refactor!: drop "record" & "server new" command

These were alpha prototypes and we'll reconsider once other layers of
Abra are more stable.

pkg/dns/dns.go

@@ -0,0 +1,50 @@
+package dns
+
+import (
+	"fmt"
+	"net"
+)
+
+// EnsureIPv4 ensures that an ipv4 address is set for a domain name
+func EnsureIPv4(domainName string) (string, error) {
+	ipv4, err := net.ResolveIPAddr("ip", domainName)
+	if err != nil {
+		return "", err
+	}
+
+	return ipv4.String(), nil
+}
+
+// EnsureDomainsResolveSameIPv4 ensures that domains resolve to the same ipv4 address
+func EnsureDomainsResolveSameIPv4(domainName, server string) (string, error) {
+	if server == "default" || server == "local" {
+		return "", nil
+	}
+
+	var ipv4 string
+
+	domainIPv4, err := EnsureIPv4(domainName)
+	if err != nil {
+		return ipv4, err
+	}
+
+	if domainIPv4 == "" {
+		return ipv4, fmt.Errorf("cannot resolve ipv4 for %s?", domainName)
+	}
+
+	serverIPv4, err := EnsureIPv4(server)
+	if err != nil {
+		return ipv4, err
+	}
+
+	if serverIPv4 == "" {
+		return ipv4, fmt.Errorf("cannot resolve ipv4 for %s?", server)
+	}
+
+	if domainIPv4 != serverIPv4 {
+		err := "app domain %s (%s) does not appear to resolve to app server %s (%s)?"
+		return ipv4, fmt.Errorf(err, domainName, domainIPv4, server, serverIPv4)
+	}
+
+	return ipv4, nil
+}