fix: ensure ipv4 is present for app deploys

See coop-cloud/organising#227.

cli/server/add.go

@@ -1,23 +1,21 @@
 package server
 
 import (
-	"context"
 	"errors"
 	"fmt"
-	"net"
 	"os"
 	"os/exec"
 	"os/user"
 	"path"
 	"path/filepath"
 	"strings"
-	"time"
 
 	abraFormatter "coopcloud.tech/abra/cli/formatter"
 	"coopcloud.tech/abra/cli/internal"
 	"coopcloud.tech/abra/pkg/client"
 	"coopcloud.tech/abra/pkg/config"
 	contextPkg "coopcloud.tech/abra/pkg/context"
+	"coopcloud.tech/abra/pkg/dns"
 	"coopcloud.tech/abra/pkg/server"
 	"coopcloud.tech/abra/pkg/ssh"
 	"github.com/AlecAivazis/survey/v2"
@@ -268,33 +266,11 @@ func initSwarmLocal(c *cli.Context, cl *dockerClient.Client, domainName string)
 }
 
 func initSwarm(c *cli.Context, cl *dockerClient.Client, domainName string) error {
-	// comrade librehosters DNS resolver -> https://www.privacy-handbuch.de/handbuch_93d.htm
-	freifunkDNS := "5.1.66.255:53"
-
-	resolver := &net.Resolver{
-		PreferGo: false,
-		Dial: func(ctx context.Context, network, address string) (net.Conn, error) {
-			d := net.Dialer{
-				Timeout: time.Millisecond * time.Duration(10000),
-			}
-			return d.DialContext(ctx, "udp", freifunkDNS)
-		},
-	}
-
-	logrus.Debugf("created DNS resolver via '%s'", freifunkDNS)
-
-	ips, err := resolver.LookupIPAddr(c.Context, domainName)
+	ipv4, err := dns.EnsureIPv4(domainName)
 	if err != nil {
 		return err
 	}
 
-	if len(ips) == 0 {
-		return fmt.Errorf("unable to retrieve ipv4 address for %s", domainName)
-	}
-
-	ipv4 := ips[0].IP.To4().String()
-	logrus.Debugf("discovered the following ipv4 addr: %s", ipv4)
-
 	initReq := swarm.InitRequest{
 		ListenAddr:    "0.0.0.0:2377",
 		AdvertiseAddr: ipv4,