web/fly: start flydns client

Signed-off-by: Xe Iaso <me@xeiaso.net>

2 files changed, 114 insertions, 0 deletions

diff --git a/web/fly/flydns/flydns.go b/web/fly/flydns/flydns.go
new file mode 100644
index 0000000..7c34f14
--- /dev/null
+++ b/web/fly/flydns/flydns.go
@@ -0,0 +1,97 @@
+package flydns
+
+import (
+	"fmt"
+	"net"
+	"net/netip"
+	"strings"
+)
+
+func GetAppAddresses(appName string) ([]netip.Addr, error) {
+	addrs, err := net.LookupAddr(fmt.Sprintf("%s.internal", appName))
+	if err != nil {
+		return nil, err
+	}
+
+	var result []netip.Addr
+
+	for _, addr := range addrs {
+		ip, err := netip.ParseAddr(addr)
+		if err != nil {
+			return nil, err
+		}
+
+		result = append(result, ip)
+	}
+
+	return result, nil
+}
+
+func GetIndividualInstanceAddress(instanceID string, appName string) (netip.Addr, error) {
+	var ip netip.Addr
+	addr, err := net.LookupAddr(fmt.Sprintf("%s.vm.%s.internal", instanceID, appName))
+	if err != nil {
+		return ip, err
+	}
+
+	ip, err = netip.ParseAddr(addr[0])
+	if err != nil {
+		return ip, err
+	}
+
+	return ip, nil
+}
+
+func GetAppInstancesInRegion(appName string, region string) ([]netip.Addr, error) {
+	instances, err := net.LookupHost(fmt.Sprintf("%s.%s.internal", appName, region))
+	if err != nil {
+		return nil, err
+	}
+
+	var result []netip.Addr
+
+	for _, instance := range instances {
+		ip, err := netip.ParseAddr(instance)
+		if err != nil {
+			return nil, err
+		}
+
+		result = append(result, ip)
+	}
+
+	return result, nil
+}
+
+func GetClosestInstances(appName string, count int) ([]netip.Addr, error) {
+	instances, err := net.LookupHost(fmt.Sprintf("top%d.nearest.of.%s.internal", count, appName))
+	if err != nil {
+		return nil, err
+	}
+
+	var result []netip.Addr
+
+	for _, instance := range instances {
+		ip, err := netip.ParseAddr(instance)
+		if err != nil {
+			return nil, err
+		}
+
+		result = append(result, ip)
+	}
+
+	return result, nil
+}
+
+func GetApps() ([]string, error) {
+	appString, err := net.LookupTXT("_apps.internal")
+	if err != nil {
+		return nil, err
+	}
+
+	var result []string
+	for _, resp := range appString {
+		result = append(result, strings.Split(resp, ",")...)
+	}
+
+	return result, nil
+}
diff --git a/web/fly/flydns/flydns_test.go b/web/fly/flydns/flydns_test.go
new file mode 100644
index 0000000..c566461
--- /dev/null
+++ b/web/fly/flydns/flydns_test.go
@@ -0,0 +1,17 @@
+package flydns
+
+import (
+	"testing"
+)
+
+func TestGetApps(t *testing.T) {
+	// Call the function to be tested
+	result, err := GetApps()
+
+	t.Logf("%v", result)
+
+	// Check for the error
+	if err != nil {
+		t.Errorf("Expected no error, but got an error: %v", err)
+	}
+}