feat: validate --host flag for IP address (#124)

internal/cmd/local/check.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"net"
 	"os"
+	"regexp"
 	"runtime"
 	"strconv"
 	"syscall"
@@ -167,3 +168,13 @@ func (e InvalidPortError) Unwrap() error {
 func (e InvalidPortError) Error() string {
 	return fmt.Sprintf("unable to convert host port %s to integer: %s", e.Port, e.Inner)
 }
+
+func validateHostFlag(host string) error {
+	if ip := net.ParseIP(host); ip != nil {
+		return localerr.ErrIpAddressForHostFlag
+	}
+	if !regexp.MustCompile(`^[a-z0-9](?:[-a-z0-9]*[a-z0-9])?(?:\.[a-z0-9](?:[-a-z0-9]*[a-z0-9])?)*$`).MatchString(host) {
+		return localerr.ErrInvalidHostFlag
+	}
+	return nil
+}

internal/cmd/local/check_test.go

@@ -272,6 +272,31 @@ func TestGetPort_InpsectErr(t *testing.T) {
 	}
 }
 
+func TestValidateHostFlag(t *testing.T) {
+	expectErr := func(host string, expect error) {
+		err := validateHostFlag(host)
+		if !errors.Is(err, expect) {
+			t.Errorf("expected error %v for host %q but got %v", expect, host, err)
+		}
+	}
+	expectErr("1.2.3.4", localerr.ErrIpAddressForHostFlag)
+	expectErr("1.2.3.4:8000", localerr.ErrInvalidHostFlag)
+	expectErr("1.2.3.4:8000", localerr.ErrInvalidHostFlag)
+	expectErr("ABC-DEF-GHI.abcd.efgh", localerr.ErrInvalidHostFlag)
+	expectErr("http://airbyte.foo-data-platform-sbx.bar.cloud", localerr.ErrInvalidHostFlag)
+
+	expectOk := func(host string) {
+		err := validateHostFlag(host)
+		if err != nil {
+			t.Errorf("unexpected error for host %q: %s", host, err)
+		}
+	}
+	expectOk("foo")
+	expectOk("foo.bar")
+	expectOk("example.com")
+	expectOk("sub.example01.com")
+}
+
 // port returns the port from a string value in the format of "ipv4:port" or "ip::v6:port"
 func port(s string) int {
 	vals := strings.Split(s, ":")

internal/cmd/local/local_install.go

@@ -8,6 +8,7 @@ import (
 	"github.com/airbytehq/abctl/internal/cmd/local/k8s"
 	"github.com/airbytehq/abctl/internal/cmd/local/local"
 	"github.com/airbytehq/abctl/internal/maps"
+
 	"github.com/airbytehq/abctl/internal/telemetry"
 	"github.com/pterm/pterm"
 )
@@ -45,6 +46,17 @@ func (i *InstallCmd) Run(ctx context.Context, provider k8s.Provider, telClient t
 		return err
 	}
 
+	extraVolumeMounts, err := parseVolumeMounts(i.Volume)
+	if err != nil {
+		return err
+	}
+
+	for _, host := range i.Host {
+		if err := validateHostFlag(host); err != nil {
+			return err
+		}
+	}
+
 	return telClient.Wrap(ctx, telemetry.Install, func() error {
 		spinner.UpdateText(fmt.Sprintf("Checking for existing Kubernetes cluster '%s'", provider.ClusterName))
 
@@ -77,11 +89,6 @@ func (i *InstallCmd) Run(ctx context.Context, provider k8s.Provider, telClient t
 			// no existing cluster, need to create one
 			pterm.Info.Println(fmt.Sprintf("No existing cluster found, cluster '%s' will be created", provider.ClusterName))
 
-			extraVolumeMounts, err := parseVolumeMounts(i.Volume)
-			if err != nil {
-				return err
-			}
-
 			spinner.UpdateText(fmt.Sprintf("Checking if port %d is available", i.Port))
 			if err := portAvailable(ctx, i.Port); err != nil {
 				return err

internal/cmd/local/local_test.go

@@ -2,12 +2,16 @@ package local
 
 import (
 	"context"
+	"errors"
+
 	"os"
 	"path/filepath"
 	"strings"
 	"testing"
 
 	"github.com/airbytehq/abctl/internal/cmd/local/k8s"
+	"github.com/airbytehq/abctl/internal/cmd/local/localerr"
+
 	"github.com/airbytehq/abctl/internal/cmd/local/paths"
 	"github.com/airbytehq/abctl/internal/telemetry"
 	"github.com/google/go-cmp/cmp"
@@ -127,5 +131,22 @@ foo:
 
 	if !strings.HasPrefix(err.Error(), "failed to unmarshal file") {
 		t.Errorf("unexpected error: %v", err)
+
+	}
+}
+
+func TestInvalidHostFlag_IpAddr(t *testing.T) {
+	cmd := InstallCmd{Host: []string{"ok", "1.2.3.4"}}
+	err := cmd.Run(context.Background(), k8s.TestProvider, telemetry.NoopClient{})
+	if !errors.Is(err, localerr.ErrIpAddressForHostFlag) {
+		t.Errorf("expected ErrIpAddressForHostFlag but got %v", err)
+	}
+}
+
+func TestInvalidHostFlag_IpAddrWithPort(t *testing.T) {
+	cmd := InstallCmd{Host: []string{"ok", "1.2.3.4:8000"}}
+	err := cmd.Run(context.Background(), k8s.TestProvider, telemetry.NoopClient{})
+	if !errors.Is(err, localerr.ErrInvalidHostFlag) {
+		t.Errorf("expected ErrInvalidHostFlag but got %v", err)
 	}
 }

internal/cmd/local/localerr/localerr.go

@@ -64,4 +64,20 @@ The ingress port can be changed by passing the flag --port.`,
 This could be in indication that the ingress port is already in use by a different application.
 The ingress port can be changed by passing the flag --port.`,
 	}
+
+	ErrIpAddressForHostFlag = &LocalError{
+		msg: "invalid host - can't use an IP address",
+		help: `Looks like you provided an IP address to the --host flag.
+This won't work, because Kubernetes ingress rules require a lowercase domain name.
+
+By default, abctl will allow access from any hostname or IP, so you might not need the --host flag.`,
+	}
+
+	ErrInvalidHostFlag = &LocalError{
+		msg: "invalid host",
+		help: `The --host flag expects a lowercase domain name, e.g. "example.com". 
+IP addresses won't work. Ports won't work (e.g. example:8000). URLs won't work (e.g. http://example.com).
+
+By default, abctl will allow access from any hostname or IP, so you might not need the --host flag.`,
+	}
 )