4 or ipv6) or the special string HostGateway.
 // for add-host flag
 func ValidateExtraHost(val string) (string, error) {
 	// allow for IPv6 addresses in extra hosts by only splitting on first ":"
-	name, ip, hasIP := strings.Cut(val, ":")
+	names, ip, hasIP := strings.Cut(val, ":")
-	if !hasIP || len(name) == 0 {
+	if !hasIP || len(names) == 0 {
 		return "", fmt.Errorf("bad format for add-host: %q", val)
 	}
+
+	// Split the hostnames by semicolon and validate each one
+	nameList := strings.Split(names, ";")
+	for _, name := range nameList {
+		if len(name) == 0 {
+			return "", fmt.Errorf("hostname in add-host %q is empty", val)
+		}
+	}
+
 	if ip == etchosts.HostGateway {
 		return val, nil
 	}

cmd/podman/parse/net_test.go

@@ -42,17 +42,23 @@ func TestValidateExtraHost(t *testing.T) {
 	}{
 		// 2001:0db8:85a3:0000:0000:8a2e:0370:7334
 		{name: "good-ipv4", args: args{val: "foobar:192.168.1.1"}, want: "foobar:192.168.1.1", wantErr: false},
+		{name: "good-multiple-ipv4", args: args{val: "host1;host2;host3:192.168.1.1"}, want: "host1;host2;host3:192.168.1.1", wantErr: false},
 		{name: "bad-ipv4", args: args{val: "foobar:999.999.999.99"}, want: "", wantErr: true},
 		{name: "bad-ipv4", args: args{val: "foobar:999.999.999"}, want: "", wantErr: true},
+		{name: "bad-multiple-ipv4", args: args{val: "host1;host2;host3:999.999.999"}, want: "", wantErr: true},
 		{name: "noname-ipv4", args: args{val: "192.168.1.1"}, want: "", wantErr: true},
 		{name: "noname-ipv4", args: args{val: ":192.168.1.1"}, want: "", wantErr: true},
+		{name: "noname-multiple-ipv4", args: args{val: "host1;;host3:192.168.1.1"}, want: "", wantErr: true},
 		{name: "noip", args: args{val: "foobar:"}, want: "", wantErr: true},
 		{name: "noip", args: args{val: "foobar"}, want: "", wantErr: true},
 		{name: "good-ipv6", args: args{val: "foobar:2001:0db8:85a3:0000:0000:8a2e:0370:7334"}, want: "foobar:2001:0db8:85a3:0000:0000:8a2e:0370:7334", wantErr: false},
+		{name: "good-multiple-ipv6", args: args{val: "host1;host2;host3:2001:0db8:85a3:0000:0000:8a2e:0370:7334"}, want: "host1;host2;host3:2001:0db8:85a3:0000:0000:8a2e:0370:7334", wantErr: false},
 		{name: "bad-ipv6", args: args{val: "foobar:0db8:85a3:0000:0000:8a2e:0370:7334"}, want: "", wantErr: true},
 		{name: "bad-ipv6", args: args{val: "foobar:0db8:85a3:0000:0000:8a2e:0370:7334.0000.0000.000"}, want: "", wantErr: true},
+		{name: "bad-multiple-ipv6", args: args{val: "host1;host2;host3:0db8:85a3:0000:0000:8a2e:0370:7334.0000.0000.000"}, want: "", wantErr: true},
 		{name: "noname-ipv6", args: args{val: "2001:0db8:85a3:0000:0000:8a2e:0370:7334"}, want: "", wantErr: true},
 		{name: "noname-ipv6", args: args{val: ":2001:0db8:85a3:0000:0000:8a2e:0370:7334"}, want: "", wantErr: true},
+		{name: "noname-multiple-ipv6", args: args{val: "host1;;host3:2001:0db8:85a3:0000:0000:8a2e:0370:7334"}, want: "", wantErr: true},
 		{name: "host-gateway", args: args{val: "foobar:host-gateway"}, want: fmt.Sprintf("foobar:%s", etchosts.HostGateway), wantErr: false},
 	}
 	for _, tt := range tests {

docs/source/locale/ja/LC_MESSAGES/markdown.po

@@ -1629,7 +1629,7 @@ msgstr ""
 #: ../../source/markdown/podman-pod-create.1.md:39
 #: ../../source/markdown/podman-run.1.md:94
 msgid ""
-"Add a line to /etc/hosts. The format is hostname:ip. The **--add-host** "
+"Add a line to /etc/hosts. The format is hostname1;hostname2;hostname3:ip. Multiple hostnames for the same IP can be separated by semicolons. The **--add-host** "
 "option can be set multiple times. Conflicts with the **--no-hosts** "
 "option."
 msgstr ""

docs/source/markdown/options/add-host.md

@@ -5,6 +5,7 @@
 #### **--add-host**=*host:ip*
 
 Add a custom host-to-IP mapping (host:ip)
+Multiple hostnames for the same IP can be separated by semicolons.
 
-Add a line to /etc/hosts. The format is hostname:ip. The **--add-host**
+Add a line to /etc/hosts. The format is hostname:ip or hostname1;hostname2;hostname3:ip if you want to map multiple hostnames to the same ip without duplicating the --add-host parameter. The **--add-host**
 option can be set multiple times. Conflicts with the **--no-hosts** option.