validate IP address used in port long syntax

validation/validation.go

@@ -18,6 +18,7 @@ package validation
 
 import (
 	"fmt"
+	"net"
 	"strings"
 
 	"github.com/compose-spec/compose-go/v2/tree"
@@ -29,6 +30,7 @@ var checks = map[tree.Path]checkerFunc{
 	"volumes.*":                       checkVolume,
 	"configs.*":                       checkFileObject("file", "environment", "content"),
 	"secrets.*":                       checkFileObject("file", "environment"),
+	"services.*.ports.*":              checkIPAddress,
 	"services.*.develop.watch.*.path": checkPath,
 	"services.*.deploy.resources.reservations.devices.*": checkDeviceRequest,
 	"services.*.gpus.*": checkDeviceRequest,
@@ -105,3 +107,13 @@ func checkDeviceRequest(value any, p tree.Path) error {
 	}
 	return nil
 }
+
+func checkIPAddress(value any, p tree.Path) error {
+	if v, ok := value.(map[string]any); ok {
+		ip, ok := v["host_ip"]
+		if ok && net.ParseIP(ip.(string)) == nil {
+			return fmt.Errorf("%s: invalid ip address: %s", p, ip)
+		}
+	}
+	return nil
+}

validation/validation_test.go

@@ -94,3 +94,49 @@ external: true
 		})
 	}
 }
+
+func TestIPAddress(t *testing.T) {
+	checker := checks["services.*.ports.*"]
+	tests := []struct {
+		name  string
+		input string
+		err   string
+	}{
+		{
+			name: "port long syntax, invalid IP",
+			input: `
+host_ip: notavalidip
+target: 1234
+published: "1234"
+`,
+			err: "configs.test.ports[0]: invalid ip address: notavalidip",
+		},
+		{
+			name: "port long syntax, no IP",
+			input: `
+target: 1234
+published: "1234"
+`,
+		},
+		{
+			name: "port long syntax, valid IP",
+			input: `
+host_ip: 192.168.3.4
+target: 1234
+published: "1234"
+`,
+		},
+	}
+
+	for _, tt := range tests {
+		var input map[string]any
+		err := yaml.Unmarshal([]byte(tt.input), &input)
+		assert.NilError(t, err)
+		err = checker(input, tree.NewPath("configs.test.ports[0]"))
+		if tt.err == "" {
+			assert.NilError(t, err)
+		} else {
+			assert.Equal(t, tt.err, err.Error())
+		}
+	}
+}